Environmental and Construction Engineering: Reality and the Future: Selected Papers (Lecture Notes in Civil Engineering, 160) 3030751813, 9783030751814

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Lecture Notes in Civil Engineering

Sergey Vasil’yevich Klyuev Alexander Vasil’yevich Klyuev   Editors

Environmental and Construction Engineering: Reality and the Future Selected Papers

Lecture Notes in Civil Engineering Volume 160

Series Editors Marco di Prisco, Politecnico di Milano, Milano, Italy Sheng-Hong Chen, School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan, China Ioannis Vayas, Institute of Steel Structures, National Technical University of Athens, Athens, Greece Sanjay Kumar Shukla, School of Engineering, Edith Cowan University, Joondalup, WA, Australia Anuj Sharma, Iowa State University, Ames, IA, USA Nagesh Kumar, Department of Civil Engineering, Indian Institute of Science Bangalore, Bengaluru, Karnataka, India Chien Ming Wang, School of Civil Engineering, The University of Queensland, Brisbane, QLD, Australia

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Sergey Vasil’yevich Klyuev Alexander Vasil’yevich Klyuev •

Editors

Environmental and Construction Engineering: Reality and the Future Selected Papers

123

Editors Sergey Vasil’yevich Klyuev Belgorod State Technological University Belgorod, Russia

Alexander Vasil’yevich Klyuev Belgorod State Technological University Belgorod, Russia

ISSN 2366-2557 ISSN 2366-2565 (electronic) Lecture Notes in Civil Engineering ISBN 978-3-030-75181-4 ISBN 978-3-030-75182-1 (eBook) https://doi.org/10.1007/978-3-030-75182-1 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Preface

The International Scientific Conference “Environmental and Construction Engineering: Reality and the Future - 2021” is held from May 18 to 19, 2021, on the basis of Federal State Budgetary Educational Institution of Higher Education “Belgorod State Technological University named after V.G. Shukhov,” Belgorod, the Russian Federation. The Conference “Environmental and Construction Engineering: Reality and the Future” covers a wide range of current research areas. Each of the areas is an important element in related fields of engineering. This also reflects the diverse research interests conducted within the conference. This conference brings together more than 300 scientists and experts from different Russian regions (up to 32) and eight abroad countries (China, Iran, India, Kazakhstan, Tajikistan, the Ukraine, Uzbekistan, Kyrgyzstan) to discuss and present the state of affairs, existing problems, as well as present the results of new research and perspectives. The main objective of the conference is that all participants will use this conference as a platform to present their scientific, technical, and technological achievements aimed at solving current problems in the construction industry and related infrastructure, which includes building materials and products, as well as structures and structures, their characteristics, research methods, production technologies, and application prospects, taking into account ecological aspect. Thus, the thematic areas discussed are aimed at studying and solving a wide range of problems in this complex, but the promising area. Knowledge sharing will create the basis and new opportunities for the commercialization of research results. The conference is held on the three following sessions: Session 1. Industrial and Civil Construction, Building Materials. Session 2. Environmental Engineering and Sustainability. Session 3. Aggregates and Processes in Construction. A major part of theoretical information and experimental data is the results of studies, which were realized within the framework of implementation of state and national programs in the scientific field as a grant, federal targeted programs, decrees of the Government of the Russian Federation, and other programs. v

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Preface

The materials included in the collection of materials were selected for quality and relevance to the topic of the conference by specialists with a degree. The magazine aims to present to readers the latest achievements in the field of materials science, production of building materials, construction of buildings and structures, as well as in various related fields. The members of the organizing committee would like to express our sincere thanks to all reviewers, both local and international, for their time and effort in reviewing articles. Their feedback to the authors was excellent and helpful in ensuring the high quality of the papers for the conference. Annual holding of such conferences is planned to be organized on the main topics of the construction industry. Klyuev Sergey Vasil’yevich Klyuev Alexander Vasil’yevich

Organization

Organizing Conference Committee Evtushenko E. I.

Davydenko T. M.

Klyuev S. V.

Lesovik V. S.

Vatin N. I.

Ayzenshtadt A. M.

Sverguzova S. V.

Doctor of Engineering Sciences (Advanced Doctor), Professor, Belgorod State Technological University named after V.G. Shukhov, Russia Doctor of Pedagogical Sciences (Advanced Doctor), Professor, Belgorod State Technological University named after V.G. Shukhov, Russia Candidate of Engineering Sciences (PhD), Associate Professor, Belgorod State Technological University named after V.G. Shukhov, Russia Doctor of Engineering Sciences (Advanced Doctor), Professor, Corresponding Member of RAASN, Belgorod State Technological University named after V.G. Shukhov, Russia Doctor of Engineering Sciences (Advanced Doctor), Professor, Peter the Great St. Petersburg Polytechnic University, Russia Doctor of Chemical Sciences (Advanced Doctor), Professor, Northern (Arctic) Federal University named after M.V. Lomonosov, Russia Doctor of Engineering Sciences (Advanced Doctor), Professor, Belgorod State Technological University named after V.G. Shukhov, Russia

vii

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Organization

Scientific Conference Committee Amir Abdulrahman Ali Belloush Kovtun M. A. Kozhukhova M. I. Loganina V. I.

Lukuttsova N. P.

Nevzorov A. L.

Nenad Stoykovich Naumov A. E.

Ol’shanskaya L. N.

Salyamova K. D.

Sovann Chin Strokova V. V.

Suleymanova L. A.

Tabet Salem Al-Azab Fisher H. B.

Iraq—Doctor of Engineering, Professor, Anbar University Morocco—Ph.D., Professor, Rector, Funtius Institute Australia—Ph.D. The USA—Ph.D., University of Wisconsin-Milwaukee Russia—Doctor of Engineering Sciences (Advanced Doctor), Professor, Penza State University of Architecture and Construction Russia—Doctor of Engineering Sciences (Advanced Doctor), Professor, Bryansk State Engineering Technological University Russia—Doctor of Engineering Sciences (Advanced Doctor), Professor, Northern (Arctic) Federal University named after M.V. Lomonosov Serbia—Ph.D., Nish Higher Technical School of Vocational Education Russia—Candidate of Engineering Sciences (Ph.D.), Associate Professor, Belgorod State Technological University named after V.G. Shukhov Russia—Doctor of Chemical Sciences (Advanced Doctor), Professor, Saratov State Technical University named after Yuri Gagarin Uzbekistan—Doctor of Engineering Sciences (Advanced Doctor), Professor, Institute of Mechanics and Seismic Stability of Structures of the Academy of Sciences of the Republic of Uzbekistan Cambodia—Ph.D. Russia—Doctor of Engineering Sciences (Advanced Doctor), Professor, Belgorod State Technological University named after V.G. Shukhov Russia—Doctor of Engineering Sciences (Advanced Doctor), Professor, Belgorod State Technological University named after V.G. Shukhov Yemen—Ph.D. Germany—Professor, Bauhaus-University of Weimar

Organization

Hisham Almama Hussein Motawi Elyan Issa Jamal Issa Eknik Jürgen

Shakarna Mahmoud Husni Ibrahim

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Syria—Ph.D., Damascus University Egypt—Ph.D., Professor, Vice-Rector, Damanhour University Jordan—Ph.D., Amman University Switzerland—Ph.D., Professor, Executive Director of a Swiss Company, Performance Selling Academy Zurich Area GmbH Palestine—Ph.D.

All conference participants express deep gratitude to the science team.

Contents

Diffraction of Shock Waves into Frame Buildings . . . . . . . . . . . . . . . . . Ali Al Shemali

1

Improving the Efficiency of Silicate Materials Through the Use of Lime-Sand-Clay Binder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. A. Volodchenko

9

Separation of Oil-Water Emulsion Using Polysulfonamide Membranes Treated by Air Plasma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I. G. Shaikhiev, V. O. Dryakhlov, S. V. Sverguzova, and L. V. Denisova

15

Rheological Properties of Molding Mixes on Composite Gypsum Binders for 3D-Additive Technologies of Low-Height Monolithic Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E. S. Glagolev, N. V. Chernysheva, M. Yu. Drebezgova, and D. A. Motorykin

23

Substantiation of the Type of Machining of a Flat Metal-MetalPolymer Surface Considering the Provision of the Required Roughness of the Part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. S. Chetverikov, D. M. Annenko, N. S. Lubimyi, and A. A. Tikhonov

31

Elastic-Plastic Model of Concrete Damage and Its Main Design Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. G. Balamirzoev, A. R. Abdullaev, and D. N. Selimkhanov

37

Experimental Investigation on Strength Characteristics of Concrete Wall Colored Stones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J. V. Denisova and E. S. Chernositova

45

Regulation of the Surface Microrelief of Titanium Hydride by Solutions of Sulfuric Acid Salts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. I. Gorodov, R. N. Yastrebinsky, A. A. Karnauhov, and A. V. Yastrebinskaya

51

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xii

Contents

Sodium Alginate Application in Self-healing Technology for Asphalt Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S. S. Inozemtcev and D. T. Toan

59

The Optimization of the Grinding Process of the Closing Joint of the Combined Forming Parts of the Mold . . . . . . . . . . . . . . . . . . . . . N. S. Lubimyi, I. A. Lymar, B. S. Chetverikov, and A. A. Tikhonov

67

Non-autoclaved Foam Concrete with Improved Foam Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V. N. Tarasenko

75

Optimization of the Disposal Process of Polydispersed Pulverized Waste and Metal Chips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. P. Nazarova and O. P. Mikhailova

83

Impact of the Granulometric Composition of Raw Sludge on the Characteristics of Portland Cement . . . . . . . . . . . . . . . . . . . . . . . D. A. Mishin, S. V. Kovalev, and D. V. Smal

93

Stress-Strain State of the Elements of a Timber-To-Timber Joint Connected by Inclined Screwed-In Rods . . . . . . . . . . . . . . . . . . . . . . . . 101 T. P. Chernova, V. V. Filippov, B. V. Labudin, and V. I. Melekhov Calculation of Vertical Deformations of Composite Bending Wooden Structures with Non-linear Behavior of Shear Bonds . . . . . . . . . . . . . . . 109 E. V. Popov, V. V. Sopilov, I. N. Bardin, and D. M. Lyapin Features of Electricity Consumption in Residential Buildings with Low-Duty Elevator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 N. P. Badalyan, V. I. Afonin, E. E. Chashchina, and G. V. Maslakova Determination of the Main Characteristics and Modeling of the Classification Matrix of the Concentrator in a Closed Grinding Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 R. R. Sharapov and V. S. Prokopenko Modeling of the Projection Control Roundness Raceway of the Inner Ring Race of a Ball Bearing Support . . . . . . . . . . . . . . . . . 131 B. S. Chetverikov, N. N. Slavkova, A. N. Unkovskiy, and M. S. Babkin The Research of the Regularities of the Influence of the Parameters of Grinding a Flat Surface on Its Roughness during Machining a Metal Polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 N. S. Lubimyi, S. A. Duhanin, I. A. Lymar, and A. A. Tikhonov Purification of Model Waters from Zinc Ions by Heat-Treated Leaves of Apricot (Prunus Armeniaca L.) and Horse Chestnut (Aésculus Hippocastanum L.) . . . . . . . . . . . . . . . . . . . . . . . . . . 147 Zh. A. Sapronova, A. V. Svyatchenko, and L. V. Denisova

Contents

xiii

Calculation of Continuous Flanged Beams for Overall Stability . . . . . . . 153 E. Yu. Voronova, V. A. Evstratov, V. Yu. Linnik, and I. V. Breslavceva Theoretical Study of the Kinetics of Material Destruction in a Disintegrator with a Preliminary Grinding Unit . . . . . . . . . . . . . . . 161 I. A. Semikopenko and D. A. Belyaev Stress-Deformed State of Soils under Compressional Contraction Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Z. M. Zhambakina, T. K. Kuatbayeva, N. V. Kozyukova, and U. K. Akishev Analysis of the Hardening Kinetics of Cements from Different Countries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 Sh. M. Rakhimbaev, E. A. Pospelova, and I. S. Chernikova Development of the Composition of a Special Mixture for Floors Using Anhydrite Binders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 A. F. Buryanov, N. A. Galtseva, I. V. Morozov, and E. N. Buldyzhova Mathematical Description of the Two-Phase Flow Motion at the Outlet of the Vertical Acceleration Tube of a Jet Mill with a Plane Grinding Chamber of Torus-Shaped Form . . . . . . . . . . . . 191 V. G. Dmitrienko, V. P. Voronov, E. G. Shemetov, and O. M. Shemetova Reliability of Normal Cross Sections of Bending Reinforced Concrete Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 A. N. Yakubovich and I. A. Yakubovich Peculiar Features of the Deformation of Horizontal Masonry Mortar Joints Under Short-Term Forceful Compression . . . . . . . . . . . . 207 O. M. Donchenko, I. A. Degtev, V. N. Tarasenko, and J. V. Denisova Selection Algorithm of Geotechnical Technologies for Amplification of Weak Bases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 N. S. Sokolov and P. Yu. Fedorov Magnetron Sputtering as a Method of Forming a Protective Coating on Titanium Hydride Shot . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 R. N. Yastrebinsky, S. V. Zaitsev, V. V. Sirota, and D. S. Prokhorenkov Possibilities of Architectural and Constructive Shaping of Spatial Forms from Rod Arches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 N. G. Tsaritova, A. A. Tumasov, A. A. Kalinina, and I. V. Kosogov Analysis of the Factors of Increasing the Efficiency of Employment Binder in High-Strength Self-Compacting Concretes . . . . . . . . . . . . . . . 237 V. S. Lesovik, M. Yu. Elistratkin, A. S. Salnikova, and E. A. Pospelova

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Contents

Belt Vibration Damping System for Closed-Type Domes . . . . . . . . . . . . 245 A. I. Shein and A. V. Chumanov Impact of the Blade Profile on the Production of the Screw Press . . . . . 253 A. S. Apachanov, E. Yu. Voronova, V. I. Grigoryev, and V. A. Evstratov Improvement of Connections Column and Beams in Wooden Houses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 M. V. Ariskin and P. P. Sizov Application of Carbon-Containing Sorption Material for Wastewater Purification from Methylene Blue Dye . . . . . . . . . . . . . 269 I. V. Starostina, D. O. Polovneva, Yu. L. Makridina, and L. V. Denisova Improving the Wear Resistance of Rotary-Vortex Mill Hammers . . . . . 277 A. A. Romanovich, S A. Dukhanin, M. A. Romanovich, and Amirhadi Zakeri Identification of the Compositions and Analysis of Changes in the Properties of Lime-Sandy Binders as a Result of Application of Petroleum Bituminous Rocks and Their Processing Waste . . . . . . . . 285 T. K. Kuatbayeva, Z. M. Zhambakina, Zh. S. Serikbayeva, and B. K. Sarsenbayev One of the Approaches to Increase the Load-Bearing Capacity of Drill-Injection Piles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 N. S. Sokolov Using Leaves and Needles of Trees as Sorption Materials for the Extraction of Oil and Petroleum Products from Solid and Water Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 A. V. Svyatchenko, I. G. Shaikhiev, S. V. Sverguzova, and E. V. Fomina The Methodology of Risk Assessment of the Technogenic Impact of Construction Enterprises on the Environment . . . . . . . . . . . . . . . . . . 307 I. A. Guschin and O. N. Ezhova The Influence of Protein-Based Foaming Agent, Obtained from Microbiological Production Mycelial Waste, on Gypsum Binders Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 I. V. Starostina, Yu. L. Makridina, L. V. Denisova, and E. V. Loktionova The Role of Water Management Technologies in the Sustainable Development of Water-Deficient Territories . . . . . . . . . . . . . . . . . . . . . . 325 A. Ya. Gaev, I. V. Kudelina, T. V. Leontyeva, and M. V. Fatyunina Pneumatic Mixer with a Spiral Energy-Carrying Tube . . . . . . . . . . . . . 333 Yu. M. Fadin, O. M. Shemetova, V. P. Voronov, and E. G. Shemetov

Contents

xv

Calculation of the Walls of Beams Under the Action of Local Stress in the Places where the Load is Applied to the Sole . . . . . . . . . . . . . . . . 341 S. A. Makeev, A. A. Komlev, P. A. Korchagin, and S. V. Savelyev Improved Surface Water Treatment Technology in the Kyrgyz Republic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 T. Kh. Karimov, N. Baygazy kyzy, Zh. I. Osmonov, and M. T. Karimova Use of Weak Foundations in the Construction of Highways . . . . . . . . . . 357 N. S. Sokolov and P. Yu. Fedorov Correction of the Test Method for Ladders with Removable Steps . . . . 365 V. A. Antonova, K. V. Zherdev, and A. Ya. Barvina Implementation of Environmental Tasks of Waste-Free Biotechnological Industries Using the Fly Hermetia Illucens Larvae . . . 373 Zh. A. Sapronova, I. G. Shaikhiev, S. V. Sverguzova, and E. V. Fomina Mechanical-Empirical Model for Predicting the Faulting on Concrete Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381 A. A. Fotiadi, S. A. Gnezdilova, and V. V. Silkin Author Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389

Diffraction of Shock Waves into Frame Buildings Ali Al Shemali

Abstract Diffraction of shock waves into multistory frame buildings is analyzed by Finite Element Analysis (FEA). The FE model consists of a ten-story superstructure rested on the slab foundation. The trigonometric approximation of the delta function was used to model the application of loads with values for shock durations t = 0.5, 1, and 1.5 s. Analysis of the interaction of shock waves with the building was performed using the software package Abaqus/CAE 6.14. Six columns and four longitudinal axes were selected and the stress values were evaluated in monitoring points distributed in specific positions on the considered columns and longitudinal axes. The dynamic analysis over a time period of 10 s reveals that the arrival of the shock waves results in dangerous stresses first in the foundation before the columns for the different shock durations. Moreover, the analysis also reveals that the columns are not affected by a shock duration smaller than 0.5 s. Keywords Seismic waves · Shock waves · Building · Frame · Diffraction · Stress · Delta function

1 Introduction When an earthquake occurs, energy is released as shock waves, or the so-called seismic waves. These waves can be classified into two basic types: body waves (Pwaves and S-waves) which travel through the Earth and surface waves (Love waves, Rayleigh waves), which travel along the Earth’s surface [1]. Usually, to facilitate the seismic resistance calculations of buildings and structures, the ground motion is assumed in the form of harmonic wave [2]. But looking at the diagrams that the seismograph provides, we may notice a few sharp peaks that can be considered as a shock load with very high amplitude and short duration, as shown in Fig. 1, which represents the seismogram of the earthquake that occurred in Kaliningrad, Russia, in 2014. To model loads that have very short duration, the delta function is used [3]. A. Al Shemali (B) Moscow State University of Civil Engineering, Moscow, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_1

1

2

A. Al Shemali

the following form of the regularized Dirac-delta function has been commonly used due to its excellent numerical properties such as smoothness and regularity [4]: δ(ξ − ζ0 ) ≈

1 (ξ − ζ0 )2 ] √ exp[− α2 α π

when a → 0

(1)

Figure 2 shows a plot of the delta function for different values of α. In numerical calculations, since the true delta pulse cannot be modeled, the triangular approximation is used. When seismic waves encounter an object, they are either reflected, refracted, diffracted, or scattered. This paper is devoted to studying the effect of shock wave diffraction into frame buildings. Diffraction is defined as a type of event produced by Fig. 1 The Kaliningrad, Russia, earthquake of September 21, 2004. From top to bottom: vertical, N–S and E–W components - some sharp peaks are indicated by an arrow [5]

Fig. 2 A plot of the delta function for different values of α

Diffraction of Shock Waves into Frame Buildings

3

Fig. 3 Plan of this building with column labels

the radial scattering of a wave into new wavefronts after the wave meets an object, particle, or obstacle. There is a number of different models to compute diffraction wave-field due to wave scattering, including the Huygens’ Principle, the RayleighSommerfeld theory, the Kirchhoff’s diffraction theory, Taylor series perturbation theory, Born and Rytov approximation, Fraunhofer and Fresnel approximations. In addition, several other methods are also available for treating diffraction problems: discrete wave-number techniques; generalized ray techniques; and various numerical methods (finite difference methods; finite element method; and boundary integral or element methods) [6]. In this article was used the numerical method (finite element method) to study diffraction.

2 Methods and Materials 2.1 Geometric Parameters of the Building The building under study is a multi-storey flat slab concrete construction, where the number of storeys is 10 and the height of each is 3.3 m. A plan of this building is shown in Fig. 3.

2.2 Members Properties For modeling were used square cross-section columns (0.5 × 0.5 m) and flat slab in addition to the slab foundation with thicknesses 0.3 and 1.5 m respectively. As for the properties of the construction material (concrete), they are shown in the Table 1:

4 Table 1 The material properties of concrete used in Abaqus program

A. Al Shemali Modulus of elasticity

Poisons ratio

Density

30 ×

0.25

2200 Kg/m3

109

N/m2

2.3 Boundary Conditions For the study of general behaviour of the building, an acceleration 3.5 m/s2 was applied under the foundations in two directions (x, z), where the resultant acceleration in both directions is 5 m/s2 (according to the Pythagorean rule). Considering that the construction is located in a zone of seismic intensity 9 according to the modified Mercalli scale [7]. Assuming that this acceleration changes with time as a triangular in time domain. Considering common problems and approaches used in FE modeling it is needed to note account of energy dissipation in structures [8]; problems related to imposing non-reflecting boundary conditions at the FE modeling are discussed in [9]; problems related to the FE modeling seismic sources, causing appearance of different types of seismic waves [10]. Applications of FE modeling to seismic protection are considered in [11, 12]. Theoretical problems related to crack initiation and propagation in various elements of buildings and structures at dynamic loadings, are discussed in [13].

2.4 FE Model Engineering software Abaqus/CAE 6.14 was used to build the finite element model and to analyze the interaction of shock waves with the building. An 8-node linear hexahedral solid element with reduced integration (C3D8R) was used for modeling the building. This element has six degrees of freedom at each node. Figure 4 shows the 3D model generated in Abaqus software.

2.5 Type Analysis A finite element implementation for instance may adopt an explicit or implicit algorithm, to solve the governing equation. These two algorithms give the same results but differ in the approach to time incrementation. In our study, the explicit analysis was chosen there are no convergence criteria to check and no iterations and instead of verifying the “global equilibrium” solver assumes that the equilibrium “simply exists”. Abaqus allows to conduct this analysis to be carried out by selecting a procedure - Dynamic, Explicit step.

Diffraction of Shock Waves into Frame Buildings

5

3 Results and Discussion The explicit dynamic analysis of the shock durations t = 0.5, 1, and 1.5 s was performed over a time period of 10 s. Figure 5 shows Schemes of change of shock wave acceleration over time. After the analysis, the stress values that arise from diffraction of shock waves into building were considered. To facilitate the process of discussing the results, monitoring points have been set up on the columns (C1–C6) and on the underside of the foundation (axes-1–4). The locations of these points are shown in Fig. 6. Considering that concrete has a tensile strength of no more than 5E6 N/m2 , the following tables have been compiled showing the names of the monitoring points that first reached the limit value, with the determination of the arrival time, in the columns and the foundation (Tables 2, 3 and 4). By looking at the values shown in the tables, a set of results were drawn, which are listed below. Fig. 4 3D finite element model of the building

Fig. 5 Schemes of change of shock wave acceleration over time: a shock duration 0.5 s, b shock duration 1 s, c shock duration 1.5 s

6

A. Al Shemali

Fig. 6 Locations of monitoring points: a on the columns, b on the underside of the foundation

Table 2 The results of the analysis for shock duration 0.5 s. Columns

Foundation

Column name

Time during which stresses exceed 5E6 N/m2 (sec)

Place of stress

Axis name

Time during which stresses exceed 5E6 N/m2 (sec)

Place of stress

Arrival time of all axes points up to 5E6 N/m2 (sec)

C1

–

–

Axis-1

0.95

mp6

1.15

C2

–

–

Axis-2

0.95

mp6

1.1

C3

–

–

Axis-3

0.95

mp6

1.15

C4

–

–

Axis-4

1.15

mp6

1.35

C5

–

–

C6

–

–

• For shock loads with a short impact time (= 1 s), note that the foundation collapses first, and then the columns of the lower floors.

Diffraction of Shock Waves into Frame Buildings

7

Table 3 The results of the analysis for shock duration 1 s Columns

Foundation

Column name

Time during which stresses exceed 5E6 N/m2 (sec)

Place of stress

Axis name

Time during which stresses exceed 5E6 N/m2 (sec)

Place of stress

Arrival time of all axes points up to 5E6 N/m2 (sec)

C1

1.25

mp1

Axis-1

0.85

mp6

1.15

C2

1.15

mp1

Axis-2

0.9

mp6

1

C3

1.25

mp1

Axis-3

0.95

mp6 + mp5

1

C4

1.5

mp2

Axis-4

1

Mp5

1.1

C5

1.25

mp1

C6

1.25

mp1

Table 4 The results of the analysis for shock duration 1.5 s Columns

Foundation

Column name

Time during which stresses exceed 5E6 N/m2 (sec)

Place of stress

Axis name

Time during which stresses exceed 5E6 N/m2 (sec)

Place of stress

Arrival time of all axes points up to 5E6 N/m2 (sec)

C1

1.25

mp1

Axis-1

0.95

mp6

1.15

C2

1.2

mp1

Axis-2

1

mp6 + mp5

1.05

C3

1.25

mp1

Axis-3

1

mp6

1.1

C4

1.3

mp1

Axis-4

1.05

Mp5

1.15

C5

1.25

mp1

C6

1.25

mp1

4 Conclusion A multi-storey building with the application of shock load under the foundation with different impact times was modeled using the Finite Element code Abaqus. The analysis showed that in the case of shock loads, it is noticed that the collapse first occurred in the building foundation before its other parts. The results of this study provide justification for the need to research how to protect the foundations of buildings and structures from soil vibration below them.

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References 1. Stein S, Wysession M (2009) An introduction to seismology, earthquakes, and earth structure. Wiley, Hoboken 2. Chopra AK (2017) Dynamics of structures. theory and applications to. Earthquake Engineering 3. Dirac PA (1981) The principles of quantum mechanics. No. 27. Oxford University Press 4. Eftekhari SA (2015) A differential quadrature procedure with regularization of the Dirac-delta function for numerical solution of moving load problem. Latin Am J Solids Struct 12(7):1241– 1265 5. Kulhanek O, Persson L (2011) Seismogram Interpretation. Geophysics 157:2303–2322 6. Arora K, Cazenave A et al (2011) Encyclopedia of solid earth geophysics. Springer 7. Jain AK Performance Based Seismic Design Of Tall Buildings: Risks And Responsibilities. https://cecr.in/CurrentIssue/pages/20147 8. Jones RM (2009) Deformation theory of plasticity. Bull Ridge Corporation 9. Li S, Brun M et al (2018) Numerical modelling of wave barrier in 2D unbounded medium using explicit/implicit multi-time step co-simulation. IOP Conf Ser Mater Sci Eng 365:042062 10. Il’yasov KK, Kravtsov AV et al (2016) Exterior 3D lamb problem: Harmonic load distributed over a surface. Mech Solids 51(1): 39–45 11. Dudchenko A (2018) Numerical analysis of surface Rayleigh wave interaction with seismic barriers and pile fields accounting elastic-plastic soil behaviour. PhD thesis, UJF: Grenoble 12. Kuznetsov SV (2011) Seismic waves and seismic barriers. Acoust Phys 57(3):420–426 13. Ilyashenko AV, Kuznetsov SV (2017) Stress–displacement intensity factors for cracks in anisotropic media. Arch Appl Mech 87(8):1365–1369

Improving the Efficiency of Silicate Materials Through the Use of Lime-Sand-Clay Binder A. A. Volodchenko

Abstract Currently, in the construction of buildings and structures, builders use a variety of building materials and products for various functional purposes, including silicate materials. On the territory of Russia, there are a large number of sands with a high content of clay impurities, which makes it difficult to use them in the production of silicate materials. The purpose of the research was to study the properties of autoclave-hardened silicate materials using sands containing clay impurities, as well as the interaction processes in the “lime—sand-clay rock—sand-aggregate—water” system. Based on the conducted studies, it was found that sand-clay rocks containing 20% wt. of clay impurities are widely distributed in Russia and can be used as a component of the raw material mixture to produce silicate composites. The use of such raw materials allows accelerating the synthesis of new things, and as a result, increasing the performance indicators of finished products. To achieve maximum efficiency, the sand-clay rock must be used as a part of an aluminosilicate binder obtained by joint grinding of the initial rock and lime, which will ensure the most uniform distribution of the clay fraction in the raw mixture. The optimal total content of sand-clay rocks in the raw material mixture, which ensures the achievement of maximum strength indicators, is 35–40 wt.%. Keywords Autoclave silicate materials · Sand-clay rocks · Wall materials · Building materials

1 Introduction Currently, in the construction of buildings and structures, builders use a variety of construction materials and products for various functional purposes. Basically, such construction composites are obtained using specific types of raw materials, which differ in a more or less constant and stable composition. However, it is worth noting that currently on the territory of the Russian Federation, the total volume of industrial A. A. Volodchenko (B) Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_2

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A. A. Volodchenko

waste generated is many millions of tons, but due to their material composition, they can be used to produce new-generation construction composites [1–8]. Currently, for almost all types of raw materials used for the production of building materials, there are strict requirements for their quality, which are regulated by the relevant regulatory documents (RD). It is based on the requirements of the RD that the geological services search for deposits of raw materials used to obtain the appropriate construction materials. However, deposits of raw materials that have deviations from the requirements of the RD are not taken into account. There is also a practice of creating a technology for obtaining construction composites at a specific field. Thus, a more thorough analysis of the properties of raw materials and identifying patterns of similarity occurring in nature of geological processes and technogenic ones will become the basis for the development, maintenance and reuse of construction composites on the basis of non-traditional construction rocks [9, 10]. Previously conducted studies have shown that it is possible to use clay rocks of the incomplete stage of clay formation [13, 14] to obtain high-performance silicate materials, due to the synthesis of new things of optimal structure [11, 12]. The mechanism and kinetics of CaO absorption by clay minerals were studied, the data of which allowed finding a way to optimize the composition of the lime-clay binder in order to obtain products with the specified properties. These studies were conducted mainly on clay rocks. However, on the territory of Russia, there are a large number of sands with a high content of clay impurities, which makes it difficult to use them in the production of silicate materials. The aim of the research was to study the properties of autoclave-hardened silicate materials using sands containing clay impurities, as well as the interaction processes in the “lime—sand-clay rock—sand-aggregate—water” system.

2 Methods and Materials As a component of the binder, quicklime with a content of active CaO + MgO—80% was used. The sand-clay rock of the Kursk magnetic anomaly region (Russia, Belgorod region) was used in the work. Sand from the Nizhneolshansky deposit in the Belgorod Region (Russia) was used as a siliceous aggregate. The raw material mixture for obtaining samples was prepared by mixing the previously obtained sand-clay binder and sand, followed by the addition of water. After quenching the lime from the resulting raw mixture by pressing at a pressure of 20 MPa, the samples were formed. The obtained samples were placed in an autoclave and subjected to hydrothermal treatment at a saturated water vapor pressure of 0.6–1.2 MPa for 8 h. X-ray phase analysis of raw materials and obtained samples was performed on a diffractometer using the method of powder diffractograms.

Improving the Efficiency of Silicate Materials …

11

3 Results and Discussion The sand-clay rock used in the research contains 20 wt.% of clay impurities. The rock does not have plasticity. Based on the data of granulometric analysis (see Table 1), this rock can be attributed to fine-grained sandy loam. The distribution of sand particles by fractions (see Table 2) was determined by sieving the sand sample on the corresponding sieves. X-ray analysis (see Fig. 1) of sand-clay rock was carried out only for a fraction less than 0.005 mm obtained by elutriation. It was found that the fraction less than 0.005 mm used for the study of sand-clay rock consists mainly of quartz (d = 4.27; 3.357; 2.295; 1.822 Å). The clay minerals present in the rock belong to kaolinite (d = 7.196 Å), as well as to hydromica (d = 10.048 Å). Also, in the studied fraction, the presence of mixed-layer clay formations is noted (reflexes in the area of reflection angles  = 4–20°). According to the test results of the obtained samples (see Fig. 2) it was found that with an increase in the proportion of sand-clay rock in the raw mixture in the amount of up to 40 wt.% (the content of active CaO in the mixture is 4%), the compressive strength index is 19 MPa. An increase in the content of the sand-clay rock fraction in the mixture in the amount of more than 40 wt.% leads to a decrease in strength indicators. For mixtures with an active CaO content of 6 and 8%, an increase in the proportion of sand-clay rock in the mixture also increases the performance of the products. The index of the compressive strength of samples containing 40 wt.% of sand-clay rock Table 1 Fractional composition of sand-clay rock The content of the fractions in %, the size of the sieves More 0.63

0.63–0.315 0.315–0.2 0.2–0.125 0.125–0.1 0.1–0.05 0.05–0.04 0.04–0.01 0.01–0.005 Less 0.005

0.18

3.5

6.12

14.52

8.69

24.69

1.72

30.91

2.68

6.99

Table 2 Fractional composition of sand The content of the fractions in %, the size of the sieves 2.5

1.25 0.63 0.315 0.14 Less than 0.14

0.5

6

Fig. 1 Radiograph of sand-clay rock

21

55

95.5 12

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A. A. Volodchenko

Fig. 2 Compressive strength of samples depending on the content of sand-clay rock and the content of active CaO in the mixture: 1—4%; 2—6%; 3—8%

Fig. 3 Radiograph of the control sample of the silicate material

(the content of active CaO in the mixture is 6%) is 23 MPa, and for a mixture with the activity of the raw mixture of 8% – 29.14 MPa. The average density of the samples is about 1750 kg/m3 . The samples of all compositions have water resistance, which is confirmed by the values of the softening coefficients (>0.8). Studies of the composition of the forming cementitious substance in control samples show the presence of low-base calcium hydrosilicates of the CSH(B) group (see Fig. 3). On the radiograph of the samples (see Fig. 4) with the addition of sand-clay rock, the formation of low-base calcium hydrosilicates CSH(B) is identified. The presence of high-base calcium hydrosilicates C2 SH2 (d = 3.0.24; 2.29; 1.88 Å) is also noted. It is worth noting that the increase in the performance characteristics of the resulting products also occurs due to the formation of a denser structure of the synthesized new things, which is provided by a denser packaging of the components of the mixture.

Improving the Efficiency of Silicate Materials …

13

Fig. 4 Radiograph of a sample of silicate material containing sand-clay rock

4 Conclusion Thus, it is established that the widespread sand-clay rocks containing 20 wt.% of clay impurities in the territory of Russia, can be used as a component of the raw material mixture to produce silicate composites. The use of such raw materials allows accelerating the synthesis of new things, and as a result, to increase the performance of finished products. To achieve maximum efficiency, the sand-clay rock must be used as a part of an aluminosilicate binder obtained by joint grinding of the initial rock and lime, which will ensure the most uniform distribution of the clay fraction in the raw mixture. The optimal total content of sand-clay rocks in the raw material mixture, which ensures the achievement of maximum strength indicators, is 35–40 wt.%. Acknowledgements The work is realized in the framework of the grant Russian Science Foundation (project № 19-79-00185).

References 1. Tolstoy AD, Lesovik VS, Kovaleva IA (2016) Composite binders for powder concrete industrial waste. Bull. BSTU Named After V.G. Shukhov 1:6–9 2. Klyuev SV, Klyuev AV, Khezhev TA, Pukharenko YV (2018) High-strength fine-grained fiber concrete with combined reinforcement by fiber. J Eng Appl Sci 13:6407–6412 3. Volodchenko AA, Lesovik VS, Volodchenko AN, Zagorodnjuk LH, Pukharenko YV (2016) Composite performance improvement based on non-conventional natural and technogenic raw materials. Int J Pharm Technol 8(3):18856–18867 4. Tolstoy A, Lesovik V, Fediuk R, Amran M, Gunasekaran M, Vatin N, Vasilev Y (2020) Production of greener high-strength concrete using Russian quartz sandstone mine waste aggregates. Materials 13:5575 5. Klyuev SV, Khezhev TA, Pukharenko YV, Klyuev AV (2018) Fiber concrete for industrial and civil construction. Mater Sci Forum 945:120–124 6. Nelyubova VV, Babayev VB, Alfimova NI, Usikov SA, Masanin OO (2019) Improving the efficiency of fibre concrete production. Constr Mater Prod 2(2):4–9 7. Tolypina NM, Rakhimbayev SM, Khakhaleva EN (2017) The materials are resistant hydration hardening the filler concrete scrap. Bull. BSTU Named After V.G. Shukhov 7:6–9

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8. Klyuev SV, Khezhev TA, Pukharenko YV, Klyuev AV (2018) To the question of fiber reinforcement of concrete. Mater Sci Forum 945:25–29 9. Fomina EV, Lesovik VS, Kozhukhova MI, Solovyova EB (2020) The raw materials genetic characteristics role in autoclave cellular concrete carbonation process. Mater Sci Forum 974:224–230 10. Volodchenko AA, Lesovik VS, Zagorodnjuk LH, Glagolev ES (2019) On the issue of reducing the energy intensity of the silicate composites production with the unconventional aluminosilicate raw materials use. Mater Sci Forum 974:20–25 11. Klimesch D, Ray A (2002) Evaluation of phases in a hydrothermally treated CaO-SiO2 -H2 O system. J Therm Anal Calorim 70(3):995–1003 12. Nourredine A, Chelghoum N, Jauberthie R, Molez L (2015) Formation of C-S-H in calcium hydroxide–blast furnace slag– quartz–water system in autoclaving conditions. Adv Cem Res 27(3):153–162 13. Volodchenko AN, Lukutsova NP, Prasolova EO, Lesovik VS, Kuprina A (2014) Sand-clay raw materials for silicate materials production. Adv Environ Biol 8(10):949–955 14. Volodchenko AN, Nelyubova VV (2020) Reactivity of the clay component of rocks at the incomplete stage of mineral formation to lime during autoclave processing. Lecture Notes in Civil Engineering, vol 95, pp 86–91

Separation of Oil-Water Emulsion Using Polysulfonamide Membranes Treated by Air Plasma I. G. Shaikhiev , V. O. Dryakhlov , S. V. Sverguzova , and L. V. Denisova

Abstract It is investigation of separation of the oil–water emulsion by polysulfonamide membranes with a molecular weight cut-off 20 kDa treated with a lowtemperature high-frequency capacitive plasma of reduced pressure in an air medium at a voltage Ua = 1.5–7.5 kV and a processing time τ = 1.5–7 min. Round flat filter elements with a diameter of 47 mm are used as membranes. The emulsion with a concentration of 3% (by volume) is prepared on the basis of Devonian oil from the Tumutuk field and distilled water, stabilized with a surfactant of the Kosintol-242 brand. The experiments were carried out on a laboratory ultrafiltration separation unit. Based on the results of studies have shown the increased productivity of the separation of oil–water emulsion for plasma treated membranes at Ua = 1.5 and 3.5 kV 1.5 times, when exposed to plasma at Ua = 7.5 kV and τ = 7 min was an increase in the efficiency of the investigated process of 95.7–99.6%. The methods of dynamic light scattering and dielectric permittivity revealed a decrease in the particle size and stability (in -potential) of the emulsion after its separation by the membrane, while lower values are observed when using a plasmatreated filter element, for which lower values of the dielectric permittivity are also observed. Keywords Polysulfonamide · Membrane · Plasma · Oil · Emulsion

1 Introduction Water is the habitat of living organisms; the solvent of mineral and organic components of natural and anthropogenic origin; the reagent for chemical reactions, that occur in nature and industry, including photosynthesis, transport for material objects, I. G. Shaikhiev · V. O. Dryakhlov Kazan National Research Technological University, Kazan, Russia S. V. Sverguzova · L. V. Denisova (B) Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_3

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ranging in size from atoms to several thousand tons; the temperature regulator, as for the individual organism, as for the climate of the entire biosphere; an integral part of agricultural activities. Thus, water is one of the main life-determining factors on the Earth. Over the past decades, due to the activities of industrial enterprises, the impact on the environment is increasing and, as a consequence, the state of the drinkinghousehold and fishery objects of water use is deteriorating. One of the main pollutants of hydrosphere are petroleum products (PP), which include hydrocarbons of petroleum, fuel oil, kerosene, ligroin, gasoline, diesel fuel, tar, oils, phenol and its derivatives, nitrogen-containing compounds and many others. The flow of the latter into aquatic ecosystems causes a change in the physicochemical composition of water, violation of the real-energetical and informative interrelationships between living organisms and their habitats, and, as a result, the deterioration of the state and the decline in the number of populations, including people. There are different methods of wastewater purification, containing oils and petroleum products, which differ in efficiency, applicability to specific technological tasks and, accordingly, cost [1–3]. Membrane technology, based on the separation of mixtures, consisting of two or more components, using a selectively permeable barrier-membrane, combines efficiency and ergonomics. The disadvantage of membrane wastewater treatment is in the concentration polarization. This process lies in the fact that, concentrated layer, leading to deterioration in the permeability and selectivity of the separating wall, is formed in close vicinity to the separation site of detachable component. In order to intensify the work of membranes, the latter are modified in a variety of ways. One of the promising methods for modifying the surface of polymers is the impact of low-temperature plasma, which makes it possible widely change the properties of these materials, and significantly expand the fields of their use. Previous experiments have shown a positive impact on the process of separation of water–oil emulsions by plasma treatment of polymeric membranes [4–10].

2 Materials and Methods The model emulsion is prepared on the basis of the Devon oil from the Tumutuk deposit (Republic of Tatarstan). The dispersion phase of the emulsion was 3% (by volume), the surfactant Kosinantanol-242 was 0.3%. Distilled water was used as the dispersion medium. Flat round filter elements of “UPM” brand, made of polysulfonamide (PSA), with the surface area of 1.735·10–3 m2 and pore sizes based on molecular weight cut-off 20 kDa were used as membranes. The treatment of membranes with low-pressure plasma was carried out in a hydrophilic regime in a gaseous atmosphere with the following parameters: anode voltage (Ua) 1.5–7.5 kV; time of plasma treatment (τ)—1.5–7 min; the current at the anode (Ia)—0.3–0.7 A; the gas mixture flow rate (G)—0.04 g/s; pressure (P)—26.6 Pa.

Separation of Oil-Water Emulsion Using Polysulfonamide Membranes …

17

The separation process was carried out using the laboratory unit—the membrane module, made in the form of a plastic cylinder, the lower part of which had a membrane mounted on the stand. Pressure was applied in the device through the lid in the form of compressed air created by the compressor. 50 cm3 of separated medium was poured into the laboratory device above the surface of the membrane and a mixing magnetic device was started simultaneously creating a tangential cross-flow on the surface of the filter element in order to prevent the phenomenon of concentration polarization. The module is sealed with a clamp system, then the necessary pressure (2 atm) is created, controlled by a manometer, which causes the beginning of separation process. The resulting filtrate was taken with the cylinder of 50 cm3 , at that the filling time of each 5 cm3 of filtrate was measured using a stopwatch to determine the productivity of the membranes. The value of chemical oxygen demand (COD) of the filtrates was also determined, followed by calculation of the separation process efficiency. The results are presented in the form of graphs on Fig. 1 and in Table 1.

3 Results and Discussion When the emulsion is separated by membranes with the molecular weight cut-off 20 kDa treated with plasma in air, as shown on Fig. 1, the decrease of productivity is observed with the plasma processing voltage increase. It also shows the increase of membrane productivity with the increase of the processing time of the latter. The result of PSA membrane plasma treatment in the air medium is emulsion separation efficiency increase by 1.5 times with respect to the initial membrane. This fact was noted at anode voltage Ua = 1.5 and 3.5 kV. The greatest value of the considered parameter is observed at the processing time t = 1.5 and 7 min. The values of COD index are decreased in 100% of cases during the plasma treatment of PSA membranes in the gas atmosphere of air. It is noted that when the anode voltage Ua increases, the decrease of COD value in the emulsion filtrates is observed. The value of filtrate COD after the passing of the initial membrane and the minimum value of COD filtrate obtained after the separation of the emulsion by plasma-treated membrane at Ua = 7.5 kV, τ = 7 min in the air medium were 853 and 78 mgO/dm3 . At that the process efficiency made 95.7 and 99.6%, respectively. The histograms of particle distribution for the initial dispersed phase of 3% emulsion and the filtrates obtained after the separation of the emulsion by an initial PSA membrane and the most efficient plasma-treated PSA membrane (Ua = 7.5 kV, τ = 7 min) with the molecular weight cut-off 20 kDa were studied for a more detailed analysis of the water–oil emulsion separation process. -potential is determined, which is the indicator of colloidal system stability, including emulsion. The permittivity of membranes was studied. Figure 2 shows the particle size distributions of the dispersed emulsion phase and filtrates, obtained by light scattering method using NanoBrook Omni analyzer.

18 Fig. 1 Separation productivity of 3% oil emulsion by membranes with the molecular weight cut-off 20 kDa, processed in a plasma flow and a gaseous atmosphere of air, at the voltage value: a 1.5 kV; b 3.5 kV; c 5.5 kV; d 7.5 kV

I. G. Shaikhiev et al.

Separation of Oil-Water Emulsion Using Polysulfonamide Membranes … Table 1 Values of COD filtrates obtained through the separation of 3% emulsion by PSA membranes treated by plasma flow in a gaseous atmosphere of air

19

Anode voltage (Ua ), kV COD value, mgO/dm3 Treatment period (τ), min 1.5

4

7

1.5

319

394 227

3.5

279

291 278

5.5

203

106 137 149 78

7.5

143

Initial membrane

853

Emulsion

20,246

Fig. 2 Histogram of the particle size distribution of the dispersed 3% water–oil emulsion phase, as well as the particles of filtrate dispersed phase in the initial and plasma-treated membrane air environment

According to the histograms of particle size distribution shown on Fig. 2, emulsion has a more coarsely dispersed composition than the filtrate, which is natural. The filtrate obtained by the emulsion separation by the initial membrane has a larger particle size as compared to the filtrate obtained during the separation by plasmatreated membrane. This is due to the fact that a modified membrane promotes the retention of large particles of the dispersed phase by its surface and pores. The largest number of particles of emulsion is 5.41·102 and 2.89·103 nm, the filtrate at the use of the initial membrane is 2.47·102 and 2.51·103 nm, the filtrate of the modified membrane is 1.08·102 and 5.33·102 nm. The values of -potential are also determined, which is the indicator of colloidal system stability. The considered index for 3% emulsion, the filtrate after the initial membrane was −47.78, −30.88 mV, respectively. This value was 23.78 mV for the filtrate obtained by emulsion separation with a plasma-treated membrane. Obviously, the most stable one is the initial emulsion with the largest -potential by modulus due to the greater content of the emulsifier. The least stable filtrate is the filtrate obtained after the separation of the emulsion by the plasma-treated membrane, because of the lower content of the emulsifier in its composition. To continue the studies, the values of the dielectric constant permeability of the initial and most effective plasma-modified membrane were determined and presented in Table 2.

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Table 2 Dielectric permittivity indicators for membranes Membrane

Thickness, mm

Dielectric permittivity

Initial

0.16

17.627

Plazma treated membrane (Ua = 7.5 kV, τ = 7 min)

0.16

* All

2.7723

values are taken at an alternating current frequency of 103 Hz

The observed changes of polymer dielectric properties during plasma processing are undoubtedly associated with the rearrangements of both supramolecular and chemical structures. Naturally, the associated changes in the mobility of macromolecule segments, the emergence or the destruction of intermolecular bonds (mainly hydrogen bonds), the orientation of dipoles play an important role in the observed pattern. The following relationship is observed: dielectric permeability of membranes decreases with the increasing efficiency of emulsified medium separation. The value of the dielectric constant is less by 6.3 times than in an original membrane for a more efficient plasma-treated membrane.

4 Conclusion Based on the results of the presented studies, the possibility of intensifying the membrane separation of oil emulsion when treating PSA membranes with a molecular weight cut-off 20 kDa with a capacitive plasma of reduced pressure created in the air atmosphere is shown. The parameters of the plasma treatment at which the highest selectivity of the membrane separation of the model emulsion is achieved (Ua = 7.5 kV, τ = 7 min) are determined. Acknowledgements This work was realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V. G. Shukhov, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

References 1. Sverguzova SV, Fetisov DD (2011) Impact of oil and gas complexes on environmental objects. Bull. BSTU Named After V.G. Shukhov 4:192–194 2. Shaikhiev IG, Faskhutdinova ZT, Abdullin ISh, Sverguzova SV (2013) Influence of HF plasma parameters of low pressure on the efficiency of waste removal from the water surface of TP-22 oil. Bull BSTU Named After V.G. Shukhov 1:133–137 3. Shaikhiev IG, Valiev RR, Sverguzova SV (2020) Removal of oil films from the water surface with mineral wool production waste modified with organosilicon liquid. Bull BSTU Named After V.G. Shukhov 12(23):89–95 4. Dryakhlov V (2015) Intensification of breaking of water-in-oil emulsions by membranes treated in the area of corona discharge or in the plasma flow. Bul Chem Commun 3(47):109–115

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5. Dryakhlov V (2015) Effect of parameters of the corona discharge treatment of the surface of polyacrylonitrile membranes on the separation efficiency of oil-in-water emulsions. Surf Eng Appl Electrochem 4(51):406–411 6. Shaikhiev IG (2016) Purification of oil-in-water emulsions using polymer membranes treated in a DC corona-discharge field. Chem Pet Eng 5–6(52):352–356 7. Fazullin DD (2016) Treatment of wastewater containing waste oil. Int J Pharm Technol 2(8):14366–14374 8. Fedotova AV (2017) Intensification of separation of oil-in-water emulsions using polysulfonamide membranes modified with low-pressure radiofrequency plasma. Pet Chem 2(57):159–164 9. Alekseeva M (2018) Enhancement of separation of water–oil emulsion using unipolar coronatreated polysulfonamide membranes. Pet Chem 2(58):152–156 10. Fedotova AV (2018) Effect of radiofrequency plasma treatment on the characteristics of polysulfonamide membranes and the intensity of separation of oil-in-water emulsions. Surf Eng Appl Electrochem 2(54):174–179

Rheological Properties of Molding Mixes on Composite Gypsum Binders for 3D-Additive Technologies of Low-Height Monolithic Construction E. S. Glagolev , N. V. Chernysheva , M. Yu. Drebezgova , and D. A. Motorykin Abstract The most important indicators of molding mixes for 3D construction technologies that determine the quality of products are rheological and technological characteristics, in particular, the preservation of viability (flowability of the mixture), the ability to regulate the thickening and setting time within the required limits, as well as the ability to maintain certain rheological parameters throughout the entire process of their preparation. The use of special molding mixes based on composite gypsum binders (CGB) will reduce the duration of the production cycle and improve the quality of products. The paper presents the results of experimental studies on the rheological characteristics of fast-hardening special molding mixtures based on CGB, including (wt. %): gypsum binder—58% (70% G-5 BII and 30% GVVS-16); cement—20%; waste of wet magnetic separation of ferruginous quartzite (WMS waste)—20%; metakaolin— 0.5% and chalk—1.5%, which were studied on a rotary viscometer “RHEOTEST RN 4.1”. The studies confirmed the ability to control the rheological properties of molding mixes on CGB due to the combined functional and rheologically active additives with optimizing their properties for features of different types of forming equipment and tasks. Keywords Rheological properties · Special molding mixtures · 3D technology

1 Introduction Low-height monolithic construction in the Russian Federation is one of the rapidly developing areas of development and implementation of new construction technologies and materials. In modern conditions, 3D technology is one of the most advanced and accelerates the pace of construction, allows creating structures of the most diverse configurations of high quality, etc. [1–10]. For monolithic low-height construction E. S. Glagolev · N. V. Chernysheva (B) · M. Yu. Drebezgova · D. A. Motorykin Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_4

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using 3D technologies, various types of Portland cement are mainly used as a binder, but due to the slow hardening, their use is not rational. For a stable technological process of construction of monolithic low-height buildings by the method of layerby-layer synthesis, special molding mixtures based on composite gypsum binders (CGB) are proposed, which allow to adjust their setting time and hardening rate within a wide range [3, 4]. Within the framework of the Program of development of the reference university on the basis of BSTU named after V. G. Shukhov until 2021, studies were conducted, the main task of which was to study the rheological properties of special molding mixtures based on CGB according to GOST 125, in which the amount of Portland cement does not exceed 20% with various organic additives, and experimental selection of their dosages.

2 Methods and Materials The criterion characteristics of molding mixtures for 3D-technology of monolithic construction are the indicators of their extrudability and form stability (ability to hold the shape), determined by the viscoplastic properties of the mixtures (viscosity and yield strength indicators), especially the duration of the induction period preceding the intensive growth of the coagulation structure. A RHEOTEST RN 4.1 viscometer was used to evaluate the rheological properties of special molding mixtures on the basis of CGB. In the laboratory, the layer-by-layer synthesis of model structures with a molding mixture based on CGB was carried out on an experimental 3D printer, which consists of a moving platform, a mixer, a hopper, a forming head with replaceable nozzles, a vibrator and a control panel. The shear stress, viscosity, shear rate gradient, and time at ambient temperature— 24 °C were studied. In the studies, CGB was used, including (wt.%): gypsum binder— 58% (70% G-5 BII and 30% GVVS-16); cement—20%; waste of wet magnetic separation of ferruginous quartzite (WMS waste)—20%; metakaolin—0.5% and chalk— 1.5%. To regulate the technical properties of the molding mixtures, dry organic modifiers produced by ADDITIVE PRLUS LLC, Podolsk, Moscow region were used: a superplasticizer of the MARF SU 84 brand—0.3% (by weight of the CGB); a stabilizer of the MARF Forbo—Crete S 010 brand at a dosage of 0.07% (by water); a thickener of the MAPF № T10 brand—0.1%, carboxymethylcellulose (CMC)—2% and a setting time retarder (citric acid)—0.2% (by weight CGB). During the extrusion process, the W/ Bin ratio, the mobility of the CGB of mixture and the shape stability of the layers of the structure were recorded.

Rheological Properties of Molding Mixes …

25

3 Results and Discussions The preparation of a special molding mixture on the CGB was carried out as follows. Initially, citric acid was inserted into the required amount of mixing water to increase the time interval between the beginning and end of setting of the molding mixture. Then, with constant stirring, pre-prepared CGB with organic and mineral additives was added, as well as CMC to give the molding mixture the required viscosity and ductility. The physical and mechanical characteristics of the mixtures were determined at a constant spread of 120 mm according to Suttard. The compressive strength of the solidified CGB was determined on cube samples with an edge of 7.07 cm (GOST 237.89–79) (Table 1). It was found that the studied molding mixtures on CGB quickly harden and gain strength, providing a compressive strength of 3.3 to 34 MPa in the early stages. The RHEOTEST RN 4.1 viscometer was used to evaluate the rheological properties of special molding mixtures on the CGB. The rheological dependencies are presented in Fig. 1–2. A special molding mixture on CGB with a complex of mineral additives – WMS waste, metakaolin and chalk (Fig. 1, 1) is characterized by expressed properties of a thixotropic nonlinear viscoplastic body with a decrease in the effective viscosity (η) to a minimum value with an increase in the shear rate gradient (γ). The rheogram of the control composition of the mixture (flow) in the coordinates “shear stress-shear rate gradient” under these conditions has an expressed peak in the initial region, starting with the shear stress value—40.18 Pa and the viscosity of 51.74 Pa : s, indicating an increased limiting shear stress at which the flow begins. On the one hand, this is positive for fixing the structure of the printed layer of the structure, and on the other hand, it significantly complicates the supply of the mixture to the forming device. When the shear rate gradient reaches 11.97 s−1 , the Table 1 Compositions and properties of the solidified molding mixture on CGB № SP

ST

TG

1 2 3 4 5

0.07 0.07

0.1 0.1

0.3 0.3

CMC

2

W/Bin 0.53 0.44 0.58 0.60 0.40

Setting time, min,-s beginendning ing 10-30 11-30 14-00 16-30 10-00 11-00 9-30 10-30 9-30 10-30

Rcomp, MPa,in terms 2 1 7 hour days days 3.3 5.8 9.6 6.2 9.2 17.9 14.0 16.4 32.2 14.4 19.8 34.0 9.0 10.8 23.6

Note. The composition of CGB – gypsum binder 58 % (G-5-40 %, G-16-18 %,); PC-20 %, finely ground WMS waste -20% metakaolin – 0.5 %, chalk -1.5 %. SP – superplasticizer МАРF SU 84 ST – stabilizer МАРF Forbo-Сrete-S-010 TG – MAPF Supplement No. T10 with a marked thixotropic thickening effect CMC – carboxymethylcellulose.

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Fig. 1 Rheograms of equal-moving molding mixtures on CGB: 1—CGB without additives, 2— CGB + SP MAPF SU 84- 0.3%, 3—CGB + MAPF Forbo-Crete S 010—0.07%; a) dependence of the effective viscosity on the shear rate gradient; b) the dependence of the shear stress on the shear rate gradient

viscosity values decrease to 3.43 Pa : s (the initial structure is destroyed), followed by a viscous flow section. The reverse branch of the studied rheogram of the control mixture is almost identical to the forward branch. The molding mixture on the CGB is subjected to thixotropic liquefaction, and when external influences are removed, it restores its structure. When 0.3% SP of MARF SU 84 is inserted into the mixture, the values of the rheological characteristics of the mixture change.

Rheological Properties of Molding Mixes …

27

Fig. 2 Rheograms of equal-moving molding mixtures on CGB: 4—CGB + MAPF №T 10; 5— CGB + KMC; 6—CGB + MAPF SU 84 + MAPF Forbo-Crete S 010 + MAPF №T10 + CMC; a dependence of the effective viscosity on the shear rate gradient; b the dependence of the shear stress on the shear rate gradient

The molding mixture (Fig. 1, 2) has a 1.8-fold lower viscosity (28.67 Pa : s) and a maximum shear stress (22.24 Pa), at which the original structure is destroyed compared to the same indicator for the non-additive composition. At the same time, the W/Bin ratio is reduced by 1.7 times, which helps to reduce shrinkage and increase strength. Selling branch rheogram of a mixture of SP is almost identical to direct and has a lower shear stress to 22 PA and a viscosity of up to 3 s−1 , reducing the load on the electric motor concrete mixer and 3D printer.

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The insertion of the MARF Forbo-Crete S 010 stabilizer (Fig. 1, 3) into the molding mixture allows controlling the rheology of the mixture without loss of workability and contributes to its resistance to delamination. When the shear stress is applied, the viscosity of the system drops sharply, and when the force is stopped, it is restored. The addition of MARF Forbo-Crete S 010 helps to stabilize the viscosity of the mixture and reduce friction between its particles, which increases its suitability for extrusion. To improve the rheological properties (viscosity, anti-separation) mixtures at CGB they used additive MAPF T 10, which has a marked thixotropic thickening effect, and decrease the water absorption (Fig. 2, 4) and CMC (Fig. 2, 5). It was found that the nature of their flow is similar, but mixed with a MAPF T the 10 lower values of viscosity due to the fact that CMC is a good film-formation (film held well on the particles), reduced significantly the friction between the particles, which contributes to its good burst and dimensional stability. These compositions restore their structure when external influences are removed. The reverse branches of the rheograms of the studied mixtures are almost identical to the straight line. Basically, they have a fairly high degree of structuring, which can create prerequisites for achieving a good fixing ability in solutions based on them. The molding mixture (Fig. 2, b) with a complex of organic and mineral additives has the lowest viscosity, the maximum shear stress (the beginning of the flow) and the structure of the CGB—water system in the entire considered range of shear rate gradients, which creates the potential to reduce the W/Bin ratio and, accordingly, to increase the strength. That is, there is a synergistic effect, as a result of the combined action of the organic additives used, which significantly exceeds the sum of the actions of each of them. This allowed obtaining an optimal ratio of the properties of the molding mixtures at all stages of the cycle: feeding the forming device, pumping the mixture and passing through the narrowest section of the extruder (nozzle), the primary fixation of the structure of the freshly formed layer (shape stability). The low gap between the forward and reverse branches of the rheogram (the small area of the hysteresis loop) indicates the possibility of rapid restoration of its structure, which is required for special molding mixtures used in 3D construction technologies for the purpose of fast fixation of the output layer (Fig. 2, b). The absence of a peak on the forward branch of the rheogram is positive from the point of view of the power supply of the forming device. Such mixtures on CGB help to reduce the load on the electric motor of the concrete mixer and 3D printer and are best suited for the preparation of fine-grained molding mixture.

4 Conclusion The studies confirmed the ability to control the rheological properties of molding mixes on CGB due to the combined functional and rheologically active additives with optimizing their properties for features of different types of forming equipment and tasks.

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Acknowledgements The work was carried out as part of the implementation of the Development Program of the reference university on the basis of BSTU named after V.G. Shukhov until 2021. Contract No. A-82/20. Research topic: Aerated concrete based on water-resistant gypsum binders for heat-insulating and heat-insulating structural layers of building envelopes constructed using the construction printing method, using equipment of High Technology Center at BSTU named after V.G. Shukhov.

References 1. Slavcheva GS, Artamonova OV (2018) Rheological behavior of 3D printable cement paste: criterial evaluation. Mag Civ Eng 84(8):97–108 2. Lesovik VS, Glagolev ES, Volodchenko AN, Drebezgova My (2016) Effective composites for 3D additive technologies in construction. Bulletin of the Central Territorial Department of the Russian Academy of Architecture and Construction Sciences. Voronezh 15, 149–156 3. Chernysheva NV, Lesovik VS, Drebezgova MYu, Shatalova SV, Alaskhanov AH (2018) Composite gypsum binders with silica-containing additives. IOP Conf Ser Mater Sci Eng 327:032015 4. Chernysheva NV, Shatalova SV, Evsyukova AS (2018) Fischer, Hantz-Bertram: features of selection of rational composition of composite gypsum binder. Constr Mater Prod 1(2):45–52 5. Elistratkin MYu, Minakov SV, Shatalova SV (2019) Influence of mineral additives in the composition of a composite binder on the effectiveness of the plasticizer. Constr Mater Prod 2(2):10–16 6. Klyuev SV, Klyuev AV, Khezhev TA, Pukharenko YV (2018) High-strength fine-grained fiber concrete with combined reinforcement by fiber. J Eng Appl Sci 13:6407–6412 7. Permyakov MB, Permyakov AF, Davydova AM (2017) Additive technologies in construction. Eur Res 1(24):14–18 8. Vatin NI, Chumadova LI, Goncharov IS, Zykova VV, Karpenya AN, Kim AA, Finashenkov EA (2017) 3D printing in construction. Constr Unique Build Struct 1(52):27–46 9. Pustovgar AP, Adamtsevich AO, Volkov AA (2018) Technology and organization of additive construction. Ind Civ Constr 9:12–20 10. Inozemtsev AS, Korolev EV, Zuong TK (2018) Analysis of existing technological solutions for 3D printing in construction. Bull. MSCU 13(7) (118): 863–876

Substantiation of the Type of Machining of a Flat Metal-Metal-Polymer Surface Considering the Provision of the Required Roughness of the Part B. S. Chetverikov , D. M. Annenko , N. S. Lubimyi , and A. A. Tikhonov Abstract The article deals with issues related to the mechanical machining of a flat surface of a metal-polymer work piece by flat grinding. The attention paid to the mechanical machining of flat surfaces is due to the use of metal-polymer as structural materials for the manufacture of parts of molds and their repair. The article provides an analysis of materials and types of machining of a combined part consisting of metal-polymer and metal, such as a forming part of a mold for casting plastic products. A brief description of the part is given on the example of the forming part of the mold and the requirements for dimensional accuracy and roughness imposed on it. Based on the analysis of the properties of two materials with different physical and mechanical properties, an analysis of the types of machining, the parameters of accuracy, roughness and deviation of the shape and location of surfaces achieved by them is given. The conclusions on the advisability of using one or another type of processing are presented in a tabular form, which is convenient to use when developing a technological process for manufacturing a combined metal-metal-polymer flat part. Keywords Machining · Grinding · Flatness · Metal-polymer · Roughness

1 Introduction In the modern world, enterprises engaged in the field of plastics processing are constantly improving processing methods, equipment, materials and tooling in order to make the production process the most technological. In single and small-scale production, the largest share in the cost of manufacturing a product is the cost of manufacturing tooling, namely the cost of manufacturing molds. Modern technologies for accelerated production preparation are described in [1, 2]. Studies obtained by Russian scientists [2–4] show that one of the most promising directions in the tool B. S. Chetverikov · D. M. Annenko · N. S. Lubimyi (B) · A. A. Tikhonov Department of Hoist Transport and Road Machines, Belgorod State Technological University named after V G Shukhov, Kostyukov St., 46, Belgorod 308012, Russia e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_5

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Fig. 1 The scheme of the combined metal-metal-polymer forming part of the mold

industry in the manufacture of molds for small-scale molding of thermoplastics is the manufacture of combined metal-metal-polymer equipment. The use of a combined tooling with molding parts made of a heat-resistant metal-polymer can significantly speed up the manufacturing time of the molding tool and reduce the cost of tooling, and therefore the cost of the final product. However, the technology of manufacturing combined metal-metal-polymer tooling is poorly studied, in particular, there are no data on the processing of flat combined metal-metal-polymer surfaces. Thus, it requires additional research and data analysis.

2 Materials and Methods As research methods, a theoretical and analytical research methods were used [5], which consist in analyzing existing data on the types of machining, comparing these data with the requirements imposed on them and making a conclusion about the possibility of using one or another type of machining. Figure 1 shows a diagram of a combined metal-metal-polymer forming part of a mold (matrix). Where, 1 is the metal part of the mold made of 40X13 steel; 2 – metal-polymer part (WEIDLING C metal-polymer) [6, 7]; 3 – shaping surface; 4 – flat mold clamping surface.

3 Results and Discussion To substantiate the choice of a method for machining a flat combined metal-metalpolymer clamping surface of the mold, it is necessary to analyze the processed materials, the requirements for the processed surface and the existing processing methods. Table 1 shows the main physical and mechanical properties of the processed materials, which are necessary while choosing a processing method.

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Table 1 Properties of Weidling C metal-polymer and steel 40X13 Material grade

Compression Strength, MPa

Young’s modulus, MPa

Hardness HB

Temperature resistance up to °C

Weidling C

140

5800–6000

630

220

Steel 40 × 13

1165–1700

214,000

229

400–450

The following requirements are imposed on the treated surface. The planes of the slabs have a surface roughness of at least 7th grade of cleanliness [8], which corresponds to at least Ra 1.25 µm. According to [9], the roughness of the clamping surface of the mold must be at least Ra 0.8 µm. The flatness tolerance of the supporting planes of the plates, the planes of parting of the molds must correspond to the 6th degree of accuracy [7] (for sizes 250–400 − 16 µm). In addition, the supporting surfaces absorb the clamping forces, keeping the mold halves in a closed state, compact and seal the mold cavity. The types of machining of flat surfaces of steel parts need to be analyzed. Planing allows to achieve an acceptable quality of surface treatment of workpieces, their dimensional accuracy and surface roughness. The loss of time during idling makes planing a less productive processing method. Scraping is a locksmith operation that is difficult to mechanize, which can achieve high accuracy (0.003–0.01 mm) and roughness (Ra 0.63 µm) of the surface. Due to the high laboriousness of machining parts by scraping, it is used with the complexity of controlling the flatness of the surface (according to the number of spots per unit of the processed surface) and the presence of manual labor, this type of surface treatment is not preferable. An alternative to manual scraping is fine (scraping) milling. Scabber milling is carried out at a high cutting speed (200–300 m/min), but at a low feed (0.05– 0.15 mm/rot), so the productivity is low, despite the use of a high cutting speed. Scraper milling provides the surface roughness of steel and cast iron billets up to Ra 0.32–1.25 µm, and billets of bronze and aluminum alloys up to Ra 0.16–0.32 µm, the achieved flatness deviation corresponds to 0.02–0.03 mm. Fine milling of aluminum alloys is carried out with single-flute cutters, and for ferrous and non-ferrous metals and alloys - with two-flute stepped ones, while a wide cutting edge of the cutter is used. Thin face milling also achieves the parameters of accuracy, roughness and flatness of the clamping surface of the mold. High speed milling (HSC) is the most promising and productive way of surface machining. However, HSC technology requires modern equipment with a high spindle speed, as well as expensive wearresistant tools. It should also be noted that the main idea of high-speed cutting is to achieve a sufficiently high temperature in the cutting zone and reduce cutting forces, while heat is removed along with the chips. This condition imposes restrictions on the machining of materials with low thermal conductivity, as while machining materials with low thermal conductivity, thermal-oxidative destruction of the material is possible [10, 11].

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Broaching is not a technologically advanced method of processing machine blanks for single and small-scale production, since it requires the manufacture of expensive special cutting tools. The machining of flat clamping surfaces of mold by flat grinding with the periphery of the wheel meets the requirements for accuracy, roughness and mutual arrangement of surfaces, but due to limitations on the depth of cut, it does not apply to highperformance types of machining. The experiment on grinding the WEIDLING C polymer composite material showed that at a cutting speed of 50 m/s with a circle of 25A at a depth of cut from 0.01 to 0.1 and over the entire range of speeds of movement of the table of the 3B722 machine from 2 to 40 m/min, the temperature in the cutting zone does not exceed a temperature of 50 °C, which is significantly lower than the temperature resistance of a metal-polymer equal to 220 °C [12, 13]. The temperature was measured with a Fluke Ti400 thermal imager. Figure 2 shows a diagram of the measurement of temperature fields while grinding a metal-polymer sample Weidling C: cutting depth 0.1 mm, table movement speed 9 m/min, the maximum temperature in the cutting zone corresponds to 35.2 °C. The data are presented on accuracy, roughness and relative position of surfaces for various types of processing in Table 2. The analysis of the types of machining shows that the specified parameters (dimensional accuracy, roughness, flatness) for the clamping surfaces of the molds can be achieved by various methods, but the question of machining the combined metalmetal-polymer surface remains open. It can be concluded that when choosing the type of machining of a flat combined metal-metal-polymer mold-clamping surface, the main criterion is the possibility of simultaneous machining of two materials with different physical and mechanical properties, in particular, different Young’s modulus and heat-conducting properties. Table 3 describes the disadvantages and reveals the feasibility of joint machining of steel 40 × 13 (steel) and metal-polymer Weidling C (polymer composite material PCM) by various types of machining. Fig. 2 The diagram of temperature fields while grinding metal-polymer Weidling C

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Table 2 Types of machining of flat surfaces of parts and the achieved parameters Types of machining

Achieved roughness, Ra µm

The quality of the size tolerance during machining

Surface flatness, achievable degree of accuracy

Fine planing (chiselling)

0.32–1.6

8

5–6–7

Face milling (fine)

0.32–1.25

7

4–5–6

High speed milling HSC

0.8–1.6

6–8

6–7

Broaching

0.32–1.25

6

3–4–5

Surface grinding (fine)

0.32–1.6

7

4–5–6

Table 3 Determination of the possibility of joint machining of Weidling C and steel 40 × 13 Types of machining

Machining features of polymer-composite material (PCM)

Advisability of using

Fine planing (chiselling)

At the moment of cutting into a part of a Not advisable PCM part at a cutting speed for steel, chips are possible due to different values of Young’s modulus of materials

Face milling (fine/ scraping) For machining PCM and steel, a tool with Not advisable a different number of teeth is used; also, due to different values of Young’s modulus of materials, chips are possible while plunging into PCM. The specified roughness values for materials are achieved at different cutting speeds High speed milling HSC

High machining temperatures require high Not advisable thermal conductivity of the processed material. The thermal conductivity of PCM is significantly lower than that of steel. The specified roughness values for materials are achieved at different cutting speeds

Broaching

Processing is not feasible for small-scale and unit production

Not advisable

Surface grinding (fine)

It can be used for joint machining of PCM and steel at the same cutting speeds [8]

Advisable

4 Conclusion The analysis of Table 3 shows that for the machining of combined metal-metalpolymer flat clamping surfaces the of molds while ensuring the specified dimensional accuracy, roughness, manufacturability and flatness, flat grinding with the periphery of the wheel correspond best. This is due to the absence of shock impact while cutting into a metal-polymer, which has a high value of the elastic modulus, which

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can lead to chips and rejects of the forming surface, as well as a low temperature in the cutting zone, which excludes thermo-oxidative destruction of the metal-polymer surface. Namely, it is recommended to use this type of machining for engineers when developing a technology for manufacturing combined parts using metal-polymer. On the basis of the three-factor planned experiment, a mathematical dependence was obtained for calculating the predicted surface roughness of a metal-polymer product during abrasive machining by flat grinding with the periphery of a circle on the depth of cut and longitudinal feed. Acknowledgements This work was supported by the grant of the President of the Russian Federation No. MK-4006.2021.4, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

References 1. Lubimyi NS, Chepchurov MS, Kostoev ZM (2020) Investigation of the processes of obtaining combined metal-metal-polymer forming parts of molds of a given quality using additive technologies. BSTU, Belgorod 2. Lubimyi NS, Chepchurov MS, Teterina IA (2017) Processing of a combined metal-metalpolymer flat surface of a mold part. Bull BSTU named after V.G. Shukhov 1:162–169 3. Kiyak M, Cakir O, Altan E (2003) A study on surface roughness in external cylindrical grinding. In Achievements in mechanical & Material engineering AMME, pp 459–462 4. Lubimyi NS, Annenko DM, Chepchurov MS, Kostoev ZM (2020) The research of the temperature effect on a metal polymer during flat grinding of a combined metal polymer part. Aust J Mech Eng 80:1–13 5. Bezzubenko NK, Evdokimov AE (1990) Microcutting stresses. Cutting Tool 43:56–63 6. Korchak SP (1974) Performance of the grinding process of steel parts. Mechanical engineering, Moscow 7. Chepchurov MS, Corop AD, Starostin SV (2010) Providing the required roughness during highperformance machining of nickel heat-resistant alloys. Repair Restor Modernization 9:23–25 8. Kurdyukov VI (2014) Abrasive Basics. KSU, Kurgan 9. Maslov EN (1974) Grinding Materials Theory. Mechanical engineering, Moscow 10. Nikitin SP, Hanov AM, Sirotenko LD (2014) Calculation of the thermal resistance of the elements of the cutting zone when grinding heat-protective coatings. Mod Probl Sci Educ 6:109–118 11. Koshin AA, Sopelcev AV (2010) Investigation of the granulometric composition and microgeometric parameters of abrasive grains of grinding wheels used in rough grinding. Bulletin of UUSU 10:77–82 12. Romanovich AA, Ebrahim A, Romanovich MA (2020) Improving the efficiency of the material grinding process. In IOP Conference Series: Materials Science and Engineering 945, 012060 13. Romanovich AA, Romanovich MA, Belov AI, Chekhovskoy EI (2018) Energy-saving technology of obtaining composite binders using technogenic wastes. J Phys Conf Ser 1118:012035

Elastic-Plastic Model of Concrete Damage and Its Main Design Parameters A. G. Balamirzoev , A. R. Abdullaev , and D. N. Selimkhanov

Abstract The article considers the damage rate of concrete and its main design parameters using an elastic-plastic model. The main dependencies that determine the operation of the model are given. An example of an approximation is given, which allows us to take into account quite accurately the shape of the curve of the dependence of damage d on deformations ε. The dependences of voltage on deformations are obtained, based on the results of calculations with different values of viscosity, which are compared with the original deformation diagram, which is set as parameters of the material model. An approach is proposed to construct a calculated diagram of concrete deformation under voltage, taking into account the descending branch, based on the concrete parameters presented in regulatory documents, and with a known value of the specific energy of destruction. Based on the analysis of the results of computational studies conducted using various sets of parameters of the nonlinear concrete model, the effect of taking into account the descending branch of the voltage strain diagram, as well as changes in the specific fracture energy and the angle of dilation of concrete on the voltage state of the structure at sufficiently large load values is shown. Keywords Concrete · Elastic-plastic model · Voltage · Plastic deformation · Crack formation

1 Introduction The current regulatory documents recommend that more fully take into account the features of the dynamic behavior of concrete hydraulic structures under the action of seismic loads, and the assessment of the strength of hydraulic structures, such as A. G. Balamirzoev (B) Dagestan State Technical University, Makhachkala, Russia A. G. Balamirzoev · A. R. Abdullaev · D. N. Selimkhanov Makhachkala Branch of «Moscow Automobile and Road State Technical University (MADI)», Makhachkala, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_6

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high gravity concrete dams, should be carried out according to the dynamic theory of seismic resistance. One of the mathematical models of materials developed specifically to describe the behavior of concrete is the so-called “concrete damage plasticity model” (CDP) [1]. Due to its versatility and a large set of tasks that it allows you to solve, this model has become widely used in recent years when conducting computational studies of concrete and reinforced concrete structures. It allows you to take into account the nonlinear inelastic behavior of concrete, both in tension and compression, and also supports the possibility of solving problems using both explicit and implicit integration schemes. This makes the CDP model a suitable tool for predicting the tensely deformed state (VAT) of concrete and reinforced concrete hydraulic structures (GTS) under the action of static and dynamic loads.

2 Methods and Materials Consider the main dependencies (Fig. 1) that determine the operation of the CDP model. For uniaxial tension, the stress-strain relationship can be assumed to be linear until the critical stress value σt0 is reached. Further stress reduction corresponds to the formation of microcracks in the concrete. Under compression, the stresses are also proportional to the deformations until σc0 is reached. Next, the material is weakened to the limit voltage σcu. The decrease in the value of the elastic modulus during cracking is characterized by two damage parameters dt and dc , which are determined by the development of the corresponding plastic deformations. These parameters can take values from 0 (undamaged material) to 1 (complete destruction). If E0 is the initial modulus of elasticity of the material (intact), then the voltage and deformation under uniaxial tension σt , εt and compression σc , εc are related by the relations.

Fig. 1 Dependence of tension and deformation on uniaxial tension (left) and compression (right) of plastic-damaged concrete material [6]

Elastic-Plastic Model of Concrete Damage ...

39

  pl σt = (1 − dt )E 0 εt − εt ,

(1)

  σc = (1 − dc )E 0 εc − εcpl .

(2)

The study of the behavior of concrete in the process of destruction usually involves setting the fracture stresses as a function of the deformations of crack formation. In this case, the crack deformations are defined as the difference between the total and elastic deformations corresponding to the intact material, as shown in Fig. 1.

3 Results and Discussion The concept of crack formation deformations is introduced εtck , which are defined as the difference between total and elastic deformations corresponding to an undamaged material. Plastic strain values are used to describe the behavior of the material during pl hardening, rather than general strain values εt . If there are data on the behavior of the material during unloading, they are set in the same way as the dependence of damage d on the deformation of cracking εtck . pl Transition from crack formation deformation εtck to plastic deformation εt described pl by the relation (3), which reduces to equality εt = εtck in the absence of damage [1]. pl

εt = εtck −

σt dt . (1 − dt ) E 0

(3)

The parameters of the deformation diagram are usually given as a set of points describing the dependence of the stresses σt on the deformations of crack formation εtck . For the transition from complete deformations to crack -forming deformations, the following relation can be used: εtck = εi − ε0 = εi −

σi . E0

(4)

It is also possible to set the model parameters in the form of the voltage dependence on the size of the conditional crack opening or directly in the form of the fracture energy. If a dependency is set for the damage parameter, the movement of the “ crack pl opening” u ck t converted to “plastic” movements, u t according to the formula (5), similar to (3), it is assumed that the initial length l0 is single and equal to 1m [1]. pl

u t = u ck t −

σt l0 dt . (1 − dt ) E 0

(5)

The implementation of the concept of voltage dependence in the finite element model requires the determination of the characteristic length associated with the

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integration points of the elements. The direction in which the cracking occurs is not known in advance, so elements with large aspect ratios will behave differently depending on the direction in which the cracking occurs. The specific values of the material parameters set for the computational model in this approach should be determined based on the dimensions of the finite elements, which requires the construction of a uniform regular grid. Often, due to the complex geometry of the simulated objects, it is impossible to meet these requirements for the grid when solving real, rather than model, problems. The concrete damage model assumes that cracking begins at points where the equivalent plastic tensile deformations are greater than zero and the maximum major plastic deformations are positive. The direction of cracking is assumed to be parallel to the direction of the maximum main plastic deformations [6]. It should be noted that the damage parameter is important when solving problems related to cyclic impacts, when the material is unloaded and then reloaded. Identification of damage parameters requires a set of rather complex experiments [2]. Simplified piecewise linear and exponential approximations of the dependence of damage on concrete deformations are often used [3]. An example of such an approximation, which allows us to accurately take into account the shape of the curve of the dependence of damage d on deformations ε, is given in [4]:  d=

0, ε < ε0 g 1 − e−b(ε−ε0 ) , ε ≥ ε0

(6)

where b - is the coefficient that determines how quickly the damage parameter reaches the value 1; g-parameter that regulates the shape of the curve; ε0 - the critical value of deformations that determines the beginning of the concrete damage process. Under cyclic loading, the mechanisms of material degradation are quite complex. These include the opening and closing of previously formed microcracks, as well as their interaction. The CDP model allows you to take into account the recovery of elastic stiffness as the load sign changes. The stiffness recovery effect, also known as the “one-way effect”, is an important aspect of the behavior of concrete under cyclic loading. It is usually more pronounced when the load changes from tension to compression, which leads to the closure of tension cracks and the restoration of compression stiffness. As extreme cases, it is possible to use the following values for the stiffness recovery coefficients: compressive stiffness recovery coefficient wc = 1, which means a complete recovery of compressive stiffness when the crack is closed and the load changes from tension to compression; for tension, wt = 0, that is, the tensile stiffness is not restored [1]. The CDP model, like other modern models of the behavior of materials, requires setting a number of additional parameters to the deformation curve that determine the operation of the elastic–plastic model for the complex-stressed state. The expression used in this model for the flow potential is a hyperbolic function Drucker-Prager [1]. G=

 (σt0 tgψ)2 + q 2 − ptgψ,

(7)

Elastic-Plastic Model of Concrete Damage ...

41

where σt0 – is the uniaxial tensile stress at fracture; − a parameter called the eccentricity; ψ – the angle of dilation; q – equivalent voltage by von Mises; phydrostatic pressure. The eccentricity determines the rate at which the plastic potential function approximates the asymptote of the plastic flow potential function (the flow potential tends to a straight line if the eccentricity tends to zero). The eccentricity of the flow potential for concrete has a value close to  = 0.1. [5]. The angle of dilation ψ determines the direction of the plastic deformation increment vector. The dilatation of concrete is understood as an increase in the volume of a conditional sample during axial and multiaxial compression at the stages close to destruction, due to the development of microcracks, as well as cracks of greater length [SNIP 2.03.01-84- Concrete and reinforced concrete structures.- M. 1986]. Modern regulatory documents of the Russian Federation do not contain any information about the dilatation of concrete, apparently, due to the complexity of accounting for this effect and the lack of fairly simple approaches to its experimental determination. The cracking angle usually follows the dilation angle, and its value for concrete can vary in the range of 20°–40° [1]. For concrete of class B50, for example, in the literature there is a value of the dilation angle equal to 38° [5]. However, it should be borne in mind that the dilation angle can be determined not only by the class of concrete, but also by the characteristics of its composition. The proposed CDP model uses the function for the yield surface proposed by Lubliner [6] with the modification of Lee and Fenves [7], which takes into account the difference in tensile and compressive strength (Fig. 2). The evolution of the yield surface is controlled by the hardening parameters of pl pl the εt and εc , and the yield function has the form [1]: F=

     1  q − 3αp + β εcpl σmax  − γ −σmax  − σc εcpl = 0, 1−α

(8)

Fig. 2 The yield surface for the two-dimensional case (left) and the yield surfaces in the deviator plane corresponding to different values of Ks (right) [1]

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Fig. 3 Diagrams of the dependence of stresses on deformations at different viscosity values obtained for a single finite element and the initial calculated piecewise linear diagram of concrete deformation σ

where is α = 3(1−K c ) . 2K c −1

(σb0 /σc )−1 ;0 2(σb0 /σc )−1

≤ α ≤ 0.5; β =

  pl σc εc   (1 pl σt εt

− α) − (1 + α); γ =

Value for the ratio of σσb0c0 , which is the ratio of the biaxial compressive strength to the uniaxial compressive strength, for concrete, it is recommended to set it equal to 1.16 [1]. The shape factor, Kc, determines the shape of the yield surface in the plane of the deviator (Fig. 2). The Kc value must satisfy the condition of 0.5 ≤ K c ≤ 1.0 and is usually assumed to be 2/3 for concrete [1]. When solving problems using material models that take into account changes in stiffness, there are often difficulties with the convergence of the numerical method. To overcome them, an additional parameter of numerical viscosity can be used, which controls the regularization of the defining equations describing the equilibrium state of concrete, thereby allowing some stress to escape beyond the yield surface. This helps to achieve faster convergence of the computational method and reduce computational costs by deliberately reducing the reliability of the results obtained. The estimation of the value of this parameter, which will avoid significant errors, can be carried out on the basis of the calculation for an individual finite element. The stress-strain dependences obtained from calculations with different viscosity values are compared with the original strain diagram, which is set as the parameters of the material model (Fig. 3). The viscosity value of 0.001 gives a sufficient match with the original deformation diagram, and it will be used in further computational studies (Fig. 4 and 5).

Elastic-Plastic Model of Concrete Damage ...

43

Fig. 4 Variants of piecewise linear approximations of the dependence of stresses σ, MPa on the deformations ε of concrete under tension, used in the course of calculated studies

Fig. 5 The dependence of the beam deflection L, mm on the applied load F, tc according to the results of finite element modeling using a linear elastic model (LE), an elastic-plastic model for different variants of the approximation of the deformation diagram (1,2,3,4, respectively) and according to the test results (Test)

4 Conclusion Summing up, we can conclude that the behavior of the elastic-plastic model of concrete damage is determined primarily by the values of the tensile and compressive strength limits, the shape of the stress-strain curves, determined in particular by the value of the specific fracture energy GF, the value of the dilation angle, and optionally the dependence of the damage parameter d on deformations. Other parameters of the material model described above, such as the  eccentricity, the ratio of the biaxial compressive strength to the uniaxial compressive σσb0c0 , strength and the value of the Kc parameter for concrete has known values, which are recommended to be used by default in the absence of additional experimental data. However, there are methods for determining them based on a series of experiments on samples [8] and the values for specific concrete compositions can be refined, which, however, requires a series of time-consuming tests.

References 1. Abaqus Analysis User’s Manual. Abaqus, Hibbit, Karlsson & Sorensen, Inc., Moskow (2010)

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2. Jankowiak T, Lodygowski T (2005) Identification of parameters of concrete damage plasticity constitutive model. Found Civil Environ Eng 6(1):53–69 3. Genikomsou AS, Polak MA (2016) Damaged plasticity modelling of concrete in finite element analysis of reinforced concrete slabs. In 9th International Conference on Fracture Mechanics of Concrete and Concrete Structures University of California pp 22–25 4. Haussler-Combe U, Hartig J (2008) Formulation and numerical implementation of a constitutive law for concrete with strain-based damage and plasticity. Int J Non-Linear Mech 43(5):399–415 5. Benin AV, Semenov AS, Semenov SG, Belyaev MO, Modestov VS (2017) Methods of identification of elastic-plastic models of concrete taking into account the accumulation of damage. Eng Constr J 8:279–297 6. Lubliner J, Oliver J, Oller S, Onate E (1989) A plastic-damage model for concrete. Int J Solids Struct 25(3):299–326 7. Lee J, Fenves GL (1998) Plastic-damage model for cyclic loading of concrete structures. J Eng Mech 124(8):892–900 8. Gerstle KH (1981) Simple formulation of biaxial concrete behavior. J Proc 78:62–68 9. Sukumar N, Moës N, Moran B, Belytschko T (2000) Extended finite element method for threedimensional crack modeling. Int J Numer Meth Eng 48(11):1549–1570 10. Grassl P, Jirásek M (2006) Damage-plastic model for concrete failure. Int J Solids Struct 43(22–23):7166–7196

Experimental Investigation on Strength Characteristics of Concrete Wall Colored Stones J. V. Denisova

and E. S. Chernositova

Abstract The results of the study of the strength characteristics of concrete wall stones are presented. The results were obtained when testing wall stones according to the methodology of the updated state standard for testing the strength of wall materials. Statistical indicators that characterize the stability of the studied characteristics are calculated. Special computer programs are used to perform calculations and statistical data processing. To increase the architectural expressiveness in construction, wall stones with a textured surface are used, as well as colored ones, made of a concrete mixture with pigments or with the use of colored cements. A comparative analysis of the compressive strength of concrete wall stones, unpainted and colored, made of concrete mixtures with pigments, is carried out. For the production of colored stones, pigments of red, yellow and green were used. Recommendations on the organization of the technological process of production aimed at obtaining colored concrete with stable quality indicators are given. Keywords Wall stones · Compressive strength · Pigments · Statistical quality analysis

1 Introduction In recent years, the production of products made of fine-grained concrete by vibropressing has become widespread. The concrete wall stones WCB manufactured using this technology have excellent consumer and operational characteristics and compete successfully with such a common building material as silicate bricks. WCB manufacturers pay special attention to the decorative properties of stones: the palette of products includes green, yellow, red, white, and other colors, which allows architects and builders to create unique modern buildings and shape the aesthetic appearance of cities. The production of colored stones differs slightly from

J. V. Denisova (B) · E. S. Chernositova Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_7

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the production of the corresponding unpainted materials [1]. The use of pigments in the technological process affects the characteristics of the finished product [2]. Along with the use of dyes, a promising direction in the production of concrete wall products is the use of industrial waste and various additives that have a positive effect on the performance characteristics of products [3]. The aim of this work was to study the stability of the strength characteristics of concrete wall stones made unpainted, as well as from concrete mixtures with the addition of pigments, by statistical analysis [4].

2 Methods and Materials For the manufacture of concrete wall stones, red and yellow pigments were used, the base substance of which is ferric oxide (Fe2 O3 ), and green (the base substance is chromium oxide, Cr2 O3 ) [5]. The optimal dosages of pigments, as a percentage of the cement weight, are shown in Table 1. The release strength of the stones was determined according to GOST R 585272019 “Wall materials. Methods for determining the ultimate strength in compression and bending”. 6 products were selected for testing. The control was carried out on whole double samples without leveling their surfaces. The obtained control results were used to construct control maps of Shewhart averages and ranges (X-R) according to GOST R ISO 7870-2-2015. The mapping process was carried out using the STATISTICA software product [5]. Checking the source data for the presence of results containing a gross error was performed using the software product [6]. The calculation of the process capability indicators was carried out according to GOST R ISO 22,514-2-2015. Table 1 The recommended dosage of pigments Pigment

Colour

Regulatory document for the pigment

Recommended dosage, as a percentage of cement weight

Ochre

Yellow

GOST 18,172–80

1–3

Yellow iron oxide

Yellow

GOST 18,172–80

5

Iron minium

Red

GOST 8135–74

3

Chromium oxide

Green

GOST 2912–79

3

Experimental Investigation on Strength Characteristics of Concrete Wall Colored Stones

47

3 Results and Discussions Painted concrete can be obtained by painting the surface after solidification or by directly mixing the pigments in the solution. The latter is preferable, because the color becomes a composite of concrete and does not require restoration operations in time. Pigments (from Latin pigmentum – paint) are highly dispersed substances that are insoluble (unlike dyes) in water, organic solvents, film-forming agents and other environments, and have a certain set of optical, mechanical, and sorption properties [7]. The pigments must be resistant to the alkaline environment of the hardening cement binder; in addition, they must be light and weather resistant. The pigments should not be dissolved in the mixing water. The amount of pigments added to concrete is 2…5% - for pigments with good coloring ability, produced, for example, by Bayer (Germany). Pigments with a lower coloring capacity (mainly domestic manufacturers) have to be inserted in an amount of up to 8%. The properties and amount of the inserted pigment affect the properties of the finished concrete product [8]. For most of the pigments used in the concrete technology, the appropriate regulatory documents indicate the optimal dosages, as a percentage of the cement weight (Table 1). An increase in the amount of pigment in concrete more than 5% can lead to an excessive increase in the fine fraction, an increase in the water demand of the concrete mixture and deterioration in the physical and mechanical properties of concrete (reduced strength, frost resistance, etc.). Compressive strength is one of the main characteristics of finished concrete wall stones, which determine the scope of their application in construction. The results of the construction of control maps for this indicator allow assessing the stability of the strength characteristics and their compliance with the established regulatory requirements [9, 10]. The results of the construction are shown in Figs. 1 and 2. As it can be seen from the presented graphs, the quality of concrete wall stones in terms of the release strength is stable [11]. The histograms shown in the figures on the left show the proximity of the distribution of the analyzed parameter to the normal law [12]. The process of stone production is statistically controlled, stable both in terms of the position of the average and the spread of the studied strength characteristics [13]. The average level of release strength of ordinary (gray) stones is 78.6 MPa, for decorative stones −75.6 MPa, which in both cases significantly exceeds the standard limits set for this type of product, as a percentage of the brand (100 kgf/cm2 ): not less than 70% in the warm season, and not less than 85% in the cold period [14]. The tempering strength of stones with pigment is approximately 4% lower than that of ordinary stones. This is probably due to the fact that when the pigments are inserted into the concrete mixture, there is a slight increase in water demand and, as a result, a decrease in the strength of the hardened concrete stone [15]. However, the evaluation of the process capabilities using the Ibs reproducibility index according

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Fig. 1 Quality control charts of strength of concrete wall stones unpainted

Fig. 2 Quality control charts of strength of concrete wall stones painted (yellow)

Experimental Investigation on Strength Characteristics of Concrete Wall Colored Stones

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to GOST R 50,779.46-2012 showed that for the production of ordinary stones it is 1.3, for non-ferrous stones – 0.75, which indicates that the process of manufacturing non-ferrous stones is not able to meet the specified tolerance field for the controlled parameter [16].

4 Conclusion For the manufacture of concrete wall stones with pigments, it is necessary to strengthen the control of the production process, analyze the factors that affect the spread of strength values and take actions to improve the state of the process. In particular, for the production of high-quality colored concrete, the following recommendations should be taken into account: 1. 2. 3. 4. 5. 6. 7. 8.

Use oxide pigments that do not react with cement. Do not change the type of cement and the cement supplier during the execution of the entire order. Take into account the custom color of the placeholders. The error in the dosage should not exceed ±5%. Mix the pigment and the filler beforehand. To firm up the mixture well. The hardening of the concrete must occur at high humidity, no drafts, and no condensation of water. When storing finished concrete products to protect them from ingress of water.

Following these recommendations, they can get a wide range of concrete wall stones in color from colored concrete of stable quality that meets both regulatory requirements and the wishes of consumers. Acknowledgements This work was realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V.G. Shukhov, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

References 1. Hospodarova V, Junak J, Stevulova N (2015) Color pigments in concrete and their properties. Int J Eng Inf Sci 10(3):143–151 2. Karthik MP, Sreevidya V (2015) Experimental investigation on strength characteristics of concrete. IJSR – Int J Sci Res 4(7):612–615 3. Shakhova LD, Chernositova ES, Denisova JV (2017) Research of influence of technological additives on the rheological properties of cement powder. Bull Belgorod State Technol Univ named after. V. G. Shukhov 2(10):123–128. https://doi.org/10.12737/article_59cd0c62ea5830. 10657970 4. Denisova YuV (2018) Additive technology in construction. Constr Mater Prod 1(3):33–42

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5. Denisova JV, Chernositova ES, Kupriyanov AN (2018) The program rejection of the results of the experiment, containing a gross error. The certificate of state registration of program for computer 2018616041 6. Borovikov VP (2003) STATISTICA. The art of data analysis on the computer. Peter, SaintPetersburg 7. Denisova YV, Kosuhin MM, Popova AV, Shapovalov NA, Leshhev SI, Kamorova ND (2016) Vibrocompressed concrete with superplasticizer based on resorcinol-formaldehyde oligomers. Builds. Mater 10:32–33 8. Poluektova VA, Shapovalov NA (2016) Fundamental patterns of influence of the structure and composition of the oxyphenol oligomers on the plastification of cement mixtures. Int J Pharm Technol 8(4):22716–22725 9. Babkov VV, Sahibgareev RR, Kolesnik GS (2006) Rational scope of modified concrete in modern construction. Constr Mater 10:20–22 10. Shapovalov NA, Denisova JV, Poluektova VA (2016) Biocidal research of oxyphenolic modifiers for fungicidal properties. Int J Pharm Technol 4(8):24976–24986 11. Narayanan N, Ramamurthy K (2000) Structure and properties of aerated concrete: a review. Cement Concr Compos 22(5):321–329 12. Zhou WL, Long JH, Zhan BG (2008) Further study on property of fly ashfluorogypsum-cement composite binder. J Build Mater 2:13−18 13. Shahova LD, Chernositova ES, Denisova JV (2017) Flowability and durability of cement containing technological additives during grinding process. AER-Adv Eng Res 133:162–167 14. Alfimova NI, Shadskiy EE, Lesovik RV, Ageeva MS (2015) Organic-mineral modifier on the basis of volcanogenic-sedimentary rocks. Int J Appl Eng Res 10(24):45131–45136 15. Klyuev SV, Khezhev TA, Pukharenko YV, Klyuev AV (2018) Fiber concrete for industrial and civil construction. Mater Sci Forum 945:120–124 16. Kamalova ZA (2013) Superplastifikatory in manufacturing technology of composite concrete. Bull Kazan Univ 16(8):148–152 17. Klyuev SV, Klyuev AV, Khezhev TA, Pukharenko YV (2018) High-strength fine-grained fiber concrete with combined reinforcement by fiber. J Eng Appl Sci 13:6407–6412

Regulation of the Surface Microrelief of Titanium Hydride by Solutions of Sulfuric Acid Salts A. I. Gorodov , R. N. Yastrebinsky , A. A. Karnauhov , and A. V. Yastrebinskaya

Abstract The article presents studies on the regulation of the surface microrelief of titanium hydride fraction by the method of sorption modification from a solution of titanium sulfate salt under static and dynamic conditions. The results of a scanning electron microscopy study with the removal of Energy-Dispersive X-Ray Spectroscopy Mapping of coatings obtained on titanium hydride fractions are presented. It has been established that the time of sorption interaction affects the structure of the coatings. Under static conditions of sorption interaction of shot with titanium sulfate salts at pH = 0–1, etching processes prevail, as a result of which crater structures and pitting pits are formed. The mechanism of interaction of titanium sulfate salt with the surface of titanium hydride fraction is established. It is shown that under dynamic conditions at pH = 4–5 on the surface of the titanium hydride fraction, a uniform formation of a modification shell occurs with its chemisorption fixation due to interaction with the hydroxo groups of the surface layer. As a result of subsequent thermal drying at a temperature of 180 °C and removal of excess hydrated water, the surface of the titanium hydride fraction is completely covered with an adsorption layer of hydroxotitanil with a pronounced aggregate-like relief and a high degree of adhesion of adsorbed ions due to the incorporation of atoms into the crystal lattice of titanium hydride. Keywords Modifier · Neutron shielding · Titanium hydride · Surface · Sorption · Scanning electron microscopy · Adhesion

1 Introduction Transition metal hydrides are one of the promising materials for neutron protection. Of particular interest are metal hydrides, which have a significant range of temperature stability (up to 600−800 °C) [1, 2]. The most promising is titanium hydride, in which the content of hydrogen atoms in 1 cm3 of metal is maximum and is 9.2 × A. I. Gorodov (B) · R. N. Yastrebinsky · A. A. Karnauhov · A. V. Yastrebinskaya Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_8

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1022 , second only to vanadium hydride 11.4 × 1022 [3]. To fill the voids and gaps between radiation-protective products during installation, a material in the form of titanium hydride crumbs is used. One of the disadvantages of titanium crumbs is the presence in its composition of up to 5% of a fine fraction (less than 0.2 mm), which is flammable and explosive. In addition, the use of such a fraction at high operating temperatures is additional hydrogen evolution. It is also worth noting that during transportation, packing and manufacturing of the mixture, the amount of fines may increase. Recently, the share of titanium hydride use in the form of spherical granules (fraction) has been increasing [4]. A fraction of titanium hydride eliminates the disadvantages of using chips and simplifies the process of installing protection. The shot can be used as a filler for a non-shrinking mixture, as a component of a filling material for filling defense structures of complex configuration and for making blocks. A distinctive feature of titanium hydride shot is its higher strength, the absence of a fine explosive fraction. One of the directions of work on the development of a technology for producing products based on a fraction of titanium hydride is the study of methods and modes of modifying its surface to increase its thermal stability at high temperatures and protect titanium from oxidation. A number of materials are known that, upon modification, significantly improved their properties, and modifiers had a protective effect [5–12]. The purpose of this work is to study the possibility of modifying the surface of titanium hydride shot from a solution of titanium sulfate salts by sorption methods.

2 Methods and Materials The object of the study was titanium hydride shot of nonstoichiometric composition TiH1.7 , 0.2−2.5 mm in diameter. Sulfuric solution of titanium salt was obtained by preliminary dissolving titanium plates in hot concentrated sulfuric acid. The interaction of hot concentrated sulfuric acid and metallic titanium can be represented by the reaction equation: t

2T i + 6H2 S O4 → T i 2 (S O4 )3 + 3S O2 ↑ + 6H2 O

(1)

Crystallization from sulfuric acid produces crystalline hydrates of acidic salts Ti2 H4 (SO4 )5 •3H2 O (blue precipitate) and TiH(SO4 )2 •4H2 O (is in the form of a violet colloidal solution). The obtained compounds were used to modify the surface of titanium hydride shot in two ways (under static and dynamic conditions): 1) 2)

titanium hydride shot was placed in a solution of titanium sulfate salts (pH = 0–1) and kept in static mode with continuous stirring for 15 min; a solution of titanium sulfate salts (pH = 0–1) was passed through a column filled with titanium hydride shot.

Regulation of the Surface Microrelief of Titanium Hydride ...

53

After the termination of the adsorption contact, the titanium hydride shot was washed with distilled water and dried at a temperature of 180° C to remove water of crystallization. The resulting coatings were examined by scanning electron microscopy (SEM) with Energy-Dispersive X-Ray Spectroscopy Mapping. The survey was performed in the secondary electron mode using a high-resolution scanning electron microscope TESCAN MIRA 3LMU (TESCAN ORSAY HOLDING, Czech Republic).

3 Results and Discussion A fraction of titanium hydride has microcracks on its surface with a size of 20–30 nm (Fig. 1a). The formation of microcracks is due to the different rates of hydrogen adsorption by the surface of the shot and the rate of its diffusion into the particles of titanium metal. Internal stresses arise, which lead to the formation of microcracks on the surface of the hydrogenated metal. The mapping of the structure of the initial fraction of titanium hydride by chemical composition and the energy dispersive spectrum at different points (Figs. 1b and 2) indicate the presence of predominantly titanium in the surface layer, without foreign impurities.

Fig. 1 Micrograph of the surface (a) and mapping the structure (b) of the initial fraction of titanium hydride by chemical composition: 1–5 - zones of mapping of chemical elements

Fig. 2 Energy dispersive spectra at different points of the initial fraction of titanium hydride (a point 1, b - point 4, c - point 5)

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Fig. 3 Micrograph of the surface (a) and mapping the structure (b) of the titanium hydride fraction modified under static conditions: 1–5 - zones of mapping of chemical elements

Fig. 4 Energy dispersive spectrum at different points of a titanium hydride fraction modified under static conditions (a - point 1, b - point 2, c - point 3)

Comparing the microstructure of the surface of the initial (Fig. 1a) and modified under static conditions (Fig. 3a) titanium hydride shot, it can be seen that a large number of non-uniformly distributed crater structures and pitting pits up to 10 µm in size are observed on the shot surface, caused by the processes of etching with strongly acidic solutions of titanium salts in places where the protective oxide layer is broken. The maps of distribution of chemical elements on the surface of titanium hydride shot modified under static conditions (first method) (Figs. 1b and 3b) and energy dispersive spectra (Fig. 4) indicate a small local adsorption of titanium sulfate salts on the shot surface. Apparently, almost the entire adsorption layer was desorbed when the shot was washed with distilled water, which is a sign of physical adsorption. Studies of the surface microstructure of a titanium hydride shot modified under dynamic conditions (according to the second method) (Fig. 5a) showed that surface etching does not occur (crater structures are not formed on the shot surface), as in the case of modification by the first method. In this case, the microcracks are partially filled with titanium compounds. The data shown on the map of the distribution of chemical elements on the surface of the titanium hydride fraction modified by the second method (Fig. 5) and energy dispersive spectra (Fig. 6), as in the previous case, indicate a small local adsorption of titanium sulfate salts on the surface of the shot. Basically, particles of titanium

Regulation of the Surface Microrelief of Titanium Hydride ...

55

Fig. 5 Micrograph of the surface (a) and mapping the structure (b) of a titanium hydride fraction modified under dynamic conditions: 1–13 - zones of mapping of chemical elements

Fig. 6 Energy dispersive spectrum at different points of a fraction of titanium hydride modified under dynamic conditions (a - point 1, b - point 3, c - point 5)

sulfate salts are concentrated in microcracks. As in the previous case, adsorption processes of a physical nature prevail. In strongly acidic solutions (at pH = 1) there is a TiO2+ ion. With an increase in pH, titanium (IV) ions are very easily hydrolyzed with the formation of poorly soluble products. The hydrolysis of titanium (IV) ions begins already at pH ≥ 1.5. At pH = 1.5–2, the hydrolysis form of the composition Ti(OH)2 2+ dominates in solutions. Further hydrolysis of Ti(OH)2 2+ at pH = 4–5 leads to the formation of [Ti(H2 O)6 ]4+ ions. During hydrolysis of titanium (IV) ions in acidic solutions, mononuclear large molecules are mainly formed, although the possibility of the appearance of higherorder forms is not excluded. In this regard, to increase the efficiency of sorption of titanium compounds on the TiH2 surface, the pH of titanium sulfate salts was increased to pH = 4–5 by adding NH4 OH, followed by passing the resulting solution through a column filled with titanium hydride shot. As in the previous experiments, after the termination of the adsorption contact, the titanium hydride shot was washed with distilled water and dried at a temperature of 180 °C. Studies of the microstructure of the surface of titanium hydride shot modified under dynamic conditions at pH = 4– 5 (Fig. 7) showed that the surface of the titanium hydride shot is completely covered with an adsorption layer with a pronounced aggregate-like relief, there are no defects in the form of cracks and depressions characteristic of unmodified titanium hydride shot. The data shown on the map of the distribution of chemical elements on the surface of the fraction of titanium hydride modified by the third method (Fig. 8a) and energy

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Fig. 7 Micrographs of the surface of titanium hydride shot modified under dynamic conditions in the presence of NH4 OH (pH = 4–5)

Fig. 8 Structure mapping (a) and energy dispersive spectrum at different points (points b - 2, c - 8) of the modified fraction of titanium hydride under dynamic conditions in the presence of NH4 OH (pH = 4–5)

dispersive spectra (Fig. 8b-c) confirm the adsorption of titanium sulfate salts on the surface of the fraction. An increase in the content of S and O ions and a decrease in Ti ions in the surface layer of the titanium hydride fraction are observed. The absence of desorption in the process of washing with distilled water indicates a high degree of adhesion of adsorbed ions due to the incorporation of atoms into the crystal lattice of titanium hydride. According to the studies presented, the following interaction mechanism can be assumed. Water-insoluble metatitanic acid (titanium dihydroxide-titanium oxide) is sorbed from the solution of titanium sulfate salts on the surface of the shot. Subsequent thermal drying of the modified titanium hydride fraction at 180 °C leads to the removal of excess hydrated water and the formation of hydroxotitanil on the surface (Fig. 9).

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57

Fig. 9 Titanium shielding of the titanium hydride shot surface

4 Conclusion The results of studying the surface of titanium hydride shot after chemical interaction with titanium sulfate salts at pH = 0–1 under static conditions indicate that etching processes prevail, as a result of which crater structures and pitting pits are formed. It is shown that the interaction of titanium hydride with titanium sulfate salts at pH = 0–1 under dynamic conditions does not etch the surface, but partial filling of microcracks is observed. The most uniform coating of the shot surface is formed in samples treated with titanium sulfate salts under dynamic conditions at pH = 4–5. As a result of subsequent thermal drying at a temperature of 180 °C, excess hydrated water is removed, as a result of which the surface of the titanium hydride fraction is completely covered with an adsorption layer of hydroxotitanil with a pronounced aggregate-like relief. Acknowledgements The work is realized using equipment of High Technology Center at BSTU named after V.G. Shukhov the framework of the State Assignment of the Ministry of Education and Science of the Russian Federation, project № FZWN-2020-0011.

References 1. Berezhko PG, Tarasova AI, Kuznetsov AA (2006) Hydrogenation of titanium and zirconium and thermal decomposition of their hydrides. Int Sci J Altern Ener Ecol 43:47–56 2. Mueller WM (1968) Titanium hydrides. Metal Hydrides 336–384 3. Ryabets AN, Bogomaz AV, Berezenko LE (2010) Study of titanium sponge saturation by hydrogen in pilot plant. New Mater Technol Metallurgy Mech Eng 85–89 4. Pavlenko VI, Cherkashina NI, Yastrebinsky RN, Demchenko OV (2017) On enhancing the thermal stability of metal hydrides by ion–plasma vacuum magnetron sputtering. J Surface Invest 11(1):254–258 5. Chrcanovic BR, Martins MD (2014) Study of the influence of acid etching treatments on the superficial characteristics of ti. Mater Res 17(2):373–380 6. Chrcanovic BR, Wennerberg A, Martins MD (2015) Influence of temperature and acid etching time on the superficial characteristics of ti. Mater Res 18(5):963–970 7. Lin X, Zhou L, Li S, Lu H, Ding X (2014) Behavior of acid etching on titanium: Topography, hydrophility and hydrogen concentration. Biomed Mater (Bristol) 9(1)

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8. Pavlenko VI, Bondarenko GG, Kuprieva OV, Yastrebinskii RN, Cherkashina NI (2014) Modification of titanium hydride surface with sodium borosilicate. Inorg Mater Appl Res 5(5):494–497 9. Pavlenko, V.I., Bondarenko, G.G., Lebedev, L.L., Prozorov, V.V.: Morphology and phase composition of protective coating on carbon steel, processed in nitrate solutions. Adv.Mater 31–35 (2013). 10. Shachneva EY (2018) Methods of sorption concentration of surface active substances. Chem Bull 1(2):24–30 11. Yastrebinsky RN, Pavlenko VI, Karnauhov AA, Cherkashina NI, Yastrebinskaya AV (2020) Thermal stability of titanium hydride modified by the electrochemical deposition of titanium metal. Mater Res Express 7(10):106519. https://doi.org/10.1088/2053-1591/abc0a2 12. Rezaei M, Tamjid E, Dinari A (2017) Enhanced cell attachment and hemocompatibility of titanium by nanoscale surface modification through severe plastic integration of magnesiumrich islands and porosification. Sci Reports 7(1)

Sodium Alginate Application in Self-healing Technology for Asphalt Concrete S. S. Inozemtcev

and D. T. Toan

Abstract The creation of “smart” materials that can independently respond to changes in structure during operation and take measures to eliminate them is a promising direction for increasing the service life of asphalt concrete pavements. The implementation of the technology of self-healing of asphalt concrete can be ensured through the use of encapsulated modifiers, which are a reducing agent inside a functional capsule. Making capsules with a reducing agent through an aqueous solution of sodium alginate is a simple method for encapsulating modifiers. The encapsulation of reducing agents for asphalt concrete can be carried out by extrusion or by means of an emulsion of a reducing agent, which is fixed dropwise through a solution of calcium salt. It has been shown that alginates are an effective component that makes it possible to implement the technology of encapsulation of modifiers (reducing agent) for self-healing asphalt concrete. The regulation of viscosity by controlling the prescription factors will make it possible to use an alginate solution with the required technological properties for encapsulation, including rate of separation of the emulsion into individual drops. The control of recipe parameters allows in a wide range to control the technological properties of alginate solution and emulsions, as well as the parameters of the resulting capsules with a modifier (reducing agent) for self-healing asphalt concrete. Keywords Alginate · Encapsulation · Modifier · Restoration · Self-healing · Asphalt concrete

1 Introduction Traditional highways are multilayer structures, in which various types of asphalt concrete are used for the construction of the upper layers, the service life of which is up to 24 yrs [1]. However, in conditions of heavy car traffic and difficult climatic conditions, together with inadequate maintenance, the service life of highways does S. S. Inozemtcev (B) · D. T. Toan National Research Moscow State University Of Civil Engineering, Moscow, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_9

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not exceed 4…8 yrs [2]. The lack of timely measures to eliminate defects in the asphalt concrete pavement arising in the process of wear under the influence of operational factors leads to a significant increase in the cost of restoring pavement. Additional cost arises when the logistics network of road freight transport and passenger traffic is disrupted due to the poor quality of the pavement. Increasing the maintenance-free life of asphalt concrete pavements is the main task of materials science in the field of road construction. The creation of “smart” materials that can independently respond to changes in structure during operation and take measures to eliminate them is a promising direction for increasing the service life of asphalt concrete pavements. The ability of a material to restore its own functionality in a structure provided for by its appointment is commonly called “self-healing” [3]. The use of encapsulated modifiers in the form of a reducing agent inside a functional capsule will make it possible to implement the technology of self-healing of asphalt concrete [3]. Capsules with a modifier are added to the asphalt concrete mixture during its preparation, and the shell prevents the reducing agent from interacting with the main components. At the stage of primary structuring, the modifier does not take part. During the operation of the asphalt concrete pavement during the formation of defects, cracks, capsules are destroyed, and the modifier is released and, interacting with the asphalt concrete, contributes to the restoration of its functionality. Making capsules with a reducing agent through an aqueous solution of sodium alginate is a simple method for encapsulating modifiers.

2 Methods and Materials An aqueous solution based on sodium alginate is used to prepare an alginate emulsion. Sodium alginate (C6 H7 O6 Na) is a sodium salt of alginic acid extracted from brown algae. Alginate emulsions were obtained by mixing sodium alginate and sunflower oil in water in various proportions and mixing for 2 min using an overhead stirrer with a drive rotation speed of at least 2000 rpm. The dynamic viscosity of the emulsion was determined using a MCR 101, Anton Paar rotational viscometer using a coaxial cylinder measuring system (Fig. 1). The outer cylinder was filled with an emulsion sample and the inner cylinder was lowered into the sample using an automatic drive. The sample was thermostated at 25 °C for 30 min before measurement. The structural parameters of calcium alginate capsules were studied using a Nikon Eclipse MA200 optical microscope using Thixomet software with calibrated electronic instruments and scales.

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Fig. 1 Coaxial cylinder measuring system Outer cylinder clamp Outer cylinder Inner cylinder

Sample area

Thermostat

3 Results and Discussion Alginates are obtained from brown algae found in the seas of temperate and polar latitudes. Alginates are part of the cell walls and intercellular substance of brown algae. Alginate molecules give plants both flexibility and strength, properties necessary for growth and survival in marine environments. Alginates are produced in the form of salts, mainly sodium alginate, which hydrates in water to form viscous solutions. The extraction of alginic acid from brown algae is slow. Alginic acid, insoluble in water, is an intermediate in the production of alginates. It is susceptible to autocatalytic acid hydrolysis and is therefore unstable. To obtain stable water-soluble salts of alginic acid (alginates), inorganic salts are introduced into the system: Na2 CO3 to obtain sodium alginate; K2 CO3 – potassium alginate; Ca2 CO3 – calcium alginate, etc. Alginates are organic substances in the form of unbranched binary copolymers, the structure of which is formed by the residues of β-D-mannuronic acid (M) and α-L-hyaluronic acid (G), which are interconnected by glycosidic bonds that differ in sequence and composition (Fig. 2) [5]. The structure of alginate consists of units of monopolymer M- and G-blocks, which form polymer chains in different distributions. The ability of alginates to bind ions is responsible for their characteristic gelling ability. The affinity of alginate molecules for polyvalent cations depends on their composition, while the affinity for alkaline earth metals increases in the order: Mg < Ca < Sr < Ba. The viscosity of an alginate solution is determined by the molecular length of this polymer and its content in solution. The results of determining the viscosity using a rheometer are shown in Fig. 3.

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a)

α-L-guluronate (G)

β-D-mannuronate (M)

b)

G

c)

G

M

M

G

MMMMMGGGGGMGMGGGGGGGGMGMGMGMG M-block G-block G-block MG-block

Viscosity,Pa·s

Fig. 2 Structure of alginates [4]: (a) kind of monomers; (b) chain conformation; (c) block distribution option

30 25 20 15 10 5 0 0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

Sodium alginate content, %

Fig. 3 Dependence of the change in the viscosity of the solution on the concentration of sodium alginate

The results show that the introduction of sodium alginate significantly increases the viscosity of the system during the preparation of the alginate suspension, which is associated with an increase in the number of sodium alginate macromolecules, which are randomly oriented in space, interact with each other and non-Newtonian properties of the liquid prevail. The molecules are oriented more or less randomly at low shear rates, but as the shear rate increases, the molecules begin to orient themselves parallel to one another. Therefore, when the shear rate goes beyond the boundaries of the initial Newtonian region, the apparent viscosity will decrease. The regulation of viscosity by controlling the prescription factors will make it possible to use an alginate solution with the required technological properties for

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Fig. 4 The dependence of the change in the rate of separation of the emulsion into individual drops of an alginate emulsion (RA/A - reducing agent content/sodium alginate content)

encapsulation [6, 7], including rate of separation of the emulsion into individual drops (Fig. 4). The encapsulation of reducing agents for asphalt concrete can be carried out by extrusion or by means of an emulsion of a reducing agent, which is fixed dropwise through a solution of calcium salt. The technological scheme of encapsulation of the modifier (reducing agent) for asphalt concrete is shown in Fig. 5. The technological process for encapsulating a modifier (reducing agent) for asphalt concrete includes four main stages: preparation of alginate solution using a high-speed stirrer; preparation of an alginate emulsion using a high-speed stirrer; dividing the alginate emulsion into separate drops; fixing individual drops through a solution of calcium salt into alginate spheres; drying of alginate spheres.

Sodium alginate + water

+ modifier (reducing agent) Alginate emulsion

SeparaƟon funnel CaCl2 soluƟon

MagneƟc sƟrrer High speed sƟrrer

Fig. 5 Scheme of encapsulation of a modifier (reducing agent)

Alginate spheres

Drying

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Diameter, mm

The block structure of alginates determines their ability to gel formation, which occurs in the presence of calcium ions, which makes it possible to fix individual drops of alginate emulsion into spheres. The mechanism of formation of alginate gels includes the joint binding of calcium ions between the ribbons of macromolecules located in one line, which have pores or cavities of 0.19.0.0.20 nm in size, corresponding to the diameter of the Ca2+ ion [8, 9]. This effect occurs as a result of the interaction of the G-block chain of one alginate molecule with the G-block of another through calcium bonds, acting as a nodal zone, while M-blocks and MGblocks participate in the formation of the gel network as elastic segments. Intense gelation occurs when the pores are filled with calcium ions, providing cross-linking of macromolecules through substituted sodium cations Na+ . During the drying process, excess moisture evaporates from the gel with a decrease in volume to form a calcium-alginate capsule containing a reducing agent. The content of alginate and reducing agent affects the size of the resulting capsules (Fig. 6). With an increase in the content of the reducing agent in the alginate emulsion, the capsule diameter and the volume of the reducing agent in the capsule change in accordance with d = a/(1 + becx ), were a = 1.42, b = 0.986, c = −0.508. The size of the capsule increases due to the increase in its volume of the reducing agent that it can accommodate. At the same time, alginate technology makes it possible to obtain capsules with a reducing agent content of up to 83% of the total volume [10]. 1,6 1.6 1,4 1.4 1,2 1.2 1,0 1.0 0,8 0.8 0,6 0.6 0,4 0.4

- Sodium alginate content 3.33 % - Sodium alginate content 2.50 % - Sodium alginate content 2.08 %

0,2 0.2 0,0 0.0 0.0 0,00

2.0 2,00

4.0 4,00

6.0 6,00

8.0 8,00

RaƟo RA/A

Fig. 6 The dependence of the change in diameter of the capsules on the ratio of the reducing agent and sodium alginate (RA/A)

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4 Conclusion Alginates are an effective component for the implementation of the technology of encapsulation of modifiers (reducing agent) for self-healing asphalt concrete. The control of recipe parameters allows in a wide range to control the technological properties of alginate solution and emulsions, as well as the parameters of the resulting capsules with a modifier (reducing agent) for self-healing asphalt concrete. With an increase in the content of the reducing agent in the alginate emulsion, the capsule diameter and the volume of the reducing agent in the capsule change in accordance with d = a/(1 + becx ), were a = 1.42, b = 0.986, c = -0.508. Alginate technology makes it possible to obtain capsules with a reducing agent content of up to 83% of the total volume. Acknowledgement This work was financially supported by the Grants Council of the President of the Russian Federation (SP-5069.2021.1).

References 1. Inozemtcev SS, Korolev EV (2019) Increasing the weathering resistance of asphalt by nanomodification. Mater Sci Forum 945:147–157 2. Kamenchukov AV (2015) Evaluation of the reliability of the work of non-rigid road pavements [Otsenka nadozhnosti raboty nezhestkikh dorozhnykh odezhd]. In: IV All-Russian Road Congress “Advanced Technologies in the Construction and Operation of Highways”: collection of articles. scientific. M.: MADI, pp 127–131. (in Russian) 3. Inozemtcev SS, Korolev EV (2020) Review of road materials self-healing: problems and perspective. IOP Conf Series: Mater Sci Eng 855:012010 4. Donchenko LV, Sokol NV, Krasnoselova EA (2019) Food chemistry. In: Hydrocolloids [Pishchevaya khimiya. Gidrokolloidy]. Textbook manual for universities. 2nd ed. rev. M.: Yurayt Publishing House. (in Russian) 5. Pereira L, Cotas J (2020) Alginates - a general overview. Alginates - Recent Uses of This Natural Polymer 6. Inozemtsev SS, Korolev EV (2018) Technological features of production calcium-alginate microcapsules for self-healing asphalt. MATEC Web of Conf 251:01008. (Electronic collection) 7. Inozemtcev SS, Korolev EV, Smirnov VA (2016) Nanomodified bitumen composites: solvation shells and rheology. In Advanced Materials, Structures and Mechanical Engineering. Proceedings of the International Conference on Advanced Materials, Structures and Mechanical Engineering, pp 393–398 8. Koryachkina SY, Prigarina OM (2011) Scientific foundations of food production [Nauchnyye osnovy proizvodstva produktov pitaniya]. A textbook for higher professional education. Orel: FGBOU VPO «Gosuniversitet UNPK». (in Russian) 9. Pryanishnikov VV, Iltyakov AV, Kasyanov GI (2012) Dietary Fibers and Proteins in Meat Technologies [Pishchevyye volokna i belki v myasnykh tekhnologiyakh]. Ekoinvest publishing house, Krasnodar. (in Russian) 10. Inozemtcev SS, Korolev EV (2020) Active polymeric reducing agent for self-healing asphalt concrete. IOP Conf Series: Mater Sci Eng 1030:012002

The Optimization of the Grinding Process of the Closing Joint of the Combined Forming Parts of the Mold N. S. Lubimyi , I. A. Lymar , B. S. Chetverikov , and A. A. Tikhonov

Abstract The article discusses two main issues that need to be addressed in the development of a technological process of abrasive machining of a combined shaping. The first issue is the optimization of the surface grinding process, taking into account technological limitations due to the heterogeneity of the work materials. The second issue is the establishment of functional relationships required for calculating the amount of heat generated during flat grinding. The optimization of machining modes for flat grinding with the periphery of the wheel according to the criterion of the minimum technological cost takes into account the parameter of roughness of the closing joint as the main criterion for the operability of the mold package. The temperature limitations imposed by the heterogeneity of the materials properties, from which the forming mold is made, also takes into account. The research and new approaches to the assignment of technological parameters of abrasive machining, presented in the article, is a great interest to engineers of tool and repair production who use metal-polymer materials in the design of their production facilities that require final machining by flat grinding. Keywords Grinding · Mold · Metal polymer · Forming part · Prime cost · Optimization · Roughness

1 Introduction The main part in the prime cost of manufacturing the mold in general and in the prime cost of the forming plate in particular is the time of manufacturing the working surface. Using modern temperature-resistant metal-polymer materials [1], it is possible to significantly reduce the prime cost of manufacturing a mold, by about 20%. Such savings are primarily associated with the replacement of the machining operation when obtaining a shaping surface with the operation of obtaining a shaping surface by obtaining an imprint of the master model in a metal polymer [1]. The use N. S. Lubimyi (B) · I. A. Lymar · B. S. Chetverikov · A. A. Tikhonov Department of Hoist Transport and Road Machines, Belgorod State Technological University named after V. G. Shukhov, Kostyukov St., 46, Belgorod 308012, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_10

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of a more efficient technological process for the manufacture of the forming part assumes the presence of mechanical machining too. The combined forming part of the mold requires a finishing abrasive machining of the closing joint of the mold to give it the required roughness, as well as making holes for sprues and ejectors on a coordinate boring machine. While cutting a combined part with a blade tool in a boring operation, due to relatively low cutting speeds, the appointment of technological modes is not difficult for the engineer. Another situation arises when machining a part with an abrasive tool, here, due to significant cutting and feed speeds, various defects can occur both on the surface of the combined surface and in the internal structure. Therefore, the issue of assigning the correct modes of abrasive machining of the combined part of the mold is relevant and requires in-depth study.

2 Materials and Methods As a research method, the method of constructing an optimization system from conditions and constraints was chosen to obtain the required product properties when the target optimization criterion is achieved. According to the recommendations [2], it is advisable to choose the minimum technological prime cost of the operation as an optimization criterion. Using the recommendations [2], the formula of the technological prime cost of operation can be written down in the following way (1): Ctech = Bc · tm + Bc · (tch

tm tm + G u ), Ts Ts

(1)

where Bc is the total cost of one minute of the machine and machine operator’s work in rubles; tm is machine time of mechanical machining, min; tch is time for replacement of a blunt tool, min; G u is expenses for the operation of the cutting tool, in rubles; Ts is dimensional tool life, min. The durability of the abrasive tool is given by the manufacturers in accordance with the machining material, as well as the specified operating conditions. According to the manufacturer’s recommendations, to ensure the specified accuracy and surface roughness when machining steel with a hardness of up to 55 HRC, an abrasive wheel should be selected that will process in two passes. The time spent on operating the tool in this case is the time that the worker spends on the main work, installing the work piece and removing the part, making measurements, etc. This time is a constant for a particular equipment and depends primarily on the mass of the part. In this case, the formula (1) looks in the following way: Ctech = Bc · (tm + taux ),

(2)

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69

where taux is auxiliary time, min. Thus, with a grinding width B and a length L using a wheel with a width Bc , the machine prime cost of the technological operation of the surface grinding process can be calculated by the formula (3):  Cmtech = Bc ·

L Slong

Sw.s. + Scr oss



     · · int +1 , t c −δ

(3)

where Slong is the longitudinal feed of the table, mm/min; Sw.s. is working stroke length, Sw.s. = Bc − δ, mm; δ is the amount of overlap of the circle; Bc is circle height, mm; Scr oss is cross feed of the table, mm/min;  is allowance, mm; t is cutting depth, mm. The wheel speed parameter Vc is assigned according to the recommendations [3] and is taken equal to 50 m/s. Due to the use of a metal polymer in the design of the forming part of the mold, which has a temperature resistance of up to 220 °C [4], defects, caused by overheating, can form in the zone of removal of the allowance with an abrasive wheel. As the part is combined, there are two potentially dangerous areas where an excess of the surface layer temperature can occur. 1. 2.

θmp is the surface temperature of the metal polymer during its machining with an abrasive tool; θm is the temperature of the metal part of the forming part of the mold at the point of contact between the metal-polymer and the metal part of the combined part, which can accumulate energy and warm up to a critical temperature for the metal-polymer.

3 Results and Discussion Based on the conclusions made earlier, it is possible to present a system for optimizing the technological process of abrasive machining of a combined metal and metalpolymer part according to the criterion of the minimum technological prime cost in the following form:  ⎧ L ⎪ Bc · Slong + ⎪ ⎪ ⎪ ⎪ ⎨ ⎪ ⎪ ⎪ ⎪ ⎪ ⎩ per

  · int BcB−δ + 1 ⇒ min

 per θmp > f 1 t, Slong  θ per > f 2 t, Slong  Ra per > f t, Slong Vc = const

Sw.s. Scr oss



·

 t

(4)

per

where θmp is the maximum allowable temperature for a metal polymer, °C; θ M is the maximum permissible temperature of the metal at the border with the metal polymer, °C; Ra per is roughness parameter of the combined closing joint of the mold.

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In studies devoted to abrasive machining [5–7], no attention is paid to the calculation of roughness in relation to the technological parameters of the cutting process; in [8], it is indicated that the roughness depends on the structure of the abrasive tool, but this dependence is valid for metal machining, and the investigated part is combined. Therefore, it is advisable to use the method for calculating the roughness developed by the Kharkov National Technical University [5], modifying it for the parameter Ra. According to this method, the roughness Ra is calculated by (5): Ra =

1 , 10tg(γ )kl

(5)

where γ is the half of the angle at the top of the tapered cutting grain; k is surface concentration of circle grains, piec/m2 ; l is the length of the surface of the circle participating in the formation of the surface roughness Ra, m. Representing the parameter l depending on the speed of the wheel Vc and the longitudinal feed of the table Slong , we obtain the following formula (6).  Ra = 2.5

3

Slong tgγ · k · Vc

2 ·

1 , Rc

(6)

where Vc is the speed of the circle, m/s; Slong is the longitudinal table feed; Rc is the radius of the circle. If we talk about the particular case of grinding with the periphery of the wheel, taking into account the tool wear, then according to [5] we obtain the formula (7). Ra max =

Slong − x, √ 2 · tgγ · k · V c · 2 · Rc · Rmax

(7)

where, x is wheel wear. The formula (6) can also be used to calculate the roughness of the metal-polymer area. The problem of the optimization system cannot be solved without setting functional or graphic relationships between the heating temperature of the metal polymer during grinding, both separately and at the interface with the metal polymer, which was mentioned earlier. Based on the theory of abrasive machining [6, 9], the heating of the surface while removing the allowance by the periphery of the circle has a cyclic character. There are heating and cooling cycles, the time of which according to [9] can be calculated from the formula (8). √ D·t 2·h , = τH = Slong Slong · 1000

(8)

The Optimization of the Grinding Process …

71

where, D is the diameter of the grinding wheel, mm; t is the depth of cut while grinding, mm; 2 · h is the width of the flat heat source. As it is necessary to know the heating temperature of the metal polymer, in other words, the power of the heat source, W, then according to [8, 10], the formula (9) can be used for this. Q = 0.4899 · μ · σ B · V · b2 · l2 · n p · B · lg,

(9)

where μ is the coefficient of friction between the grain and the workpiece along the rear surface of the grain; σ B —is the ultimate strength of the processed material, MPa; V is the cutting speed during grinding, mm/s; b2 is the grain cut width, mm; l2 is the length of contact of grain with the processed material along the back surface, mm; n p is the number of grains in simultaneous contact; B is the circle height, mm; lg is the length of contact of the circle with the workpiece, mm. The parameter μ = 0.46 according to the recommendations [12], the angle of sharpening of the grain is 85°, and the parameter lg is calculated by the formula (10). lg = π D

) arcsin( D−2t D , ◦ 360

(10)

where D is the diameter of the circle, mm; t is the cutting depth, mm. To determine the average probability of the number of grains in an abrasive tool according to [13], it is necessary to use the formula (11). 0.0126 np = 2 · χaver

√ Slong · t D · K , V · 0.25

(11)

where χaver is the grain size (0.55 mm) for a given roughness Ra = 0.8 µm; K is the concentration of cutting material in the wheel, %, recommended by the manufacturer K = 1 (100%). By using the above functions, we will use the discrete programming method. The essence of the discrete programming method is to enumerate all possible combinations of pairs S longitudinal table feed and t from arrays [Slong ] and [t]. The optimal pair is Slong and t, which satisfies all the constraints and gives the minimum value of the objective function C tech (Slong , t) = min. For enumeration, we will use the scilab 5.5.2 software package. The optimum values of the processing modes are shown in Table 1. Table 1 Optimal values of metal polymer processing modes

Parameter

Value

Ra, µm

0.8

t, mm

0.09

Slong , m/min

34

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Fig. 1 Graph of the surface of the function of the prime cost of the grinding operation from cutting conditions

The graph of the surface of the function of the prime cost of the grinding operation from the cutting conditions is shown in Fig. 1.

4 Conclusion The formed and presented optimization system (4) makes it possible to calculate and find the optimal modes of abrasive machining of the combined metal and metalpolymer closing joint of the mold, excluding temperature destruction of the metal polymer during grinding and at the same time ensuring the minimum technological prime cost of the technological operation. Using the mathematical apparatus MathCAD and its optimization tools, an engineer can easily use (6) to optimize the process of flat grinding of the combined surface not only for the forming part of the mold, but also in other cases when it becomes necessary to process the combined part, for example, during repair flat parts of technological equipment. Ultimately, this will provide the required machining quality and the minimum cost of the technological operation. Acknowledgements This work was supported by the grant of the President of the Russian Federation No. MK-4006.2021.4, using equipment of High Technology Center at BSTU named after V.G. Shukhov.

References 1. Lubimyi NS, Chepchurov MS, Kostoev ZM (2020) Investigation of the processes of obtaining combined metal-metal-polymer forming parts of molds of a given quality using additive technologies. BSTU, Belgorod 2. Lubimyi NS, Chepchurov MS, Teterina IA (2017) Processing of a combined metal-metalpolymer flat surface of a mold part. Bull BSTU Named After V.G. Shukhov 1:162–169

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3. Kiyak M, Cakir O, Altan E (2003) A study on surface roughness in external cylindrical grinding. Achiev Mech Mater Eng AMME 459–462 4. Lubimyi NS, Annenko DM, Chepchurov MS, Kostoev ZM (2020) The research of the temperature effect on a metal polymer during flat grinding of a combined metal polymer part. Austr J Mech Eng 80:1–13 5. Bezzubenko NK, Evdokimov AE (1990) Microcutting stresses. Cut Tool 43:56–63 6. Korchak SP (1974) Performance of the grinding process of steel parts. Mechanical Engineering, Moscow 7. Chepchurov MS, Corop AD, Starostin SV (2010) Providing the required roughness during high-performance machining of nickel heat-resistant alloys. Repair Restor Modern 9:23–25 8. Kurdyukov VI (2014)Abrasive Basics. KSU, Kurgan 9. Maslov EN (1974) Grinding materials theory. Mechanical Engineering, Moscow 10. Nikitin SP, Hanov AM, Sirotenko LD (2014) Calculation of the thermal resistance of the elements of the cutting zone when grinding heat-protective coatings. Modern Prob Sci Educ 6:109–107 11. Koshin AA, Sopelcev AV (2010) Investigation of the granulometric composition and microgeometric parameters of abrasive grains of grinding wheels used in rough grinding. Bull UUSU 10:77–82 12. Romanovich AA, Ebrahim A, Romanovich MA (2020) Improving the efficiency of the material grinding process. IOP Conf Ser Mater Sci Eng 945:012060 13. Romanovich AA, Romanovich MA, Belov AI, Chekhovskoy EI (2018) Energy-saving technology of obtaining composite binders using technogenic wastes. J Phys Conf Ser 1118:012035

Non-autoclaved Foam Concrete with Improved Foam Characteristics V. N. Tarasenko

Abstract In the production technology of non-autoclaved cellular concrete, there are a number of technological changes, the possibility of intensifying which is possible by inserting chemical and mineral additives-stabilizers of the foam matrix. These additives can simultaneously act as accelerators of hardening and setting, as well as stabilize the foam matrix at the initial stage. For the research, the foam matrix mineralizers—fine-ground sulfates were selected for the purpose of possible intensification of the injection molding technology of cellular concrete. The solution to this problem lies in the assessment of the main mixing parameters, the choice of raw materials, the availability of additives and the overall manufacturability of the production process. The paper clarifies the effect of foam matrix mineralizers together with additives that accelerate setting, and also evaluates the effect of a complex of additives on the main properties of foams: durability, multiplicity and syneresis. The influence of the pH environment on the primary characteristics of foams obtained on the basis of foaming agents of various nature is considered separately. The regularities of the influence of the hydrolysis constants of additive on the multiplicity of the resulting foam were identified; the possibility of changing the pH value of the environment on the stability of the foam matrix and initial syneresis was evaluated. Recommendations on the use of some sulfates together with foam thickeners in the technology of non-autoclaved foam concrete are given. Keywords Foam matrix · Structural heterogeneity · Efficiency of use · Durability · Multiplicity · Uniformity · Stability · Syneresis

V. N. Tarasenko (B) Belgorod State Technological University named after V.G. Shuhova, Kostyukov, 46, Belgorod, Russia e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_11

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1 Introduction The technological problem of intensifying the setting process of non-autoclave foam concrete can have several solutions: warming up the molds or increasing the ambient temperature or the raw material mixture [1–3], using setting accelerators [4, 5], etc. The study of the effect of hardness salts and the possibility of correcting the structural viscosity and uniformity of the foam concrete array system through the joint introduction of accelerators and foam-stabilizing components are one of the ways to solve this problem. Due to the differences in raw materials and the lack of an approach to their reasonable selection, the use of foaming agents of different nature and effectiveness, additives-stabilizers, etc., the capabilities of small enterprises are often limited, high competition in the market of building materials and high cost have become the main constraints on the way to improving the technological effectiveness of the production of molded foam concrete.

2 Methods and Materials It was shown in [1–6] that the maximum height of the foam column from solutions of sodium alkyl sulfates corresponds to a certain concentration of the electrolyte, and the foaming capacity is inversely proportional to the radius of the hydrated monovalent cations of the electrolyte. An increase in the cation charge also increases the foaming capacity of alkyl sulfates [7]. It was shown in [8] that the insertion of electrolytes has a different effect on the stability of foam bubbles. If the adsorption layer is not saturated with surfactant molecules, the introduction of an electrolyte slightly increases the stability of the foam bubbles, which is confirmed by experiments. For the research, electrolyte salts that accelerate the cement hardening processes were selected: ammonium, potassium, sodium, and magnesium sulfates. The concentration of the additives varied in the range of 0.5…2% in increments of 0.5%. Foaming agents of anionic and nonionic types at a working concentration of 0.08% were used for research [8, 9]. The best way in the foam system of an anionic foaming agent is 1…1.5% (NH4 )2 SO4 , which allows to increase the foam resistance by 10 … 25%, increase the multiplicity to 20 … 24. MgSO4 in the specified concentration allows to obtain only low-density foams (multiplicity 7—8.3), which is insufficient for the production of foam concrete. Na2 SO4 in the studied concentration range increases the multiplicity of the foam based on alkynesulfonates, but the stability of the system as a whole deteriorates. K2 SO4 in the amount of 0.5 … 1% allowed to increase the resistance of the foam to almost 6.4 h (by 60%). There is reason to assume that the introduction of such additives will accelerate the process of setting and hardening of the foam concrete mixture [16, 17]. Comparing the main indicators of foams obtained on the basis of foaming agents of different nature, it should be noted that the foams of a non-ionic foaming agent

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have initially lower resistance at a comparable multiplicity. Evaluating the effect of sulfates on the main characteristics of foams, it should be noted that an increase in their concentration in the system negatively affects the stability of foams, however, the primary volume of foam increases by 15–20%. The effect of hardness salts is particularly noticeable for surfactants containing 12 or more carbon atoms in the alkyl chain [1]. Solutions of compounds with 10 carbon atoms in the molecule are less susceptible to the action of hardness salts. Primary and secondary alkyl sulfates and alkyl sulfonates have a reduced foamability in hard water; nonionic surfactants do not reduce the foaming ability in it [10]. To improve the foaming ability of surfactant solutions in various application conditions, special additives are introduced into the compositions (for example, phosphates that increase the volume of foam and its stability, carboxymethylcellulose, polyacriamide, polyvinyl alcohol, hydrolyzed proteins, latexes [11–13]). These substances, by increasing the viscosity of the solution and foam films, help to slow down syneresis. Foams from solutions of sodium alkyl sulfonates are stabilized by fatty alcohols and some esters, in the presence of which the permeability of the films to air decreases sharply and the viscosity of the surface layer increases, but this is manifested in a very narrow concentration range.

3 Results and Discussion Additives—stabilizers of the foam matrix cause a significant decrease in the critical concentration of micelle formation of the surfactant solution. The most effective are those whose molecules contain an unbranched chain and polar groups capable of forming hydrogen bonds with water molecules (−OH, −NH2, = NH, etc.). If the solution contains surfactants of various types, the stabilization effect can be caused by the formation of mixed micelles consisting of molecules of nonionic and anionic surfactants. The effect of the pH environment of aqueous surfactant solutions has been studied by many authors [4, 7, 11, 13–17]. It should be noted that the change in the pH of the environment from neutral to slightly acidic (Table 1) is critical for the stability of foams obtained on the basis of the studied nonionic surfactant. In low concentrations, acidic electrolytes can improve the performance of foams obtained on the basis of a non-ionic surfactant. Under the conditions of the eponymous sign of the charge of the dissociated electrolyte and surfactant molecules, the adsorption of the latter contributes to the stability of the ion-stabilized system due to an increase in the charge density of the particles at the air—solution phase boundary. The phase boundary, which has a primary charge of ions from the foaming agent, completes the missing balance, tends to ion-stabilized cluster systems. At the same time, the more homogeneous the charge of the cluster system is throughout the bubble, the more stable the system as a whole (Fig. 1, 2). Undoubtedly, it is necessary to take into account the hydrolysis constant of the chemical additive inserted into the foam matrix and the pH of the environment when

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Table 1 Effect of the concentration of electrolytes in surfactant solutions on the pH of the environment Name of salt

Dissociation constant of the substance [2]

Calculated value of the hydrolysis constant

Logarithmic value of the hydrolysis constant

Calculated pH value of the solution at the electrolyte concentration in the system, wt. % 0.50

1.00

1.50

(NH4 )2 SO4

1.79 × 10–5

0.0559 × 10–8

0.301

5.81

5.65

5.57

MgSO4

2.5 × 10–3

0.400 × 10–11

2.397

7.08

6.93

6.84

Na2 SO4

5.9

1.695 × 10–14

5.523

8.12

7.96

7.87

K2 SO4

2.9

0.344 × 10–14

4.795

8.50

8.35

8.26

Fig. 1 Effect of the sulfate concentration on the pH of the environment of the anionic foaming agent solution

using non-autoclave hardening foam concrete in the production using an ionogenic foaming agent. The syneresis evaluation in Fig. 3 indicates an open flow of liquid from the foam. The Plateau-Gibbs channels are quite wide during the insertion of sulfates, during the first 40–60 min of observation, the foam matrix loses up to 60–80% of the primary aqueous solution, passes from monodisperse to polydisperse, and then its stability is limited only by external factors (ambient temperature, solution, etc.), discussed earlier in [12]. An increase in the resistance of foams without matrix restruction is necessary to ensure the stability of the properties of foam concrete products in production. In this case, it is necessary to start from the time of the beginning of

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Fig. 2 Effect of the electrolyte hydrolysis constant in an aqueous solution of the foaming agent on the foam multiplicity at its concentration in the system: 1—1%; 2—1.5%; 3—2%

Fig. 3 The outflow of liquid from the foam prepared on a non-ionic foaming agent with the insertion of a foam matrix stabilizer at its concentration in the system: A—0%; B—0.05%; C—0.10%; the concentration of K2 SO4 : 1—0.5%; 2—1.0%; 3—1.5% also varied

setting, which for foam concrete of non-autoclave hardening should be no more than 3 h. During this period, the foam matrix should have maximum stability and rigidity. The flow of liquid from the foam when using the foam stabilizer additive decreased more than twice in the first 60 min of observation. The structure of the foam matrix thus became more homogeneous (Fig. 4) and monodisperse. After 12 h of observation, syneresis reached 35% of the total volume of the primary solution. At the same time, the foam passed into the category of rigid with a wellformed frame. The use of an additive that increases the viscosity of the foam matrix allows neutralizing partially the negative impact of hardness salts, reducing syneresis

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2

3

Fig. 4 Effect of the foam matrix stabilizer additive on the foam structure at the concentration of the foam stabilizing additive: 1—0.5%; 2—1.0%; 3—1.5%

by 2 times, achieving stability indicators (6 … 8 h) and uniformity of the foam matrix. Increasing the viscosity of the solution allows offering higher performance characteristics of foams, including in the production of foam concrete.

4 Conclusion Ammonium, sodium and calcium sulfates have a relatively weak effect on the multiplicity and durability of foams, but not all of them are of interest as additives to foam concrete mixtures, as the ammonium ion decomposes in the alkaline environment of Portland cement systems with the release of ammonia gas. Magnesium sulfate in the optimal dosage of 1–1.5% stabilizes the foam well, but in the liquid phase there is a reaction of precipitation of magnesium hydroxide. In this regard, magnesium salts are not of interest as additives in foam concrete. Potassium sulfate in an amount of 0.5% has a stabilizing effect on the foam, especially in the first hour, so it can be used as an accelerator for setting foam concrete of non-autoclave hardening, which has a stabilizing effect. Increasing the viscosity of the solution due to the joint insertion of the electrolyte salt and an additional foam stabilizer allows improving the main technical characteristics of foams by 2–2.5 times. The effect of electrolyte salts on the foam matrix is ambiguous, as additives in the production of cellular foam concrete, they should be used, having previously evaluated the possibility of interaction with individual foaming agents, stabilizing and accelerating the hardening process additives. It should be taken into account that the data presented in the work were obtained using anionic and nonionic foaming agents of synthetic origin. Acknowledgements The work is realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V.G. Shukhov, using equipment of High Technology Center at BSTU named after V.G. Shukhov.

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References 1. Merkin AP (1995) Cellular concrete, scientific and practical prerequisites for further development. Constr Build Mater 5:57 2. Muromsky KP (1996) Cellular concrete in external walls of buildings. Concr Ferrous Concr 5:31–32 3. Tikhomirov VK (1983) Theory and practice of their production and destruction. 2nd ed., reprint. and add. Chemistry, Moscow 265 4. Svatovskaya LB, Ovchinnikov VP, Solov’eva SV, et al. (1996) Management of the activity of cement mixtures using additives of the “Elbi” type. Cement 2:28–32 5. Rakhimbayev ShM, Degtev IA, Tarasenko VN, Anikanova TV (2007) On the issue of reducing shrinkage deformations of foam concrete products. News High Educ Instit Constr 12:41–44 6. Tarasenko VN (2015) Cellular concrete in low-rise residential construction. In: 10th International Scientific and Practical Conference, pp 142–144 7. Suleymanova LA, Kara KA (2011) Energy-saving technologies of highly porous concrete. In: Belgorod region: past, present, future. Mat. of reg. scientific-practical conference in 3 hours, pp 98–102 8. Tarasenko VN (2016) Predicting the sound-proofing properties of cellular concrete composites. In Intelligent building composites for green construction. Collection of reports of the International Scientific and Practical Conference dedicated to the 70th anniversary of the Honored Scientist of the Russian Federation, Corresponding Member of the Russian Academy of Sciences, Doctor of Technical Sciences, Professor Valery Stanislavovich Lesovik, pp 135–140. Belgorod State Technological University named after V.G. Shukhov 9. Tarasenko VN (2016) Non-destructive methods of control of cellular concrete construction materials. In: Collection of reports of the International Scientific and Practical Conference, pp 194–198 10. Ishhenko AV, Baskakov PS, Strokova VV, Molchanov AO (2018) Development of a comparative criteria for evaluation of nonionic surface-active agents as disperse systems emulsifiers. Success Modern Nat Sci 8:18–23 11. Suleymanova LA (2017) High-quality energy-saving and competitive building materials, products and structures. Bull BSTU V.G. Shukhov 1:9–16 12. Strokova VV, Netsvet DD, Nelubova VV, Serenkov IV (2017) Properties of composite binder based on nanostructured suspension. Constr Mater 1–2:50–54 13. Shahova LD, Chernositova ES, Denisova JV (2017) Flowability and durability of cement containing technological additives during grinding process. AER-Adv Eng Res 133:162–167 14. Tarasenko VN (2019) On the question of the stability of the foam matrix in foam concrete. Bull BSTU Named After V.G. Shukhov 1:112–118 15. Tarasenko VN (2018) Impact of foamed matrix components on foamed concrete properties. In: MEACS 2017. IOP Conference Series: Materials Science and Engineering, vol 327, p 032054 (2018). 16. Tarasenko VN (2018) The influence of the structuring components the foam matrix on the properties of foam concrete. Danish Sci J 18(2):61–64 17. Tarasenko VN, Strokova VV (2018) Influence of surface properties of additives-mineralizers on the resistance of foam systems. Danish Sci J 17(1):52–55

Optimization of the Disposal Process of Polydispersed Pulverized Waste and Metal Chips N. P. Nazarova

and O. P. Mikhailova

Abstract Based on the analysis of the volume of waste generation in the production halls and the technological calculations performed, a bag filter of the brand with a purification degree of 99.9% was selected. It was found that only 14.5% of metal chips (unpolluted) are involved in recycling. More than 80% of the metal chips that are not involved in the secondary production cycle are unsuitable for remelting in traditional drum furnaces of foundries. It was proposed to install a rotary tilting furnace in the workshops instead of the usual rotating drum furnaces, which will reduce energy consumption, and melt any charge without preliminary preparation. Optimization measures for waste disposal at enterprises are proposed, including the capture of pulverized waste using the FRI-120-km, followed by the inclusion of extracted iron and silicon in the metal charge and the remelting of metal chips in the RTF for the preparation of the metal charge. Keywords Foundry · Pulverized waste · Bag filter · Recycling · Metal chips · Rotary kiln

1 Introduction The constant depletion of raw materials leads to the need to develop new technologies for its processing. Existing pyrometallurgical technologies are extremely energyintensive and labor-intensive, and do not meet modern environmental requirements, especially for the disposal of industrial waste [6]. According to S. L. Rovin, L. E. Rovin (2018), the traditional equipment that foundries have today does not allow for the cost-effective processing of dispersed N. P. Nazarova (B) Department of Design and Engineering Technologies, Kazan National Research Technical University named after A. N. Tupolev-KAI, Almetyevsk Branch, Almetyevsk, Russia O. P. Mikhailova Department of Natural Sciences and Information Technologies, Kazan National Research Technical University named after A. N. Tupolev-KAI, Almetyevsk Branch, Almetyevsk, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_12

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materials. At the same time, many of these wastes are high in Fe content, and even surpass, iron ore concentrates [3]. The main raw material in the foundry at the enterprise is gray cast iron. Grey cast iron is an alloy of iron, carbon and silicon. Materials based on Fe2 O3 are widely used as catalysts for various chemical processes, anti-corrosion metal processing, in the manufacture of solar collectors, in the manufacture of fire extinguishing systems [1]; for removing oil spills from the water surface [4]. In the course of the activities of foundries, about 95 types of waste are generated. According to the form of the federal statistical observation “Information on the formation, use, neutralization, transportation and disposal of production and consumption waste”—2-TP (waste), the collection and processing of data on which is carried out in the system of Federal Service for Supervision of Natural Resources Management, in 2017, 4 707 thousand tons of waste were formed in Tatarstan [5].

2 Materials and Methods To develop optimization measures for waste disposal at the foundry in Almetyevsk, the Republic of Tatarstan, it is necessary to identify the excess amount of waste and determine the reasons for the formation of excess volumes of these types of waste. The amount of metal-containing dust for machines equipped with a dust-collecting plant was determined by the method of calculating the volume of waste generation specified in the Temporary Guidelines for Calculating the Standards for the Formation of Production and Consumption Waste. St. Petersburg, 1998. The standard amount of ferrous metal waste generation is calculated using the Collection of Methods for Calculating the Volume of Waste Generation, St. Petersburg, 2004. The selection of the bag filter was carried out using GOST 31826–2012 Gas cleaning and dust collecting equipment. The bag filter. Wet dust collectors. Security requirements. Test methods (as amended). When choosing the design of the free filter with a flexible filter partition, we took into account the characteristics of the cleaned gases at the filter inlet, the properties of the dust, the characteristics of the dust source, the characteristics and requirements for the captured dust, the main requirements for filters. When selecting a rotary tilting furnace (RTF), the materials of experimental studies of S.L. Rovin were used (2016) presented in [2].

3 Results Having analyzed the waste disposal measures at the foundries of our city, we found that metal scrap, metal chips are transferred for disposal to LLC “Intermettrade”, dust from aspiration plants is transferred for disposal to LLC “Green World”. At casting, heat treatment, melting oxides of carbon (CO and CO2 ), nitrogen (NO2 , NO), sulfur (SO2 , SO3 ), formaldehyde (HCHO), as well as solid particles

Optimization of the Disposal Process ... Fig. 1 Amount of pollutants generated in 2019, t/year (1-blanking shop, 2—foundry, 3—engineering shop)

85 72.63 41.72

40.11 23.66

11.38

1.071 0

1 silicon dioxide

2

3 iron oxide

contained in the composition of raw material—dust containing oxides of Fe and SiO2 are emitted. Fe2 O3 and SiO2 are dust waste in the processing of iron and steel. In this regard, it was important to calculate the gross content of raw materials that make up the dust and gas emission M poli (kg/year) formed during the preparation, casting and heat treatment of metals. The gross emission of pollutants was determined by the formula (1):   ηT D × A , M poli = qi × B × β × 1 − 100

(1)

where, qi − specific release of substances per unit of production, kg/t; B—the amount of metal produced per year, t; β—the correction coefficient to account for the conditions of melting; ηT D —cleaning efficiency of trapping devices, %; A—the coefficient that takes into account the precise operation of the treatment plants. The results of calculations of pollutants formed in 2019 in 3 foundry workshops (blanking, foundry and engineering) are shown in Fig. 1. The largest amount of SiO2 and Fe2 O3 for 2019 was formed in the foundry and amounted to 40.11 and 72.63 tons/year, respectively. The engineering shop was in the second place in terms of waste volumes, where the amount of SiO2 and Fe2 O3 formed was 11.38 and 41.72 tons/year. In the blanking shop, the amount of generated pulverized waste was the smallest, which is due to the minimal concentration of sources of pollution emissions in this shop. Table 1 shows the indicators of the volume of pulverized waste generated at the foundry for 1 year. Table 1 shows that in 2019, excess volumes (1 t) of SiO2 and Fe2 O3 (23.66 t) were formed in the blanking shop. In the foundry, an excess amount (72.67 t/year) of Fe2 O3 was noted. In the engineering shop, the amount of Fe2 O3 from all three sources (machine tools) exceeded the annual standard for waste generation (11.23 tons/year). Excessive formation of pulverized waste may indicate a violation of technological processes and malfunction of the dust and gas cleaning system. Based on the analysis of the volume of waste generation in production workshops, we propose to optimize the operation of the dust and gas cleaning system by installing bag filters with a dust collection efficiency of up to 99.9%.

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Table 1 Volumes of waste generated at the foundry Name of substance SiO2

Generated for 2019, t/year 1.071

Annual standard of generation t/year 0.62

Fe2 O3

23.66

14.97

SiO2

22.09

27.30

18.02

26.95

Fe2 O3

72.63

2.07

SiO2

11.38

17.11

Fe2 O3

12.28

11.23

Fe2 O3

15.07

11.23

Fe2 O3

14.37

11.23

Name of the shop Blanking Foundry

Engineering

3.1 Proposed Optimization Measures for the Disposal of Iron-Containing Waste 3.1.1

Calculation of the Bag Filter FRI

We offer to carry out cleaning of process gases from dust in bag filters FRI. Bag filters of the FRI-120-km brand are installed in the foundry, engineering shop for more efficient capture of fine dust. The trapped dust is collected in the hopper. The filter surface of the device FF S was calculated by us using the formula (2):  FF S =

Vcom + Vr eg 60q

 (2)

where Vcom —the amount of gas coming into the purification, m3 /h; Vcom = 14000 m3 /h Vr eg —volume of gas or air consumed for tissue regeneration, m3 /h; Vr eg = 1000 m3 /h q—specific gas load of the filter baffle during filtration, m3 (m2 × min); The dust content after filtration should not exceed 15 mg/m3 .  FF S =

(14000 + 1000) = 192 m2 60 × 1.3

The specific gas load q in bag filters was calculated using the expression (3): q = qst × c1 × c2 × c3 × c4 × c5

(3)

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87

where qst —standard specific load, depending on the type of dust and its tendency to agglomeration (metal oxides—1.7; cement, limestone—2.0; dust when knocking castings out of molds—2.6); c1 —coefficient that characterizes the ability to regenerate filter elements (c1 = 1); c2 —coefficient that takes into account the effect of dust concentration on the specific gas load; (c2 = 0.97); c3 —coefficient that takes into account the influence of the dispersed composition of dust in the gas; c3 = 0,8 as N = 4 and d m < 3 m km; c4 —coefficient that takes into account the influence of the gas temperature; c4 = 0.72, as the gas temperature = 140 ºC. c5 —coefficient that takes into account the requirements for the quality of purification; (c5 = 0.9).

q = 2.6 × 1 × 0.97 × 0.8 × 0.72 × 0.9 = 1.3 m3 (m2 × min) The hydraulic resistance of the filter ΔPF in Pa consists of the resistance of the housing Ph and the resistance of the filter baffle ΔP f p . ΔP F = Ph + ΔP f p

(4)

ΔP F = 182 + 2308 = 2490 Pa The gas velocity vin in the inlet pipe, m/s, was calculated by the formula (5): vin =

Vcom , 3600 × Sin

(5)

where, Sin – the area of the inlet, Sin = 120 m2 . vin =

14000 = 13.5m/s 3600 × 2.4 × 0.12

The hydraulic resistance of the body was: 2 Ph = ξd × vin ×

ρg 0.998 = 2 × (13.5)2 × = 182.25 Pa. 2 2

where, value ξd when designing filters is usually assumed to be equal to 1.5 . . . 2.0. The hydraulic resistance of the filter baffle includes pressure losses due to the  ) It was baffle itself (Pp ) and losses due to dust deposited on the baffle (Pdust calculated using the formula (6):

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(6) The value P p (in Pa) was calculated using the formula (7): P p = C f p × μ × v n

(7)

where C f p —coefficient that characterizes the resistance of the filter partition, m−1 ; μ—dynamic viscosity of the gas, Pa × s; μ = 19 × 10−6 Pa × s v—filtration velocity, m/s; (v = 0.015 m/s); n—the exponent that depends on the gas flow mode through the partition (for laminar flow mode n = 1, for turbulent n > 1). 

Pp = 4500 × 109 × 19 × 10−6 × 0.015 = 1282 Pa The resistance in Pa caused by the dust deposited on the partition was calculated by the Eq. (8): (8) where τ – duration of the filter cycle, s; τ = 600 s; cin – dust concentration at the filter inlet, kg/m3 ; —parameter resistance of the dust layer, m/kg. The vale K 1 depends on dust properties and porosity of dust layer on the partition.  = 19 × 10−6 × 600 × 20 × 0.00025 × 20 × 109 = 1026 Pa Pdust

It is worth noting that the total resistance of bag filters should not exceed 2800 Pa, and the resistance of the dust layer on the partition is 600 … 800 Pa. Having obtained the values of the hydraulic resistance of the filter baffle and the housing, we calculate the hydraulic resistance of the filter according to the formula (4): P F = 182 + 2308 = 2490 a ≈ 2500 a Thus, the hydraulic resistance of the bag filter we select must be at least 2500 Pa. The efficiency of dust collection η was calculated by the formula (9):  η=

cin − cout cin

 × 100%

where cin – the dust concentration at the inlet to the filter bag, mg/m3 ; cout – dust concentration at the outlet of the bag filter, mg/m3 .

(9)

Optimization of the Disposal Process ...

 η=

89

20000 − 15 20000

 × 100% = 99.9%

Thus, the efficiency of dust capture with cin = 20000 mg , with the help of FRI is m3 99.9%. Then we calculate the amount of incoming dust by the formula (10), (11) and (12): M1 = V × cin , g/s V = 14000

(10)

m3 m3 m3 transform in , then V = 3.88 h s s (11)

M3 (emitted in the environment) = M1 − M2 , g/s

(12)

M3 (emitted in the environment) = 77.6 − 77.5 = 0.1g/s. Thus, we selected a bag filter of the FRI 120-km brand with a filtration surface area FF S = 192 m2 ; the hydraulic resistance of the filter P F = 2500 Pa; the degree of filter cleaning 99.9%; the consumption of incoming dust M1 = 77.6 g/s; the amount of dust trapped by the device M2 = 76.8 g/s; the amount of dust emitted into the environment M3 = 0.1 g/s.

3.1.2

Calculation of the Amount of Metal Chip Formation

The calculation of the amount of metal chip formation was carried out according to the formula (13): M=

Q × kch , t/year 100

(13)

t where Q− the amount of metal to be processed, year (2.4 + n × 0.1) t of ferrous metal); kch – standard for the formation of metal chips, % (kch = 10% according to the inventory data). The results of the calculations are listed in Table 2. Thus, about 2500 tons of metal chips are formed at the enterprises per year.

As it can be seen from Table 2, only 14.5% of metal chips (unpolluted) are involved in recycling. Thus, 370 tons of metal waste in the form of chips enters the secondary production cycle (recycling) for the preparation of the metal charge. More than 80%

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Table 2 Indicators of the amount of generated and disposed metal waste Name of waste (charge material)

Amount of chips formed, t/year

Amount of recycled %, return of metal waste (recycling), t/year chips to the production cycle

Bronze chips

200

15

7.5

Steel chips

600

200

33

Brass chips Cast iron chips Copper chips TOTAL

240

3

1.2

1500

150

10

15

2

13

2555

370

14.5

of metal waste is stored on the territory of the enterprise, and then transferred to thirdparty organizations. Metal chips that are not involved in the secondary production cycle are unsuitable for remelting in the drum furnaces of the production workshops of the enterprise, as they are contaminated with lubricants and coolants. Remelting such chips without proper processing in melting furnaces will lead to a decrease in the technical and economic indicators of melting, significant chip fumes and may worsen the operation of melting plants. In connection with the above, we propose to optimize the process of recycling metal chips at the enterprise with the help of a special installation—RTF, developed by S.L. Rovin. RTF allows melting significant amounts of metal waste without special treatment. Optimizing the utilization of metal chips with the help of RTF will increase the volume of waste involved in recycling, as well as reduce financial costs for the purchase of raw materials for the preparation of metal charge from gray cast iron.

3.1.3

Advantages of Recycling Metal Chips with a Rotary Tilting Furnace

In foundries, metal chips are processed in rotating drum furnaces. However, the heating of the polydisperse material (metal waste) occurs at a shallow depth of 20–30 mm. When heating cast iron chips, the efficiency of the RTF exceeds 50%, which is twice as high as that of traditional drum-flow furnaces, due to the complex loop-like movement of gases. The operating efficiency of the furnace is provided by such parameters as the angle of inclination, temperature, rotation speed, material consumption and discharge rate. In the RTF, it is possible to carry out drying and removal of oils, high-temperature heating and melting of chips. Heating of both cast iron and crushed steel chips in the RTF can reach a temperature of 750–850 °C [2]. The advantages of using the proposed RTF are that there is a twofold reduction in the duration of chip melting, smoke emissions into the working area of the workshops are eliminated, the environmental parameters of melting and the quality of the metal are improved.

Optimization of the Disposal Process ...

91

4 Discussion Using high-efficiency bag filters (FRI-120-km), the cleaning efficiency is significantly increased (up to 99.9%). Highly efficient collection of pulverized waste, followed by the separation of valuable raw materials, will increase the volume of its own metal charge. Remelting of metal chips in the RTF will reduce energy consumption, remelting any charge without preliminary preparation. In addition, it is worth emphasizing that the economic effect of the work consists of the difference in the sale price of chips ~ 11,000 rubles/t and the cost of the charge for smelting cast iron ~120,000 rubles/t.

5 Conclusion Thus, based on the analysis of the volume of waste generation in the workshops, we proposed to install in addition to the existing dust and gas cleaning system FRI bag filters of the FRI-120-km brand with a dust collection efficiency of up to 99.9%, which will increase the volume of their own metal charge. It was found that only 14.5% of metal chips are involved in recycling. More than 80% of metal chips that are not involved in the secondary production cycle are unsuitable for remelting in the drum furnaces of foundries, as they are contaminated with oils. In this regard, we proposed to install RTF in the workshops instead of conventional rotating drum furnaces, which will reduce energy consumption, and melt any charge without preliminary preparation. Our proposed optimization measures on waste management in enterprises, including the capture of pulverized waste using FRI-120-km, followed by the inclusion of extracted Fe and Si in the metal charge and melting of the metal in the RTF for preparing metal charge, allow to solve the problem of the return to production of valuable raw materials, greatly reduce the cost of finished goods to a significant environmental effect.

References 1. Golev SA, Ryzhov AA (2015) On some new means of extinguishing various substances and materials. Modern Technol Civ Defense Emerg Resp 2(5):183–184 2. Rovin SL (2016) Design of rotary tilting furnaces: modeling and calculation. Mech Equip Metallur Plants 1(6):30–47 3. Rovin SL, Rovin LE (2018) Creation of own raw material base for foundry production of machine-building enterprises. Cast Metallur 2(91):29–36 4. Rubanov YuK, Tokach YuE (2015) Removal of oil spills from the water surface by complex sorbents based on iron oxides. Bull Technol Univ 18(7):268–270

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5. The territorial scheme in the field of waste management, including solid municipal waste, of the Republic of Tatarstan is approved by the resolution of the Cabinet of Ministers of the Republic of Tatarstan of 13.03.2018 № 149. 123 p 6. Natorkhin MI, Bobyl AV, Cheremisin AV, Sokolov MS (2019) A novel method of waste processing of polymetal raw materials to make useful nanoproducts. Journal of Physics Conference Series 1236. https://www.researchgate.net/publication/334364730_A_novel_method_of_ waste_processing_of_polymetal_raw_materials_to_make_useful_nanoproducts. Accessed 28 Jan 2021

Impact of the Granulometric Composition of Raw Sludge on the Characteristics of Portland Cement D. A. Mishin , S. V. Kovalev , and D. V. Smal

Abstract An increase in the activity of the cement of Plant 1 was made by changing the granulometric composition of its sludge. The change in the granulometric composition of the sludge of Plant 1 was made due to the coarsening of the grinding, by inserting limestone with a fraction of 0.315–0.2 mm in the amount of 3 and 6% wt. and due to the re-grinding of the sludge during the 0, 5, 10, 30, 60, 90 min in a 1-L mill with a standard range of grinding environment at a humidity of 37%. It was found that with an increase in the fineness of the sludge grinding, a more complete absorption of calcium oxide is observed. The binding rate of free calcium oxide increases slightly up to a mixture with 10 min of re-grinding. Then, at 30 min of re-grinding, the binding rate of calcium oxide increases dramatically. In the clinker from the ground sludge, an increase in the proportion of synthesized alite is observed. The relation between the fineness of the raw mix and the strength of the cement is not linear. There is optimum fineness of grinding at 10 min of the re-grinding, which maximizes the strength of cement at 28 days of hardening in water. An increase in the time of re-grinding more than 10–30 min leads to a decrease in strength. Keywords Cement strength · Granulometric characteristics · Raw material mixture · Cement · Fineness of grinding

1 Introduction The change in the activity of cement can be achieved by optimizing the fineness of its grinding and granulometric composition. This is achieved by selecting the grinding method [1], the design features of the mills [2, 3], the selection of grinding environment [4–6], the granulometry of the source material [7], its microstructure [8] and the insetion of special additives [8, 9]. However, research and industrial practice show that the physico-chemical and technological processes that occur with solid substances or with the participation of the latter, in most cases, proceed the faster D. A. Mishin (B) · S. V. Kovalev · D. V. Smal Belgorod State Technological University named after V. G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_13

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and more completely, the larger the surface of the substance involved in the process. The degree of grinding of materials determines such important factors as reactivity, burnability, and clinker activity [10]. One of the ways to increase the activity of clinker and cement is to increase the degree of grinding of the raw mixture. It is believed that the higher the fineness of the raw mix, the higher the strength of the cement. However, the relationship between the fineness of the grinding of the raw mixture and the strength of the cement is somewhat more complex. The main objective of these studies was to determine the relationship between the fineness of the grinding of the raw material mixture (granulometric composition) and the activity of cement on the example of the factory raw material mixture of Plant 1.

2 Methods and Materials As the initial raw material mixture, the finished raw sludge of Plant 1 (Table 1) was used. The chemical composition of the raw sludge provided for research did not correspond to the clinker provided, as the company operates on pulverized coal fuel, so it was adjusted. The characteristics of the corrected factory sludge are shown in Table 1. The corrected sludge has the following characteristics: AM = 1.57; SM = 2.2; saturation coefficient (according to Kind) KH = 0.92. To obtain a sludge of different granulometric composition, it was subjected to re-grinding and coarsening, by inserting limestone with a fraction of 0.315–0.2 mm in the amount of 3 and 6% by weight. The re-grinding time was 0, 5, 10, 30, 60, 90 min. The sludge was ground in a metal laboratory mill with a volume of 1 L with a standard range of grinding environment, at a humidity of 37%. The specific surface area of the cement was determined by the method of air permeability on the PMC-500 device (cement surface meter). The granulometric composition of the sludge was determined using a laser particle size analyzer ANALYSETTE 22 NanoTec plus. The samples were roasted in a laboratory furnace at control temperatures, with an isothermal holding time of 10 min. The heating speed of the furnace is 10 °C/min. The sinterability of clinker was estimated by the content of free calcium oxide in the samples. The content of CaOfree in clinker was determined by the ethyl-glycerate method. Table 1 Chemical composition of the raw sludge, % wt Sludge

LOI*

SiO2

Al2 O3

Fe2 O3

CaO

MgO

SO3

R2 O**

Source

34.62

13.87

3.87

2.46

43.10

0.87

0.17

1

Corrected

34.54

13.85

3.61

2.98

43.07

0.81

0.16

0.93

* LOI

– loss on ignition ** R2 O = Na2 O + 0,658 K2 O.

Impact of the Granulometric Composition …

95

The phase composition of the clinker was determined using an ARL X’TRA powder X-ray diffractometer.

3 Results and Discussion As a result of the roughening and re-grinding of the sludge, compositions with different granulometric characteristics were obtained (Figs. 1, 2 and 3). The particles characteristic sizes were calculated based on the values of grain size uniformity coefficient at the points of the main inflections (Table 2). In order to study the effect of the degree of grinding of the studied sludge on the processes of clinker formation, tablets weighing 2 g were prepared and roasted with an isothermal exposure of 10 min at control temperatures. The sinterability of clinker was estimated by the content of free calcium oxide in the samples. The results are presented in Table 3. Table 2 Characteristics of the raw sludge after regrinding and desensitization Name of parameters

The amount of insertion of limestone with 200–315µ fraction

Regrinding duration, min.

6%

0

Grain size uniformity coefficient n

3%

2.88

Characteristic particle diameter, microns

2.76

133.49

131.9

5

10

2.16

2.64

2.8

107.57

87.35

59.3

30 2.68

33.4

60

90

3.1

3.15

23.9

23.14

Particle fraction, mass %

10

0 minutes of regrinding 0 минут домола 8

input of 3% limestone frac on ввод 3% известняка фракции 0,315-0,2 0.315-0.2 mm мкм input of 6% limestone frac on ввод 6% известняка фракции 0,315-0,2 0.315-0.2 mm мкм

6 4 2 0 0

100

200

300

400

500

Sludge particle size, μm

Fig. 1 Granulometric composition of the corrected sludge without regrinding and with the insertion of 3 and 6% limestone fractions of 0.315–0.2 mm

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minutes of regrinding 55минут домола

7

10минут minutes of regrinding 10 домола

6 5

30минут minutes of regrinding 30 домола

4 3 2 1

.

Particle fraction, mass %

8

0 0

100

200

300

400

500

Sludge particle size, μm

Particle fraction, mass %

Fig. 2 Granulometric composition of the corrected sludge subjected to 5, 10 and 30 min of regrinding 10

60минут minutes of regrinding 60 домола

8

90минут minutes of regrinding 90 домола

6 4 2 0 0

100

200

300

400

500

Sludge particle size, μm

Fig. 3 Granulometric composition of the corrected sludge subjected to 60 and 90 min of regrinding Table 3 Impact of the grinding time of the raw sludge mixture on the content of CaOfree at clinker roasting, wt.% Regrinding time, min

Roasting temperature 1100 °C

1200 °C

1300 °C

1400 °C

0

37.93

30.42

13.04

4.93

5

35.21

29.58

7.51

4.91

10

35.34

20.93

7.02

4.56

30

32.57

10.87

5.21

1.49

60

25

18.87

2.63

0.56

90

22.25

18.82

2.46

0.43

Insertion of 3% of limestone fraction 0.2–0.315 mm

34.58

30.15

8.02

4.6

Insertion of 6% of limestone fraction 0.2–0.315 mm

37.65

36.42

8.00

5.28

Impact of the Granulometric Composition …

97

Fig. 4 The phase composition of the clinker from the sludge: I—0 min of regrinding; II—5 min of regrinding

Fig. 5 The phase composition of the clinker from the sludge: I—30 min of grinding; II—90 min of grinding

With an increase in the fineness of the sludge grinding, a more complete absorption of calcium oxide is observed. It is important to note that the binding rate of free calcium oxide increases slightly up to the mixture with 10 min of regrinding. Then, in the raw mixture, after 30 min of regrinding, the rate of binding of calcium oxide increases sharply. X-ray phase analysis of the obtained roasted samples (Figs. 4, 5) showed that an increase in the proportion of synthesized alite is observed in the clinker made

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Table 4 Characteristics of cement from corrected sludge Regrinding time, min

Characteristics of cement Content of CaOfree , %

Specific surface area, m2 /kg

Compressive strength, MPa 2 days

7 days

28 days

0

0

333

21.74

41.61

47.94

5

0

298

25.52

41.47

55.19

10

0

306

33.01

58.89

65.28

30

0

313

20.93

39.88

57.29

60

0

307

21.16

53.51

64.88

90

0

309

22.67

43.94

53.74

of pre-ground sludge. This is indicated by an increase in the intensity of the peaks belonging to the alite, with an increase in the regrinding time. In the resulting clinkers, the synthesis was complete. No free calcium oxide was found in them. To obtain cement from the resulting clinker, the latter was ground in a laboratory mill to a specific surface area of ≈300 m2 /kg with the addition of 4% wt. natural gypsum. Then cement paste with a water-cement ratio of 0.3 was prepared, which was then placed in molds to obtain cubes with a face size of 1.41 cm. The results of the cement tests are presented in Table 4.

4 Conclusion The relationship between the fineness of the raw mix and the strength of the cement is not linear. There is an optimum fineness of grinding at 10 min of regrinding, at which the maximum strength of the cement is achieved in 28 days. An increase in the regrinding time more than 10–30 min leads to a decrease in strength. Acknowledgements The study is implemented in the framework of the Flagship University Development Program at Belgorod State Technological University named after V.G. Shukhov, using the equipment of High Technology Center at BSTU named after V.G. Shukhov.

References 1. Zlobin IA, Mandrikova OS, Borisov IN, Smal DB (2018) Evaluating the influence of grinding method on the cement dispersion characteristics. J Phys Conf Ser 1118(1):012010. https://doi. org/10.1088/1742-6596/1118/1/012010 2. Bogdanov VS, Alexandrova EB, Bogdanov DV, Bogdanov NE, Gavrunov AY (2019) Optimization of material grinding in vibration mills. J Phys Conf Ser 1353(1):012059. https://doi. org/10.1088/1742-6596/1353/1/012059

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3. Bogdanov VS, Fadin YM, Lozovaya SY, Latyshev SS, Bogdanov NE, Vasilenko OS (2016) Ball mill power calculation with inclined partition. Int J Pharm Technol 8(3):19031–19041 4. Barbanyagre VD, Stronin AA (2018) Comparison of Use Efficiency of Different Types of Densive Ball Load during the Grinding of Portlandcement Clinker. IOP Conf Ser J Phys 1066:012005. https://doi.org/10.1088/1742-6596/1066/1/012005 5. Barbanyagre VD, Stronin AA (2018) Effect on particle size distribution range of clinker grinding bodies and grinding intensifier. Bull BSTU Named After V.G. Shukhov 1:71–76 6. Barbanyagre VD, Stronin AA (2018) Investigation of the influence of the diameter of a large ball and the grinding load of open-cycle mills on the dispersed characteristics of clinker. Bull BSTU Named After V.G. Shukhov 5:60–65 7. Sharapov RR, Kharlamov EV (2019) To the question of the cement production materials destruction. IOP Conf Ser Mater Sci Eng 698(6):066043. https://doi.org/10.1088/1757-899X/ 698/6/066043 8. Shahova LD, Schelokova LS, Chernositova ES (2021) Influence of clinker microstructure on grinding efficiency in the presence of grinding intensifiers. Lecture Notes in Civil Engineering, vol 95, pp 23–29.https://doi.org/10.1007/978-3-030-54652-6_4 9. Hashim SFS, Hussin H (2018) Effect of grinding aids in cement grinding. J Phys Conf Ser 1082(1):012091. https://doi.org/10.1088/1742-6596/1082/1/012091 10. Klassen VK, Klassen AN, Mikhin AS, Korobkov MI, Dmitrienko ZI (2006) Influence of quartz on mineral formation processes and clinker activity. Proc Univ. Constr 3:44–47

Stress-Strain State of the Elements of a Timber-To-Timber Joint Connected by Inclined Screwed-In Rods T. P. Chernova , V. V. Filippov , B. V. Labudin , and V. I. Melekhov

Abstract The paper considers the stress–strain state of the timber-to-timber joint elements on inclined screwed-in rods. Experimental studies of timber-to-timber joints were performed for three types of connections: screws with anchorage details, screws, and threaded rods. The connections are established with the angle of deviation of the connecting element from the normal to the shear plane—45°. It is found that the proposed technical solution for connecting wood elements on screws with anchorage details allows increasing the load-bearing capacity of the joints and reducing their deformability. The threaded rods joint has a greater deformability than the screw joint and a lower load-bearing capacity. The load-bearing capacity of joints with screws with anchorage details and threaded rods increases with increasing cross-section and strength of the connecting element, load-bearing capacity of the joint on screws—with increasing the washer area and anchoring length of the screws into the wood. The destruction of joints with screws with anchorage details and threaded rods comes from crumpling of the wood under the washers (if it is not enough washer area) and rupture of the rod. It is found that the load-bearing capacity and deformability of the joints on the screws increase with increasing anchoring length of the screw. As a result of field experiments, a calculation model is proposed for determining the load-bearing capacity of a timber-to-timber joint on inclined screwed-in rods. The load-bearing capacity of timber-to-timber joints on inclined screwed-in rods is determined from the geometric and mechanical characteristics of the wood and the joints. The calculation model takes into account the resistance of wood under the contact surface of the washer. The results of the calculation according to the developed method are compared with the results of the experiment. Keywords Timber-to-timber joint · Inclined screwed-in rods · Strength · Deformability · Experiment

T. P. Chernova (B) · V. V. Filippov · B. V. Labudin · V. I. Melekhov Nothern (Arctic) Federal University named after M.V. Lomonosov, Arkhangelsk, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_14

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1 Introduction For most multi-element load-bearing wooden structures, the strength is determined by the nodal and mounting joints. In the calculations of wood structures, it is necessary to determine the load-bearing capacity and deformability of the joints of the elements, especially for spatial structures. To determine the strength of the joints of wooden elements on the crumpling of wood by the contact surface of the dowel located across the wood grain, it is customary to consider two fundamental models of Kochenov [1] and Johansen [2]. The V.M. Kochenov’s model is confirmed by the results of experimental studies of Dmitriev [3], Lin’kov [4], and others. The K.W. Johansen’s model is applied in the scientific works of Smirnov [5], Yun [6], Blaß [7], Girhammar [8], Kavaliauskas, [9] and others. In addition Arkaev [10], Naychuk [11], Chernova [12] and others studied the issues of ensuring the composition of wood elements with screwed-in rods. The disadvantage of the location of the dowel in the joint across the wood grain is the crumpling, which weakens the joint and violates the integrity of the wood when the dowel diameters are more than 5 … 6 mm [13]. In [7, 9], the load-bearing capacity of the joint with the location of the dowels at an angle to the shear plane is determined not only from the conditions of embedment the wood by the contact surface of the screw, but also from the condition of withdrawal dowel. At the same time, the calculation methods do not take into account the increase in the force resistance of the screw section due to the resistance of the contact surface of the washer. The aim of the study is to check the adequacy of the model for calculating the load-bearing capacity of the timber-to-timber joint on inclined screwed-in rods. The objectives of the study: – to develop a calculation model of interaction of elements of timber-to-timber joints on screwed-in rods; – to determine the strength and deformation characteristics of the joints; – to compare the results of the calculation according to the developed method with the results of the experiment.

2 Materials and Methods The paper clarifies the calculation models for determining the load-bearing capacity of timber-to-timber joints on inclined screwed-in rods. The models apply the equations [7] and take into account the increase in the force resistance of the screw section due to the resistance of the contact surface of the washer with wood at an angle to the grain. The load-bearing capacity of timber-to-timber joints on inclined screwed-in rods is determined from the geometric and mechanical characteristics of the wood and the

Stress–Strain State of the Elements of a Timber-To-Timber Joint …

6

а

103

7

8

б

Fig. 1 Experimental device: a—sample testing scheme; b—types of the connecting element; 1, 2—timber elements; 3—screw; 4—displacement transducer; 5—entering plate; 6—S; 7—SA; 8— TR

connections. Then, the load-bearing capacity of the wood for embedment the contact surface of the screw Rh is determined from the equations [7]. Load-bearing capacity of wood for withdrawal the screw Rax : Rax,i = Fax,i · sin α,

(1)

where Fax,1 for element 1 and Fax,2 for element 2 are determined according to [14]; α—inclination angle of the screw from the normal to the shear plane (Fig. 1a). Load-bearing capacity of wood for embedment under the washer Rc : Rc = f h,α · A · sin α,

(2)

where f h,α —the characteristic embedment strength of wood at an angle to the grain; A—washer area. Tensile strength of the screw: fu · π · Rt = sin α

d12 4

,

(3)

where d1 —the inner diameter of the screw thread, f u —the resistance of the screw to tension.

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To calculate the load-bearing capacity of the timber-to-timber joint on screws with anchorage details, the dependence is proposed: N=

N I I −I I I min(Rax + Rc + Rh ; Rt ) = , K K

(4)

where N I I −I I I —load corresponding to the beginning of damage; K —coefficient of reliability in case of plastic failure; Rax = min(Rax,1 ; Rax,2 ). To calculate the load-bearing capacity of the timber-to-timber joint on screws, the dependence is proposed: N=

N I I −I I I Rc + Rax,1 + Rax,2 + Rh = , K K

(5)

where Rc = 0 at Rc > Rax,2 and Rc > Rax,1 + Rax,2 ; Rax,1 = 0 and Rax,2 = 0 at Rc > Rax,2 and Rc < Rax,1 + Rax,2 ; Rax,2 = 0 at Rc < Rax,2 and Rax,2 > Rax,1 + Rc ; Rax,1 = 0 and Rc = 0 at Rc < Rax,2 and Rax,2 < Rax,1 + Rc . Studies of the joints were carried out according to a single shear scheme (Fig. 1, a). For experimental studies of timber-to-timber joints 3 types of connections are accepted: screws with anchorage details—SA, screws (without anchorage details)— S, threaded rods—TR (Fig. 1, b). The dimensional characteristics of the elements of the timber-to-timber joints are given in Table 1. Loading of the joints was carried out with a step-increasing load, a jack with a maximum force of 50 kN in accordance with the recommendations of the Central Research Institute of Building Structures named after V.A. Kucherenko [15]. The tests were carried out in the laboratory at a temperature of 22 ± 2 °C and an air humidity of 50–60%. During the tests, the following parameters were determined: NI-II , δI-II —load and deformations corresponding to the area of linear deformations; Nt , δt —load and deformations corresponding to damage. Deformations are determined by the displacement transducers.

3 Results and Discussion For timber-to-timber joints with different types of connections of dependence “load— shear” are shown in Fig. 2. During the tests, a continuous increase in deformations without changing the value of the applied force (for screw joints) and a violation of the continuity of the material of the joint elements (for SA and TR joints) are accepted for the moment of damage. According to the V.M. Kochenov’s model [1], for joints with threaded

Stress–Strain State of the Elements of a Timber-To-Timber Joint …

105

Table 1 Dimensional characteristics of timber-to-timber joint elements Element sizes

Screws with anchorage details

Screws without anchorage details

Threaded rods

Symbols in the timber-to-timber joint

SA1 12-45-100 SA2 12-45-100

S 12-45-100 S 12-45-160

TR 12-45-100

Anchoring length in the element 1 “wood” lanc1 , mm

100

100

100

Anchoring length in the element 2 “wood” lanc2 , mm

100

100, 160

100

Thread outer diameter d, mm

12

12

10

Thread inner diameter d1 , mm

9

9

9

Diameter of the drilled hole d0 , mm

0.7d = 8

0.7d = 8

10

Angle, degrees

45

45

45

Washer area A, mm2

936 (SA1) 2720 (SA2)

936

936

40

1

2

35

1

4

Load, kN

30

2

3

25

3

20

5

15

4

Nδ=10.5 kN

10

5

5 0 0

1

2

3

4

5

6

Shear δ, mm Fig. 2 Dependences N = f(δ) for shear testing of timber-to-timber joints on screwed-in rods: 1—SA1 12-45-100; 2—SA2 12-45-100; 3—S 12-45-100; 4—S 12-45-160; 5—TR 10-45-100

rods, it is fair to consider the destructive load that corresponds to the value of 2δI-II . The force corresponding to 2δI-II was denoted Nδ . The SA joint has the highest load-bearing capacity and the lowest deformability with the same length of the threaded part of the screw. The TR joint has a deformability greater than that of the screw joint by 3 times, and a load-bearing capacity less than 1.6

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times. The load-bearing capacity of the joints SA and TR increases with increasing cross-section and strength of the connecting element, load capacity of the screw joint – larger washer area and length of the anchoring screws into the wood. The nature of the destruction of the samples is shown in Fig. 3. The destruction of the SA and TR joints occurs from the crumpling of the wood under the washers (if the washer area is insufficient) and from the rupture of the rod. It is found that the load-bearing capacity and deformability of the joints on the screws increase with increasing anchoring length of the screw. A comparison of the theoretical and experimental results of studies of joints on shear for timber-to-timber samples is shown in Table 2. The difference between the results of theoretical and experimental studies ranges from 1.6 to 4.4%.

а

б

c

Fig. 3 The nature of the destruction of samples: a—screws with anchorage details SA 1-12-45-100; b—screw without anchorage details S 12-45-100; c—threaded rods TR 10-45-100

Table 2 Results of testing of joints on screwed-in rods Difference , %

Sample

Calculation model, kN

Experiment, kN

Nt

NII-III

Nt

Nδ

Nt

NII-III (Nδ )

SA1 12-45-100

35.56

35.56

35

35

1.60

1.60 2.86

SA2 12-45-100

35.97

35.97

37

37

2.86

S 12-45-100

26.06

26.06

25

25

4.24

4.24

S 12-45-160

31.61

31.61

33

33

4.40

4.40

TR 10-45-100

24.98

10.89

24

10.5

4.08

3.74

Stress–Strain State of the Elements of a Timber-To-Timber Joint …

107

4 Conclusion 1.

2. 3.

A new technical solution for joint wood elements on screwed-in rods with anchorage details is proposed, which allows increasing the load-bearing capacity of the joints by up to 35%. A calculation model is developed to determine the load-bearing capacity of the timber-to-timber joint on inclined screwed-in rods. The joint on the threaded rods has a significantly greater deformability than the connection on the screws, the load-bearing capacity is less by 1.6 times.

Acknowledgements The work was implemented within the framework of the grant “U. M. N. I. K.” under the contract No. 14123GU/2019 dated 10.06.2019.

References 1. Kochenov VM (1953) The carrying capacity of the elements and connections of wooden structures. Gosstroyizdat, Moscow 2. Johansen KW (1949) Theory of timber connections. International Association of bridge and structural Engineering. Bern 3. Dmitriyev PA (1975) Experimental studies of timber elements connections using metal and plastic dowels and their calculation theory with elastic-viscous and plastic deformations. Doctoral thesis 4. Linkov VI (2016) Bearing capacity and deformability of connections on inclined rods with combo washers. Civ Eng 9:40–43 5. Smirnov PN (2013) Comparison of calculating methods for dowel connections of timber structures. Domestic and foreign experience. Constr Mech Calc Struct 251(6): 68–72 6. Syuy Y (2015) The calculation of the withdrawal strength of connection SHERPA in the wooden structure form the combination of wall panel-CLT and beam from CLT or LVL. Modern Probl Sci Educ (1):7 7. Bejtka I, Blaß HJ (2002) Joints with inclined screws. In: Proceedings of the 35th Meeting of the International Council for Research and Innovation in Building and Construction, pp 1–12, Kyoto 8. Girhammar UA, Jacquier N, Källsner B (2017) Stiffness model for inclined screws in sheartension mode in timber-to-timber joints. Eng Struct 136:580–595 9. Kavaliauskas S (2010) Kompozitini˛u medini˛u-betonini˛u sij˛u tarpsluoksnio ˛ižambin˙es medsraigtin˙es jungties elgsena. Daktaro disertacija, Lithuania 10. Arkayev MA (2017) Strengthening of wooden constructions with the use of twisted cruciform rods. Candidate’s thesis 11. Naychuk AY, Babaev MV (2010) Concerning the assessment of bearing capacity of steel screw rods screwed up angularly to wood fibres. Civ Eng 1:21–23 12. Chernova TP (2018) Improvement of the design and technology of connection CLT-panels with glued laminated elements. Candidate’s thesis 13. Building code 64.13330.2017. Timber structures 14. EN 1995-1-1 (2004) Eurocode 5: Design of timber structures - Part 1-1: General – Common rules and rules for buildings. Brussels 15. Recommendations for testing joints of wooden structures (1981) TsNIISK named after V.A. Kucherenko, Moscow

Calculation of Vertical Deformations of Composite Bending Wooden Structures with Non-linear Behavior of Shear Bonds E. V. Popov , V. V. Sopilov , I. N. Bardin , and D. M. Lyapin

Abstract The mathematical model presented in this research allows for the calculation of composite elements with nonlinearly compliant shear bonds by deformations by the step method. The article presents an algorithm based on the theory of calculation of composite bars by A.R. Rzhanitsyn, with specification of the stiffness of shear bonds at each calculation step for each bond depending on the magnitude of the shear force. Using the system of equations, arbitrary expressions are determined that describe the distribution of shear forces at the boundaries of sections, the length of which is taken to be equal to the distance between discrete shear bonds. The system of differential equations of the 2nd order allows one to determine the shear forces in the bonds and the vertical displacements of the beam at each step of loading. The article presents the results of theoretical studies of vertical displacements of a composite wooden beam, consisting of layers connected by bolts; deformation of bonds occurs according to a nonlinear law. To compare the results, a linear calculation was performed with constant values of the stiffness coefficients of the shear bonds. The results show that failure to consider the actual nature of the deformation of the bonds can introduce a significant error in assessing the deformability of composite beams on mechanical bonds. Keywords Structural wood · Non-linear behavior · Composite beams · Shear bonds · Rigidity · Bending · Vertical displacements

1 Introduction Composite materials are widely used in modern building [1, 2]. A precondition for the proliferation of wooden composite rods is, as a rule, a limited range of sawn products. This necessitates joining several elements together to obtain cross-sections of the required size. Similar solutions are widely used when strengthening wooden E. V. Popov (B) · V. V. Sopilov · I. N. Bardin · D. M. Lyapin Department of Engineering Structures, Architecture and Graphics, Northern (Arctic) Federal University named after M.V. Lomonosov, 163002 Arkhangelsk, Russian Federation © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_15

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floor elements as well [3]. Wood-composite beams reinforced with synthetic materials based on carbon fiber [4–7], composite elements made of CLT, LVL and other materials [8, 9] are widely used in construction. In most cases, the work of mechanical shear bonds will be nonlinear, which is due to the peculiarities of the structure of the wood and the nature of its deformation. The method for calculating the composite elements presented in Russian norms and rules [10] and foreign ones [11] does not consider these circumstances, and therefore it is necessary to clarify the classical method of calculating such structures, as well as to conduct additional research.

2 Materials and Methods The solution algorithm presented in this work is considered using a two-layer composite element as an example. Within the limits of the selected infinitely small section, we conditionally assume a continuous distribution of bonds along the length of the contact seam, which will allow to use the solutions of the differential equation of the composite element to determine the shear forces: T  =γ ·T + ξ

(1)

where T is the shear force; ξ is the coefficient of stiffness of shear bonds; γ ,  is the coefficient and free term of the differential equation determined by formulas (2) and (3), respectively. γ =

1 c2 1 + + EI E 1 · F1 E 2 · F2

(2)

where E 1 , E 2 , F 1 , F 2 are the elastic moduli and cross-sectional areas of the composite bar branches; c is the distance between the barycenter of the branches; EI is the sum of stiffnesses EI = E 1 I 1 + E 2 I 2 . M0 (t) · c (t) = −  EI

(3)

where M 0 (t) is the distribution function of the bending moment within the considered area. The composite structure is divided in length into n sections, length lj , where j is the section number (Fig. 1a). The boundaries of the sections are determined by the distances between discrete bonds with numbers i = 1, 2…, n − 1, i.e. the section number coincides with the number of the left discrete bond. The value l denotes the n−1  l j . The stiffness coefficient of the shear calculated length of the element l = j=1

Calculation of Vertical Deformations of Composite Bending Wooden Structures …

111

Fig. 1 To the calculation of a composite beam: a—scheme of breaking down a composite element into sections; b—conditional and actual diagram of the distribution of shear forces in the bonds along the length of the element (span)

bonds within the sections is conventionally assumed to be uniformly distributed, ) , where C (T ) is the stiffness coefficient of the discrete bond, equal ξ j (Ti ) = C(T lj which determines the value of its longitudinal displacement at given load. The solution of the differential Eq. (1) when substituted into it (2) and (3) will have the form: ξj T l j (x j ) = Ai j · sh(λ j · x j ) + Bi j · ch(λ j · x j ) + λj

x

  (t) · sh λ · (x j − t) dt

0

(4) where Aij , Bij are arbitrary constants depending on the boundary conditions (the first digit of the index indicates the number of the section j, the second—the number of the discrete bond i); t is an auxiliary coordinate along which the integration is performed; λj —characteristic number; ξ j —stiffness coefficient of joint, reduced to linear. The right side of expression (4) is designated as a function Fj (x j ), where j is the number of the corresponding section; x j —coordinate, measured from its beginning, from left to right, thus x j = 0 at the beginning of the section and x j = l j at the end. As the boundary conditions connecting the equations with each other, the equality of the shear forces can be put at the boundaries of the sections: T1 (l1 ) = T2 (0), T2 (l2 ) = T3 (0), Tn−1 · (ln−1 ) = Tn (0)

(5)

as well as equality at the boundaries of the sections of concentrated shifts “G” along the dividing plane of the seam, which are the differences in the displacement of the lower fiber of the overlying rod ul and the upper fibers of the underlying rod uu , that is:     = T j (x j )/ξ j = A j · λ j · ch(λ j · x j ) + B j · λ j · sh(λ j · x j ) + j (x j ) /ζ j (6)

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Taking into account (4), (5) and (6), as well as the equalities sh(0) = 0; ch(0) = 1; j (0) = 0; B j = T l j−1 (l j−1 ), it is possible to compose a system of equations to determine the shear forces along the length of the rod and arbitrary constants Aj : 

A j−1 · sh(λ j−1 · l j−1 ) + T j−1 (l j−1 ) · ch(λ j−1 · l j−1 ) +  j−1 (l j−1 ) = T j−1 (l j−1 ) [ A j−1 · λ j−1 · ch(λ j−1 · l j−1 ) + T l j−1 (0) · λ j−1 · sh(λ j−2 · l j−2 ) + j−1 (l j−1 )]/ξ j−i = A j · λ j /ξ j

(7)

where j is the section number j = 1…n–1. The diagram of shear loads will have leaps, the nature of the conditional and actual diagram of the distribution of shear forces is shown in Fig. 1.b. To solve the system of Eqs. (7), it is necessary to set boundary conditions at the ends, for example, for a simply supported beam without obstacles to shear at the ends, one can set equal to T l1 (0) = T ln−1 (ln−1 ) = 0. The equation for the bent axis of a bent member is:   yl j x j =

 

     j  

M xj 1 d xd x = Ti · c d xd x M0 x j − E I E I i=1

(8)

where M(x) is the total bending moment equal to the sum of the moments arising from the external load and from the forces in the shear bonds. The graph of the function M(x) will have breaks at the boundaries of the sections; therefore, expression (11) should be compiled for sections l1 , l 2 … l n−1 , and the equality of deflections at the boundary of the sections should be related by boundary conditions. From the condition of equality of deflection to zero on the supports, as well as equality of deflections yl1 (l 1 ) = yl2 (0); yln–2 (ln–2 ) = yln–1 (0), yln–1 (l n–1 ) = 0     (0); yl2 (0); and the angles of rotation of the cross-sections yl1 (l1 ) = yl2 (l2 ) = yl3   yln−2 (ln−2 ) = yln−1 (0) at the boundaries of the sections lj , a system of equations is drawn up to determine arbitrary constants C j and Dj : ⎧ ⎪ D =0 ⎪ ⎪ 1  ⎪ ⎪

1 + C1 = C2 ⎨ 1 + C1 · l1 + D1 = D2 

2 + C2 · l2 + D2 = D3

2 + C2 = C3 ⎪ ⎪ ⎪ ... ... ⎪ ⎪ ⎩

+ C · l + D = 0

n−1 n−1 n−1 n−1 n−2 + C n−2 = C n−1

(9)

where j denotes a definite antiderivative of the double integral (8), j is the number of the section.

3 Results As an example, let us consider a composite wooden beam (Fig. 2, a) made of pine wood of strength class C22 [12], the layers of which are interconnected by cylindrical

Calculation of Vertical Deformations of Composite Bending Wooden Structures …

113

Fig. 2 To the calculation of a composite beam on yielding bonds: a—beam diagram; b—diagram “load-deformation” (P–δ) for a single bond under the action of longitudinal shear

steel dowels, the deformation of which occurs according to a nonlinear law, i.e. ξ = ξ (T) (Fig. 2, b). The material behavior is assumed to be linearly elastic. The following parameters are taken as initial data: design span: l = 3 m, cross-sectional dimensions of branches are 150 × 150 mm, spacing of shear bonds is 0.3 m. The beam is loaded with a uniformly distributed load q = 9 kN/m. It is necessary to determine the maximum vertical displacement of a composite beam. The half-span of the beam is divided into sections with several lengths lj . The functional dependences of the distribution of bending moments along the length of the sections M 0,j (x j ) has form: 1 section :

  Ml1 (x j ) = 0, 5 q · t · l − q · x 2j · c/ E I ⎛

2−5 section :

Ml j (x j ) = 0, 5ql ⎝

j−1

k=1

⎞

lk + t ⎠ − q ·

j−1

⎛

lk ⎝0, 5 ·

k=1

j−1

(10)

⎞

lk + x j ⎠ − 0, 5q x 2j

(11)

k=1

Substituting these expressions into the right-hand side of solution (4) after integrating the expressions, we obtain the functions j and their derivatives. The load application process is divided into 12 steps. For the initial stage of loading, the stiffness coefficient of the joint is taken equal to the tangent of the angle of inclination of the tangent line drawn through the starting point of the graph to the axis of abscissae (δ). A system of equations is compiled according to (7) to find the values of arbitrary constants Ai and shear forces at the boundaries of the sections T l (0) and T l (l j ). Taking symmetry into account, half the span of the beam is considered 

and the boundary conditions will be: T l1 (0) = 0 and T l5 (l5 ) = 0. According to the obtained values, depending on the shear forces in the bonds T i , at the previous stage of the calculation, the stiffness coefficient of the bond is refined for the next stage C(T ) = P(T )/δ(T ) where δ is the linear deformation determined from the graph in Fig. 2.b. Then a system of equations is compiled, according to (9), from which arbitrary constants C j , Dj of expressions (12) and (13) are determined, describing

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the distribution of deflections along the sections lj : 1 section : 2−5 section :

yl1 (x1 ) = yl j (x j ) =

ql 3j 12

⎛

 l12  2ql · l1 − ql12 − 12T1 c + C1 x1 · D1 (12) 24 E I ⎞ ⎛

⎝l − 2

j−1

k=1

⎞

lk ⎠ −

ql 4j 24

+

⎛ ⎞2 j−1 j−1



l 2j ⎜ ⎟ ⎝ l − q l q · l · ⎝ k k ⎠ − 2Ti= j c⎠ + C j x j D j 4 k=1

k=1

(13) After calculating arbitrary constants C j , Dj the vertical displacements of the beam in the middle of the span are determined by formula (13) at x j = l 5 . To compare the results, a calculation was made in a linear formulation with two values of the shear bonds stiffness, which is assumed to be constant. In the first case of linear calculation, the stiffness of the bonds is taken equal to the tangent of the angle of inclination of the tangent line to the graph in Fig. 2.b drawn through the starting point. In the second case, the stiffness of the bonds is taken equal to the tangent of the angle of inclination of the secant drawn through the initial and final points of the curve corresponding to the ultimate deformation of the dowel joints [10].

Fig. 3 Graphs of dependence of: a—efforts in bonds T i at each step of loading; b—vertical displacements in the middle of the beam span

Calculation of Vertical Deformations of Composite Bending Wooden Structures …

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4 Discussion The graphs of the increase in vertical displacements at each stage of loading are shown in Fig. 3.

5 Conclusion 1.

2.

A mathematical model has been developed for the calculation of two-layer composite rods considering the nonlinear work of shear bonds; with an uneven arrangement of bonds; when using idealized bonds deformation diagrams, described, for example, in accordance with the Prandtl diagram. The calculation of the vertical displacements of the composite beam by the step method was carried out, the values of the forces in the bonds and the normal stresses in the edge fibers of the branches were determined. The use of linear diagrams of the deformation of shear bonds in the present case can give a significant error (15–41%) and does not allow to get a real idea of the deformability of a composite structure.

References 1. Klyuev SV, Klyuev AV, Khezhev TA, Pukharenko YV (2018) High-strength fine-grained fiber concrete with combined reinforcement by fiber. J Eng Appl Sci 13:6407–6412 2. Makhmud K, Sergey K, Dmitry K, Chiadighikaobi PC, Roman F, Andrej O, Nikolai V, Nataliya A (2020) Heat treatment of basalt fiber reinforced expanded clay concrete with increased strength for cast-in-situ construction. Fibers 8:0067 3. Karelsky AV, Zhuravleva TP, Labudin BV (2015) Load–to failure bending test of wood composite beams connected by gang nail. Mag Civil Eng 2(54):77–85. https://doi.org/10.5862/ MCE.54.9 4. Corradi M, Vemury CM, Edmondson V, Poologanathan K, Nagaratnam B (2021) Local FRP reinforcement of existing timber beams. Comp Struc V. 258(113363) 5. Ling Z, Liu W, Shao J (2020) Experimental and theoretical investigation on shear behaviour of small-scale timber beams strengthened with Fiber-Reinforced Polymer composites. Comp Struc 240(111989) 6. Koshcheev A, Roshchina S, Lukin M, Lisyatnikov M (2018) Wooden beams with reinforcement along a curvilinear trajectory. Mag Civil Eng 5(81):193–202. https://doi.org/10.18720/mce. 81.19 7. Siham M, Mittelstedt C (2020) Mixed-mode buckling of shear–deformable composite laminated I-beams. Int J Mech Sci 169(105332). https://doi.org/10.1016/j.ijmecsci.2019.105332 8. Roche S, Robeller C, Humbert L, Weinand Y (2015) On the semi–rigidity of dovetail joint for the joinery of LVL panels. Eur J Wood Wood Prod 5(73):667–675 9. Hassanieh A, Valipour H (2020) Experimental and numerical study of OSB sheathed-LVL stud wall with stapled connections. Constr Build Mater 233(117373). https://doi.org/10.1016/j.con buildmat.2019.117373

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10. Russian Constraction Code SP 64.13330.2017. Timber structures. http://docs.cntd.ru/doc ument/456082589. Date of Application 12 Feb 2021 11. DIN EN 1995-1-1/A2-2014 Eurocode 5 (2008) Design of timber structures-Part 1-1: GeneralCommon rules and rules for buildings; English version EN 1995-1−1:2004/A2:2014. European committee for standardization, Brussels 12. Russian State Standard GOST 33080–2014. Timber structures. Strength classes of structural sawn timber and methods of its determination. http://docs.cntd.ru/document/1200115778. Date of Application 12 Feb 2021

Features of Electricity Consumption in Residential Buildings with Low-Duty Elevator N. P. Badalyan , V. I. Afonin , E. E. Chashchina , and G. V. Maslakova

Abstract Dual speed drives (AC2), which are currently widely used in elevator drives of residential constructions, are gradually being replaced by electric drives without speed control with speed governor (VSD)—(electric motor + drive). Asynchronous motors in such drives operate in variable frequency and variable voltage (VVVF) systems. They are often called inverters. Usage of these systems in elevators without an engine-room led to the abandonment of gears, a downsizing of the engine, and an improvement in the quality of movement. This work shows the results of the analysis of the operation of different types of elevators in different buildings. For example, elevators with a lifting capacity of 400 kg and 500 kg were analyzed. The advantages and disadvantages of using adjustable and unregulated drives are shown. The analysis of energy consumption in elevators installed in buildings of different storeys and operating at different intensities has been made. It showed that there is a significant variation in the results for the daily number of cycles and daily energy consumption. However, despite the limited number of test objects, there are certain patterns, which that were also mentioned in this paper. It was found out that the energy consumption in standby mode is usually in the range of 20% to 85%, and the average value is about 70% for residential buildings. Keywords Civil engineering · Elevator · Inverter systems · Energy saving

N. P. Badalyan · V. I. Afonin Vladimir State University named after A. G. Stoletov and N. G. Stoletov, Vladimir, Russia E. E. Chashchina Moscow State University of Civil Engineering (National Research University), Moscow, Russia G. V. Maslakova (B) Lipetsk State Technical University, Lipetsk, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_16

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1 Introduction Elevator equipment manufacturers believe that the use of inverter systems reduces energy consumption by up to 50% compared to traditional elevator systems with a rope-driven pulley [1, 2]. In addition to systems without an engine-room, inverters began to be offered for traditional elevators with a with a rope-driven pulley, in which an engine-room and a gear system (engine + gear + inverter) are provided. This is an energy saving alternative to elevators with dual speed drives. It is known [3] that more than 70% of passenger elevators in the European Union countries are installed in buildings of 6 floors and below. Drives with inverters were considered an energy saving solution for all installations as inverters add energy consumption to the overall energy balance of the system. Along with the increasing competition in the market of elevators for low-rise buildings (especially up to 6 floors), the use of elevator drives with inverters has become a trend. One of the studies of the Swiss Agency for energy saving (SAFE), conducted on 33 elevators, showed that the share of energy consumed by the elevator in standby mode reaches up to 80% of the total energy consumption. In low-use elevators, the installation of inverters leads to an increase in energy consumption in standby mode. Calculations show that if the elevator is in standby mode about 70% of the time, the inverter will consume about 400 kWh per year for each elevator. This means that there will be an increase in energy consumption for many low-use elevators, despite the use of the latest energy-saving technology.

2 Methods and Materials The authors of a number of articles also point out that any energy-saving elevator system under such conditions does not result in a reduction in costs [6, 7]. The devices that have for the maximum energy consumption include permanent cabin lighting and a door lockout system [3]. Since the beginning of the 1980s, the elevators began to use the achievements of microelectronics. At the same time, they began to abandon the relay control systems of the elevator. Thanks to the using of electronic controllers, a number of problems that were associated with the using of relay-based control systems were eliminated: frequent failure, short service life, large size and low design flexibility. Against the background of these advantages, the additional energy consumption of electronic control systems was neglected. The beginning of the using of door locking systems, variable speed drives, illuminated buttons, displays in the cabin and outside the shaft, warning, protective and other similar elevator systems, has led to an increase in the need for energy consumed in standby mode to maintain all this equipment. Usually in Europe, gear mechanisms are used for buildings of medium height (from 7 to 20 floors), and a winch without a gear is used in taller buildings at an

Features of Electricity Consumption in Residential Buildings …

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elevator speed of 2–4 m/s or higher. The gearbox in traditional traction systems allows to use of cheaper engines with a smaller size, but their efficiency is about 55% due to the using of a worm gear. It is known that energy is used most efficiently in adjustable voltage and frequency drives.

3 Results and Discussion We will try to perform a similar analysis in relation to Russian elevator drives, which are being introduced in recent years in the Russian Federation. The results of measuring the electricity consumed by elevators at the surveyed facilities in Moscow are shown in the Table 1 [5]. Elevators with a lifting capacity of 400 and 500 kg with a travel speed of 1 m/s. A comparison of the power consumption of AC2 and ACVVVF drives shows a systematic trend in the distribution of energy consumed in dynamic (acceleration and deceleration) and stationary (moving at a constant speed) modes for regulated and unregulated drives. The power consumption in the stationary mode of the adjustable drives is slightly higher. This is due to an increase in the current consumed by the motor, which is caused by the harmonic components of the current (up to 10%) created by the frequency converter. But in dynamic modes, due to the regulation of the stator current with a smooth change in the supply voltage and current frequency, the advantages of variable-speed motor are obvious. These trends had to be verified by calculations using a single methodology for a variety of drives. In the paper of J. Nipkova “Electricity consumption and energy saving opportunities in elevators” [4] the standard energy consumption of an elevator is proposed to be calculated using the following formula: E=

z · k1 · k2 · h max · P (kW/ h/year ) V · 3600

(1)

Table 1 The results of measuring the electricity consumed for different type of elevators Type of drive

Direction

Active acceleration energy, Watt-second

Active work energy, Watt-second

Active deceleration energy, Watt-second

Active cycle energy, Watt-second

AC2; 3.55 kW

Descent, 0 kg

40,000

16,000

3400

59,400

Lifting; 0 kg

52,000

6000

8000

66,000

AC2; 7 kW

Descent, 0 kg

44,700

27,500

4750

76,950

Lifting; 0 kg

23,750

2250

2000

28,000

Descent, 0 kg

19,120

21,220

3770

44,110

Lifting; 0 kg

2875

9800

4025

16,700

ACVVVF; 4.4 kW

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N. P. Badalyan et al.

Table 2 The classification of buildings Usage category

1

2

3

4

5

The intensity of application/friquency

Very low Very rarely

Low Rarely

Medium Sometimes

High Often

Very high Very often

Number of cycles per year

40 000

120 000

200 000

500 000

700 000

Average driving time in hours per day

0.2 Less than 0.3

0.5 0.3…1.0

1.5 1.0…2.0

3.0 2.0…4.5

6.0 More than 4.5

Average resting time in hours per day

23.8

23.5

22.5

21

18

Types of buildings and their purpose

*Residential buildings up to 6 floors *Low-duty small offices or administrative buildings

*Residential buildings up to 20 floors *Small offices or administrative buildings with 2 or 5 floors *Small hotels *Low-duty freight elevators

*Residential buildings up to 50 floors *Small offices or administrative buildings up to 10 floors *Medium-sized hotels *Medium-duty freight elevators

*Residential buildings with more than 50 floors *High offices or administrative buildings with more than 10 floors *Large hotels *Small and medium-sized hospitals *Freight lift in the production process with one level

*Offices or administrative buildings over 100 m high *Large hospitals *Freight lift in the production process with multiple levels

where E is the energy consumption per year, k 1 is the average load factor, hmax is the maximum height of the shaft, m; k 2 is the height factor of the shaft (two floors—1, the rest—0.5), P is the engine power, kW, V is the elevator speed, m/s, z is the annual number of trip cycles. The classification of buildings according to VDI 4707 [6, 8], used in the European Union, is shown in Table 2. Based on this classification, you can pre-predict the energy consumption in elevators installed in buildings of different storeys and operating at different intensities. It makes possible to carry out a differentiated assessment of the energy consumption of elevators that operate in different conditions. For this purpose, measurements of electricity consumption in residential buildings in Moscow were carried out at different periods of time. The results of the measurements are shown in Table 3. The analysis shows that there is a significant variation in the results for the daily number of cycles and daily energy consumption. However, despite the limited number of test objects, there are certain patterns: • the energy consumption per cycle of the regulated drives is less than that of the unregulated ones. • the use of drives with a high degree of load (a large number of cycles per day) is higher; • the intensity of work to a certain extent depends on the time of year (month).

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Table 3 The results of the measurements of electricity consumption Object

1

2

3

4

5

6

Elevator, kg/m/sec

320/1

320/1

320/1

500/1

500/1

500/1

Driver

5 kW 1000/250

4,4 kW 1000

5,5 kW 1500

7 kW 1000\250

7 kW 1000/250

5,5 kW 1500

Controller

VLT5013

HF40-021

Number of 8 floors

8

8

9

8

8

HF40-028

Action period

688 h 40 min 772 h 25 min

688 h 40 min

138 h 50 min

2616 h 30 min

2080 h 40 min

Machine time

78 h 50 min

79 h 25 min

144 h 40 min

7 h 10 min

360 h 50 min

215 h 40 min

Number of 13,370 cycles

12,723

20,350

1033

63,627

40,114

Number of 19.4 cycles per hour

9.8

29.6

7.5

24.3

19.2

Number of 466 cycles per 24 h

235

710

179

583

461

Cycle time 21 s

22,44 s

20,3 s

24,7 s

20,4 s

19,4 s

Energy during operation

453.9 kWh

190.5 kWh 341.5 kWh

54.2 kWh

2311 kWh

723 kWh

Energy during the cycle

0.0339 kW h 0.015 kWh 0.0168 kWh 0.0525 kWh 0.0363 kWh 0.018 kWh

Energy during the 24 h

15.8 kWh

3.525 kWh 3.948 kWh

9.4 kWh

21.16 kWh

8.3 kWh

The power consumption is calculated taking into account the data from Table 4 for a gear electric drive with a two-speed asynchronous motor AC2 and an asynchronous drive ACVVVF. The results of the calculation according to formula (1) are shown in the Table 4. They show that the energy consumption in standby mode is usually in the range of 20% to 85%, and the average value is about 70% for residential buildings. It follows that the annual number of trip cycles in a typical building with 9 floors is on the order of 70,000 (up to 190 cycles per day), and about 80% of energy consumption is in standby mode, despite the use of an energy-saving system. For elevators in buildings with 200,000 cycles per year (up to 550 cycles per day) with the same drive system, standby mode accounts for 40% of the energy consumed, and in hospitals and large office blocks with 700,000 cycles per year (up to 1,900 cycles per day) this figure is 25% [3].

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Table 4 The power consumption for a gear electric drive with a two-speed asynchronous motor AC2 and an asynchronous drive ACVVVF Q

V

in

hmax

zr

AC2 drive (with reducer)

ACVVVF drive (with reducer)

P kW

E action kW h

Pdrive kW

Pinvertor kW

E action kW h

E standby mode kW h

320

0.71

1:1

30

40,000

3.0

528.17

3.0

4.5

320.4

400

0.71

1:1

30

40,000

3.0

528.17

3.0

4.5

320.4

782

400

1.0

1:1

75

70,000

4.5

2461

5.5

7.5

1403.7

782

630

1.0

1:1

75

70,000

6.5

3554.78

7.5

11

1786.4

782

1000

1.0

1:1

75

120,000

7.5

7968.69

11.0

15

5454.2

772

400

1.6

2:1

85

120,000

5.0

3320.4

7.5

11.0

2324.1

772

630

1.6

2:1

85

200,000

8.0

8854.17

11.0

15.0

5681.5

-

1000

1.6

2:1

85

200,000

12.0

13,281.15

15.0

22.0

7747.4

-

Table 5 The energy consumption in standby mode for inverters

782

Firm

Inverter, kW

Energy consumption in standby mode, W

A

4.6–7.5

36–44

11–15

45–53

D

5.5

27–35

7.5

32–40

11

38–46

15

47–55

Table 5 shows the energy consumption in standby mode for inverters of leading companies (taking into account the energy consumed by fans) [3]. With the daily use of the elevator for residential buildings of medium height, the elevator carries out about 110 cycles per day, in houses of the “country private house” type—less than 20 cycles per day, and in multi-apartment buildings-about 160 cycles per day. Therefore, the decision to use the so-called “energy-saving elevators” should be made after studying the energy consumption in standby mode.

4 Conclusion There are a number of ways in which you can reduce the energy consumption of the elevator by improving the software and hardware of electronic control systems. For low-use elevators, the dominant factor of energy use is its consumption in standby mode. In general, in cases where drives with inverters are intended for use in low-rise buildings (40,000 cycles per year or less), it is necessary to critically assess the losses in standby mode.

Features of Electricity Consumption in Residential Buildings …

123

The additional cost of an energy-efficient elevator for low-use elevators can increase the payback period so much that it exceeds the renovation period of the elevator equipment. This factor should be taken into account in the case of possible installation of elevators with a travel speed of up to 1 m/s in buildings with low storeys during their modernization. This is possible, as life expectancy in the Russian Federation is steadily increasing. Finally, customers should have an understanding of the power consumption of the various drives, and choose the most reliable solution that best meets their needs.

Reference 1. Al’-Sharif L (2004) The energy consumption of the Elevator. Overview (1974–2001 years). Elevcon 1–10 2. Al’-Sharif L (2004) Simulation model of the energy consumed by the elevator. Elevcon 11–20 3. Selic F (2010) Energy consumption by low-duty elevators in standby mode. Elevator 2:43–48 4. Nipkov Dzh (2005) Energy consumption and energy saving opportunities in elevators. S.A.F.E, Zurich 5. CHuvatov AB (2000) Introduction of energy-saving technologies in the modernization of elevator equipment. Liftinform 10:5–7 6. Efficiency of energy consumption in elevator installations. WITTUR Group, 26 (2009) 7. Barny Dzh (2010) The efficiency of energy use in elevators - proposals for the classification from the point of view of energy consumption. Elevator 5:25–29 8. Energy-efficient elevators and escalators. E4 WP3-Report 77 (2007)

Determination of the Main Characteristics and Modeling of the Classification Matrix of the Concentrator in a Closed Grinding Cycle R. R. Sharapov

and V. S. Prokopenko

Abstract The paper shows the complexity of closed systems for grinding fine powders based on grinding-classifying complexes. The problems of modeling the separation process and predicting the granulometric composition of fine powders are presented. It is shown that the main parameter that determines the operation of the separator of any generation is the efficiency of its operation. Analytical expressions of national and foreign researchers are given, which allow determining the efficiency of the separation process in an air separator. It is indicated that these expressions do not take into account the design features of separation devices, their layout schemes, etc. It is shown that a more complete informative characteristic will be a model for determining the fractional efficiency of particle capture of the developed installation. In this paper, probabilistic dependencies are used to predict the fractional efficiency of the device used. For the proposed apparatus, the full deposition coefficients of the corresponding fractions are obtained. Its high efficiency is shown. The main task of modeling the separation process is to predict the granulometric composition of the finished product. This finished product depends on the composition of the starting material, the design and technological parameters of the machines and mechanisms involved in the separation process. However, at the present time, only previously known systems for separating grinding products are used. Therefore, it is necessary to search for technical and technological solutions aimed at increasing the productivity of grinding complexes. It is proposed to introduce an additional concentrator between the separator and the cyclone in the grinding complex, which will increase the productivity of the complex itself. Keywords Concentrator · Granulometric composition · Separation process · Grinding and classifying complexes

R. R. Sharapov Moscow State University of Civil Engineering National Research University, Moscow, Russia V. S. Prokopenko (B) Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_17

125

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1 Introduction In the production of building materials at the present stage, the efficiency of equipment that is already outdated and does not meet the requirements of modern production is of great importance. In this regard, new systems and equipment for dust removal in the production of building materials are being developed and upgraded. The main characteristic of such equipment is the hydraulic resistance that occurs during operation. One such equipment is concentrators designed to capture coarse dust [1]. By upgrading the design and changing the operating parameters of the concentrator, it is possible to reduce the hydraulic resistance. The total hydraulic resistance consists of such components as pressure losses at the entrance to the concentrator, losses to overcome the friction of the gas flow against the walls of the concentrator, losses to turn the flow and losses at the exit from the concentrator [2]. Closed grinding systems are elaborated complexes of elements and subsystems that are interconnected by material and aeromaterial flows [3]. At the same time, the most complex and poorly studied system is the separation of grinding products, which determines both the quality of the final product and the efficiency of the entire process as a whole. The main task of modeling the separation process is to predict the granulometric composition of the finished product. This finished product depends on the composition of the starting material, the design and technological parameters of the machines and mechanisms involved in the separation process [4].

2 Methods and Materials The prediction of the fractional efficiency of particle capture is based on the assumption that the random value of the fractional degree of particle capture obeys the logarithmic normal distribution law [5, 6]. Then, probabilistic dependencies are used to predict the fractional efficiency η(δ): 1 η(δ) = √ 2π

 t2 dt = (x), exp − 2 

x −∞

(1)

where x=

lg δ − lg δ50 , lg ση

(2)

δ84 δ50 = . δ50 δ16

(3)

ση =

Determination of the Main Characteristics …

127

To predict general efficiency E E = (x),

(4)

lg δ0.5 − lg δ50 . x= lg2 ση + lg2 σr

(5)

where

In these dependences (x)—the probability integral, δ—the particle size, ση —the root-mean-square distribution of the fractional purification coefficients, δ50 , δ16 , δ84 —the sizes of particles captured by the device by 50, 16 and 84%, δ0.50 — the median particle size, which divides the dust mass into two equal parts, σr —the root-square deviation of the particle size distribution. If the particle sizes obey the logarithmic normal distribution law, then σr =

δ0.5 δ84.1 = . δ0.16 δ15.9

(6)

where δ0.16 , δ0.74 —the particle sizes for which the mass fractions with a smaller size are 0.16 and 0.84, respectively, δ15.9 , δ84.1 —the size of the particles collected at 15.9 and 84.1%.

3 Results and Discussion The efficiency can be calculated using the fractional efficiency ratio, which gives the dependence of the capture efficiency on the particle size. In combination with data on the size distribution of particles entering the dust collector, the fractional efficiency makes it possible to determine the overall capture efficiency [7–10]. For chambers with L H > 3, the value of the partial purification coefficients (in %) can be found with a sufficient degree of accuracy based on calculations of the average concentration of particles of the appropriate size in the output section of the dust-collecting chamber according to the formula (%):   1 Ni , εn = 100 · 1 − i

(7)

where i—the number of points for which the particle concentration is calculated; Ni—the ratio of the concentration of particles of a given size at the calculated point of the output section of the chamber to their concentration in the input section [11]. The particle size distribution in this case obeys the normal distribution law. Then

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Fig. 1 The diffraction efficiency of the concentrator

Ni = (x1 ) + (x2 )−1

(8)

The purification parameters x1 and x2 (the parameters of the partial distribution function F(x)) are determined by the formulas: x1 =

H + h − L vvB H − h − L vvB  , x2 =  , 2Dt − vl 2Dt − vl

(9)

where h—distance from the camera ceiling; Dt—the coefficient of turbulent diffusion of particles. The total purification coefficient is found as the sum of the products of the fractions of the particles of the corresponding fractions by their fractional purification coefficients (Fig. 1) [12, 13]. ε=



εn

N Δd. 100

(10)

The matrix of the coefficients of the passage of individual fractions by the concentrator is given by the expression  K ii = η di .

(11)

The use of multi-stage purification leads to an increase in efficiency (Fig. 2). The analysis shows that for particles with a diameter of more than 80 microns, the separator purification efficiency is 73%, the separator with a concentrator is 99%.

Determination of the Main Characteristics …

129

Fig. 2 Efficiency at installing multiple devices sequentially: curve 1—separator, 2—separator and concentrator, 3—separator, concentrator and cyclone

4 Conclusion A matrix model of the transformation of the granulometric composition of the material in a closed-type technological system is developed. The model allows expressing the dispersed composition of the finished product in terms of the dispersed composition of the source, as well as in terms of the specified characteristics of the concentrator. The modeling showed the uniformity of the grain composition at the system output. Acknowledgements This work was supported by the RFBR grant No. 18-08-01050, using equipment of High Technology Center at BSTU named after V.G. Shukhov.

References 1. Romanovich AA, Amini E, Romanovich MA (2020) Improving the efficiency of the material grinding process. IOP Conf. Series Mater Sci Eng (945)1:012060 2. Romanovich LG, Chekhovskoy EI (2018) Determination of rational parameters for process of grinding materials pre-crushed by pressure in ball mill. IOP Conf Ser Mater Sci Eng (327)4:042091 3. Orekhova TN, Kachaev AE, Prokopenko VS (2020) Plane model of particle separation in disintegrators with internal circulation of the grinding material. IOP Conf Ser Mater Sci Eng (945)1:012043 4. Prokopenko VS, Orekhova TN, Sharapov RR (2020) Methodology for constructing the main characteristics and classification matrix of the concentrator. Mater Int Sci Pract Conf 299–303

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5. Barsky MD, Revnivtsev VI, Sokolkin YuV (1974) Gravitational classification of granular materials. Nedra, Moscow 6. Agarkov AM, Sharapov RR, Prokopenko VS (2016) Analysis of the hydraulic resistance of the concentrator. Bull BSTU Named V.G. Shukhov 3:87–90 7. Vetoshkin AG (2005) Processes and devices of dust cleaning. Penza State University, Penza 8. Birger MI, Waldberg AYu, Myagkov BI, Padva VYu, Rusanov AA, Urbakh II (1983) Handbook of dust and ash collection. Energoatomizdat, Moscow 9. Paus KF, Evtushenko IS (1977) Chemistry and technology of chalk. Stroyizdat, Moscow 10. Barsky MD (1976) Optimization of the processes of separation of granular materials. Nedra, Moscow 11. Mizonov VE, Ushakov SG (1989) Aerodynamic classification of powders. Chemistry, Moscow 12. Sharapov RR (2018) Determination of the granulometric composition parameters of the grinding product in a ball mill. MATEC Web Conf (251):03010 13. Sharapov RR (2020) The compaction zone parameters’ determination when grinding the cement clinker particles. IOP Conf Ser Mater Sci Eng (913):042057

Modeling of the Projection Control Roundness Raceway of the Inner Ring Race of a Ball Bearing Support B. S. Chetverikov , N. N. Slavkova , A. N. Unkovskiy , and M. S. Babkin

Abstract The article discusses issues related to the process of controlling the deviation of the shape of complex-profile surfaces of parts. The object of research is the inner ring of a ball bearing support, the subject of research is the possibility of determining the deviation of the raceway shape by a non-contact method. The analysis of the methods of machining the raceway showed the urgency of the problem of ensuring the accuracy of control operations and the need for the development of means and methods of control capable of ensuring sufficient measurement accuracy. The article researches the possibility of using projection control, sets the accuracy limits for determining the deviation from roundness. A mathematical model for the control of the raceway has been obtained, based on the geometric dependences of the individual elements of the inner ring of the support. The experiment made it possible to set the possible obtained control accuracy depending on the values of errors in the measurement process. Analyzing the obtained values, it can be concluded that the mathematical model makes it possible to apply the revealed dependencies to implement the method of projection control of the raceway shape. Keywords Contactless control · Model · Function · Roundness · Raceway

1 Introduction Bearing supports are one of the most critical units of assembly units for road-building, lifting and earth-moving machines [1, 2]. The reliability and durability of both the entire machine and its individual units will depend on the quality of the working surfaces of the bearing parts, which include the raceways or sliding of the bearing rings, as well as the surfaces of the bodies of revolution. B. S. Chetverikov (B) · A. N. Unkovskiy · M. S. Babkin Department of Hoist Transport and Road Machines, Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia N. N. Slavkova Department of Electric-Power and Electromechanical Engineering, Saint-Petersburg Mining University, St Petersburg, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_18

131

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Fig. 1 Surface of the raceway of the bearing inner ring

The accuracy of machining raceways directly depends on a number of parameters, for example, such as the geometry and degree of wear of the cutting tool, the accuracy class of metal-cutting equipment, as well as the accuracy of the measuring instruments used in the process of control operations. It is the control operations that make up about 15–20% of the cost of the finished product, which indicates their special importance in the overall technological process. One of the main criteria for the quality of a bearing support [3] is the deviation from the roundness of the shape of its bearing trace, which is a raceway formed by the rotation of an arc of a certain radius along a closed path (circle). Geometrically, such a surface can be described as a torus (Fig. 1).

2 Materials and Methods According to ISO 230-4, “circular deviation” (G) is the minimum radial separation of two concentric circles enveloping the actual path (minimum zone circles) of a clockwise or anticlockwise (counter-clockwise) contoured path and which may be evaluated as the maximum radial range around the least squares circle (Fig. 2). In Fig. 2 Evaluation of circular deviation G

Modeling of the Projection Control Roundness Raceway …

133

Fig. 2: ± center of least squares circle of the two actual parts, 0 is a starting point, 1 is the minimum zone circles, 2 is an actual path. The final roundness of the raceway is usually formed at one of the final stages of the technological process: grinding with a workpiece clamping in a chuck, centerless grinding on rigid supports, or “hard” turning, which is often used in modern mechanical engineering production. The latter method of machining allows to obtain the same roughness as after fine grinding Ra = 0.2 μm with machining accuracy up to IT 4 … 5 quality. The roundness deviation (cir ) of the raceways depends on the bearing size and is within the tolerance on the radius of the generating circle, for example, for bearing 307A: cir = 0.08 mm. With the analysis of the methods [4] of the final machining of the raceway (Fig. 3), it can be concluded that since the accuracy of the obtained surface is high enough, and the roughness is small, it becomes necessary to develop new means of control that would provide the necessary accuracy of measurements. As a method of roundness control, it is proposed to use non-contact projection control [5, 6], which makes it possible to determine the deviation of the dimensions and shape of surfaces with an accuracy that depends on the CCD matrix used in this case [7, 8]. The size of one pixel of the CCD matrix should not exceed the value of the accuracy of the determined geometric parameter: cir ≥ h px

(1)

There is a known method of projection control of the raceway of the drilling bit leg [9], which is based on the analysis of a monochrome image of a cross-section of a

Fig. 3 Deviation from the roundness of the cross-sectional shape of the raceway of the inner ring of the bearing, depending on the type of machining: 1 is grinding with the workpiece clamping in the chuck, 2 is centerless grinding on rigid supports, 3 is “hard” turning

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geometric object captured by a CCD-matrix. By identifying the cross-sectional shape, the amount of deviation from roundness and a correctable or irreparable product defect are set.

3 Results and Discussion While determining the parameters of toroidal surfaces of parts (for instance, such as the groove of the raceway of ball bearing rings), it was used the method of measuring the torus in 4 sections, each of which is measured in 4 sections. Algebraically, the torus surface can be described as (2): (x 2 + y 2 + z 2 + (D/2)2 − R 2 )2 − 4(D/2)2 (x 2 + y 2 ) = 0

(2)

To determine the geometric parameters of the torus (central point, axis vector, diameter and radius of the generating circle) from the coordinates of the measured points, we use the method of least squares and, based on this, compose function (3): F(D, R, O0 , v) =

n 

δi2

(3)

i=1

Where D, R, O0 , v are the required parameters of the torus: diameter, radius of the generating circle, coordinates of the center point and vector of the torus axis; δ is the deviation from the constructed surface of the i-th measured point; n is the total number of measured points. Since the parameters of the generated surface (Dnom, Rnom) are known, it is possible to estimate the errors that arise in determining the parameters of the measured torus (Dmeas, Rmeas), as well as when determining its position and orientation in space. Schemes for determining deviations and basic geometric parameters of the toroidal raceway surface are shown in Fig. 4. The obtained values of the deviations of the torus parameters (4, 5) are summarized in Table 1. D = |Dmeas − Dnom |

(4)

R = |Rmeas − Rnom |

(5)

In order to estimate the error in determining the position of the torus in space, the deviation of the position of its central point should be estimated. Values of deviations of the position of the central point O (Xo, Yo, Zo) (6):

Modeling of the Projection Control Roundness Raceway …

135

Fig. 4 Geometrical parameters of the toroidal surface of the raceway and their deviations during measurements: a in the XY plane, b in the YZ plane Table 1 Deviations of the values of the main parameters of the toroidal surface of the raceway №

D, mm

R, mm

OL, mm

Ox, mm

Oy, mm

Oz, mm

δ, mm

1

0.03

0.009

0.002

0.001

0.004

0.003

0.054

2

0.03

0.004

0.002

0.003

0.003

0.001

0.048

3

0.02

0.003

0.001

0.002

0

0.001

0.027

4

0.005

0.004

0.001

0.002

0.001

0.002

0.045

5

0.06

0.004

0.001

0.002

0.001

0.005

0.073

6

0.008

0.008

0.001

0.004

0.001

0.004

0.025

7

0.008

0.006

0

0.003

0.001

0.001

0.066

8

0.002

0.006

0

0.003

0.001

0.005

0.037

9

0.012

0.005

0.001

0.001

0.002

0.005

0.026

10

0.006

0.003

0.002

0.002

0.002

0.006

0.021

136

B. S. Chetverikov et al.

⎧ ⎪ ⎨ O x = |O xmeas − O xnom | O y = |O ymeas − O ynom | ⎪ ⎩ Oz = |Oz meas − Oz nom |

(6)

The ability to estimate the orientation of the raceway in space is represented by the normal vector of the toroidal surface. The same vector defines one of the bases of the measuring device. The angle α between two vectors (7) V meas (Vx meas , Vymeas , Vzmeas ) i V nom (Vx nom , Vynom , Vznom ) is determined by the formula: V xmeas · V xnom + V ymeas · V ynom + V z meas · V z nom cosα =   2 + V y2 + V z2 2 + V y2 + V z2 V xmeas · V xnom meas meas nom nom

(7)

Deviation arising when determining the position of the axis of rotation of the raceway OL:  O L = h 2(1 − cosα)

(8)

The values of the non-parallelism of the axis of rotation of the raceway OL from the axis of measurements [11], arising from errors in determining the orientation of the object in space, are given in Table 1. To determine the deviations of each parameters from their nominal values, 10 measurements were carried out according to the control model described by expressions (3–7). The total deviations in each of the ten measurements are between 0.021 mm and 0.073 mm, which satisfies a roundness tolerance of 0.08 mm.

4 Conclusion The analysis of Table 1 (Fig. 4) shows that the values of the deviations ΔD and ΔR are within the tolerance for the deviation of the raceway roundness equal to Δcir = 0.08 mm, and the values of the remaining deviations are much less than this tolerance. Based on this, it can be concluded that the model is adequate and can be used for projection control of the raceway. The obtained mathematical model allows using of the revealed dependencies for the implementation of the method of projection control of the raceway shape. Acknowledgements This work was supported by the grant of the President of the Russian Federation No. MK-4006.2021.4, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

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References 1. Romanovich AA, Romanovich MA, Belov AI, Chekhovskoy EI (2018) Energy-saving technology of obtaining composite binders using technogenic wastes. J. Phys Conf. Ser. 1118:012035 2. Romanovich AA, Ebrahim A, Romanovich MA (2020) Improving the efficiency of the material grinding process. IOP Conf. Ser Mater Sci Eng 945:012060 3. Randall RB, Antoni J (2011) Rolling element bearing diagnostics-a tutorial. Mech Syst Signal Process 25:485–520 4. Kiyak M, Cakir O, Altan E (2003) A study on surface roughness in external cylindrical grinding. In: Achievements in mechanical & material engineering AMME, pp 459–462 5. Kurc K, Burghardt A, Gierlak P, Szybicki D (2019) Non-contact robotic measurement of jet engine components with 3D optical scanner and UTT method. In: Lecture Notes in Electrical Engineering, vol 548, pp 151–164 6. Cai J, Zhao Y, Li Y, Xie YA (2018) 3D laser scanning system design and parameter calibration. J Beijing Univ. Aeronaut. Astronaut 44:2208–2216 7. Chetverikov BS, Chepchurov MS, Teterina IA (2017) Automation of component selection of ball-bearing support of drilling bit. Int J Adv Manuf Technol 90:1059–1065 8. Zhang S (2016) High-speed 3D imaging with digital fringe projection techniques. Publisher CRC Press, New York 9. Tabekina NA, Chetverikov BS, Chepchurov MS (2016) Influence of the phenomenon of diffraction of light on accuracy of the automated process of the definition of geometric parameters of profile of objects. Bull BSTU Named V.G. Shukhov 1:90–93 10. Sheng J, Zhang J, Mi H, Ye M (2020) Research on point-cloud collection and 3D model reconstruction. In: IECON proceedings (Industrial electronics conference), vol 5336, p 9255086 11. Chepchurov MS, Chetverikov BS (2016) Positioning of parts in automated contactless control of the form of its rolling surface. Bull BSTU Named V.G. Shukhov 2:99–103

The Research of the Regularities of the Influence of the Parameters of Grinding a Flat Surface on Its Roughness during Machining a Metal Polymer N. S. Lubimyi , S. A. Duhanin , I. A. Lymar , and A. A. Tikhonov Abstract The article deals with issues related to the mechanical machining of a flat surface of a metal-polymer workpiece by flat grinding. The article describes an experiment on flat grinding of a workpiece and determines the dependence of surface roughness as the main parameter on the modes of machining, namely, feed and depth of cut. The data collected in the course of the experiment were analyzed and, according to the results of statistical processing of the experimental results, a model of the roughness of a flat metal-polymer surface was developed depending on the modes of abrasive machining. The article presents both a functional model, presented as a function of roughness from the parameters of the depth of cut and feed, and a graphical representation in the form of a surface graph. The graphical roughness model is a great interest for engineers during setting cutting conditions, as it is more visual and simple. Scientists, who research ways to improve the efficiency of the machining process of parts in the design of which a metal-polymer material is used, can use the functional relationship of roughness, this will optimize the technological parameters according to the required optimization criterion. Keywords Grinding · Model · Function · Metal polymer · Optimization · Roughness · Experiment

1 Introduction Metal-polymer materials, originally used as a repair composition, the field of application of which is described in [1, 2], have become more often used as structural materials, both independently and as part of one-piece assembly units [3]. Using a metal polymer as a filler for building up the body of a part to be repaired, as a sealing compound or as a part that receives workloads, it is necessary to machine the metal N. S. Lubimyi (B) · S. A. Duhanin · I. A. Lymar · A. A. Tikhonov Department of Hoist Transport and Road Machines, Belgorod State Technological University named after V G Shukhov, Kostyukov St., 46, Belgorod 308012, Russia e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_19

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polymer in order to give the workpiece the required shape, dimensional accuracy and surface quality. Recommendations for technological modes in the machining of metal-polymer compositions by turning are given by the manufacturers of metal-polymer compounds in the technical data sheet [4, 5]. However, the metal polymer is used in the design of parts for which requirements are imposed not only on dimensional accuracy, but also requirements for surface roughness, flatness, etc. Therefore, it is necessary to have the tools for setting technological modes for abrasive machining of metal polymer.

2 Materials and Methods As a research method, an experimental-analytical research method was used [6], which consists in putting forward a hypothesis for representing a functional model of roughness, representing this model in the form of a regression equation, planning an experiment and conducting an experiment. Based on the obtained experimental data, significant coefficients of the regression equation are established and reverse decoding into the form of a functional relationship is carried out. Metal-polymer samples were prepared taking into account previous studies and recommendations [7, 8], as the curing modes of the metal-polymer composition significantly affect the physical and mechanical properties of the cured metalpolymer material and, as a result, on the experimental results. The samples were ground on a 3B722 surface grinder. As the machine has a stepless adjustment of the longitudinal feed of the table, to obtain the upper, lower and main numerical values of the factor of the longitudinal feed of the table, its movement speed was measured. Control risks were drawn on the handle of the throttle control of the longitudinal feed of the table for three speeds, a control risk was marked on the casing and the table was marked with a division value of 0.1 m. Then, using a digital camera, the movement of the table was recorded at three speeds and the numerical value was recalculated longitudinal table feed in m/min. Table 1 shows the numerical values of the time for passing the distance of 0.5 m by the table at three levels for calculating the longitudinal feed of the table and the calculated value of the longitudinal feed of the table at three speeds, at the upper, lower levels and in the center of the experiment plan. Table 1 Factors and intervals of experiment variation Lower level (−1) Base level (0) Upper level (+1) Variation interval Factor name x1 9

18.4

27.8

9.4

Longitudinal table feed, m/min

x2 0.00001

0.00005

0.00009

0.00004

Cutting depth, m

x3 0.030

0.040

0.050

0.010

Circle height, m

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The measurement of the surface roughness of the metal-polymer sample after grinding was carried out with a certified TIME TR110 profilometer. During grinding, 3 wheels with a diameter of 450 mm and a width of 32, 40 and 50 mm were used, made of white electrocorundum grade 25A, medium grain size (F90), medium hardness (L), medium structure (6), ceramic bond (V), with a working speed of 50 m/s, second class of accuracy. According to the experimental conditions, the surface roughness of the metalpolymer sample is influenced by the longitudinal feed of the table Slong , m/min, the height of the circle B, mm and the depth of cut t, mm. To solve the problem, it was assumed that the dependence of the surface roughness Ra on the factors under study can be represented by a power regression Eq. (1). Ra = c · S αpr · t β · B γ

(1)

After taking the logarithm, the equation looks like (2). lnRa = lnc + α · lnS pr + β · lnt + γ · lnB

(2)

If the results of the experiment are expressed by a polynomial of the form (3), y = b0 + b1 x1 + b2 x2 + b3 x3 + b12 x1 x2 + b13 x1 x3 + b23 x2 x3 + b11 x12 + b22 x22 + b33 x32

(3)

where y = lnRa, a x1 , x2 , x3 is factor coded values Slong , t, B. The independent variables were encoded using the relation (4) xi =

ln X i − x0i , X i

(4)

where xi is the value of the i-th factor in coded form; X i is the value of the i-th factor in natural form; X i is variation interval of the i-th factor; x0i is the natural value of the main level of the i-th factor. The coded values of the factors x1 , x2 , x3 and the output parameters of the experiments for the experiment design type B-D13 are shown in Table 2. We find the regression coefficients by formulas (5), (6) and (7) [6]. ⎤ ⎡ N κ  N   A⎣ 2 2 b0 = y j − 2λc xi j y j ⎦ 2λ (κ + 2) N j=1 i=1 j=1

(5)

N c  xi j y j N j=1

(6)

c2  x i j xl j y j N λ j=1

(7)

bi =

N

bil =

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c +n 0 ) where N is the total number of experiments; λ is some constant, λ = κ(n ; n 0 is (κ+2)n c the number of experiments in the center of the plan; n c = N − n 0 ; κ is the number of factors; j is the experiment number; y j is the value of the optimization parameter 1 in the j-th experiment; i, l are factor numbers; A = 2λ[(κ+2)λ−κ] ; c =  NN x 2 . j=1

ij

3 Results and Discussion The amount of computing work in determining the regression coefficients is quite large, therefore, we will calculate the regression coefficients using a computer and the commercial licensed program PlanExp B-D13 v.1.0. The program architecture is described in [9, 10]. The calculations in the PlanExp B-D13 v.1.0 program are shown in Table 3. After substitution of the values of the coefficients in Eq. (3), it takes the form: y = 2.208 + 1.246 · x1 + 0.407 · x2 − 0.0249 · x3 + 0.326 · x1 x2 + 0.1052 · x1 x3 − 0.0454 · x2 x3 + 0.106 · x12 − 0.085 · x22 + 0.011 · x32 (8) After obtaining the model in regressive form, we need to check the significance of its coefficients and its adequacy. For this, it is necessary to find the variance of the reproducibility of the coefficients of the regression equation [6] using the following Table 2 Experiment plan and output parameters of experiments Experience number (u)

Planning matrix

Output parameter (Ra μm)

Natural values of variables

x1

x2

x3

Longitudinal table feed m/min

Depth of cut mm

Height of circle, mm

y(u, 1)

y(u, 2)

1

−1

−1

−1

9

0.01

30

0.12

0.1

2

+1

−1

−1

27.8

0.01

30

0.12

0.11

3

−1

+1

−1

9

0.09

30

0.68

0.7

4

−1

−1

+1

9

0.01

50

0.09

0.11

5

−1

0

0

9

0.05

40

0.36

0.35

6

0

−1

0

18.4

0.01

40

0.11

0.12

7

0

0

−1

18.4

0.05

30

0.24

0.26

8

0

0

0

18.4

0.05

40

0.25

0.24

9

0

0

0

18.4

0.05

40

0.23

0.25

10

0

0

0

18.4

0.05

40

0.26

0.24

Table 3 Regression coefficients of the polynomial (3) b0

b1

b2

b3

b11

b12

b13

b22

b23

b33

2.208

1.246

0.407

−0.0249

0.106

0.326

0.1052

−0.085

−0.0454

0.011

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formulas (9), (10). 2 Aλ2 (κ + 2) 2 2 c c2 2 s y ; s {bi } = s y2 ; s 2 {bil } = s ; N N λN y n 0 (yu − y)2 Ac2 [(κ + 1)λ − (κ − 1)] 2 2 s 2 {bii } = s y s y = u=1 N n0 − 1 s 2 {b0 } =

(9)

(10)

where y is the average value of the optimization parameter in the center of the plan; yu is the value of the optimization parameter in the u − th experiment; n 0 is experiment number; n 0 is the number of experiments in the center of the plan. The error in determining the i-th regression coefficient is calculated by the formula (11).  s{bi } = + s 2 {bi }

(11)

Next, we find the confidence interval bi . bi = ±tT s{bi }

(12)

The tabular value of the Student’s test at a 5% significance level and the number of degrees of freedom f = 10 is selected from [6]. In this experiment, the variance of reproducibility in parallel experiments is 0.049, the number of degrees of freedom is 10, and the tabular value of the Student’s test is t tabl = 2.23. Comparing the absolute value of the coefficient with the value of the confidence interval, we determine its significance. Having performed calculations in the PlanExp B-D13 v.1.0 program, we obtain the values of the confidence intervals in Table 4 and draw conclusions about the significance of the coefficients. Coefficients b3 , b13 , b23 , b11, b22 b33 are less than the confidence interval in absolute value, so they can be considered statistically insignificant and excluded from the regression equation. After eliminating insignificant coefficients, the Eq. (8) takes the form: y = 2.208 + 1.246 · x1 + 0.407 · x2 + 0.326 · x1 x2

(13)

2 of adequacy [5]: To test the adequacy of Eq. (13), we calculate the variance Sad

Table 4 Confidence intervals for the coefficients of the regression equation and their significance Coefficient

b0

b1

b2

b3

b11

b12

b13

b22

b23

b33

Value

2.208

1.24

0.40

– 0.02

0.106

0.326

0.105

–

-0.04

0.011

0.08 Confidence interval

±0.13 ±0.08 ± 0.08 ± 0.08 ±0.13 ±0.11 ±0.11 ±0.13 ±0.11 ±0.13

Significance 1

1

1

0

0

1

0

0

0

0

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N 2 Sad

=

j=1

y 2j − N

κ i=1

bi2

N − (κ + 1)

= 0.163

(14)

The adequacy of Eq. (13) is tested by the F - criterion. We find the calculated value of FP - criterion [5]: FP =

2 Sad = 3.33 s y2

(15)

The tabular value of the Fisher criterion is Ftabl = 3.71 at a 5% significance level and the number of degrees of freedom f 1 = 3 and f 2 = 10 [6], which is more than the calculated = FP 3.33, which means that according to Fisher’s criterion the equation of the mathematical model is adequate. The model can be applied to solving problems. Replacing the coded values of the levels of the input factors with the values in accordance with the expression (4), we have the following equation:  lnSlong − 18.4 lnt − 0.00005 + 0.407 · 27.8 − 9 0.00009 − 0.00001   lnSlong − 18.4 lnt − 0.00005 · + 0.326 · 27.8 − 9 0.00009 − 0.00001



lnRa Slong , t = 2.208 + 1.246 ·



(16)

The resulting Eq. (16) needs to be simplified. We can use the application Mathcad 15.0 to simplify the expression arithmetic. After the exponentiation of a simplified mathematical model, we obtain the dependence (1717).

Ra Slong , t = 29.271 · S 0.2168·ln(t)+0.077 · t 1.099 , mcm

(17)

For the convenience of data analysis using the MSExcel [11, 12] software environment, we plot graphs (Fig. 1) of function (17) for three values of cutting depths 0.01 mm, 0.05 mm and 0.09 mm. We denote on the graphs the values of the natural values of the roughness of metal-polymer samples at different cutting conditions in accordance with the experimental data. On the functional graphs, we denote the error limits (5%), as well as the approximating graphs of the natural roughness values.

4 Conclusion Analysis of Fig. 1 shows that the approximating graphs of the natural values of the roughness of the metal polymer at various cutting conditions are in the region of 5% of the error of the mathematical dependence. Some outliers are explained by the presence of significant errors both during machining by grinding and during measuring roughness. In general, the analysis of nomograms in Fig. 1 allows us to conclude about the reliability of the mathematical model (17).

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Ra, mcm

r=0.84; rн=0.89

r=0.82; rн=0.88 r=0.77; rн=0.73

2

5

10

15

20

25

30

35

4

longitudinal feed Slong, m/min Ra(Slong;t=0.01) Ra(Slong;t=0.05) Ra(Slong;t=0.09)

Fig. 1 The graphs of the functional dependence of Ra(S long ;t) and natural values of the roughness of the metal polymer during surface grinding

Using the built-in correlation function in MSExcel, it is possible to calculate the correlation coefficient r for functional dependence and rH for the graph of natural values. The value of the correlation coefficient over 0.7 indicates a strong positive relationship between the variables, namely, the roughness of the metal-polymer surface and the longitudinal feed of the table. Acknowledgements This work was supported by the grant of the President of the Russian Federation No. MK-4006.2021.4, using equipment of High Technology Center at BSTU named after V.G. Shukhov.

References 1. Baurova NI, Zorin VA (2016) The use of polymeric materials in the manufacture and repair of machines. MARI, Moscow 2. Osvald TA, Tung LS, Gremann P (2006) Plastic injection molding. Profession, SPb 3. Pershin NS, Chepchurov MS (2015) Manufacturing of mold parts from composite materials. Bull Siberian State Autom High Acad 4:86–90 4. Metal polymers LEO. https://www.leopolimer.ru/index.htm. Accessed 17 Jan 2021

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5. Romanovich AA, Romanovich MA, Belov AI, Chekhovskoy EI (2018) Energy-saving technology of obtaining composite binders using technogenic wastes. J Phys Conf Ser 1118:012035 6. Spiridonov AA (1989) Planning an experiment in the study of technological processes. Mechanical engineering, Moscow 7. Lubimyi NS, Chepchurov MS (2015) Influence of the use of evacuation during curing of a metal polymer on its thermal conductivity. Interdisc Approach Mater Sci Technol Theory Pract 159–162 8. Pershin NS (2015) Air saturation of potting metal polymers. In: International Scientific and Technical Conference of Young Scientists BSTU named after V.G. Shukhov, pp 1456–1459 9. Belov VV, Obrazcov IV, Kuryatnikov UU (2014) Development of a software-algorithmic tool for data processing of a three-factor planned experiment for calculating a mathematical model of concrete strength. Softw Prod Syst 108:254–259 10. Belov VPh (2001) Math modeling. Publisher Mordovia University, Saransk 11. Vilenkin SYa (1979) Statistical processing of the results of the study of random functions. Publisher Energy, Moscow 12. Gerasimov MD (2016) Addition of vibrations in vibration absorbers. Bull BSTU Named After V.G. Shukhov 3:116–121

Purification of Model Waters from Zinc Ions by Heat-Treated Leaves of Apricot (Prunus Armeniaca L.) and Horse Chestnut (Aésculus Hippocastanum L.) Zh. A. Sapronova , A. V. Svyatchenko , and L. V. Denisova

Abstract Deciduous waste from agriculture and urban utilities is a widely available and virtually unclaimed material, especially in Eastern European countries. The objects of research were the leaves of apricot (Prunus armeniaca L.) and horse chestnut (Aésculus hippocastanum L.). It was found that in the range of roasting temperatures of 200–300 °C, the values of the efficiency of purification from zinc ions for modified apricot and chestnut leaves are the greatest. At 300 °C, they are 94% for chestnut leaves and 92% for apricot leaves. High cleaning efficiency is achieved already with the addition of 0.04 g/100 ml, and is 81–84%. When adding 0.08 g/100 ml of the material, the values are 95–96% and do not change with an increase in the amount of the sorbent. In general, 0.06 g/100 ml of the sorbent allows getting 93–95% efficiency, which is very close to the maximum, so under similar experimental conditions, this amount of sorption material can be considered the most rational. It was found that the specific surface area of the studied sorbents increases by 7 times with an increase in the roasting temperature. Microphotographs of the surface of the samples of the original deciduous materials are presented. Keywords Wastewater treatment · Waste disposal · Zinc ions · Chestnut leaves · Specific surface area

1 Introduction Human use of chemicals began to have a noticeable impact on the environment during the “industrial revolution”. Although some compounds naturally enter the environment as a result of both geological and biological activity, human activity today makes a greater contribution. A significant part of these pollutants is accounted for by industrial wastewater. The industrial sector consumes large volumes of water and, consequently, creates similar volumes of wastewater discharge containing both mineral and organic pollutants. Wastewater treatment is becoming increasingly important Zh. A. Sapronova · A. V. Svyatchenko (B) · L. V. Denisova Belgorod State Technological University named after V. G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_20

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due to the reduction of water resources, and the widespread deterioration of their quality [1]. Among the various methods of wastewater treatment, adsorption is considered one of the most effective and cost-effective because of the relatively low cost of treatment and the simple design of the devices [2]. We are constantly searching for inexpensive and widely used in nature sorbent materials that can serve as an actual alternative to activated carbon [3]. In this regard, the attention of scientists was drawn to the adsorption properties of other non-traditional solid materials offered as inexpensive, effective and environmentally friendly adsorbents for the removal of pollutants. The last three decades have shown a rapid growth in the development of new materials, including new coals produced from waste or natural by-products, natural or synthetic adsorbents, as well as biological materials or biosorbents [4, 5]. Special attention should be paid to natural fibers, straw, grain husks, flax processing waste, sawdust and peat, which were used as sorbents. Cellulose deserves close attention as one of the important structural components of plant raw materials. One of the most advanced natural sorbents is peat moss [5, 6]. The quality of adsorption in wastewater treatment is related to various physical and chemical factors, including pore volume, surface area, pore diameter, and pore size distribution. A slight change in these properties significantly increases the adsorption capacity of the material [7]. As a result of economic activity, a large amount of cellulose waste is formed—the leaves of fruit and ornamental trees and shrubs, spoiled fruits, unused peel, pulp or fibrous material, as well as inedible parts of fruits (bones, husks, kernels, seeds) [8]. There are publications on the production of activated carbons from the seeds of fruit trees, in particular, apricot [9, 10]. At the same time, deciduous waste from agriculture and the economic activities of urban utilities is widely available and practically unclaimed material, especially in Eastern European countries. Deciduous wood waste is very promising as a potential raw material for the production of effective sorbents. There are publications on the use of leaf litter of some tree species as sorption materials for the purification of model waters from petroleum products and heavy metals [11–15]. As at present the sustainable development of the human community requires a widespread and comprehensive reduction of the anthropogenic load on natural systems, the search for ways to use such a valuable material as leaf litter is an urgent task.

2 Methods and Materials The objects of research were the leaves of apricot (Prunus armeniaca L.) and horse chestnut (Aésculus hippocastanum L.). These types of trees are ubiquitous in the southern regions of the Russian Federation, Eastern Europe and the Caucasus.

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The initial and thermally modified deciduous material was examined under the electron microscope Tescan MIRA 3 LMU (Tescan, Czech Republic). To estimate the specific surface area by the method of low-temperature nitrogen adsorption, the Sorbi-MS device (Russia) was used. Heat treatment of the crushed deciduous material was carried out at temperatures in the range from 105 to 300 ° C in the Loip LF-7/13-G2 muffle furnace (RF) for 20 min. The purification of model solutions was carried out in a static manner by mixing the samples of the sorbent with an aqueous system followed by the filtration of the spent sorption material. The concentrations of chemical substances before (C1 ) and after (C2 ) of water purification were determined by photocolorimetric method. The purification efficiency (E) was calculated according to the formula (1): E=

C1 · C2 · 100% C1

(1)

3 Results and Discussion To evaluate the properties and quality of sorbents, an important parameter is the specific surface area. The most effective sorbents—active coals have the highest values, so, for example, for some samples of active coals, they are 1395 m2 /g and 2636 m2 /g [16, 17]. The experimentally determined values of this parameter for the initial and heattreated deciduous materials are presented in Table 1. The values obtained for apricot and chestnut leaves are similar. They are significantly lower than those of traditional active coals, but correspond to the level of values for non-traditional sorption materials [18, 19]. Table 1 Specific surface area of samples

Treatment temperature, t, °C

Sample weight, g

Moisture, %

Specific surface area Ssp , m2 /g

100

0.385

4.80

2.6

200

0.385

2.50

4.0

300

0.454

3.00

17.6

100

0.379

4.6

2.5

200

0.381

3.1

3.5

300

0.399

3.0

18.0

Chestnut leaves

Apricot leaves

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Zh. A. Sapronova et al.

a

b

Fig. 1 Microphotographs of deciduous material: a—apricot, b—chestnut

Fig. 2 Dependence of the cleaning efficiency of the model solution on the roasting temperature of the deciduous material

Microphotographs of the surface of the samples of the original deciduous materials are shown in Fig. 1. To test the sorption properties, studies were conducted on the purification of model waters from Zn2+ ions. The initial concentration of Zn2+ ions was 15 mg/dm3 . The model solutions were cleaned in a static single-stage mode. The duration of contact of the samples of the initial and thermally modified deciduous material with the model solutions was 25 min, the volume of the model solutions taken for cleaning was 100 ml, the temperature was 22 °C. The concentration of Zn2+ ions in the solutions before and after purification was determined by the photocolorimetric method. The dependence of the cleaning efficiency of the model solution on the roasting temperature of the deciduous material is shown in Fig. 2. It can be seen that in the temperature range of 200–300 °C, the efficiency of the values for modified apricot and chestnut leaves is the greatest. At 300 °C, it is 94% for chestnut leaves and 92% for apricot leaves. It was decided not to study the sorption properties of materials obtained at higher temperatures, as after 300 °C, almost complete burning of the leaf mass occurs.

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Fig. 3 Dependence of the cleaning efficiency of the model solution on the amount of the added sorbent (roasting temperature 300 °C)

Figure 3 shows the results of studies on the effect of the amount of added sorption material, burned at 300 °C, on the cleaning efficiency of the model solution. The experimental conditions were similar to those described above. Studies of the dependence of the cleaning efficiency on the weight of the added heat-treated deciduous material showed that a high cleaning efficiency is achieved already with the addition of 0.04 g/100 ml, and is 81–84%. When adding 0.08 g/100 ml of the material, the values are 95–96% and do not change with an increase in the amount of the sorbent. In general, 0.06 g/100 ml of the sorbent allows getting 93–95% efficiency, which is very close to the maximum, so under similar experimental conditions, this amount of sorption material can be considered the most rational.

4 Conclusion Studies were conducted to determine the specific surface area of the original and thermally modified deciduous materials of apricot and chestnut. At a roasting temperature of 300 °C, the Ssp is 17.6 m2 /g for chestnut leaves and 18.0 m2 /g for apricot leaves. These values correspond to the level of values for non-traditional sorption materials. Studies on the purification of model solutions from Zn2+ ions showed that the best cleaning effect is achieved when using leaves roasted at 300 °C in an amount of 0.06–0.08 g of sorbent per 100 ml of solution. Acknowledgements The work was carried out within the framework of the grant of the President of the Russian Federation for state support of young Russian scientists—candidates of sciences and doctors of sciences—and leading scientific schools of the Russian Federation, application number MD-1249.2020.5, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

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References 1. Shapkin NP, Zhamskaya NN, Skobun AS (2001) Adsorption of proteins and fats from waste water of food enterprises in natural sorbents. Food Technol 4:14–18 2. Ankyu E, Otsuka T, Noguchi R (2017) Economic evaluation of wastewater treatment system based on recovery characteristics of oil and suspended solids by filtration. J Jpn Inst Energy 4(96):102–111 3. Benaïssa H (2010) Influence of ionic strength on methylene blue removal by sorption from synthetic aqueous solution using almond peel as a sorbent material: experimental and modelling studies. JTUSCI 4:31–38 4. Crin G, Lichtfouse E, Wilson L, Morin-Crini N (2019) Conventional and non-conventional adsorbents for wastewater treatment. Environ Chem Lett 17(10):195–213 5. Sapronova Zh, Sverguzova S, Svyatchenko A (2019) Use of municipal vegetative waste as raw material for sorbent production. IOP Conf. Series Mater Sci Eng 687:066061 6. Rotar OV, Iskrizhitskaya DV, Iskrizhitsky AA, Oreshina AA (2014) Cleanup of water surface from oil spills using natural sorbent materials. Procedia Chem 10:145–150 7. Awais A, Jini D, Aravind M, Parvathiraja C, Rabia A, Zaheer KM, Asma A (2020) A novel study on synthesis of egg shell based activated carbon for degradation of methylene blue via photocatalysis. Arab J Chem 13:8717–8722 8. Ordoudi SA, Bakirtzi C, Tsimidou MZ (2018) The potential of tree fruit stone and seed wastes in Greece as sources of bioactive ingredients. Recycling 3(9):19 9. Corbett DB, Kohan N, Machado G, Jing C, Nagardeolekar A, Bujanovic BM (2015) chemical composition of apricot pit shells and effect of hot-water extraction. Energies 8:9640–9654 10. Tekueva KM, Klushin VN, Antipova OV (2013) Experimental assessment of rational conditions for obtaining active coals from fragments of apricot and peach seeds-waste from food enterprises of the Republic of Kabardino-Balkaria. Adv Chem Chem Technol 9(149):31–34 11. Shaykhiev IG (2017) The use of components of trees of the genus Quercus as sorption materials for the removal of pollutants from water. Literature review. Bull Kazan Technol Univ 5(20):151– 160 12. Stepanova SV, Shaymardanova ASh, Shaykhiev IG (2013) Birch litter and its chemical modifications for oil removal. Bull Kazan Technol Univ 14(16):215–217 13. Shaymardanova ASh, Stepanova SV, Shaykhiev IG, Abdullin ISh (2015) Influence of plasma treatment parameters on sorption properties of birch litter in relation to iron ions. Bull Kazan Technol Univ 15(18):253–256 14. Shaymardanova ASh, Stepanova SV (2013) The effect of plasma treatment on the oil capacity of birch litter. J Ecol Ind Safety 3(59):47–49 15. Stepanova SV, Shaykhiev IG, Sverguzova SV (2014) Purification of model wastewater containing heavy metal ions by wheat husk. Bull BSTU Named V.G. Shukhov 6:183–186 16. Arvind K, Hara MJ (2016) Preparation and characterization of high surface area activated carbon from Fox nut (Euryale ferox) shell by chemical activation with H3PO4. Results Phys 6:651–658 17. Sun Y, Zhang JP, Yang G, Li ZH (2007) Preparation of activated carbon with large specific surface area from reed black liquor. Environ Technol 28(5):491–497 18. Galimova RZ (2017) Purification of phenol-containing wastewater with native and modified adsorption materials based on agricultural and industrial waste. Diss ... Candidate of Engineering Sciences: 03.02.08. Kazan Federal University, Kazan 19. Vurasko AV, Simonova EI, Minakova AR (2019) Sorption materials based on technical cellulose from straw and rice husk. Proc St. Petersburg Forestry Acad 226:139–154

Calculation of Continuous Flanged Beams for Overall Stability E. Yu. Voronova , V. A. Evstratov , V. Yu. Linnik , and I. V. Breslavceva

Abstract In the regulatory documents regulating the design of beam structures, insufficient attention is paid to checking the overall stability of thin-walled beams. Recommendations for testing the stability of single pin-ended beams and rigidly sealed cantilevers are given. There are no recommendations for calculating the stability of continuous multi-span beams. Insufficient attention to the general stability of thin-walled beams can be explained by the fact that the load on the beam structures is transmitted, as a rule, through other beams, decking, etc., that is, additional connections are imposed on the beam, preventing the rotation and lateral displacement of the loaded sections, which positively affects its stability. The specifics of the working conditions of crane beams, namely, the lack of additional connections and the level of load application, negatively affect their stability. The lack of recommendations for checking the overall stability of continuous crane beams leads to an unjustified assignment of geometric cross-section parameters during design, and, as a result, to serious accidents. In this paper, the solution of the equations of stability of a flat bending shape is given by the finite difference method. The derivatives of the deflection and the angle of torsion of the beam are replaced by the central finite differences of the second order. The boundary conditions are written for the extreme and intermediate supports. The use of the finite difference method in solving the stability equations allows obtaining a result for continuous multi-span crane beams, taking into account the level of load application and the influence of neighboring spans on the stability of the most loaded span. Keywords Continuous multi-span beam · Flat bending stability · Bending moment · Bimoment · Critical load

E. Yu. Voronova · V. A. Evstratov (B) · I. V. Breslavceva Shakhty Automobile and Road Construction Institute (Branch) of Platov SRSPU(NPI), 1, Lenin Square, Shakhty, Rostov Region 346500, Russia V. Yu. Linnik Federal State Educational Institution of Higher Education, State University of Management, Moscow 109542, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_21

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1 Introduction One of the types of loss of load-bearing capacity of beam structures is the loss of overall stability (the exit of the beam axis from the plane of action of the bending moment) [1, 2]. The regulatory documents for the design of steel structures [3–5] provide recommendations for calculating the strength and rigidity of a wide class of beams made of various thin-walled profiles, with different conditions of support and loading. Recommendations for checking the stability of the flat bending shape are only available for single pin-ended beams and rigidly sealed cantilevers, provided that the load acts in the plane of greatest rigidity and passes through the axis of symmetry of the beam. There are no recommendations for calculating the stability of continuous multi-span beams. Insufficient attention to the general stability of thin-walled beams can be explained by the fact that the load on the beam structures is transmitted, as a rule, through other beams, decking, etc., that is, additional connections are imposed on the beam, preventing rotation and lateral displacement of the loaded sections, which affects its stability positively. The specifics of the operating conditions of crane beams, namely, the lack of additional connections and the level of load application, affect their stability negatively [6, 7].

2 Methods and Materials Let us consider a beam with a rectilinear axis, loaded with forces normal to the beam axis, intersecting the axis of the bending centers, and lying in a plane parallel to the plane of greatest rigidity. Let the Z axis coincide with the longitudinal axis of the beam, and the X and Y axes are directed along the main axes of the section (Fig. 1). We assume that Jx > Jy , therefore, the YZ plane is the plane of greatest rigidity. The nature of the anchorages will be established when considering individual special cases. So far, it is only suggested that the anchors in the main planes ensure the immutability of the system, and at least one section is anchored from rotation relative to the Z axis. For this case, under the above hypotheses and assumptions, for a beam with a constant rigidity along its entire length, V.Z. Vlasov [8] obtained the following equations, valid within the limits of elasticity 

E JY U I V + (M X θ ) I I = 0; E Jω θ I V − G JT or θ I I − (2βY M X θ I ) I + qY (eY − aY )θ + M X U I I = 0.

where E JY —the minimum rigidity of the beam; E Jω —sectorial rigidity; G JT or —torsional rigidity;

(1)

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Fig. 1 H-beam profile with one axis of symmetry



(X 2 +Y 2 )Y d A

βY = A 2JX − aY —beam cross-section parameter (integration extends to the entire cross-section area); aY —the coordinate of the bending center (on the Y-axis); qY —the intensity of the load parallel to the Y-axis; eY —coordinate of the load application point (on the Y-axis); M X —bending moment relative to the X-axis. The solution of system (1) is carried out by the finite difference method. We write the system of Eqs. (1) in the following form ⎧ M X θ I +2M XI θ+M XI I θ IV ⎪ ; ⎨U = − E JY G JT or I I MX IV θ − EJ θ = −EJ UII ⎪ ⎩ 2βY (M X θ I ω) I −qY (eY −aY )θ ω + . E Jω We divide the beam into N equal sections and at the interface points of these sections we replace the derivatives U and θ by Z the central finite differences of the second order according to one of the following formulas U K +1 − U K −1 ; 2Z i U K −1 − 2U K + U K +1 ; U KI I = Z i2 U K −2 − 4U K −1 + 6U K − 4U K +1 + U K +2 U KI V = , Z i4

U KI =

where U K −2 , U K −1 , U K , U K +1 , U K +2 —the value of the function at the split points.

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Substituting in Eq. (2) the values of the derivatives U and θ and the specific boundary conditions, we obtain a system of homogeneous equations, which can be written in matrix form as follows  A1 U = d1 A2 θ; (2) A3 θ = d2 A4 U + d3 A5 θ , where A1 , A2 , A3 , A4 , A5 —coefficient matrices; d1 , d2 , d3 —coefficients depending on the geometric parameters of the beam: d1 =

ql 4 ql 4 ql 4 h ; d2 = ; d3 = . E JY E Jω E Jω

The coefficients of the matrices A1 , A4 , A5 depend on the values of the multipliers at θ , θ I , θ I I and U I I in the right-hand sides of the equations of system (2) at different values Z . The coefficients of the matrices A1 and A3 are from the multipliers in the left parts of the equations of the system (2). From the first equation of the system (2), we define U = A−1 1 A2 d1 θ. Substituting in the second equation of the system (3), we get −1 −1 θ = (d1 d2 A−1 3 A4 A1 A2 + d3 A3 A5 )θ .

Denoting −1 −1 R1 = A−1 3 A 4 A 1 A 2 ; R2 = A 3 A 5 ,

we get θ = (d1 d2 R1 + d3 R2 )θ, or θ = d1 d2 Lθ , where L = R1 + R2 d3 /d1 d2 . Denoting λ = 1/d1 d2 , we have (L − λE)θ = 0, where E—unit matrix.

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3 Results and Discussion In regulatory documents, the critical load parameter is expressed by the coefficient ψ = Mcr l 2 /(2E JY h), where Mcr —the critical value of the bending moment M x for a given type of load. We express the value of the coefficient ψ in terms of λ—the eigenvalue of matrices L. Taking into account that for an flanged beam profile with one axis of symmetry Jω = JY 1 JY 2 h 2 /JY , the value can be represented as λ=

E 2 JY 1 JY 2 h 2 1 = . d1 d2 q 2l 8

Let us write the critical moment Mcr as Mcr = cqcr l 2 , where qcr —value of the critical load. Then λ=

c2 JY 1 JY 2 E 2 JY 1 JY 2 h 2 c2 = . Mcr l 4 4JY2 ψ 2

As there is an inverse relationship between the parameters ψ and λ, the minimum value of the coefficient ψ is expressed in terms of λmax —the maximum eigenvalue of matrices L. Denoting j=√

JY , JY 1 JY 2

we have ψ=

c . √ 2 j λmax

The value of the ratio of coefficients before the matrix R2 √ d3 E JY h = 2 4 = j λ. d1 d2 qκ p l √ Thus, in the general case, the matrix L = R1 + j λR2 i.e., belongs to the class of λ-matrices. To determine the largest eigenvalue of the matrix L, the method of successive approximations was used – the number obtained in the first approximation λmax was substituted into the matrix L. Then a new value λmax was found, and

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so on, until the values λmax of two consecutive approximations coincided with the specified accuracy. For a single pin-ended beam, when the load is located at the level of the bending centers of the beam profile, a matrix R2 = 0 is used. At the same time, the process of determining λmax of the matrix L = R1 is significantly simplified. For flanged beam with two axes of symmetry β = 0 and a y = 0. Sectorial moment of inertia Jω = JY h 2 /4. Accordingly d1 = λ=

ql 4 4ql 4 4ql 4 ; ; d2 = ; d = 3 E JY E JY h 2 E JY h

E 2 JY2 h 2 c ; ψ = Mcr l 2 /(2E JY h); ψ = √ 2 8 4q l 4 λmax

The coefficient in front of the matrix R2 √ d3 E JY h = = 2 λ. d1 d2 ql 4 The coefficient Ψ for flanged beams with two axes of symmetry depends on the boundary conditions, the shape of the bending moment plot, and the parameter α = G JT or 4l 2 /(E JY h 2 ). We consider a thin-walled continuous multi-span beam with a constant crosssection along its entire length, with a rectilinear axis, loaded with transverse forces and bending moments in the plane of greatest rigidity. We write down the boundary conditions for the extreme and intermediate supports, assuming that all the supports are supported in the form of a “fork”. To the extreme beam supports (Z = 0 iand Z = 1) we have U0 = U0I I = θ0 = θ0I I = 0; Ul = UlI I = θl = θlI I = 0.

(3)

In sections over the intermediate supports (Z = l1 , Z = l1 + l2 , Z = l1 + l2 + l3 , …, Z = l1 + l2 + l3 . . . ln−1 ) there are the bending moments M X and MY , the torque MT or and the bimoment B. The torque is perceived by the support. The remaining moments (M X , MY , B) in the sections of the left and right spans of the beam above the support are equal. For the cross section Z = l1 , we can write U1I I = −

MY B ;θII = − , (E JY )1 1 (E Jω )1

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where U1I I and θ1I I —values of the second derivatives of the deflection and the torsion angle of the reference section Z = l1 , belonging to the first span of the beam. As this section also belongs to the second span of the beam, we have MY B ; ;θII = − (E JY )2 2 (E Jω ) U1I I (E JY )1 = U2I I (E JY )2 ; θ1I I = θ2I I (E Jω )2 . U2I I = −

For a beam with constant rigidity along its entire length U1I I = U2I I ; θ1I I = θ2I I .

(4)

From the condition of continuity of the deformation we have U1I = U2I ; θ1I = θ2I .

(5)

U = 0; θ = 0.

(6)

In addition, at Z = l1

The boundary conditions for deflections and torsion angles on the other intermediate supports are written in the same way. We consider the replacement of the boundary conditions (4–6) with the Z = l1 difference analogs for the first and second spans of the beam (Fig. 4). When writing the basic differential equations in finite differences for functions U and θ at the points closest to the supports (N 1 − 1, N 2 + 1) for the fourth derivatives, the values of the functions at the law points N 1+1, N 2−1 are included. To determine them, we use the conditions U1I I = U2I I and U1I = U2I at the point N . Having written the difference analogs for U I I and U I , we have two equations with unknown U N 1+1 and U N 2−1 . Taking into account that U N 1 = U N 2 = 0, for beams with constant rigidity over the entire length, we have U N 2−1 + U N 2+1 U N 1−1 + U N 1+1 = ; 2 Z 1 Z 22 U N 1+1 − U N 1−1 U N 2+1 − U N 2−1 = . 2Z 1 2Z 2

(7)

Whence Z 2 − Z 1 Z 22 )U N 1−1 ; )U N 2+1 + 2( Z 1 + Z 2 Z 1 (Z 1 + Z 2 ) Z 1 − Z 2 Z 12 )U N 2+1 . =( )U N 1+1 + 2( Z 1 + Z 2 Z 2 (Z 1 + Z 2 )

U N 2−1 = ( U N 1+1

(8)

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The twisting angles θ at the contour points N 2 − 1 and N 1 + 1 are expressed at the same way.

4 Conclusion Writing the basic Eqs. (1) in terms of the second—order central finite differences according to one of the formulas (3–6), we obtain a system of homogeneous algebraic equations, the order of solution of which is described above. The use of the finite difference method in solving Eqs. (1) allows obtaining a result for continuous multi-span beams, taking into account the level of load application and the influence of neighboring spans on the stability of the most loaded span.

References 1. Tsavdaridis KD, D’Mello C (2012) Vierendeel bending study of perforated steel beams with various novel web opening shapes through nonlinear finite-element analyses. J Struc Eng 138(10):1214–1230 2. Pritykin AI, Lavrova AS (2017) Prediction of the stress level and stress concentration in cellular beams with circular openings. Mechanika 23(4):488–494 3. AISC 360-10 (2010) Specification for structural steel building. American institute of steel construction Chicago, Illinois 552 4. BS 5950-1:2000 (2010) British Standard. Structural use of steelwork in building. Code of practice for design. Rolled and welded sections. The Institute of Civil Engineers. Berkshire 136 5. EN 1993-1-5:2006 (2006) Eurocode 3. Design of steel structures. Part 1-5: Plated structural elements. European Committee for Standardization. Brussels 53 6. Pritykin A (2011) Calculation of deformations of perforated I-form Beams with Hexagonal Holes. In: Proceedings of the 16th international conference «Mechanika-2011». «Technologija» Lithuania, Kaunas, pp 266–269 7. Tsavdaridis KD, D’Mello C, Huo BY (2013) Experimental and computational study of the vertical shear behaviour of partially encased perforated steel beams. Eng Struct 56:805–822 8. Vlasov VZ (1959) Thin-walled elastic rods M. 568

Theoretical Study of the Kinetics of Material Destruction in a Disintegrator with a Preliminary Grinding Unit I. A. Semikopenko

and D. A. Belyaev

Abstract In recent decades, disintegrator mills have become widespread for grinding, activating and mixing building materials. The efficiency of these mills is largely influenced by the design parameters of the working chamber, loading and unloading units, as well as some technological parameters, such as the rotational speed of the rotors. This article discusses a new design of a disintegrator with a unit for preliminary grinding of the material, designed to obtain finer particles of the finished product and increase the uniformity of its granulometric composition. The process of preliminary destruction of material particles is considered within the framework of the inhomogeneous Markov process based on the time variation of the statistical quantity M(t) (mathematical expectation). The result of this work is an analytical dependence that determines the regularity of the change in the size of material particles as a result of the action of the cam mechanism in the central part of the disintegrator grinding chamber. The graphical dependence of the particle size of the material leaving the pre-grinding unit on the particle size supplied to the loading unit is presented. The results of this article can be used in the design of a disintegrator with a preliminary grinding unit, presented in the form of a cam mechanism, as well as in the educational process of bachelors and masters students. Keywords Disintegrator · Grinding chamber · Grinding · Cam mechanism · Initial particle size · Final particle size

1 Introduction The effectiveness of disintegrators in grinding, mixing and activating various building materials is due to their following main advantages: compactness; flexibility of changeover; the ability to automate the process; the ability to vary the parameters of the environment; the introduction of functional additives at the time of grinding;

I. A. Semikopenko · D. A. Belyaev (B) Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_22

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Fig. 1 Scheme of a disintegrator with a preliminary crushing unit: 1—case; 2—boot device; 3— unloading device; 4—upper disc; 5—lower disc; 6, 7—percussion elements; 8—vertical cylinder; 9—vertical blades; 10—distribution cone; 11—cam flywheel; 12, 13—armor plates; 14—blade spreader

using the ventilation flow created by the rotors; regulation of the granulometric composition of the finished product; relatively low installed capacity [1, 2]. However, disintegrators also have drawbacks, which determine the need for leading manufacturers of machines of this type to continue searching for new design and technical solutions aimed at increasing their efficiency and expanding the scope. This, in turn, requires additions to the existing theory of calculating the design and technological parameters of disintegrators. In Fig. 1 shows a diagram of a disintegrator with a unit for preliminary grinding of material. This design is protected by a patent of the Russian Federation for an invention [3]. The grinding chamber of this disintegrator is limited by a housing 1 having an axial loading 2 and a tangential unloading 3 device. Discs 4, 5 and striking elements 6, 7 are components of the rotors. A vertical cylinder 8 and vertical blades 9 are installed in the center of the lower surface of the upper rotor. Distribution cone 10 is fixed to the lower ends of the blades. The radial clearance between the outer ends of the vertical blades 9 and the inner surface of the vertical cylinder 8 must be greater than the maximum size of the original pieces of the crushed material Dmax . On the upper surface of the lower rotor is a cam flywheel 11 having an elliptical cross-section, with a maximum radial clearance Dmax and a minimum radial clearance (0.1 − 0.5) Dmax to the inner surface of the vertical cylinder 8. The inner surface of the vertical cylinder 8 and the side the vertical surface of the cam flywheel 11 is lined with wear-resistant armor plates 12 and 13. On the upper surface of the lower rotor there is a blade spreader 14, which provides accelerated supply of pre-crushed material to the inner row of impact elements. Vertical blades 9, cylinder 8 and distribution cone 10 provide uniform supply of material particles into the radial gap between the cam flywheel 11 and the cylinder 8. The cam flywheel 11 provides crushing and abrasive loads on the particles of the crushed material, which have a cyclic nature, as a result of which preliminary grinding

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of the material is carried out. The above design features will provide preliminary grinding of the material in the central part of the grinding chamber, which will increase the efficiency of the grinding process in the disintegrator by increasing the productivity of the finished product. In view of its novelty, this disintegrator design requires theoretical research. Thus, the purpose of this work is a theoretical description of the process of grinding materials in a disintegrator with a preliminary grinding unit.

2 Materials and Methods The task of this paper is to determine the pattern of change in the size of the material particles, as a result of the impact of the cam mechanism in the central part of the grinding chamber of the disintegrator. Consider the process of preliminary grinding of material particles in the framework of the inhomogeneous Markov process based on the time variation of the statistical quantity M(t) [4, 5]: d M(t) = γ (t) · M(t), dt

(1)

where γ (t)—functional dependence characterizing the intensity of the Markov process. Suppose that this dependence is linear in the following form: γ (t) = C1 · t + C2 ,

(2)

where C 1 and C 2 constant values.

3 Results and Discussion At the initial moment, the intensity of the Markov process is determined by the interaction of the cam mechanism with all particles of the layer with volume V 0 . Based on the design scheme shown in Fig. 2 the value of this volume is determined by the relation (3) [6–9]. V0 = d0 · (π · R − S1 − S0 ),

(3)

where S 0 —area inaccessible to material particles; S 1 —area of the elliptical base of the cam rotary mechanism with semiaxes a and b;

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a)

b)

Fig. 2 Calculation scheme for determining the volume, into which particles of material can enter from the loading unit of the disintegrator

R—inner radius of a vertical cylinder; d 0 —particle diameter of the material whose minimum size is exposed to the cam mechanism at the gripping angle ϕ 0 . Based on the foregoing, one can obtain a relation of the form: γ (t = 0) = 1.

(4)

For a moment in time t = τ all particles of the layer by volume V0 subject to interaction with the cam mechanism. Interval value τ can be found based on the following relations: τ=

ϕ , ω

(5)

ϕ = π − 2 · ϕ0 ,

(6)

 ⎛ ⎞   R−d0 2  − 1 1 ⎝ τ = · π − 2 · ar ctg  a  2 ⎠, ω 1 − R−d0

(7)

b

where ω—disintegrator rotors speed. γ (t = τ ) = 0. Applying (4) and (8) to expression (2) leads to the following result:

(8)

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1 C2 = 1, C1 = − . τ

(9)

Differential Eq. (1) taking into account (2) and (9) takes the form:  d M(t) t = 1− · M(t). dt τ

(10)

If we assume that the probability of destruction of material particles when interacting with the cam mechanism is a constant value, therefore the value of the mathematical expectation will be proportional to the number of particles N(t): M(t) − N (t) =

γ0 · π·d 3 6

V0 ·ρ

.

(11)

Taking into account (11), Eq. (10) can be reduced to the form:  d  (t) 1 t =− · 1− · d(t). dt 2 τ

(12)

Let us integrate Eq. (12) within certain limits [10]:

dk d0

1 d(d(t)) =− d(t) 2

0

τ

 t 1− dt. τ

(13)

Calculation of definite integrals in (13) leads to the following relation:  τ dk = d0 · exp − . 4

(14)

Thus, the obtained relation (14) determines the regularity of the change in the size of material particles as a result of the action of the cam mechanism in the central part of the disintegrator grinding chamber. In Fig. 3 shows a graphical dependence of the particle size of the material leaving the pre-grinding unit on the initial particle size. It can be seen from this graph that the particle size of the material d k , coming out of the preliminary grinding unit are less than the initial d 0 by 30—40%. Moreover, the smaller the size of the initial particles, the more efficiently their destruction occurs. So, for example, at d 0 = 0.008 m, the particle size is d k = 0.0052 m (decrease by 35%), and at d 0 = 0.018 m, the particle size is d k = 0.0123 m (decrease by 31.5%). Analysis of the graphical dependence allows us to conclude that it is advisable to use a preliminary grinding unit in the disintegrator grinding chamber.

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Fig. 3 Dependence of the particle size of the material d k , emerging from the node preliminary grinding from the initial particle size d 0

4 Conclusion As a result of the theoretical studies, relation (14) was obtained, which determines the regularity of the change in the particle size of the material as a result of the impact of the preliminary grinding unit on the pieces of material, presented in the form of a cam mechanism and installed in the central part of the disintegrator grinding chamber. This ratio allows you to determine the size of the particles emerging from the pre-grinding unit, depending on the size of the original pieces of material. It was also found that the smaller the size of the original pieces, the more efficiently they are destroyed. Acknowledgements This work was realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V. G. Shukhov, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

References 1. Bogdanov VS, Semikopenko IA, Voronov VP (2016) Disintegrators. Designs. Theory. Experiment. BSTU, Belgorod 2. Dvoˇrák K, Paloušek D, Dolak D, Celko L (2018) The effect of the wear of rotor pins on grinding efficiency in a high-speed disintegrator. Mater Sci (medžiagotyra) 24(1):29–34 3. Semikopenko IA, Chuzhinov VO, Borozdin EA, Semikopenko DI (February 2020) Patent no. 2714771. Disintegrator, bull. 5 4. Lozovaya SYu (2005) Creation of calculation methods and constructions of devices with deformable working chambers for fine and ultrafine grinding of materials. The dissertation of a doctor of technical sciences: 05.02.13. BSTU, Belgorod

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5. Pozdnyakov SS (2007) Air-jet counterflow mill for selective grinding and enrichment. The dissertation of the candidate of technical sciences: 05.02.13. BSTU, Belgorod 6. Ankilov AV(2011) Higher mathematics: textbook. Part 1. Ulyanovsk 7. Babicheva IV, Boldovskaya TE (2010) Handbook of mathematics (in formulas, tables, figures): a training manual. SIBADI, Omsk 8. Semikopenko IA, Voronov VP, Vyalykh SV, Manyakhin AS (2018) On the issue of the throughput of the preliminary grinding unit and the classification of material in the disintegrator. Bull BSTU named after V.G. Shukhov (4), 119–123 9. Dvoˇrák K, Macháˇcková A, Ravaszová S, Gazdiˇc D (2020) Effect of imposed shear strain on steel ring surfaces during milling in high-speed disintegrator. Materials 13(10):10–22 10. Kuznetsov SI, Rogozin KI (2013) A short course in physics: textbook, 2nd edn, Tomsk

Stress-Deformed State of Soils under Compressional Contraction Conditions Z. M. Zhambakina , T. K. Kuatbayeva , N. V. Kozyukova , and U. K. Akishev

Abstract The work is devoted to the study of the stress-deformed state of soils under compression and shear conditions. The results of comparative studies of the stress-strain state of soils under conditions of the impossibility of lateral expansion with the measurement of lateral pressure and single-plane shear on sandy and loess soils of undisturbed structure are presented. It is found that under the conditions of compression, the Coulomb limit equilibrium condition is realized, which is caused by the development of irreversible deformations during compaction due to micromovements of soil particles. Coulomb’s condition of ultimate equilibrium, as a state of stability, determines the stress state at rest, for the preservation of which the maximum horizontal force is necessary. In the case of compression without the possibility of lateral expansion, this is the compression spacer. The concept of the equality of Coulomb and Mohr conditions, which is accepted in soil mechanics, allows extending them to compare the parameters of the stress state at shear and compression. The developed method with the measurement of lateral pressure makes it possible to apply the Mohr solution to evaluate the strength parameters. This conclusion is confirmed by 850 experiments conducted by the authors of these tests, which give a close convergence in the range of 1.8–2.9%. Keywords Limit state · Lateral and vertical pressure · Parameters of strength · Clutch · Shift · The angle of internal friction · Strain gauges · Shear and normal stresses · Microshear · Self-strengthening

1 Introduction Soils in the process of their formation under the influence of external and internal forces acquire a state of stable equilibrium, which is a function of its own stress Z. M. Zhambakina (B) · T. K. Kuatbayeva · N. V. Kozyukova Satbayev University, Almaty, Kazakhstan U. K. Akishev Kazakh-Russian International University, Aktobe, Kazakhstan © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_23

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state. For the first time, the equilibrium state for soils was formulated in 1773 by Ch. Coulomb [1]. Based on the Coulomb scheme, a violation of the equilibrium state of the collapse wedge, held by its coupling and friction, is possible with the application of the maximum shear force, while the stiffness of the application of this load should be much higher than the stiffness of the ground. When cutting, the reaction to the external force action, which is modeled by the vertical pressure o,v, is the ultimate shear resistance τult, due to “connectivity and friction”. The state of ultimate equilibrium in this case is described by Coulomb’s law: τ = ơ tgφ+ c

(1)

Under compression conditions, the reaction to the external compactive pressure is the maximum horizontal force, which will decrease in the case of the slightest compliance of the system. In this case, the assessment of the stress-deformed state of the soil under compression conditions can be estimated by the graph-analytical solution of Mohr [2], which is determined by: 1.

2.

The condition of ultimate Coulomb equilibrium or the state of stability of the array at rest, for the preservation of which the maximum horizontal force is necessary. In the case of compression without the possibility of lateral expansion, this is the compression spacer. In this case, the concept of the equality of the Coulomb and Mohr conditions, adopted in soil mechanics, allows applying them to compare the parameters of stress states during shear and compression. In the process of the soil compaction, when lateral expansion is not possible, micro-shears of soil particles occur, which depend on the indicators of physical properties. In this case, the soil is self-hardening under the action of a vertical compacting load. Mohr’s solution, which establishes the relationship between lateral and vertical pressures, allows comparing the parameters of the Coulomb strength with the stress state indicators during self-strengthening of the soil under compression conditions.

2 Methods and Materials Experimental studies of this work were carried out on improved compression and shear devices equipped with strain gauges [3]. A thorough metrological examination of the equipment was carried out, and the factors influencing the values of the measured indicators were determined [4]. A “floating cover” system was created, which provides a condition for the alignment of the geometric axis of the sample and the measuring axis of the device. The main criteria for assessing the stress state under compression conditions: these are the vertical Qv and lateral Ql of the ground pressure, which must be measured directly at the contact with the ground. For measurements of these quantities strain gauges with hydraulic booster (load cells) were used.

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To conduct comparative tests to determine the parameters of soil strength, a modified shear device was used [5, 6], as a generally recognized method for determining the strength characteristics of the soil. Previously, similar tests were carried out on various modifications of compression devices with measurement of lateral ground pressure by Brooker and Ireland [7], (Lazebnik G.E., [8], Dyvik et al. [9], Gareau et al. [10], Smith, R.E., and Wahls, H.E. [11], Colmenares [12], confirming the possibility of determining the mechanical characteristics of soils (not only deformability, but also strength) in an odometer with the measurement of lateral stresses. The impact of the rigidity of the vertical load application and the need for constant monitoring of its value are found [13]. Thus, the strength of sandy soil is characterized by a constant ratio of tangential and normal stresses, the phenomena of peak and residual strengths are associated with methodological errors in determining the limit , values of tangential τlim and vertical pressure Olim [14]. The results of the compression test with measurement of lateral pressure were compared with the parameters obtained with Mohr’s graph-analytical solution, what allows to evaluate the nature of changes in the stress state of the soil sample during the compression process with the determination of the average stress and the intensity of shear stresses; the lateral pressure coefficients ξ and transverse expansion ν; the limit state criteria, grip c and angle of internal friction ϕ; module total strain E with the specification of the coefficient β.

3 Results and Discussion The compression device of the developed design uses rigid pressure sensors, which practically eliminates the flexibility of the sensors themselves and measures the lateral pressure in the absence of a vertical boundary shift. In the studies, a modified shear device equipped with strain gauges was used to register vertical and shear forces. The series of tests were carried out on sandy soils of different densities, granulometric composition and humidity. Thus, the tests of loose (e = 0.82) and average density of sand (Fig. 1) show a close coincidence of the results obtained in the odometer and in the shear device. The dependence Q3 = f(Q1 ) for loose sand is linear, without changing the angle of inclination. The internal friction angle ϕ is close in value: 17.3° (compression tests) and 18° (shear tests). The results of tests of dense fine sand (e = 0.5), with a density of 1.75 g/m3 , showed a significant influence of the stress state created during the formation of dense sandy soils. The creation of the required density required the application of significant force influences, the vertical sealing pressure Qv and the residual lateral pressure Ql, registered at the end of the formation process, were recorded. In contrast to the previously studied sands, the dependences Q3 = f(Q1 ) are characterized by two linear sections and, respectively, two coefficients of lateral pressure ξ and internal friction angles ϕ (Fig. 2). The point of fracture or intersection of the Mohr’s envelopes corresponds to the vertical stresses applied during the formation of the samples. According to the results

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Fig. 1 Limit lines for loose sand

Fig. 2 Extreme straight lines for dense sand

of shear tests, a coupling close in value to the residual lateral pressure c, equal to 0.01 MPa for shear and 0.012 for compression, and an internal friction angle of 22.8° and 25°, which indicates the fulfillment of the assumption about the realization of the condition of the Ch. Coulomb’s limit equilibrium in compression conditions. For dense sandy soils, the loading trajectory characterizes two stress states, the first of which is the ultimate equilibrium, the second is the equilibrium stress state provided by the condition of pure compression. As a result of the tests, it was found that with increasing compliance (the possibility of lateral movements of the device wall), the intensity of the lateral pressure increment decreases when the soil sample is compressed. The impact of the granulometric composition of the sandy soil and humidity on the parameters of strength and deformability is noted, while the identity of the

Stress-Deformed State of Soils under Compressional Contraction Conditions

173

Fig. 3 Results of compression tests of dense sand with lateral pressure measurement

results obtained, the angle of internal friction showed a correspondence within one or two degrees. For compacted sands, the dependence of the main stresses has two sections of different intensity, which reflects the influence of the initial stress state formed by the compaction of the sandy soil (Fig. 3). The performed studies indicate that the considered method of determining the mechanical properties of soils in a compression device with the measurement of lateral stresses allows determining not only the deformation, but also the strength characteristics of soils.

4 Conclusion 1.

2.

3.

It is found that with increasing compliance (the possibility of lateral movements of the device wall), the intensity of the lateral pressure increment decreases when compressing the soil sample. The impact of the granulometric composition of the sandy soil and humidity on the parameters of strength and deformability was also established, while the identity of the results obtained, the angle of internal friction showed a correspondence within one degree. As a result of tests of dense fine sand (e = 0.5), with a density of 1.75 g/m3 , a significant influence of the stress state created during the formation of dense sandy soils was found. When creating the required density, the vertical sealing pressure Qv and the residual lateral pressure Ql, registered at the end of the formation process, were recorded.

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As a result of shear tests, a coupling close in value to the residual lateral pressure c, equal to 0.01 MPa for shear and 0.012 for compression, and an internal friction angle of 22.8° and 25°, which indicates that the assumption about the implementation of compression to be fulfilled by the condition of the equilibrium state C of Sh. Coulomb.

References 1. Duncan JM, Wright SG, Brandon TL (2014) Soil strength and slope stability. 2nd edn. Wiley, New York, p 317 2. Brinkgreve RBJ (2005) Selection of soil models and parameters for geo technical engineering application. Am Soc Civ Eng 128:69–98 3. Boldyrev GG, Sidorchuk VF (2003) Determination of the mechanical properties of soils in a compression device with measurement of lateral stresses. Autom Surv Technol Des 9(10):69–71 4. Zhambakina Z, Kozyukova N (2020) Determination of the durability parameters of sand soils under compression. News Natl Acad Sci Repub Kazakhstan 3(441):133–141 5. ASTM D4186: D4186M - 12 (2012) Standard test method for one-dimensional consolidation properties of saturated cohesive soils using controlled-strain loading 6. ASTM D2435: D2435M - 11 (2011) Standard test methods for one-dimensional consolidation properties of soils using incremental loading 7. Baki B, Mustafa L (2011) Balkans conference on challenges of civil engineering, BCCCE, pp 1–7 8. Guslistogo GE (2009) Calculation of bezankernoi shpuntovoy wall with the help of finite element simulation in the software complex. Constr Mater Sci Mech Eng (50), 162–166 9. Dyvik R, Laclasse S, Martin R (2005) Coefficient of lateral stress from oedometer cell. In: Proceedings of the eleventh international conference on soil mechanics and foundation engineering, San Francisco, vol 2, pp 1003–1006 10. Per S, van den Akker JJH, Thomas K (2015) JRS technical reports. Soil threats in Europe. Status, methods, drivers and effects on ecosystem services. A review report, deliverable 2.1 of the RECARE, pp 69–77 11. Abderrahmane H, Smain B (2018) Numerical simulation to select proper strain rates during CRS consolidation test. Periodica Polytechnica Civ Eng 62(2):404–412 12. Colmenares JE (2011) Suction and volume change of compacted sand bentonite mixtures. Ph.D. thesis, University of London, Imperial College, vol 112, p 141 13. Boldyrev GG, Arefiev DV, Gordeev AV: LLC “NPP Geotek”. https://npp-geotek.ru/upload/ibl ock/a89/a8952438334fbd753194fed916404d38.pdf 14. Sidorchuk VF, Dzagov AM (2011) On the structural strength of clayey soils Tr. NIIOSPa 100:335–345

Analysis of the Hardening Kinetics of Cements from Different Countries Sh. M. Rakhimbaev , E. A. Pospelova , and I. S. Chernikova

Abstract Using the coefficients of the hardening intensity, as well as on the basis of calculations using the transport theory equations containing the initial hardening rate and the deceleration coefficient, the analysis of the regulatory and technical requirements established in various countries of the world for the rate of strength gain of cement stone is carried out. It is shown that the kinetic constants of cement hardening in the United States and China mostly correspond to modern ideas about the kinetics of hardening of Portland cement stone. On this basis, the analysis of the hardening kinetics of cements from different countries was carried out. Regulatory and technical requirements for the strength of cements of certain brands in Japan and India require adjustments. The regularities revealed in the analysis of the physical and mechanical properties of cements at different curing times are considered. It is shown that at the age of 28 days, samples of cement stone have more reproducible physical and mechanical parameters than at the age of 1, 3, 7 days. The shorter the hardening time of the samples, the lower their mechanical strength, the greater the coefficient of variation during their testing. It is established that the kinetics of cement hardening in different countries with a correlation coefficient of 0.9 and higher is described by an equation with intensive braking based on the transport theory. Keywords Kinetics of hardening · Relative intensity of hardening · Initial speed · Braking coefficient

1 Introduction Earlier [1] it was shown that the hardening kinetics of cement systems of various compositions with a high correlation coefficient (0.90–0.99) can be described either by an equation based on the theory of transport, or by a well-known semi-logarithmic Sh. M. Rakhimbaev · E. A. Pospelova (B) Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia I. S. Chernikova Joint Stock Company “Plant of Reinforced Concrete Structures No. 1”, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_24

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law. The first of these equations is more preferable for describing the hardening kinetics of conventional and high-quality binder systems, while the semi-logarithmic equation better describes the features of strength growth over time of low-grade cements and concretes, as well as most cement systems at low temperatures (+5… +10 °C). The methods considered in [1–10] for predictive evaluation of the strength and activity of binders, in particular, Portland cement, based on the results of shortterm tests (1–7 days) require high-quality initial data. The regulatory and technical requirements for the coefficient of variation in determining the physical and mechanical properties of cements, as it is known, are usually at the level of 3–5% for samples that harden within 28 days, but at an earlier time are higher. The laws of the kinetics of cement hardening and the equations for their description are necessary not only for predicting their grade and strength class, but also for developing regulatory and technical requirements for them at different hardening times. In this regard, we will analyze the regulatory and technical requirements of different countries for the physical and mechanical properties of Portland cement [11], as they provide for the requirements for the strength of the stone in different countries. Table 1 provides information on the hardening kinetics of Portland cements produced in different countries, and in Fig. 1 they are shown in graphs. When considering the kinetics of the strength growth of cement systems, the authors proceed from the assumption that the hardening of a stone with normal properties can be described by one or another mathematical expression, which is a continuous smooth function of time. In some cases, various irregularities in the Table 1 Regulatory and technical requirements for cements from different countries № of

Country-organization

Standard

curve

1

China

Setting time, day

Coefficient of hardening intensity

1

3

7

28

K3 = σ28 /σ3

K7 = σ28 /σ7

425

–

17.7

26.5

41.7

2.35

1.57

2

525

–

22.6

33.3

51.5

2.27

1.54

3

625

–

28.4

42.2

61.3

2.15

1.45

P-RH 525,2

15

32.5 (23)

–(~32.5)

52.5

2.27

~1.62

5

P-RH 575

17

37.5 (26)

–(~37.5)

57.5

2.21

~1.54

6

P-RH 625

19

42.5 (29)

–(~42.5)

62.5

2.15

~1.47

4

7

GB 175

Brand, strength class

GB 199

IS 269

33

–

16

22

33

2.1

1.5

8

India

IS 8112

43

–

23

33

43

1.87

1.3

9

IS 12269

53

–

27

37

53

1.96

1.43

–

12

19.3

27.6

2.3

1.43

10

USA

ASTM

Type I

11

Japan

JIS R 5210

300

–

7

15

30

4.28

2

330

6.5

13

23

33

2.54

1.43

350

13

20

28

35

1.75

1.25

12 13

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177

а

b

c

d

e

f

g

h

Fig. 1 The dependence of the hardening intensity of cements from different countries on the brand (strength class)

hardening kinetics of cement stone are observed, which may be due to the presence of abnormal properties in the binder [9]. This leads to strength drops, a delay in its growth in time, etc., which can be described by the equation of the theory of transport with intensive deceleration in time [1, 2]. In the A.V. Volzhensky’s work [3], it is shown that an effective way to assess the kinetics of cement hardening is to analyze the ratio of the 28-day-old to 3-dayold and 7-day-old (K3 = 2.86, K7 = 1.54). Table 1 and Fig. 1 show the results of calculations of K3 and K7 and their dependence on the grade of cements (for Chinese and Japanese cements) and strength class (for Indian cements). From the above data, it can be seen that as the grade or strength class of cements increases, the numerical value of K3 and K7 decreases. In Chinese cements, K3 is significantly lower than 2.8, and K7 is 1.5 for grades 525.5 and 575. For Indian cements, these ratios are Class 33 cements, and for Japanese cements, class 330 cements. It follows from Fig. 1E that the cement of class 43 is more rapidly hardening than that of Class 53, which is unlikely. The ratio σ28 /σ3 in Indian cements is 0.7–0.9 lower than in other cements, which may be due to their increased aluminateness and fineness of grinding. The numerical values of K3 for Indian cements, if we adjust the data for the strength class 43, are close to the value of 1.54, especially for cements of classes 30–33. Figure 1B shows that for Chinese cements, the coefficient K7 = σ28 /σ7 for cements of grades 430–530 does not depend much on the brand of cement, which obviously does not correspond to reality.

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The above method of analyzing the rate of hardening of cement-sand samples and concrete at different times is a necessary condition and the first stage in performing calculations related to predicting the brand strength of cement systems based on the results of short-term tests. The above data show that even in industrially developed countries, a sufficiently rigorous analysis of the hardening kinetics of cement systems is not always performed. In most foreign cements, the brand strength σ28 is one and a half times higher than the seven-day strength σ7 , i.e. σ28 = 1.5σ7 , which is consistent with the data given in [2]. Figure 1B and E shows how it is advisable to shift the points of cements of the Chinese brand 525 and the Indian class 43 so that they correspond better to the known laws of hardening of cement systems In the works on hydration and hardening of Portland cement and other binders, the semi-logarithmic law of strength increase over time is most often used: σ = a + b · lg τ,

(1)

where τ—time; σ—ultimate strength of cement stone, MPa; a and b—constants that depend on the composition, preparation and hardening conditions of the samples [3]. The equations of the transfer theory have the following form: τ  τ + k1 · σ = σ σ 0 τ  τ = + k2 · τ, σ σ 0

(2) (3)

where τ—hardening time (hydration), day; σ—compressive strength, MPa; (τ/σ)0 —the inverse of the initial rate of hardening (hydration),day/MPa; k1 and k2 — braking coefficients of the hardening process. Comparative data on the kinetic constants of hardening of cements from different countries are given in Table 2. Attention is drawn to the very high rates of initial hardening rates and low-braking coefficients inherent in cements of Chinese production, in comparison with American and Japanese cements. This is mainly due to the fact that the American type I cement for general construction purposes is characterized by a low grade in strength, while the Chinese can be attributed to high-strength. Comparison of cements of the same strength class shows that the values of their initial hardening rates and braking coefficients are close. Chinese grade 425 and Indian grade 43 cement, as well as Chinese grade 525 and Indian Grade 53 cement have close U0 and Ktor . For Chinese cement grade 625, U0 is close to the Indian 53, and Ktor is lower by 0.02. Indian cement of the IS 269 type has similar values of U0 = 8.23 and Ktor = 0.026 to the Japanese 330 JIS R 5210 (7.3 and 0.0254, respectively).

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Table 2 Values of kinetic constants: initial hardening rate U0 (MPa/day) and braking coefficient Ktor (MPa−1 ) №

Country-organization

Standard*

Brand, strength class

U0 , MPa/day

Ktor , MPa−1

U0 ·Ktor

1

China

GB 175

425

8.55

0.0199

0.17

2

525

11.26

0.0164

0.148

3

625

15.23

0.014

0.21

P-RH 525,2

22.32

0.0174

0.388 0.42

4

GB 199

5

P-RH 575 26.63

0.016

6

P-RH 625 31.09

0.0148

0.46

IS 269

33

8.23

0.026

0.21

8

IS 8112

43

14.91

0.0209

0.31

9

IS 12269

53

14.91

0.0165

0.246

7

India

10

USA

ASTM

Type I

6.53

0.0307

0.2

11

Japan

JIS R 5210

300

~8

0.0209

0.6

12

330

9–10

0.0254

0.1

13

350

16.23

0.0264

0.428

* Note: GB 175-2007 State Standard of the People’s Republic of China. Portland Cement of General

Purpose; IS 269:2015 Indian Standard. Ordinary Portland Cement—Specification (Sixth Revision); IS 8112:2013 Indian Standard. Ordinary Portland Cement, 43 grade—Specification (Second Revision); IS 12269:2013 Indian Standard. Ordinary Portland Cement, 53 grade—Specification (First Revision); ASTM C150. Standard Specification for Portland Cement; JIS R 5210:2009. Portland Cement. Japanese Industrial Standard

The authors believe that the compressive strength limits of cements No. 4–No. 6 of Chinese production after 1 day, according to the equations of the hardening kinetics based on the transfer theory [1, 9], should not be 15–19 MPa, but 21–25 MPa, i.e. 5–6 MPa higher. Calculations show that it is at such values of 1-day strength that the standard strength class of these cements, equal to 52.5–62.5 MPa, is provided. At the values of the one-day strength of cements No. 4–No. 6 (Table 2), the inhibition coefficients of their hardening acquire too small values, which leads to values of 28-day strength exceeding the actual 1.4–1.7 times or more. Graphs of the dependence of the initial hardening rate and the braking coefficient on the grade and strength class of cement were constructed and analyzed. It follows from the analysis that as the grades or strength class of cements increase, the braking coefficient of Ktor decreases, with the exception of Japanese-made cements, which have the opposite phenomenon. This is due to the imperfection of cement testing methods and errors made in the development of regulatory and technical requirements. Analysis of the hardening kinetics curves of cements produced in different countries leads to the following conclusions:

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a

b

d

c

e

Fig. 2 Hardening kinetics of cements of various countries. The numbering of the curves according to Table 1. The value of σ7 is greatly overestimated (by 10 MPa) for curve 6. The value of σ7 is underestimated for curve 12, and the value of σ1 is underestimated for curve 13

– most of the above data with a high correlation coefficient (0.9) can be described by the equation of the theory of transport with intensive braking; – the hardening of most cements, the properties of which are shown in Table 1, corresponds to modern ideas about the kinetics of the strength set of binding systems, but in some cases there are inaccuracies in the physical and mechanical parameters of cements, especially at the age of 3 days. This applies, first of all, to cements of Indian, Chinese and Japanese production (compositions 4–9, No. 11) Fig. 2B, C, D, 3-day strength of which is underestimated; cements of Chinese production (No. 4–6) overestimate the values of 3-day strength of the stone; – the analysis of the calculated data values showed that the considered cements significantly differ in the value of the initial hardening rate (U0 ), while their Ktor is within relatively narrow limits for cements produced in different countries. However, the errors of testing and normalizing the physical and mechanical characteristics of cements differ quite slightly in the braking coefficient, which indicates its high resistance to factors affecting the numerical value of the Ktor . These inaccuracies in the strength values of cements seem to be related to the methods of sample production, as well as the granulometric composition and other properties of the sand used in the test. In Japan, the reproducibility of the results of physical and mechanical tests may be affected by the method of sample preparation, as well as the use of very fine monofractional sand, which makes it necessary to bring the W/C ratio to 0.65, which is 1.3–1.5 times higher than in other countries. In China, a fairly modern technology of sample preparation is used, and a rational W/C ratio is used, so the reason for the insufficient strength of samples in the early stages is not clear.

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According to the requirements of the standards of China and Japan (see Table 1, compositions 4, 5, 6 and 11), in the first 3 days there should be an acceleration in the growth of the strength of the cement stone, which is not typical for most Portland cements. The experience of physical and mechanical tests of various cements accumulated by the authors, as well as general considerations, lead to the conclusion that at the age of 28 days, samples of cement stone have more reproducible physical and mechanical parameters than at the age of 1, 3, 7 days. The shorter the hardening time of the samples, the lower their mechanical strength, the greater the coefficient of variation during their testing. From the above, it follows that the requirements for strength indicators of cements No. 4, 5 and 6 of Chinese production, as well as No. 11 of Japanese production, given in Table 1 and Fig. 1, are significantly underestimated for samples of 1-day-old age. Acknowledgements This work was realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V. G. Shukhov, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

References 1. Pospelova EA (1999) Improving the efficiency of construction materials technology by regulating transfer processes: Autoref. Dissertation of the Candidate of Engineering Sciences. BelSTACM, Belgorod 2. Kogan MZ (1984) Comparison of the properties of cements on the lines of forecasting. Concr Reinf Concr (2), 18–20 3. Volzhensky AV (1986) Mineral binders. Stroyizdat, Moscow 4. Nesvetaev GV, Zhilnikova TV (2003) Prediction of the brand strength of concrete by the kinetics of hardening in different periods. Bull BSTU named after V.G. Shukhov 5:344–347 5. Berdov GI (1987) A method for predicting the activity of cement and concrete. Concr Reinf Concr 12:4–5 6. Lagoyda AV (1994) Predicting the strength of concrete at elevated temperatures. Concr Reinf Concr 42:11–13 7. Solov’eva VYa (1996) Evaluation and forecasting of the strength of materials. Cement 3:38–40 8. Smirnova EA, Rakhimbaev ShM (2005) A method for predicting the brand strength of cement stone. Bull BSTU named after V.G. Shukhov 9:293–296 9. Akieva EA (2006) Predicting the brand strength of cement systems based on the results of shortterm tests and mineralogical composition: Autoref. Diss. Candidate of Engineering Sciences. BSTU named after V.G. Shukhov, Belgorod 10. Akieva EA, Rakhimbaev ShM (2006) Features of the kinetics of cement hardening. In: Tenth academic RAASN readings. Achievements, problems and directions of development of the theory and practice of construction materials science, pp 345–346. KSACE, Penza-Kazan 11. Entin ZB, Nefedova LS, Zelvyanskaya NI (2001) The current state in Russian and foreign standards. Cement 2:8–12

Development of the Composition of a Special Mixture for Floors Using Anhydrite Binders A. F. Buryanov , N. A. Galtseva , I. V. Morozov , and E. N. Buldyzhova

Abstract In the construction industry, the development of gypsum materials is one of the priority and promising areas. As world experience shows, the availability of dry building mixes on the market is in demand by the consumer, which leads to the development of the industry and the development of new, improved materials. It is possible to create a competitive and high-quality product by constantly conducting laboratory tests. Dry floor mixtures consisting of natural and technogenic anhydrite have not been sufficiently studied. However, it is known that the technical characteristics of anhydrite binders are on a par with Portland cement and building gypsum, occupying the golden mean between them. At the theoretical level, it can be assumed that using anhydrite binders as the main component of dry mixes, it is possible to achieve a solution with no disadvantages of similar dry building mixes based on lime, cement or gypsum, as well as with improved rheological characteristics. The paper highlights the possibilities of using anhydrite binders based on ground gypsum-anhydrite stone from the Poretsky deposit in dry building mixes for floors. The effective composition of the anhydrite binder was found, particle size distribution of mineral filler was defined, a plasticizer was selected. Keywords Anhydrite · Anhydrite binders · Floor mix · Dry building mixes · Chemical additives · Superplasticizers · Additives

1 Introduction As you know, natural stone serves as a raw material component for the production of hardening anhydrite. Large pieces are subjected to a fine grinding process in a specially designed machine device—a ball mill, reaching a particle size of less than 0.2 mm at the output of the unit. From an economic point of view, this kind of material processing carries high financial costs for energy supply, which, in turn, is several times less than the cost of roasting. In practice, the combination of alkaline sulfates A. F. Buryanov (B) · N. A. Galtseva · I. V. Morozov · E. N. Buldyzhova National Research Moscow State University of Civil Engineering, Moscow, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_25

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or heavy metals together with calcium hydroxides in a numerical amount of no more than 2% of anhydrite is used as one of the ways to activate hardening [1–3]. The anhydrite obtained as a result of roasting also passes the technological stage of fine grinding. Hardening activators are used, such as potassium sulfates and calcium hydroxide or Portland cement, added to the mixtures directly in the factory conditions. The main difference between natural anhydrite and the one that passed the roasting stage is in the chemical structure. In the second case, the material at the end of grinding is composed of small crystals with a predominant part of the defective structures, which is a consequence of the presence of high activity when entering into the reaction. In the first case, on the contrary, the existing large crystalline particles interfere with the active reactivity. All over the world, when installing floor screeds, a universal building material is used—a dry building mix. Mixtures of various types are used: based on natural, roasting and synthetic anhydrite binders. To obtain the specified properties, certain chemical additives are used. For example, in Germany, by mixing up to 50 wt. h. of natural gypsum and hardening activators (potassium and zinc sulfates), a mixture suitable for the device of self-expanding screeds is obtained. The process goes as follows: about 34 wt. h. of water is poured into the pre-prepared dry mixture and plasticizers are added. At the end of mixing for 60 s quartz sand is filled in, the grain size of which should not exceed 2 mm, and the optimal amount is up to 150 wt. h. In the end, sufficiently high physical and mechanical parameters of the solidified solution are obtained, so the compressive strength is about 20.2 MPa, and the bending strength is within 5.8 MPa. The Polish company “ATLAS of BUILDING TECHNOLOGIES” specializes in the production of floor mixes. The composition of the mixtures of this manufacturer is represented by a mineral binder based on anhydrite flour, α-gypsum and Portland cement, fillers and modifying additives. When dried, the solidified mortar mixture has a high strength and a minimum percentage of shrinkage [4–8]. The beginning of setting of ground natural anhydrite can occur after a day. The hardening process takes a long period of time, which is unprofitable on a production scale. The setting time is regulated in two ways: the first one—by increasing the fineness of the grinding, the second—by including chemical additives in the composition. Compliance with two factors in the production technology contributes to the production of a binder with accelerated setting and hardening times, as well as high strength indicators [9–12].

2 Methods and Materials The gypsum-anhydrite stone of the Poretsky deposit was used to study the technology of producing anhydrite binder. The raw material component was crushed in a jaw crusher to obtain fractions of 3–5 mm, which passed the stage of sieving through a sieve with a lumen of 1 mm and were placed for further grinding in a vibrating mill. The specific surface area of the material obtained at the output was 5300–5700 cm2 /g. The water demand of the gypsum anhydrite binder was in the range of 28–30%.

Development of the Composition of a Special Mixture for Floors …

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Preliminary testing of dry mixes for floors was carried out with the use of fractionated sand at different ratios of fractions. The most optimal grain composition was determined. The experimental work on the development of a special mixture for floors consisted in the production of samples-beams with a size of 40 × 40 × 160 mm on various varieties of anhydrite binders. The compositions based on ground binder with complex hardening catalysts were tested: Portland cement CEM I + potassium sulfate + FeSO4 ·7H2 O (1); lime-boiling water + potassium sulfate + FeSO4 ·7H2 O (2) and compositions based on a binder prepared by mixing anhydrite flour with hardening catalysts: Portland cement CEM I + potassium sulfate + FeSO4 ·7H2 O (3).

3 Results and Discussion An experimental work was carried out to select the optimal composition of dry mixes for floors intended for creating screeds and self-expanding self-leveling bases, including anhydrite binders. In the process, dry mixtures were made with the addition of superplasticizers. The addition of Melment F10, F15 G, and C-3 to the compositions of plasticizing additives improves the strength characteristics with an increase in B/S to 2.5, and at the same time reduces the W/S. The positive effect of superplasticizers on the setting time of the anhydrite binder, in comparison with the rest, is achieved when inserted into the composition of C-3. The results of tests on the strength of samples with the addition of C-3 with a water-solidification ratio of 0.12–0.13 are shown in Fig. 1. The setting time in this case was: the beginning—4–5 h, the end—8–9 h. It is worth mentioning that the aggregates of the inert type have a greater effect on the spreading rate of the freshly prepared solution, on which the self-leveling effect directly depends. The type of used filler is no less important, including its grain form. Visually, the grains should not have a flat shape, but a rounded one; in addition, the degree of water adsorption by the fillers themselves should be taken into account: it should be low. To produce a dry mixture for floors, where the ratio of binder: sand (B/S) is 1: 2.6 w. h., with the main technical properties corresponding to the strength grade of 20 MPa, it was possible to use anhydrite binder, the composition of which is represented by anhydrite flour with a specific surface area of 5500 cm2 /g and additives as an alkaline catalyst of Portland cement CEM I (Stavropol Cement Plant), as well as substances that accelerate hardening—K2 SO4 and FeSO4 ·7H2 O. Providing such indicators is possible with the insertion of fractional quartz sand and organomineral additives such as MB and Embelit, which will allow the preparation of the solution to change the water-solid ratio W/S: reduce to a value of 0.13 and increase the strength indicators. The change in strength characteristics over the course of 28 days with the introduction of MG-1 is shown in Figs. 2, 3.

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Fig. 1 Compressive strength of mortar mixtures with the addition of C-3

Fig. 2 Compressive strength of mortar mixtures with the addition of MG-1

Thus, when performing the work, it was found out that self-leveling floor mixes can be made on the basis of a binder obtained by the method of fine grinding of stone with the inclusion of Portland cement and complex sulfate additives. It was determined that the substitution of dry mixtures of carbonate filler quartz sand of small fractions leads to a reduction in water demand of mortar mix at a constant fluidity of solutions equal

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Fig. 3 Flexural strength of mortar mixtures with the addition of MG-1

Table 1 Component composition of laboratory samples

Composition 37

Composition 38

Components

Amount, %

Components

Amount, %

AKM

27.8

AKM

28.4

0.6

Sand fr

67.3

Portland cement CEM I Sand fr

66.0

Embelit

5.5

Agitan

0.1

MB

4.2

Agitan

0.1

to 14–15 cm (according to the methodology specified in EN 12,706). Mortar mixtures have the highest viability for 30 min, the set of initial strength is fixed on the first day. Ultimately, the solidified solution has the following physical and mechanical properties: compressive strength after 28 days—15–20 MPa, bending—3–4 MPa, shrinkage effect—no more than 0.45 mm/m. As an experiment, it was decided to make additional compositions of dry floor mixes. Their compositions are shown in Table 1. During the experiment, it was revealed that the addition of water to the composition No. 38 and the subsequent molding of the samples leads to a swelling of the mass and a volume increase of the samples, and there is also a slowdown in the setting time to 1 day. In turn, the formation of composition No. 37 is not accompanied by swelling, but the duration of the hardening process is more than 1 day. In both cases, the water-solid ratio was 0.12–0.13. The obtained samples-beams were tested for compression, the results are shown in Fig. 4.

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Fig. 4 Compressive strength of mortar mixtures with additives

4 Conclusion The research work on the study of the composition of a special mixture for floors and the subsequent verification of the main technical properties of the resulting material was the result of the following conclusions: 1.

2. 3.

Among the 4 available varieties of anhydrite binder, in the course of further work, it is rational to take a binder that includes a complex addition of Portland cement—CEM I and sulfate catalysts for hardening—K2 SO4 and FeSO4 ·7H2 O; A mineral aggregate based on quartz sand of the optimal grain composition was selected, which contributed to achieving the maximum result; Based on the tests carried out in relation to the plasticizer as a potential component in the composition, organomineral additives showed the greatest effectiveness in the application.

References 1. Gontar YuV, Chalova AI, Gainutdinov AK (2006) Gypsum and gypsum anhydrite mortar mixes for finishing works. Build Mater 7:6–7 2. ST RK 1168-2006. Dry building mixes. General technical conditions 3. Belyaev EB (2002) On the development of the Russian market of dry building mixtures. Building materials, equipment, technologies of the XXI century, vol 11, pp 18–19 4. Popov KN, Caddo MB (2002) Building materials and products. High School, Moscow 5. Meshkov PI, Mokin VA (2000) Methods for optimizing the composition of dry building mixtures. Build Mater 5:12–15 6. Galtseva NA, Buryanov AF, Buldyzhova EN, Morozov IV (2020) On the question of using synthetic anhydrite in dry mixtures. In: Collection of reports of the all-Russian scientific conference, pp 47–52 7. Buryanov AF, Gontar YuV, Chalova AI (2010) On the question of using gypsum and anhydrite binders in dry mixtures for the device of floor bases. Dry Mixes 1:11–13

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8. Vtoroye B, Fischer H-B (2001) Effect of hardening activators on the properties of anhydrite binders. In: Volokitin GG (ed) Materials of the second international scientific and technical seminar: non-traditional technologies in construction, pp 371–376 9. Buryanov AF, Petrachenko VV (2006) The influence of additives on the hydration of anhydrite binding. Increasing the efficiency of production and use of gypsum binders and products: materials of the All-Russian seminar with international participation. Alvian, Moscow, pp 209–217 10. Buryanov AF, Kolkataeva NA (2008) Prospects for use of gypsum and anhydrite binders for floor screws. Stroykompleks 2008:160–163 11. Kardumyan GS, Dondukov VG, Isaev SA (2005) A new organomineral modifier of the MB series for the production of dry building mixtures for special purposes. Building materials, equipment, technologies of the XXI century 12 12. Buryanov AF, Petrachenko VV (2005) Gypsum and anhydrite binders for self-leveling floor screeds. Bull BSTU named after V.G. Shukhov 10:39–43

Mathematical Description of the Two-Phase Flow Motion at the Outlet of the Vertical Acceleration Tube of a Jet Mill with a Plane Grinding Chamber of Torus-Shaped Form V. G. Dmitrienko , V. P. Voronov , E. G. Shemetov , and O. M. Shemetova Abstract Nowadays building material industry as well as other industry branches exercise bigger demand to use powders with high dispersion. Jet mills are used to produce such powders, that’s why development of new jet mill designs, increase of grind efficiency, reduction of specific energy consumption is an important objective. This article provides a mathematic description of the two-phase flow motion at the outlet of the vertical acceleration tube of a jet mill with a plane grinding chamber of torus-shaped form. The part of the acceleration tube above the impact plate is essential for grinding, as the initial particle grind occurs at this very section, in the grind chamber. Moreover, the initial grind defines the size of particles, that are further reground at the mill chamber. As the result of theoretical calculations a formula, that enables to define the height of an acceleration tube from the baffle element at the specified velocity parameters of the two-phase flow. The article also contains the graph, that shows how particle velocity depends on the current (specific) height point (value) of the acceleration tube. This graph shows that particle size strongly affects the way they move in the grind chamber. Using the formula we can calculate the effective propulsion range of particles, depending on theirs’ size, by presuming they have the maximum velocity. Keywords Jet mill · Grinding chamber · Acceleration tube · Particle · Two-phase flow

1 Introduction It is well-know, that in order to produce ultra-fine powder, fluid energy mills, also known as jet mills, with different grind chamber particle motion, are used [1–7, 9– 14]. To increase grind efficiency of materials with different density, BSTU named after V.G. Shukhov, is constantly searching for new technical solutions for jet mill V. G. Dmitrienko · V. P. Voronov · E. G. Shemetov (B) · O. M. Shemetova Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_26

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grind chambers. So, the authors offer design of a plane grinding chamber with a torus-shaped form to produce colorant, pharmaceutical drug, as well as powder for dry building mixes [8]. The aim of this paper is a theoretical research of the two-phase flow motion at the outlet of an acceleration tube of jet mill with a plane grind chamber of a torus-shaped form.

2 Methods and Materials Let’s examine the motion of a particle material, moving at an initial velocity ϑ0 from the acceleration tube of a vertical position through gas flow at an initial velocity U0 (Fig. 1). Velocity variation of a particle material in a two-phase flow can be described with the help of an equation, based on Newton’s second law: m

dϑ(z) = P + f, dt

(1)

where m—is particle material mass; z—is a current coordinate, which is measured from an acceleration tube cut; f —is the force of phase-to-phase interaction; P— particle material force of gravity. Force of gravity is measured by Newton’s second law by the following formula: P = mg.

(2)

Considering the form of an ideal particle, its mass correlates with particle’s density through the following equation: m=

Fig. 1 Design scheme to calculate gas (air) flow velocity

π d3 ρ. 6

(3)

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The force of phase-to phase interaction « f » can be described as following: f = f0 ·

ρ0 · S (U (z) − ϑ(z))2 , 2

(4)

Where f 0 —particle drag coefficient; ρ0 —gas (air) density; S—particle cross section area, m2 ; U (z)—gas(air) velocity variation towards the OZ axis; ϑ(z)— particle velocity variation towards the OZ axis. Drag coefficient in the Eq. (4) depends on motion mode, which, in return, is defined by Reynolds number (Re): Re =

(U (z) − ϑ(z)) · d , v

(5)

Where d—is particles diameter; v—kinematic viscosity of the gas (air). We will use the drag coefficient relationship by Klaychko formula in theoretical calculations [15]: f0 =

24 4 +√ Re Re

(6)

Replacing the formulas (2)–(6) into the Eq. (1) results in the following: 1

18ρ0 v dϑ(z) ρ0 v 3 5 3 =g+ (U (z) − ϑ(z)) + 3 4 (U (z) − ϑ(z)) , 2 dt ρ·d ρ ·d3

(7)

In the left part of the Eq. (7) we swap from time differentiation to coordinate differentiation according to the formula: dϑ(z) dz dϑ(z) = · , dt dz dt

(8)

dz = ϑ(z), dt

(9)

and, considering, that:

Equation (7) becomes the following: ϑ(z)

dϑ(z) 5 = A + B(U (z) − ϑ(z)) + C(U (z) − ϑ(z)) 3 . dz

(10)

Following definitions have been introduced into the Eq. (10): A = g;

(11)

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B=

18ρ0 v ; ρ · d2

(12)

1

C =3

ρ0 v 3 4

ρ ·d3

.

(13)

Let’s suggest, that gas (air) velocity variation at the outlet of the acceleration tube has a linear function: U (z) = a · z + b,

(14)

According to the calculation scheme, presented on Fig. 1, we define unknown parameters a and b: at z = z 0 U (z) = 0;

(15)

at z = 0U (0) = U0 ;

(16)

By applying Eq. (15) to Eq. (14) we get: 0 = a · z 0 + b,

(17)

same, applying Eq. (16) to Eq. (14) we get: U0 = b,

(18)

By replacing U0 instead b from Eq. (18) into Eq. (17) we define the unknown parameter: a=−

U0 , z0

(19)

By replacing Eq. (18) and (19) into Eq. (14) we get the following formula:   z U (z) = U0 1 − . z0

(20)

Considering Eq. (20), Eq. (10) takes the final version: ϑ(z)

      z z dϑ(z) 5 − ϑ(z) + C(U0 1 − − ϑ(z)) 3 , (21) = A + B U0 1 − dz z0 z0

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The derived equation can be used to define the particle velocity variation, grinded material, at the section between acceleration tube cut and baffle plate.

3 Results and Discussion The derived formula has been integrated into the Maple Software by applying numerical methods. The result of such numerical formula integration (21) for particle size from 0.5 to 4 mm are depicted as graphic function of velocity variation of grinded material particles between acceleration tube cut and baffle plate. The integration result shows that the particle size essentially influences the way the particles move in the grind chamber. Almost all particles, regardless of size at the starting point of a grind chamber, continue being accelerated by gas (air) while its velocity exceeds the velocity of particles. For example, particles with 2–4 mm in diameter reach its maximum velocity at a distance of 10 to 16 mm from the acceleration tube cut, meanwhile particles with 0.5–1 in diameter—at a distance of 16 to 20 mm (Table 1). The foregoing allows to use formula (21) to model particle behavior of grinded material in a jet mill with a plain grind chamber with a torus-shaped form. Using the graphic (Fig. 2, 3), one can define particle effective range depending on its size, as long as particles achieve its maximum velocity, that will positively affect the calculation of rational distance between the acceleration tube cut and the baffle element. Table 1 Function of velocity variation of grinded material particles between acceleration tube cut and baffle plate №

Particle shape

Particlediameter, mm

Maximum velocity of the particles, m/s

Distance from the accelerating tube, m

1

Ball

0.0005

97.056

0.019–0.020

2

0.001

97.020

0.017–0.019

3

0.002

97.007

0.015–0.17

4

0.003

97.004

0.013–0.016

5

0.004

97.002

0.011–0.014

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Fig. 2 Graphic function of velocity variation of grinded material particles between acceleration tube cut and baffle plate

Fig. 3 Velocity field in the grinding chamber

4 Conclusion The analysis of the frequency of damage accumulation in the epoxy polymer structure subjected to tensile load showed that the proposed approach can be successfully used to identify “critical” levels of loading and deformability that cause the greatest number of structural defects. Moreover, to obtain the most objective results, it is advisable to analyze not a single “most representative” sample, but all samples of the series under study.

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Acknowledgements This work was realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V G Shukhov, using equipment of High Technology Center at BSTU named after V G Shukhov.

References 1. Akunov VI (1961) Experimental studies of installations for fine grinding with countercurrent jet mills. VNIINSM, Moscow 2. Bogdanov VS, Dmitrienko VG (1995) Obtaining ultrafine chalk powder in a countercurrent jet mill. Abstracts of reports. Belgorod 3. Uvarov VA (1961) Development, research, methodology for calculating the design and technological parameters of countercurrent jet mills. BelGTASM, Belgorod 4. Starchik YuYu (2009) A jet mill with a cylindrical grinding chamber. BelGTASM, Belgorod 5. Bogdanov VS, Shopina EV, Bulgakov SB, Galushko RV (16 November 2020) Patent no. 2000128608/03. Device for vortex grinding of materials, bull. 5 6. Loskutyev YuA, Maksimov VM, Veselovsky VV (1986) Mechanical equipment for enterprises producing cementitious building materials. Mashinostroenie, Moscow 7. LNCS Homepage. https://studfile.net/preview/7493544/page:15/. Accessed 20 Oct 2020 8. Dmitrienko VG, Logachev IN, Logachev KI, Shemetov EG, Shemetova OM, Cherednichenko ES (22 May 2019) Patent no. 2019115765. Jet mill for ultrafine grinding, bull. 20 9. Thomas P (1991) Development of mill for the Zement Industry. In: 33-nd IEEE cement industry technical conference, pp 171–189 10. Bogdanov VS (1996) Mechanical equipment for enterprises of the building materials industry. BelGTASM, Belgorod 11. Schneider LT (1985) Energy saving clinker-grinding systems. World Cem 16(2):20–27 12. Schneider LT (1985) Energy saving clinker-grinding systems. World Cement (3), 20–27 13. Mayerhauser D (1990) FlieBbett: chemical production (3), 32–35 14. Sternin LE (1974) Fundamentals of gas dynamics of two-phase flows in nozzles. Engineering, Moscow 15. Starchik YuYu (2009) To the calculation of the design and technological parameters of the cylindrical grinding chamber of the jet mill. Bull BSTU named after V.G. Shukhov (1), 104–106

Reliability of Normal Cross Sections of Bending Reinforced Concrete Elements A. N. Yakubovich

and I. A. Yakubovich

Abstract The dependence of the reliability of the reinforced concrete bending section on the statistical characteristics of the strength of its constituent materials— concrete and reinforcement—is considered. It is shown that the reason for the high reliability of the calculated values of the strength of the reinforcement (at least 1 − 1.39·10−9 when the coefficient of variation of strength 4%), it is advisable to limit the reliability requirements of section levels of reliability strength of concrete. To quantify the reliability of the cross-section, the safety factor for concrete is used, showing the amount by which it is possible to increase the estimated time to the reliability section remained at the level of concrete strength. It is found that B30 class concrete and reinforcement steel grade A400 may increase the estimated bending moment by 10% in the range of rebar from 0.5 to 2.5%, when they are used in a reinforced concrete element, in addition, at the number of rebar from 1 to 2% the estimated bending moment may increase by 15%. The use of low-strength concrete in combination with high-strength reinforcement significantly reduces the permissible increase in the design bending moment. Keywords Reinforced concrete elements · Reliability · Statistic modeling

1 Introduction A large number of works are devoted to the issues of probabilistic calculations of building structures. General issues related to the presence of randomness and uncertainty in engineering systems and processes are discussed in [1]. The practical significance of quantitative reliability indicators is investigated in [2]. Among the works devoted to the study of probabilistic factors that affect the durability and maintenance of structures, [3] can be identified, where the influence of such parameters as the size of the cross section, the strength of concrete and steel reinforcement ratio on the strength of reinforced concrete and fiber-reinforced concrete A. N. Yakubovich (B) · I. A. Yakubovich Moscow Automobile and Road Construction State Technical University (MADI), Moscow, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_27

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elements. The system of factors affecting the operational state of road surface structures is shown in [4, 5]. The construction of the probability density function for the strength of the building material is performed in [6]. In [7], statistical characteristics of the damage value of the reinforced concrete structure are obtained, which are considered as a random variable. Time is an important factor affecting the reliability of structures, as the statistical characteristics of loads and strength of materials can change significantly during the period of operation of the structure. The influence of climate change on reliability is considered in [8, 9]; in [10], time-dependent reliability curves of reinforced concrete structures are constructed. Changes in the mechanical properties of concrete over time and the effect of this process on the reliability of the structure are shown in [11, 12]. The semi-Markov time model in [13] was used to model the wear of the concrete bridge deck. Probabilistic calculations performed when evaluating the reliability of building structures require significant computational resources. One of the ways to speed up the computational process is the use of response surfaces; the advantages of this approach in comparison with direct probabilistic modeling with Monte Carlo methods are shown in [14]. Quantitative reliability indicators based on the response surfaces were obtained in [15, 16]. In this paper, we study the reliability of a rectangular reinforced concrete section under a deterministic load, taking into account the probabilistic nature of the strength of the cross-section materials—concrete and reinforcement.

2 Methods and Materials The maximum bending moment perceived by a rectangular reinforced concrete cross˜ depending on the geometric dimensions section is considered as a random variable M, of the cross-section G and the strength of the materials that make up the cross-section. It is assumed that the strength of concrete and reinforcement are also random variables ˜ respectively), distributed according to the normal law. Thus, the bending (C˜ and S, moment perceived by the cross-section can be expressed as:   ˜ S˜ , M˜ = FM G, C,

(1)

where F M —algorithm for determining the maximum bending moment for fixed geometric dimensions and strengths of concrete and reinforcement. When designing structures, the ultimate bending moment M 0 is determined using (1), where instead ˜ the deterministic calculated strengths of concrete C 0 of random variables C˜ and S, and reinforcement S 0 are used. Accordingly, M 0 will be referred to as the calculated moment in the future. The calculated moment M 0 can be considered as one of the possible realizations ˜ The reliability of the calculated moment QM is defined as of the random variable M.

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the probability that the actual moment M, perceived by the cross-section, will be at least M 0 : Q M = p(M ≥ M0 ),

(2)

˜ Similarly, the where p—probability, M—the realization of a random variable M. strength reliability of reinforced concrete cross-section materials QC for concrete and QS for reinforcement can be determined. The bending moment, which has the same reliability as one of the materials of the reinforced concrete section, is called the reduced moment for this material. The reduced concrete moment M C is determined from the condition: Q C = p(M ≥ MC ).

(3)

In the same way, the moment M S reduced by the valve is determined. Reliability coefficients of the bent section for concrete β and for reinforcement α: β=

MC MS ,α = . M0 M0

(4)

The current Russian norms for the calculation of reinforced concrete structures (code of rules SP 63.13330.2018 “Concrete and reinforced concrete structures”) prescribe the following procedure for assigning the calculated strength of concrete and reinforcement. First, the standard value of the strength of the material Rn , which has a reliability of 0.95, is determined. Next, the calculated strength R is determined: R=

Rn , k

(5)

where k = 1.3 for concrete and k = 1.15 for reinforcement. As a result of the reliability of the calculated strength of the materials, QC and QS are dependent on the coefficients of variation of the random variables C˜ and S˜ (vC and vS , respectively). In accordance with the above calculation standards, the calculation of the maximum bending moment M perceived by the cross-section at fixed strengths of materials C and S (F M algorithm) requires the determination of the height of the compressed concrete zone x and the curvature ρ. For a rectangular cross-section without reinforcement in a compressed zone and for single-row reinforcement of a stretched zone, the values of x and ρ are related by the ratio: 

h0

σC [ρ(z + x − h 0 )] · bdz = σ S [ρ(h 0 − x)] · A S ,

(6)

0

where h0 —working cross-section height, b—section width, AS —the total area of tensile reinforcement, σC (εC )—stresses in compressed concrete, depending on

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State chart of stretched reinforcement of classes A400 and A500

State chart of compressed concrete Rs Stresses in reinforcement

Stresses in concrete

Rb 0.6Rb

εb1

4.8·10–3

3.4·10–3

Relative deformation of concrete

Rs/Es 0.025 Relative deformation of reinforcement

Fig. 1 State charts for reinforced concrete cross-section materials

the relative deformation of concrete εC and determined by the diagram in Fig. 1, σS (εS )—stresses in the stretched armature (Fig. 1). The limiting bending moment is defined as the maximum of all the moments corresponding to the possible combinations of x and ρ: 

h0

M = max x,ρ

σC [ρ(z + x − h 0 )] · b · zdz.

(7)

0

In general, the procedure for quantifying β and α is performed in the following sequence. First, the concrete and rebar classes are assigned (which determine the strength characteristics of these materials), as well as the coefficients of variation in the strength of the materials vC and vS , the dimensions of the rectangular section b i h0 , as well as the number of rebar in the stretched zone AS are fixed. Further, based on the vC and vS are determined by the normative and the calculated values of strengths of materials, reliability design strengths QC and QS (2), the design moment M 0 (7) is calculated (7). Then the methods of statistical simulation get n pairs of ˜ and for each pair in accordance with the realizations of random variables C˜ and S, design standards bending moment M is calculated. On the basis of n realizations ˜ the most suitable law of its distribution (from the number of a random variable M, described by Pearson curves) is determined. Based on the obtained distribution law, the reduced moments M C and M S (3) are calculated and the reliability coefficients for concrete and reinforcement (4) are determined.

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3 Results and Discussion

Reliability coefficient by concrete

1.2

1.1

1.0

0.9

Reliability coefficient by reinforcement

Concrete B12.5 Reinforcement A600

0

Concrete B12.5 Reinforcement A600

1.2 1.0

0.5

0

0

Concrete B30 Reinforcement A400

1.2

1.1

1.0

0.9

1 2 3 Longitudinal reinforcement, %

Reliability coefficient by reinforcement

Reliability coefficient by concrete

In this paper, we investigated the reliability of cross-sections of bending reinforced concrete elements without pre-stressing. For such elements, the design standards recommend the use of concrete of class no higher than B30, and reinforcement of classes A400—A600. The determination of the values of the reliability coefficients for the materials was carried out with two extreme combinations of their strength properties. In the first variant, low-strength concrete (class B12.5) and highstrength reinforcement A600 provided the maximum area of the compressed concrete zone (and the maximum height of the compressed zone x) required to balance the

1.2

0

1 2 3 Longitudinal reinforcement, %

Concrete B30 Reinforcement A400

1.0

0.5

0 0 1 2 3 1 2 3 Longitudinal reinforcement, % Longitudinal reinforcement, % Coefficient of variation of the strength of the reinforcement: 1% 2% 3% 8.2 % 4% 6%

Fig. 2 Reliability coefficients β and α for a bending rectangular reinforced concrete section

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tensile force in the reinforcement. In the second variant (concrete B30 and reinforcement A400), the x value was minimal, due to the significant possible stresses in the compressed zone of high-strength concrete. The coefficient of variation of the concrete strength in all cases was assumed to be 13.275%. In this case, the reliability of the calculated strength of concrete QC was 0.99865, which corresponds to three standard deviations from the average value of the random variable C˜ and is widely used in reliability theory as a sign of an acceptably low probability of failure for most technical objects. The coefficient of variation in the strength of the reinforcement varied from 1% (reliability QS ≈ 1 − 9.43·10−48 ) to 8.287% (QS = 0.99865). The number of combinations of realizations of random variables C˜ and S˜ when performing statistical modeling was 25,000. The results of the quantitative evaluation of the reliability coefficients β and α for the amount of stretched reinforcement from 0.01 to 3% of the total area of the concrete section are shown in Fig. 2. In Fig. 2, we can see that if we require the same reliability from concrete like material of reinforced concrete cross-section and reinforced concrete section as a whole, in most cases, there is a stock of the bearing capacity of flexible element (the value of the safety factor for concrete, β > 1). This is especially noticeable with high-strength concrete or with small values of the coefficient of variation of the reinforcement. Requirements of equal reliability of reinforced concrete crosssection and reinforcement, on the contrary, lead to conclusions about insufficient reliability of the bending elements (α < 1), and the use of reinforcement with more stable strength characteristics (reduced vS values), as a rule, leads to lower values of α (except for cases when the amount of reinforcement is small).

4 Conclusion Based on the comparison of the values of β and α obtained in this study, it can be concluded that the reliability coefficient for concrete reflects more adequately the requirements for the reliability of the reinforced concrete section of the bending element as a whole than the reliability coefficient for reinforcement. The most typical values of the coefficient of variation in the strength of reinforcement (2–4%) cause very high values of the safety of the calculated resistance of this material (not less than 1 − 1.39·10−9 ). It is impractical to transfer these reliability values to the entire cross-section, which includes concrete that has a significantly lower reliability of strength than reinforcement. The values of the safety factor for concrete in all types of reinforcement and any variability of its strength obey the same laws: with increasing percentage of reinforcement cross-section (followed by an increase in the height of the compressed zone of concrete x) the value of β increases first, and then with a further increase in reinforcement returns to the values β ≈ 1. The occurrence of a descending branch on the graph β is caused by an increase in x to values at which the stresses in the reinforcement become less than its strength, and the load-bearing capacity of the

Reliability of Normal Cross Sections of Bending Reinforced Concrete Elements

205

reinforcement ceases to be fully used. As a result, the reliability of the entire section as a whole begins to be determined only by the reliability of the concrete, while the values of β tend to 1. From a practical point of view, it should be noted that for certain values of the percentage of reinforcement, it is possible to increase the bearing capacity of the element (increase the maximum permissible bending moment) by up to 10%, and in the case of using reinforcement with low coefficients of variation of its strength—up to 15%. With the increase of concrete strength (ceteris paribus) and increases the range of values of the reinforcement ratio, which may increase the bearing capacity of the element without compromising its reliability. In particular, for concrete B30 and reinforcement A400 with a coefficient of variation of its strength up to 4%, an increase in the load-bearing capacity by 10% is possible with the amount of reinforcement from 0.5 to 2.5%, that is, in almost the entire range of possible values. Moreover, in the range from 1 to 2 percent of reinforcement, it is possible to increase the load-bearing capacity by 15%. The use of low-strength concrete reduces significantly this range: with B12.5 concrete and A600 reinforcement, a 10% increase in load-bearing capacity is only possible with an amount of reinforcement from 0.25 to 0.5%.

References 1. Doltsinis I (2012) From determinism to probabilistic analysis and stochastic simulation. Eng Comput 29(7):689–721. https://doi.org/10.1108/02644401211257227 2. Spyridis P, Strauss A (2020) Robustness assessment of redundant structural systems based on design provisions and probabilistic damage analyses. Buildings 10(12):213. https://doi.org/10. 3390/buildings10120213 3. Amran M, Fediuk R, Vatin N, Mohammad AM, Aamar D, Mohamed E-Z, Klyuev SV, Nikolai V (2020) Fibre-reinforced foamed concretes: a review. Materials 13(19):4323 4. Yakubovich AN, Yakubovich IA, Trofimenko YuV, Shashina EV (2019) Intelligent management system of the automobile road’s technical and operational condition in the cryolithozone. In: Proceedings systems of signals generating and processing in the field of on board communications, SOSG 2019’03. https://doi.org/10.1109/SOSG.2019.8706742 5. Yakubovich A, Mayorov S, Pyatkin D, Yakubovich I (2020) Monitoring and predicting the state of the road network in Russia’s cryolitic zone. Adv Intell Syst Comput 1116:924–933. https://doi.org/10.1007/978-3-030-37919-3_91 6. Loebjinski M, Rug W, Pasternak H (2020) The influence of improved strength grading in situ on modelling timber strength properties. Buildings 10(2):30. https://doi.org/10.3390/buildings 10020030 7. Feng D-C, Yang C-D, Ren X-D (2018) Multi-scale stochastic damage model for concrete and its application to RC shear wall structure. Eng Comput 35(6):2287–2307. https://doi.org/10. 1108/EC-09-2017-0371 8. Kharun M, Klyuev S, Koroteev D, Chiadighikaobi PC, Fediuk R, Olisov A, Vatin N, Alfimova N (2020) Heat treatment of basalt fiber reinforced expanded clay concrete with increased strength for cast-in-situ construction. Fibers 8:0067 9. Trofimenko YuV, Yakubovich AN, Yakubovich IA, Shashina EV (2020) Modeling of influence of climate change character on the territory of the cryolithozone on the value of risks for the road network. Int J Online Biomed Eng 16(07):65–74. https://doi.org/10.3991/ijoe.v16i07.14557

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10. Croce P, Formichi P, Landi F (2020) Influence of reinforcing steel corrosion on life cycle reliability assessment of existing R.C. Buildings 10(6):99. https://doi.org/10.3390/buildings 10060099 11. Ma YS, Wang YF (2012) Creep effects on the reliability of a concrete-filled steel tube arch bridge. J Bridge Eng 18(10):1095–1104. https://doi.org/10.1061/(ASCE)BE.1943-5592.000 0446 12. Cifuentes H, Montero-Chacón F, Galán J (2019) A finite element-based methodology for the thermo-mechanical analysis of early age behavior in concrete structures. Int J Concr Struct Mater 13:41. https://doi.org/10.1186/s40069-019-0353-0 13. Manafpour A, Guler I, Radli´nska A, Rajabipour F, Warn G (2018) Stochastic analysis and timebased modeling of concrete bridge deck deterioration. J Bridge Eng 23(9):04018066. https:// doi.org/10.1061/(ASCE)BE.1943-5592.0001285 14. Gomes MH, Awruch MA (2005) Reliability analysis of concrete structures with neural networks and response surfaces. Eng Comput 22(1):110–128. https://doi.org/10.1108/026444005105 72433 15. Su C, Liao W, Tan L, Chen R (2016) Reliability-based damage identification using dynamic signatures. J Bridge Eng 21(3):04015058. https://doi.org/10.1061/(ASCE)BE.1943-5592.000 0819 16. Yakubovich A, Yakubovich I (2021) Using the response surface to assess the reliability of the Russian cryolithozone road network in a warming climate. Adv Intell Syst Comput 1258:486– 495. https://doi.org/10.1007/978-3-030-57450-5_42

Peculiar Features of the Deformation of Horizontal Masonry Mortar Joints Under Short-Term Forceful Compression O. M. Donchenko , I. A. Degtev , V. N. Tarasenko , and J. V. Denisova

Abstract Designers’ attention is drawn to the necessary constructive calculations not only for the strength of multi-storey, multi-layered, and multi-loaded walls, but also for deformations. The article shows peculiar features of deformation-strength properties of mortars in horizontal masonry joints under forceful compression, compared with those in standard mortar samples in standard tests. It is necessary to jointly consider the conditions of equilibrium and deformations, since the work conditions in the masonry of stone and mortar of different types are polar opposite. The stone is vertically compressed by the load and transversely stretched by the mortar that is usually more subjected to deformation, as a result of which its strength in the masonry is significantly lower than the standard compressive strength. The mortar, whose transverse deformations are constrained by less deformable stones, on the contrary, is unevenly compressed both in the vertical and transverse directions, due to which its strength, unlike deformations, increases significantly. Keywords Mortar · Horizontal joints · Strength · Deformability · Masonry · Compression · Reduction of the modulus of deformation · Spatial strain state · Change in the modulus of deformation

1 Introduction Many problems and issues of the theory of operation and methods of calculating masonry designs require the knowledge of the actual laws of mortar deformation in its horizontal joints under forceful compression. Masonry deformations need to be known at all stages and levels of its operation. They include such aspects as: the absence of first vertical cracks in the stones at the 1st stage, occurrence of such cracks in two adjacent rows of stones at the 2nd stage, development of vertical main cracks in unreinforced masonry at the 3rd stage, and, of course, at the 4th stage after its resistance depletion [1]. O. M. Donchenko · I. A. Degtev · V. N. Tarasenko · J. V. Denisova (B) Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_28

207

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O. M. Donchenko et al.

The knowledge of these deformation laws is necessary for the calculations of elements’ design when operating differently loaded multi-layered walls, walls with external and internal lining, intersections of external and internal walls of various height to prevent their cracking and destruction [2]. Scientific and technical publications rarely provide the results of studies of the nature and characteristics of mortar deformation, as they consider these issues irrelevant, while over 65% of buildings’ walls are built with masonry made of bricks and small artificial stones. There is an increasing number of reports about the laws of deformation of various types of modern concretes [3]. And the deformation nature of mortars that are used for masonry is commonly considered the same as determined when testing the mortar in standard samples (70-cm cubes and same size crosssection prisms, in which the value of the initial deformation modulus E0 , usually called the initial modulus of elasticity, gradually decreases to zero as the loading increases [4]. Naturally, this approach cannot be considered correct. Since the tangent modulus of deformation E at the depletion of the material’s resistance is equal to zero, the corresponding compression deformation σR must be infinite, which completely contradicts the results of physical experiments. Therefore, researchers more and more often try to use not the tangent, but the secant modulus of deformation E , the so-called the “average modulus of deformation.” As an example of the nature of standard cement mortar samples’ deformation, only the curves of deformation of M50 and M200 cement mortars are shown on the graph (Figs. 1a, b). These curves result from our studies [2, 3, 5] and differ significantly from each other and from the single curve of deformation of all grades of cement mortars according to the research of V.V. Pangaev (Fig. 1). Fig. 1 The change of the secant modulus of deformations E of cement mortars with a loading level: A, B—are the authors’ experiments for grades M50 and M200, respectively; C—are the calculated values according to the theory of V.V. Pangaev; D—are the calculated values according to the authors’ method for grade M50; E—are the values calculated by the authors’ method for grade M200 in horizontal masonry joints

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209

This method allowed to establish the uniformity of the prototype tests, which resulted in better stability of the obtained results, but still did not eliminate the need to develop a special method for their processing, due to their natural dispersion at the first and last stages of loading [6]. This method consisted in correcting the zero readings, establishing the valid value of the initial modulus of deformation E0 and  the most reliable values of the maximum secant modulus of deformation E R .  This graph, drawn in the new coordinates σ/R − E /E0 , ensures better observability with the ratio of the strain values and absolute deformation l, which are easily found from the experimental results of each loading stage [7–9]. The monotonic smoothness of our deformation curves (without occasional overshoots) of standard cement mortar samples, unusual for experimental studies, and the  determination of specific maximum values of their moduli of deformations E R and corresponding critical compression deformations σR without ordinary dispersion, typical of other studies [4–6], is due to the constant use of the uniform methodology for testing and processing their results in our studies [8]. This sample test procedure included the following steps: – The supporting faces of the prisms were carefully ground. – The centering was carried out under a load of 0.05…0.3 Pdestr with subsequent triple unloading and loading. Having ascertained a sufficient equality of deformations along all the four faces (the difference between readings did not exceed 10…15%), we proceeded with further sample testing until its destruction [1, 9]. – Two twin samples were tested to determine R under continuous loading at a rate of 0.8…0.15 kg/cm2 per second until their destruction. The rate was determined with a stopwatch and at the time preceding the destruction, the rate of the sample deformation had to be increased [10]. – The next two twin samples were tested with one-minute stops at each stage for reading values and examining the sample until the level of 0.9 Pdestr , after which the loading was carried out continuously until the sample destruction. The readings for all four faces were checked simultaneously [11]. – The entire series, consisting of 4 prisms, was tested for 24 h. Laboratory practical experience shows that finding the initial modulus of deformation E0 is associated with certain errors in initial loading, dead motion of devices, and some conventionality of initial readings. Professor O.Ya. Berg [5, 12] noted that laboratory testers usually disregard the initial deformations. The first deformation measurements associated with the sample centering are not taken into account further. In addition, we always take a certain minimum load on the sample, with respect to which the zero readings are taken. Errors associated with it sometimes result in a much lower initial modulus of deformation at the strains of (0.02…0.10) R, than at the strain of 0.2 R, which is erroneous [13].

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2 Methods and Materials To eliminate these shortcomings and obtain comparable data, we processed the test results by a universal method, which consisted in correcting the zero and limiting readings and finding the valid values of the initial moduli of deformation E0 . The essence of this method was based on the fact that the initial value of the modulus of deformation E cannot be less than the value of the secant modulus of deformations E , corresponding to the strain of 0.2 R. In practice, this resulted in the requirement to correct the first, second, third, and fourth reading differences to ensure the equality or monotonous increase in the increments of the last readings. Such corrections of the experimental values of E0 and E as a rule were needed until the third or fourth  differences only. This made it possible to obtain more reliable values of E0 , E , E R ,  and σR and reach a certain uniformity of the E /E0 − σ/R curves’ shape for all tested cement mortars of different strengths, including grades M25—M200 [10, 14]. To approximate the obtained cement mortar deformation curves with simple analytical functions, it was necessary to meet the requirements of their passage through three main points: before the loading, when σ/R = 0, and E = E0 ; at the loading level σ/R = 0.2, and at the limit value of the load, when σ/R = 1.0, i.e. when the resistance of the sample is depleted. According to our experimental results, these requirements are best met with the dependence of the secant modulus of deformations in the following form using Eq. (1):   E = E0 1 − λ(σ/R)2

(1)

where ratio λ depends only on the strength (grade) of the mortar and is equal to using Eq. (2): λ = 1 − E /E0

(2)

In dependences (1) and (2), ratio λ best corresponds to the characteristic of plasticity at the depletion of the cement mortar resistance, equal to the ratio of the work input for plastic deformation to the general work input for the sample deformation and destruction. An analysis of the results of the authors’ research made it possible to obtain a simple dependence of this ratio on the strength of cement mortars in the following form using Eq. (3): λ = 1/(1.10 + 0.03R)

(3)

which particularly for grade M50 and M200 mortars provides their plasticity values of 0.80 and 0.59, respectively. In this case, ratio ER /E0 can represent the elasticity of cement mortars at their destruction. All the foregoing concerned only the deformation of cement mortars in standard samples (cubes and prisms), in which the loads and deformations are measured by precise methods. As for similar measurements of strains and deformations of mortars

Peculiar Features of the Deformation of Horizontal Masonry Mortar Joints …

211

in horizontal masonry joints, modern methods and instruments virtually fail to ensure the appropriate precision. Unlike the linear strained-deformed state (SDS) of standard samples under axial compression, the mortar in horizontal masonry joints resides in a complex spatial compression state, in which its strength increases significantly as the resistance of the masonry is depleted, unlike deformations.

3 Results and Discussions The very representative example of the above is the strength of masonry with M300 bricks and M25 mortar, the strength of which (50 kg/cm2 ) is twice the strength of the mortar and the masonry destruction occurs through bricks, rather than through the mortar. Indeed, as shown by the experiments of many studies, and in particular by those provided by S.A. Sementsov, S.V. Polyakov, the authors of [2–4, 10], the mortar deformations in masonry joints differ significantly from the deformations of prisms made from the same mortar, and their exact measurement is extremely difficult. This is due to the complex macro-inhomogeneous composite environment of the masonry, consisting of a conglomerate of discretely placed stones and enveloping layers of the mortar, i.e. multiply statically indeterminate system, which should not be solved through differential equations of the classical theory of elasticity and plasticity, since their basic assumptions about the continuity and homogeneity of the material are not met [14]. It is necessary to jointly consider the conditions of equilibrium and deformations, since the work conditions in the masonry of stone and mortar of different types are polar opposite. The stone is vertically compressed by the load and transversely stretched by the mortar that is usually more subjected to deformation, as a result of which its strength in the masonry is significantly lower than the standard compressive strength [15]. The mortar, whose transverse deformations are constrained by less deformable stones, on the contrary, is unevenly compressed both in the vertical and transverse directions, due to which its strength, unlike deformations, increases significantly. A significant influence of the thickness of the horizontal mortar joints on the strength of masonry in Central compression confirmed by the results of testing the bearing capacity of the samples is presented in Table 1. There was an increase of tadinya from 5 to 50 mm, which reduced the strength of the samples 2.6…2.7 times (from 12.6 V to 4.6 MPa) (Fig. 2) [16]. As experimental results, the average strength of 5…6 twin prototypes is given. Thus, according to the Maximum Distortion Energy Theory of Failure of Huber– Mises–Genki as recorded by P.P. Balandin, we can consider proven the obvious increase in the tensile strength of mortar in masonry, and the actual change in the  usual development of its deformations and the secant modulus E R , which, for the time being, is very difficult to identify, should comply with it. With the current absence of a physically reliable deformation theory of mortar plasticity, our theoretical studies

212

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Table 1 Influence of the thickness of horizontal mortar joints on the strength of masonry under central compression Serial number

The type and strength of the brick, MPa

Type and strength of the solution, MPa

1

Silicate full-bodied, 22.4

Cement-based, 1.8

Silicate full-bodied, 22.4

Cement-based, 6.0

2

4

Silicate Hollow, 10.4

Silicate Hollow, 10.4

Breaking strength, MPa Experienced

According to the SNiP

By the decision of the author

5

12.60

3.2

12.91

12

10.30

3.2

9.56

30

6.40

3.2

6.18

50

4.60

3.2

4.50

5

16.10

4.4

15.93

12

13.00

4.4

12.79

30

9.10

4.4

8.94

50

6.87

4.4

6.71

3

10.10

–

9.62

10

6.00

3.4

6.70

15

5.90

3.4

6.02

20

4.90

3.4

5.47

30

4.10

3.4

3.87

10

6.83

3.6

6.94

Polymer, 7.9

3

8.10

–

8.87

Polymer,10.8

3

9.80

–

8.45

Polymer,10.8 3

Seam thickness, mm

Cement-based, 7.8

Cement-based, 9.6

Fig. 2 Influence of the thickness of horizontal mortar joints on the strength of masonry under central compression: A—Strength of masonry made of silicate solid bricks on cement mortar (mortar strength 1.8), respectively; B, D—calculated strength index according to the authors’ method; C— Strength of masonry made of silicate solid bricks on cement mortar (mortar strength 6.0); D—are the calculated values according to the authors’ method for grade M50; F—the breaking strength provided for in the normative literature, MPa

Peculiar Features of the Deformation of Horizontal Masonry Mortar Joints …

213

and calculations were supported by our refinement analytic dependence (for this case) form using Eq. (4):   E = E0 1 − 0.5λ(σ/R)2

(4)

where the mortar plasticity ratio λ in the conditions of three-sided uneven compression is almost halved. As an example, the deformation curves of two cement mortars M50 and M200 in masonry under indices “g” and “d”, drawn based on this dependence, are shown in the graph in Fig. 1, whose limiting values of the moduli of deformation E’ R at resistance depletion are reduced to 0.6 and 0.7 E0 , accordingly.

4 Conclusion As shown by the processed results of our numerous studies, this method provides for the closest agreement between theoretical and experimental results. Acknowledgements This work was realized under the support of the President Scholarship; in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V G Shukhov, using equipment of High Technology Center at BSTU named after V G Shukhov.

References 1. Pangaev VV, Serdyuk VM (2014) On the deformative characteristics of cement mortars. In: Proceedings of higher educational institutions. Series of construction, vol 9, no 549, pp 110–113 2. Degtev IA, Donchenko OM (1982) Experimental studies of deformation and resistance of silicate brick masonry based on various mortars under axial compression. In: Building structures and engineering facilities. Collection of papers, pp 3–10. MISI, BTISM, Moscow 3. Donchenko OM, Degtev IA (2000) About the development of the theory of crack resistance and masonry resistance under compression. In: Proceedings of higher educational institutions construction and architecture, vol 10, pp 16–20 4. Donchenko OM, Degtev IA (2011) Effective construction and technological solutions and materials for mass civil construction. In: The collection: innovations in the sectors of the national economy, as a factor in solving the current social and economic problems. Proceedings of the international scientific and practical conference, pp 32–36. Moscow State Academy of Public Utilities and Construction, Moscow 5. Donchenko OM, Pashchenko ZhN (2013) The current state of the theory of resistance and methods for calculating artificial-stone masonry. Bull BSTU named after V.G. Shukhov 4:19–21 6. Donchenko OM, Degtev IA (2013) Deformations of masonry under axial short-term compression. Bull BSTU named after V.G. Shukhov 3:44–46 7. Degtev IA, Donchenko OM, Tarasenko VN (2016) Development of expedient process methods for manufacturing stone structures. In: High technology and innovation. Proceedings of the international scientific and practical conference, vol 2, pp 21–26 8. Grunau EB (1976) Ziegelmauerwerk. Deutsche Bauzeitschrift 5:641–644 9. Jain AK (1978) Tests or Brick couple. Proc J Civ Eng XII(65/2):90–915

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10. Polyakov SV (1959) Long compression of brickwork. Gosstroizdat, Moscow, p 183 11. Berg OYa (1961) Physical foundations of the theory of strength of concrete and reinforced concrete. Gosstroizdat, Moscow 12. Geniev GA, Kisyuk VN (1974) Theory of plasticity of concrete and reinforced concrete. Stroyizdat, Moscow 13. Donchenko OM, Al-Hashimi O, Ismail (2018) The current state of the theory of resistance and methods for calculating masonry from cellular concrete stones under compression. In: 2017 through the eyes of scientists: collection of scientific papers, Krasnodar, pp 81–84 14. Kosarikov SV (1976) Properties of masonry from a silicate brick on solutions with liquid glass binder. Constr Archit Uzbekistan 6:14–18 15. Geniev GA (1979) On the criteria for the strength of masonry in a flat stressed state. Const Mech Calc Struct 2:7–11 16. Donchenko OM, Degtev IA, Tarasenko VN, Zhikharev ND (2019) Deformation of horizontal joints’ mortar of masonry under compression. Bull BSTU named after V.G. Shukhov 5:42–49

Selection Algorithm of Geotechnical Technologies for Amplification of Weak Bases N. S. Sokolov

and P. Yu. Fedorov

Abstract One of the main directions of geotechnical construction is the reconstruction of objects. This type of construction in most cases is associated with the need to strengthen the foundations of the bases. Geotechnicians are particularly concerned about the presence of weak underlying layers at the base, which complicate the reliable operation of the constructed objects. Due to the availability of modern geotechnical technologies, it is possible to minimize their negative impact. When choosing them, the principle of “technical feasibility and economic efficiency” must be observed. The paper considers several geotechnical technologies for strengthening weak bases. The principle of selecting a technically feasible and cost-effective type is considered. Keywords Load-bearing capacity · Geotechnical technology · Drill-injection pile · Ground concrete pile

1 Introduction Reconstruction of objects, as a rule, provides for an increase in loads on the foundations and in this regard, it is associated with the use of buried reinforced concrete structures, their device is supposed to be performed in cramped conditions [1–7]. In this regard, from a number of modern geotechnical technologies, the most suitable for specific engineering and geological conditions is selected according to the criteria of technical feasibility and economic efficiency. In this paper, for comparison, the three most adapted geotechnical technologies for reconstruction purposes are considered: 1)

technology of the device of drilling-injection piles without compaction of the ground of the drilling well;

N. S. Sokolov (B) Chuvash State University named after I. N. Ulyanov, Moskovskiy prosp., 15, Cheboksary 428015, Russian Federation N. S. Sokolov · P. Yu. Fedorov NPF (LLC SPC) “FORST”, Ul. Kalinina, 109a, Cheboksary 428000, Russian Federation © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_29

215

216

2) 3)

N. S. Sokolov and P. Yu. Fedorov

electric discharge technology of drilling-injection piles (EDT technology); technology of the setting of soil–cement piles (Get-technology).

2 Methods and Materials The problem of ensuring their further reliable operation of both new construction projects and existing buildings remains a very urgent task. To solve this problem, it is often necessary to use geotechnical technologies that do not have a negative impact on existing structures and exclude the occurrence of undesirable deformations in them. One such advanced technology of geotechnical and underground space development is the discharge-pulse technology of setting drilling-injection piles (EDT technology)—micropiles and building transformation of properties of the foundation soils, have low values of physical–mechanical characteristics. Having significant advantages over other methods of construction of the underground part of buildings and structures, the geotechnical EDT technology has a scientific novelty. As a basic structure for the development of isotope technologies, it has a great potential for scientific research for the purpose of inserting it into modern underground construction. The symbiosis of electric discharge technology with other technologies (for example, ground-cement technology) gives hope for the creation of promising geotechnical methods for strengthening the foundations. It should be noted that the feasibility of using micropiles is determined by the specific conditions of the construction site and the feature of the object based on the results of a technical and economic comparison of possible design solutions. That is, the principle of interactive design of the “technical feasibility and economic efficiency” of the adopted design decision must be observed. The considered geotechnical electric discharge technology has a practical significance confirmed by the construction experience.

3 Results and Discussion According to the data of the materials in the engineering-geological section of the site with a depth of 55.0 m, the following sediment complexes are distinguished (in the direction from top to bottom):—modern technogenic deposits (tQIV);— alluvial-fluvioglacial deposits of the 3rd above-floodplain terrace of the Moscow River (af3QII);—fluvioglacial deposits (fQIst-d);—deposits of the Upper Jurassic system (j3);—deposits of the Upper Carboniferous system (C3). Modern technogenic formations (tQIV) were widely distributed around the perimeter of the reconstructed building. They were deposited from the surface under the asphalt surface. They are represented by bulk soils: gray-brown, medium-sized sands, small, heterogeneous, clayey, wet interlayers, with lenses of sandy loam and

Selection Algorithm of Geotechnical Technologies …

217

sanded loam, with construction debris (crushed stone, broken bricks, slag) up to 20%. The thickness of the technogenic formations was 3.2–5.2 m. Mid-quaternary alluvial-fluvioglacial deposits were uncovered during surveys of previous years, during surveys in 2004. They were not present—they were selected when opening the pit of the reconstructed building and replaced with bulk soils along its perimeter. The sediments were represented by gray, yellowish-gray, fine sand, with inclusions of gravel, pebbles and crushed stone, with frequent interlayers of loam of high-plastic, sanded, moist, medium density. The following water- and lake-glacial deposits of the Setun-Don horizon (fQIstd) were uncovered under technogenic deposits. The sediments were represented by:—gray sand, medium size, with the inclusion of pebbles and gravel, watersaturated, with a medium density;—sandy loam brownish-gray, yellowish-gray, plastic, interbedded dusty sand. The total thickness of the deposits is 6.6–9.3 m. The Oxfordian layer of the Upper Jurassic system (J3ox) was discovered under the water- and lake-glacial sediments of the Setun-Don horizon at a depth of 12.3– 14.6 m. They are represented by grayish-black, solid clays, semi-solid, micaceous interlayers, with fragments of fauna. The thickness of the deposits was 6.2–10.1 m. Deposits of the Izmailovo pack of the Kasimov stage of the upper part of the Carboniferous system (G3izm) were exposed under Jurassic clays at a depth of 19.5– 23.0 m. The Izmailovo deposits were represented by gray, yellowish-gray, cavernous, fractured, medium-strength limestones, strong, water-bearing layers, with interbeds of variegated, marly clays and marls, and dolomitized interbeds. The thickness of the Izmailovo pack sediments reached 13.3 m. The results of studies of the physical and mechanical properties of soils are shown in Table 1 below. The calculation of the load-bearing capacity Fd of a pile without widening is made in accordance with SP 24.13330.2011 “Updated version of SNiP 2.02.03–85 Pile foundations”.  (γc f · f i · h i )) (1) Fd = γc · (γc R · R · A + u · Where γc —the coefficient of working conditions of the pile in the ground, assumed to be equal to 1 and 1.3 for electric discharge technology; R—calculated ground resistance under the lower end of the pile, kPa (ts/m2 ), accepted according to Table 7.2 of SP 24.13330.2011 “Updated version of SNiP 2.02.03–85 Pile foundations”; A—the area of the pile support on the ground, m; u—external perimeter of the pile cross-section, m; fi —the calculated resistance of the i-th layer of the foundation soil on the side surface of the pile, kPa (ts/m2 ), accepted according to Table 7.3 of SP 24.13330.2011 “Updated version of SNiP 2.02.03–85 Pile foundations”; hi— thickness of the i-th layer of soil in contact with the side surface of the pile, m; γcf , γcR —the coefficients of the working conditions of soil, respectively, under the lower end and on the side surface of the pile, taking into account the effect of immersion of piles on the values of the calculated resistance of the soil and taken at the Table 7.4 SP 24.13330.2011 “Updated edition of SNiP 2.02.03–85 Pile foundations”.

5

4

Limestone of medium strength, strong in layers, with silicification

Solid clays

2.34

1.79

2.00

2.02

Technogenic soil R0 = 150kPa

-

2.74

2.65

2.69

5

0.070

0.381

0.147

0.221

6

-

1.10

0.65

0.63

7

e

-

-

0.069

0.001

0.019

10

c, MPa

-

19

28

17

11

E, MPa

34

12

RCK MPa

2.29

1.78

1.98

2.01

13

-

16

33

15

14

-

0.067

0.001

0.018

15

c, MPa

2.28

1.78

1.96

2.00

16

-

16

32

15

17

ϕ, degree

-

0.065

0.00

0.018

18

c, MPa

ρ, g/cm3

ϕ, degree

ρ, g/cm3

Calculated characteristics With confidence probability 0.95

Calculated characteristics With confidence probability 0.85

; W —humidity, s.u.; e—porosity coefficient; I L —turnover rate; ϕ—internal friction angle, degree; c—specific

-

17

39

16

9

ϕ, degree

coupling, MPa; E—modulus of deformation, MPa; RCK —calculated compression resistance, MPa

g cm 4

-0.074

-

0.52

8

IL

Notes: Strat.index—stratigraphic index; ρ—soil density, cmg 3 ; ρ1 —particle density, ,

4

3

G3izm

Medium-sized, water-saturated, medium-density sand

2

fQI st-d

J3ox

Sandy loam, dusty, plastic

1

tQIV

3

2

1

Brief description Regulatory characteristics of soils ρ, ρ1 , W, g/cm3 g/cm4 s.u

№ of EGE

Strat. Index

Table 1 Normative and calculated values of physical and mechanical properties of soils

218 N. S. Sokolov and P. Yu. Fedorov

Selection Algorithm of Geotechnical Technologies …

219

The EDT pile manufacturing technology with multi-seat widenings allows [8–20] to increase significantly the load-bearing capacity of the Fd pile, which should be calculated using the following formula obtained after converting the formula (1) [10]: Fd = γc · (γc R · R · A + γc R ·



(Ri,side Ai.side ) + u ·

 (γc f · f i · h i ))

(2)

where n—number of extensions; Rj,side —the calculated resistance of the soil under the j-th broadening; Aj,side —the bearing area of the j-th extension, calculated by the formula: Ai.side =

π · (Dc · kush )2 π Dc2 − 4 4

(3)

where Dc —the diameter of the well; k ush —the coefficient of widening, taken according to Table 2 TR50-180–06 “Technical recommendations for the design and installation of pile foundations performed using discharge-pulse technology for highrise buildings” (Moscow 2006). Table 2 Technical and economic calculations of drilling piles №

Type of buried Diameter, mm reinforced concrete structure

1

Drill-injection pile without sealing the well walls

Ø350

896.0

704.0

15.0

2

EDT drill-injection pile

Ø350

1340.0

957.0

11.0

3

EDT single-expansion drill-injection pile

Ø350

1787.0

1276.0

8.0

4

EDT drill-injection pile with two widenings

Ø350

2022.0

1444.0

7.0

5

EDT drill-injection pile with three widenings

Ø350

2302.0

1644.0

6.0

6

Ground concrete pile

Ø600

2157.0

1541.0

7.0

7

Ground concrete pile

Ø700

2680

1910.0

5.0

Bearing capacity, Fd , kN

Design load, kN

The number of piles under the reinforced foundation

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Table 3 Technical and economic calculations of drilling piles №

Type of buried reinforced concrete structure

1

Number of piles, Pcs

Length of piles, r/m

Total stock, r/m

Cost of a running meter of a pile, rubles

Total cost, million rubles

Drill-injection pile 15.0 without sealing the well walls

16.0

240.0

4000–6000

9.6–14.4

2

EDT 11.0 drill-injection pile

16.0

176.0

4000–6000

7.0–10.6

3

EDT single-expansion drill-injection pile

8.0

16.0

128.0

4000–6000

5.1–7.7

4

EDT drill-injection pile with two widenings

7.0

16.0

112.0

4000–6000

4.5–6.7

5

EDT drill-injection pile with three widenings

6.0

16.0

96.0

4000–6000

3.8–5.8

6

Ground concrete pile

7.0

16.0

112.0

9000–11,000

10.1–13.8

7

Ground concrete pile

5.0

16.0

90.0

9000–11,000

8.1–9.9

When arranging the widening along the heel of the pile, the area of its support will be (Table 3): A=

π · (Dc · kush )2 4

(4)

4 Conclusion 1.

2.

According to the results of technical and economic calculations, for the purpose of strengthening the base of an overloaded foundation, the most optimal is the use of EDT drill-injection piles with multiple widenings. The use of ground concrete piles (ground cement pile, reinforced with EDT pile) is also possible to strengthen the foundations of the bases. At the same time, its cost is cheaper than a drill-injection pile without compacting the soil of the well walls.

Based on the results of the determination of the bearing capacity on the ground of buried reinforced concrete structures, we can propose the following algorithm

Selection Algorithm of Geotechnical Technologies …

221

for choosing a technically sound and economically feasible type of geotechnical technology with increasing loads on the foundations: 1.

2. 3. 4. 5.

The number of reinforcement piles under the supporting structure is determined (or per 1 m2 of the belt foundation, or on a columnar foundation, or on a foundation f/c plate); The cost of performing drilling piles is determined; The terms of production of a unit of a buried structure are determined; Static tests determine the actual load-bearing capacity of the pile and compare it with the calculated values. The number of drilling piles per foundation unit is specified.

References 1. Bogov SG, Zuev SS (2010) The Experience of application of inkjet technology for stabilization of soft soils during the reconstruction of the building on Pochtamtskaya street in St. Petersburg. In: Proceedings of the scientific and technical conference of SPbGASU SPb. 80–86 2. Van Impe VF (2005) Foundations of deep Foundation: trends and prospects of development. Reconstr Cities Geotech Constr 9:7–33 3. Vasilyuk LV (2017) vibration Loading of sheet pile near existing buildings in the soil conditions of St. Petersburg. Engineering-geological surveys, design and construction of bases, foundations and underground structures/S6. Tr. All-Russian scientific. Technical Conference 1–3 February 2017 St. Petersburg 307–316 (2017) 4. Gavrilov AN, Gryaznova EM, Starkov RR (2006) The complex of survey and research works for the design of new construction in dense urban areas. Found Bases Soil Mech 6:10–13 5. Gursky AV (2016) Considering the effect of indentation of pile on additional sediment adjacent buildings: Cand. dis. SPb. 133 6. Deckner F, Viking K, Hintze S (2017) Wave Patterns in the ground: case studies related to vibratory sheet pile driving. Geotech Geol Eng 35(6):2863–2878 7. Korff M, Meijers P, Wiersma A, Kloosterman F (2019) Mapping liquefaction based on CPT data for induced seismicity in Groningen. In: Earthquake geotechnical engineering for protection and development of environment and constructions-proceedings of the 7th international conference on earthquake geotechnical engineering, pp 3418–3425 8. Deckner F, Viking K, Guillemet C, Hintze S (2015) Instrumentation system for ground vibration analysis during sheet pile driving. Geotech Test J 38(6):893–905 9. Brinkgerve RBJ (2006) Plaxis: finite element code for soil and rock analyses. Balkema, pp 53–56 10. Denies N, Holeyman A (2017) Shear strength degradation of vibrated dry sand. Soil Dyn Earthq Eng 95:106–117 11. Karol RH (2003) Chemical grouting and soil stabilization. American Society of Civil Engineers 536 12. Moseley MP (2004) Ground improvement. London, p 440 (2004) 13. Dalmatov BI (1981) Mechanics of soils, bases and foundations: textbook for universities. Stroyizdat, Moscow, p 319 14. Dyakonov IP (2017) Assessment of bearing capacity of bored piles with oversized tip. Engineering-geological surveys, design and construction of bases, foundations and underground structures. SB. Tr. All-Russian scientific. Technical Conference, 1–3 February 2017, St. Petersburg, pp 316–322

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15. Nikolay S (2017) Sergey, ezhov, svetlana, ezhova: preserving the natural landscape on the construction site for a sustainable ecosystem. J Appl Eng Sci 482:518–523 16. Sokolov NS (2018) Electroimpulse installation for the production of flight augering piles. Hous Constr 1–2:62–66 17. Sokolov NS (2018) One of the approaches to solve the problem to increase the capacity of bored piles 5:44–47 (2018) 18. Sokolov NS (2018) Ground anchor produced by electric discharge technology, as reinforced concrete structure. Key Eng Mater 76–81 19. Sokolov NS (2018) Use of the piles of effective type in geotechnical construction // log in database. Key Eng Mater 70–74 20. Sokolov NS. One of geotechnological technologies for ensuring the stability of the 1–11

Magnetron Sputtering as a Method of Forming a Protective Coating on Titanium Hydride Shot R. N. Yastrebinsky , S. V. Zaitsev , V. V. Sirota , and D. S. Prokhorenkov

Abstract In the construction practice of nuclear facilities, medical institutions and other special structures, special construction concretes are used. Basalt, limonite, serpentinite, chromite, hematite, barite and metal aggregates and others minerals are used as fillers. However, the most effective materials for radiation protection are metal hydrides, in particular titanium hydride. A limiting feature of its use as a filler is its low operating temperature. Increasing the thermal stability of titanium hydride will make it possible to use this material to obtain a new generation of radiation-protective building materials. In this study, the method of magnetron sputtering is used as a method of forming a protective shell on the surface of a TiH2 shot. A technical solution has been developed and optimal conditions have been determined for uniform coating of the titanium hydride shot. One-layer metal protective coatings of copper and titanium, two-layer Ti/Cu and three-layer Cu/Ti/Cu protective coatings on titanium hydride shot were obtained. By scanning electron microscopy was studyes protective coatings structure and their thickness is determined. The use of such coatings will increase the thermal stability of TiH2 shot and, as a consequence, the efficiency of using titanium hydride as a radiation-protective material. Keywords Magnetron sputtering · Multilayer metal coatings · Protective coatings · Titanium hydride

1 Introduction The modern use of a large number of radiation devices and installations in various spheres of life, from nuclear energy to nuclear transport installations and medical equipment, brings to the fore the problem of ensuring a high degree of biological protection when organizing the safe work of workers and maintenance personnel with such equipment, as well as safe contact with such equipment of the population. R. N. Yastrebinsky (B) · S. V. Zaitsev · V. V. Sirota · D. S. Prokhorenkov Belgorod State Technological University named after V. G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_30

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The issues of the development of modern radiation-shielding materials are becoming increasingly important. Neutron and γ—radiation have the highest penetrating ability among all types of ionizing radiation and represent the main danger to personnel and equipment [1, 2]. The main protection materials are substances consisting of elements with low atomic weights, namely metal hydrides, in particular titanium hydride, since a rather large number of hydrogen atoms can be dissolved in the crystal lattice of metals [3–5]. Titanium hydride is the most promising material for biological shielding of new generation ship nuclear power plants due to its high shielding characteristics with respect to neutron radiation. Its use as the main filler in building materials will make it possible to obtain new, promising materials for biological protection against radioactive radiation. It is most technologically advanced to use titanium hydride in the form of a shot, since it is strong enough, does not crack during operation and does not form a fine explosive fraction. However, titanium hydride has a low exploitative temperature (up to 300 °C), which limits its use [6]. In this regard, an important task is to increase the thermal stability of titanium hydride. One of the ways to increase the thermal stability of titanium hydride shot is to create a metal shell on its surface, which should prevent material decomposition during operation and ensure its effective use at higher temperatures. One of the ways to increase the thermal stability of titanium hydride shot is to create a metal shell on its surface, which should prevent material decomposition during operation and ensure its effective use at higher temperatures. The deposition of metallic copper on the hydride from aqueous solutions of copper sulfate [7] increases the thermal stability of titanium (II) hydride powder by about 60 °C. In the works [8, 9] authors modify the surface of a titanium hydride shot with boron-containing compounds. The object of this work is to apply a protective shell on a titanium hydride shot by magnetron sputtering. Vacuum-plasma technology is taken into assessment as a method of effective modification of the surface of TiH2 shot [10]. The formation of a homogeneous film on the surface of titanium hydride will increase its thermal stability. The main advantage of using magnetron sputtering is effective control of the thickness and chemical purity of the films, which makes it possible to form a very uniform high-quality coating over the entire surface of the TiH2 shot.

2 Methods and Materials The coating was applied to titanium hydride shot in the form of spherical granules 0.2–2.5 mm in diameter. The titanium hydride shot was developed by Open Joint Stock Company VNIINM (Moscow, Russia) according to the specifications of Open Joint Stock Company NIKIET (Moscow, Russia). The coating was applied in a QUADRA 500TM vacuum installation equipped with a quadrupole unbalanced magnetron sputtering system. A stainless steel bowl with shot was placed on the planetary mechanism at an angle of 45° from the normal position and rotated at a speed of 18 rpm. As a result of this rotation, the titanium hydride shot were uniformly

Magnetron Sputtering as a Method of Forming …

225

Fig. 1 Scheme of the formation of a magnetron coatings on a titanium hydride shot

Table 1 Deposition parameters of Ti and Cu coatings

Coating type

Coating thickness, μm

Spraying time, min

Spray power, kW

Cu

0.89

7

0.5

Ti

1.46

15

0.35

Ti/Cu

1.6/0.8

17/7

0.5/0.35

Cu/Ti/Cu

1/1.1/0.8

9/14/7

0.35/0.5/0.35

mixed during spraying. Four magnetrons are vertically installed along the perimeter at a distance of 70 mm from the bowl. Such a device (see Fig. 1) allows a relatively large amount of titanium hydride shot to be efficiently mixed and coated uniformly. The vacuum chamber was pumped out to a pressure of no more than 9 · 10–3 Pa. Before applying the coating, the surface of the shot was cleaned by ion etching in argon for 10 min at a pressure of 8 · 10–2 Pa and a voltage across the ion source of 1.8 kV. The magnetrons were operated in a bipolar pulsed 50 μs (18 kHz) mode of keeping the power at the level of 0.5 and 0.35 kW for Ti and Cu, respectively. The working pressure in the chamber was 0.22 ± 0.001 Pa. Pure argon (99.999% purity) was used as the spray gas and the flow rate was 80 SCCM. The target was pre-sprayed for 2 min to remove any surface contamination. During coating, the substrate was not additionally heated. The following coatings Ti, Cu, Ti/Cu, Cu/Ti/Cu were applied to the surface of the shot. Parameters of Ti and Cu coating deposition are shown in Table 1. The morphology of the surfaces and chips of the coatings were investigated using a scanning electron microscope (TESCAN MIRA 3 LMU). SEM images were obtained at an accelerating voltage of 5 kV.

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3 Results and Discussion The results of studying the surface morphology of the coatings on titanium hydride shot are shown in Fig. 2. The synthesized single-layer Cu and Ti coatings (Fig. 2 (a, b)) have a homogeneous nanocrystalline structure without visible pores. Multilayer Ti/Cu and Cu/Ti/Cu coatings (Fig. 2c, d) have a pronounced agglomeration of nanocrystalline grains into spherical crystallites with the same growth direction. In Fig. 3 shows SEM images of fracture of TiH4 shot coated with Cu, Ti, Ti/Cu, Cu/Ti/Cu. All coatings: both single-layer Cu and Ti, and multilayer Ti/Cu and Cu/Ti/Cu have a columnar structure. The applied coatings demonstrate good fit to the substrate (shot), and there are no pores and microcracks at the interface between the coating and the substrate. The thickness of the coatings was determined by SEM methods from the brittle fracture of the sample and is shown schematically in Fig. 3 next to the corresponding images of the coatings.

Fig. 2 SEM images of surface of titanium hydride shot after coating: Cu (a), Ti (b), Ti/Cu (c), Cu/Ti/Cu (d)

Magnetron Sputtering as a Method of Forming …

227

Fig. 3 SEM images of brittle fracture of the sample of titanium hydride shot after coating and cross-sectional schemes: Cu (a), Ti (b), Ti/Cu (c), Cu/Ti/Cu (d)

4 Conclusion In this work, a new approach to the deposition of protective single-layer and multilayer shells on titanium hydride in order to improve its thermal stability has been developed and tested. The coatings were successfully applied to titanium hydride shot by magnetron sputtering. It was found that the obtained single- and multilayer coatings uniformly cover the surface of the titanium hydride shot and have a uniform dense nanocrystalline structure. Based on the results obtained, it can be sum up that magnetron sputtering of coatings on titanium hydride shot can be considered as an effective way to create a protective shell. Increasing the thermal stability of titanium hydride will make it possible to use this material to obtain a new generation of radiation-protective building materials. Acknowledgements The work is realized using equipment of High Technology Center at BSTU named after V.G. Shukhov the framework of the State Assignment of the Ministry of Education and Science of the Russian Federation, project No. FZWN-2020-0011, using equipment of High Technology Center at BSTU named after V.G. Shoukhov.

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References 1. Cherkashina NI (2015) Constructional radiation-protective materials of a new generation. Int Sci Res J 9–2(40):113–116 2. Poltabtim W, Ekachai W, Kiadtisak S (2018) Properties of lead-free gamma-ray shielding materials from metal oxide/EPDM rubber composites. Radiat Phys Chem 153:1–9 3. Yastrebinskaya AV, Matyukhin PV, Pavlenko ZV, Karnaukhov AV, Cherkashina NI (2015) Use of hydride-containing composites to protect nuclear reactors from neutron radiation. Int J Appl Fund Res 12–6:987–990 4. Hayashi T, Tobita K, Nishio S, Ikeda K, Nakamori Y, Orimo S (2006) Neutronics assessment of advanced shield materials using metal hydride and borohydride for fusion reactors. Fusion Eng Des 81(8–14):1285–1290 5. Yastrebinskii RN (2018) Attenuation of neutron and gamma radiation by a composite material based on modified titanium hydride with a varied boron content. Russ Phys J 60(12):2164–2168 6. Ma M, Wang L, Tang B, Lyu P, Xiang W, Wang Y, Tan X (2018) Kinetics of hydrogen desorption from titanium hydride under isothermal conditions. Int J Hydrogen Energy 43(3):1577–1586 7. Vansovskaya KM (1985) Metallic coatings applied by a chemical method. Mechanical Engineering, Leningrad 8. Yastrebinsky RN, Karnaukhov AA, Pavlenko VI, Poluektova VA, Yastrebinskaya AV (2020) Physicochemical modification of titanium hydride (II) with organoborosiliconate. Bulletin of BSTU named after V.G. Shukhov 23(11):17–22 9. Pavlenko VI, Bondarenko GG, Kuprieva OV, Yastrebinsky RN, Cherkashina NI (2014) Surface modification of titanium hydride sodium borosilicate. Perspect Mater 6:19–24 10. Cherkashina NI, Pavlenko ZV, Demchenko OV (2016) Creation of a protective coating on the surface of titanium hydride shot. Bulletin of BSTU named after V.G. Shukhov (10):166–171

Possibilities of Architectural and Constructive Shaping of Spatial Forms from Rod Arches N. G. Tsaritova , A. A. Tumasov , A. A. Kalinina , and I. V. Kosogov

Abstract The process of forming new technological methods of construction of buildings and structures, a high degree of industrialization of construction and unification of elements, lead to the study of various principles of forming the spatial structure of the object from flat scans. The authors consider a new transformable architectural and structural system consisting of rod spatial arches, the main elements of the developed system are rods and hinges that connect them at the ends. The latter are made as an analog of bionic mobile communication. Research has shown that on the basis of the resulting arched strezhnevoy system, it is possible to form spaces close to the cylindrical and spherical shape. The variability of forms based on a single set of structures, low-labor-intensive installation process using the principles of self-construction, create prerequisites for new research in the field of improving this type of transformable architectural and structural systems. These issues provide a wide range of tools for solving architectural, structural and technological factors of shaping, which contributes to the development of creative activity. Keywords Architectural and structural system · Spatial arches · Rod elements

1 Introduction In an era of dynamic development, society values simplicity and convenience. Therefore, modern architecture should not only be functional and aesthetic, but also convenient, practical and economical. Architectural and structural systems have unlimited possibilities for creating new forms. The growing number of structures manufactured using this technology indicates the prospects for using such structures, especially in harsh climatic conditions and remote areas. Currently, architectural and structural systems are a manifestation of the interaction of engineering thought and architectural creativity. The unity of design and architectural form in the core spatial systems opens up wide possibilities for searching for various geometric formations, new N. G. Tsaritova (B) · A. A. Tumasov · A. A. Kalinina · I. V. Kosogov Platov South-Russian State Polytechnic University (NPI), Novocherkassk, Russian Federation © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_31

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aesthetic principles of object development, and new technological methods of the dynamic process of shaping. The South Russian State Polytechnic Institute (NPI) is developing a new transformable architectural and structural system consisting of the main spatial arches and has received the serial name NPI [1–3]. The main elements of the developed system are rods and hinges connecting them at the ends. The latter are made in the form of an analog of bionic rolling stock [4, 5].

2 Methods and Materials Initially, the structure was a linear spatial element—a stranded beam consisting of two belts and racks. The upper and lower belts are linear flat rod structures based on a triangulation grid that forms the shapes of hexagonal and rhombic geometric shapes, respectively (see Fig. 1). When the length of the rods of one of the directions of the lower belt triangulation decreases, and due to the hinge joints of the rods and the constant length of the other rods of the system, the beam moves to the design position—it bends upwards with a bulge. According to recent studies, such structures are able to undergo a reverse cycle-dismantling, also using the ability of the lower belt rods to change their length. Due to various combinations of such deformations, the architectural and structural systems has a wide range of forming capabilities. The NPI series arch can be formed from two semi-arches and represent a threehinged kinematic system, or from a single arch, while being a two-hinged system. Studies have shown that on the basis of the resulting arched rod system, it is possible to form spaces that are close to cylindrical and spherical in shape. Additional spatial rigidity of the frames is provided by the connections between them.

Fig. 1 The scheme of the rod spatial arch of the NPI series: 1—elements of the upper belt; 2— rods with an adjustable length of the lower belt; 3—brackets connecting the upper and lower belts; 4—connections of the rods

Possibilities of Architectural and Constructive Shaping …

231

Using the known methods of changing the rod elements (hydraulic, mechanical), it is possible to transform the rod spatial element into an arch of various shapes using the following methods: 1.

2.

3.

Traverses (Fig. 2a). This method is one of the simplest, but expensive. The slings of the traverse are lowered to a different height, calculated in advance for a certain bend of the arch, and are attached to the nodes of the upper belt of the structure. Under the influence of its own weight during lifting, the rod arch of the NPI series changes its geometry from a straight rod beam to a spatial arch, after which the structure is installed in the design position, and the nodes are fixed. Jacks (Fig. 2b). To lift the structure, a system of jacks is used, driven by a central pump, to act on the spatial rod structures simultaneously at several points. Each jack is given its own pre-calculated lifting height, so that the rod beam takes the form of an arch. After that, as in the previous method, the support nodes and the joints of the lower belt rods are fixed, the jacks are lowered and moved to the next structure. Pneumatic structures (Fig. 2c). The assembled systems of the NPI series are mounted on top of pneumatic structures, and under the influence of the pressure of the injected air, the geometry of the mounted system changes from a rod beam to an arch. After that, the hinge joints of the lower belt rods, as well as the support nodes, are securely fixed. The pneumatic structure is deflated and moved to a new location.

Fig. 2 Schemes of installation of structures by separate arches (beginning)

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Fig. 3 Schemes of installation of structures by separate arches: a-traverses, b-jacks, c-pneumatic structures, d-automated method

4.

Automatic method (see Fig. 2d). The NPI series structures are assembled directly on the construction site from the supplied rods of various lengths. One of the ends of the resulting beam rod is fixed to the support, the second is in a free position. The lower belt of this design consists of rods of variable length. After completing all the preparatory work, the rods are set in motion. As they decrease, the spatial system turns into an arched structure moving towards the second support. As with all the methods discussed above, the connection nodes are fixed.

The arches of the NPI series allow us to rationally search for various options for spatial planning solutions, create “universal” buildings of multi-purpose functional purpose through the use of large-span and transformable structures, and diversify architectural forms and compositional means (Fig. 3). With the help of rod arches, you can create buildings and structures of various shapes, the shape of which more or less corresponds to the organized internal space. Each of them can be considered as a three-dimensional pavilion-type structure. Such buildings and structures are characterized by a single form of organized internal space. The necessary internal divisions in buildings and structures are carried out at the expense of movable structural means that are not related to the main loadbearing and self-supporting structures. Ultimately, the versatility of such spaces allows buildings and structures based on basic spatial arches to be multifunctional. The external shape of buildings and structures is a compact composite solution. Its individual sections are spatial arched structures consisting of two types of rods (variable and constant length) connected at nodal points. All this structural division of the form of buildings and structures has a specific tectonic meaning, expressing the desire for dynamism and lightness. This characteristic is emphasized by the spatial rhythms of the faces from the center to the support. Table 1 shows the options for using NPI series rod arches in the shaping of buildings and structures.

Possibilities of Architectural and Constructive Shaping … Table 1 Options for geometry forms architectural and structural system

Geometric surface 2

1

Spherical

Ogive

1

domed

Elliptical

Parabolic

Conical

Free-form

2

cylindrical

1/2 circle

1/3 circle

Three-dimensional shape 3

233

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Table 2 Geometric parameters of the transformable double-hinged arch of the NPI series

Span L, м

H

1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

2 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

L

The height of the segment H, m., with a rod length of 2 m . The percentage decrease in the length of the rod 5% 10% 15% 20% 3 4 5 6 6.74 7.17 6.37 7.51 6.80 5.94 7.99 7.14 6.38 5.42 7.62 6.71 5.87 4.80 7.20 6.21 5.27 4.01 6.71 5.62 4.53 2.94 6.14 4.90 3.58 5.46 3.98 4.63 2.70 3.54 -4 -5 -6 -

H

L

The height of the segment H, m., with a rod length of 3 m . The percentage decrease in the length of the rod 5% 10% 15% 20% 7 8 9 10 9.23 8.89 10.18 8.50 9.84 8.06 11.05 9.46 7.56 -7 10.71 9.04 6.99 11.74 10.33 8.56 6.32 11.39 9.91 8.02 5.52 11.01 9.44 7.40 4.54 10.59 8.92 6.69 3.18 10.12 8.34 5.86 9.60 7.67 4.82 9.02 6.91 3.41 8.37 6.00 7.63 4.88 6.78 3.33 5.75 -

3 Results and Discussion Arched rod systems allow you to form objects of close to domed, cylindrical. Thanks to them, you can significantly diversify the space-planning solutions of buildings and structures [6–9]. In each case, you can find a harmonious combination of different types of buildings with the proposed forms. The dependence of the geometric parameters of spatial arches is studied experimentally and theoretically. Table 2 shows the dependence of the change in the span of the arch on the percentage change in the length of the rods for the double-hinged arches of the NPI series.

Possibilities of Architectural and Constructive Shaping …

235

The implementation of the bending process of the rod system is possible by reducing the length of the rod due to a controlled automatic device based on a hydraulic cylinder.

4 Conclusion The forms presented in Table 1 are complete objects that can actively participate in the formation of open spaces, in the development and reconstruction of existing ensembles. The ability to create spatial formations that differ in shape and function allows you to create several objects that have a single structural fabric, and on this basis form an ensemble. Small spatial systems can form recreation areas, solve problems of small architecture, serve as temporary public buildings, large ones-will become the compositional core of an urban planning ensemble or will perform important social functions of a public center.

References 1. Tsaritova N, Buzalo N, Tumasov A, Platonova I, Kurbanov A, Kalinina A (2019) Transformable systems of spatial structures based on bionic analogues. Atlantis Highlights Mater Sci Technol 1:333–336 2. Zimin VN, Boikov VG, Faizullin FR (2013) Peculiarities of simulation of unfoldinga transformable frame-type structure Bulletin of the Bauman Moscow state technical University. Ser. Mech Eng 2:98–108 3. Gaydzhurov P, Iskhakova E, Tsaritova N (2020) Study of stress-strain states of a regular hingerod constructions with kinematically oriented shape change. Int J Comput Civil Struct Eng 16(1):38–47 4. Buzalo NA, Alekseev SA, Tsaritova NG (2016) Numerical analysis of spatial structural node bearing capacity in the view of the geometrical and physical nonlinearity. Procedia Eng 150:1748–1753 5. Tumasov AA, Tsaritova NG (2016) Transformable spatial core structures of coatings. Int Res J 12–3(54):190–194 6. Garifullin MR, Semenov SA, Belyaev SV, Poryvaev IA, Safiullin MN, Semenov AA (2014) The search of rational shape of spatial metal roof of longspan sport arena. Constr Unique Build Struct 2:107–124 7. Marutyan AS (2009) Light metal structures from cross-cutting systems (Federal Agency for Education, Pyatigorsk State Technological University. Pyatigorsk: RIA-KMV) 346 8. Forster Bb, Mollaert M (2004) European design guide for tensile surface structures (TensiNet. Brussel) 332 9. Motro R (2003) Tensegrity: structural systems for the future (Kogan Page Science)

Analysis of the Factors of Increasing the Efficiency of Employment Binder in High-Strength Self-Compacting Concretes V. S. Lesovik , M. Yu. Elistratkin , A. S. Salnikova , and E. A. Pospelova Abstract The trend in the development of modern construction is an increase in the span and number of floors of the structures being built. To solve such problems, it is advisable to use high-strength concretes with a strength class of B60 and higher. To date, the production and use of such concretes has a number of difficulties, both technological and economic in nature (high cost). Therefore, high-strength concrete, in particular in Russia, is experiencing strong competition from metal structures that are inferior to them in terms of fire safety, durability and cost. Increasing the availability and adaptability of high-strength concrete is possible by eliminating the use of standard cement with the transition to composite binders based on it. The paper considers the issue of increasing the efficiency of self-compacting concretes, due to the use of a carbonate additive and fine-dispersed waste from the processing of heavy concrete. It is established that the use of these additives enhances the resistance to delamination and separation of the mixture, the high correlation of filler grains and reduce the friction between the particles of coarse components for maximum yield under the action of gravitational forces to improve the physical, mechanical and operational characteristics of concrete. A method for comparing different strength compositions is proposed, which makes it quite simple and clear to assess the influence of heterogeneous factors under study on the effectiveness of the use of the clinker component. Keywords High-strength concrete · Composite binder · Self-compacting mixture · Hyperplasticizer · Carbonate-containing fillers · Clinker component

1 Introduction Modern construction is developing dynamically. One of the consequences of this process is a steady increase in the requirements for construction materials. A steady trend is an increase in the span and number of storeys of constructed structures, V. S. Lesovik · M. Yu. Elistratkin (B) · A. S. Salnikova · E. A. Pospelova Belgorod State Technological University named after V.G. Shukhov, Kostyukov Street, 46, Belgorod 308012, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_32

237

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and to solve such problems, it is advisable to use high-strength concrete with a strength class of B60 and higher, and often exceeding B100. However, today the production and use of such concretes has a number of difficulties: technological (multi-stage technology, multicomponent, the need for strict control of all stages of the production cycle, etc.) and economic (high cost). Therefore, high-strength concrete, in particular in Russia, is experiencing strong competition from metal structures, which are obviously inferior to them in a number of indicators (fire safety, durability, cost). One of the obstacles to the large-scale use of high-strength concrete is that the main component—the binder, which in the vast majority of cases is Portland cement, does not fully meet the features of the problem being solved in its basic indicators. As a result, it becomes necessary to insert additional mineral and chemical components into the composition of concrete mixtures, designed to correct the properties of the binders to the desired extent. The insertion of new components is often accompanied by negative side effects, to compensate for which new additives are inserted, which further complicates the composition and reduces its effectiveness. The solution to this problem, described in the works of foreign [1, 2] and Russian [3–6] researchers, is the transition from the use of conventional cements to composite binders based on them. Due to the reasonable choice of a combination of chemical and mineral modifiers, as well as the preparation mode, it becomes possible to optimize the properties of the binder to the maximum extent possible under the conditions of a certain task. This allows improving the basic properties, increasing the efficiency of using raw materials, and simplifying the technology by replacing the sequential input of many components with a single composite binder. An important aspect is the possibility of preserving trade secrets (the actual composition of the CB) for the end user (CMI, reinforced concrete products, etc.), as the binder can act as a finished commodity product. Within the framework of this work, the goal was to develop composite binders that implement various ways to increase their efficiency, high-strength concretes based on them, as well as to perform a numerical evaluation of the effectiveness of the used approaches and methods.

2 Materials and Methods In the making of composite binders, the sulphate-resistant Portland cement CEM II/A-P 42.5 N produced by JSC “Novoroscement” was used. Quartz sand with residues on sieves of 0.63 mm – 14%, 0.315 mm – 45% and 0.16 mm – 41%, with a fineness modulus of 1.49, was used as filler. Marble powder obtained by grinding marble chips in a ball mill to specific surfaces of 700 and 900 m2 /kg was used as a carbonate mineral additive. The dosage of marble powder was 3, 5, 7 and 10% by weight of cement. With an amount of water corresponding to the normal density of the mixture, samples of 2 × 2 × 2 cm were

Analysis of the Factors of Increasing …

239

made. The composite binder was prepared by joint grinding to a specific surface area of 500 m2 /kg of cement and crushing dropuots of heavy concrete. To give the mixtures the ability to self-compaction, a hyperplasticizer “MC-PowerFlow 3100 RU” produced by MC-Bauchemie was used. The determination of physical and mechanical parameters was carried out according to standard methods.

3 Results and Discussion When designing high-strength concrete, the main task is to use all the possibilities to increase the strength without increasing the consumption of cement, and preferably reducing it, which will result in an increase in the efficiency of using the expensive clinker component. To improve the strength indicators in this work, we tested approaches that have proven themselves well according to the literature and our own research: – insertion of finely ground carbonate fillers; – insertion of mineral additives [7]; – variation of fine aggregate content [8, 9]. As such filler, finely ground marble powder was chosen. Figure 1 shows the data of studies on the effect of the amount of finely ground marble inserted to replace part of the cement on the strength of the stone. When fine-ground marble is inserted into the cement in an amount of 3–5%, an increase in strength by 34–49% is already observed on the 7th day, which, according to [9, 10], can be explained by the acceleration of C3 S hydration in the early stages of hardening, including due to the formation of crystallization centers in the form of calcium bicarbonate. At a later date, the strength gain slows down, but the overall

Fig. 1 The effect of finely ground marble on the strength characteristics of cement stone (a) Ssp = 700 m2 /kg of marble; (b) Ssp = 900 m2 /kg of marble

240

V. S. Lesovik et al.

strength gain in the vintage age eventually amounts to 35–53%. With a further increase in the amount of the additive, the strength decreases by 20%. Despite this, the strength of 7% fine-ground marble is higher than the control composition by more than 20%, with a corresponding reduction in the amount of the clinker component. The change in the specific surface area of marble powder in the considered range from 700 to 900 m2 /kg has a rather weak effect on the change in strength, the difference does not exceed 1–4%. Thus, the use of finely ground marble powder with a corresponding reduction in the clinker component is advisable when inserting it to 10%. At the next stage, a composite binder for self-compacting mixtures was obtained. The reasonable choice of fine fillers in the composition of the binder should increase the resistance to delamination and water separation of the mixture, high expansion of the aggregate grains and reduce friction between the particles of coarse components to obtain maximum fluidity under the influence of gravitational forces, increase the physical, mechanical and operational characteristics of concrete. As such a filler, fine-dispersed scrap of heavy concrete (HC) was selected, the share of which in the composition of the binder was assumed to be 30%. An important aspect of obtaining composite binders with such additives is that in order to reduce the porosity of filler particles from secondary construction products, it is advisable to grind them to a higher specific surface area of at least 350– 400 m2 /kg than that of cement [11–14]. Fine grinding also helps to restore the astringent properties of the non-hydrated components of the cement stone. To optimize the binder consumption, the effect of the ratio of cement glue and aggregate on the strength was studied [15]. The proportion of fine aggregate in the mixture varied from 1 to 1.7, the results are shown in Fig. 2.

Fig. 2 a Effect of the fraction of fine aggregate on the strength; b Microstructure of the stone based on CB70 (HC) with fine aggregate (the size of the visible field is 1 mm)

Analysis of the Factors of Increasing …

241

As it can be seen from Fig. 2a, the composition with the ratio of 1:1 has the greatest strength in all ages. With an increase in the proportion of sand in the mixture (1:1.3 and 1:1.5), the strength decreases by 30–35%, with a further increase (1:1.7), the strength additionally decreases by 19% in the vintage age. The decrease in strength is due to the gradual increase in the area of the contact zone of the stone, with the aggregate being the weak point of the system. In the microphotograph (Fig. 2b), the zones of separation of the cement stone from the fine aggregate, in the form of holes or partially exposed sand grains, are clearly visible. The effect of self-compaction is sufficiently evident up to the ratio of 1:1.5. With a further increase in the ratio, a decrease in the self-compacting effect is observed, accompanied by a drop in strength in comparison with the 1:1 composition by 64%. In this work, the task was not to obtain concretes with certain strength indicators, and all the considered methods of influencing the strength have a different simultaneous effect, both on the strength and on the consumption of the clinker part. In this regard, a complete comparison of all compositions is of great practical interest. As a comparison criterion, the strength value of the clinker component provided by 1% of the total mass of solid components (specific strength, MPa/1% CC) was adopted, which allows selecting the most effective solutions for different strength groups (classes). As it can be seen from Table 1, the specific strength of the compositions varies from 4.2 to 5.4 MPA/1% CC. The most effective in terms of the use of the clinker component are compositions No. 1, 4 (>4.9 MPA/1% CC), which differ in the amount of aggregate and the level of strength. The compositions 6 and 7 are the outsiders among those considered. The remaining compositions demonstrate an average level of efficiency in the use of the clinker component. Table 1 Physical and mechanical properties of the developed compositions and the efficiency of the use of the clinker component № of composition

Composition Binder

GP, %

1

CB70 (HC)

2

CB70 (HC)

3

Finely ground marble, % by weight of the binder

W/B

Ratio Binder: Sand

Density, kg/m3

Strength on the 28th day, MPa

Strength class

Share of the clinker component,%

MPa/1% CC

3

–

0.2

(1:1)

2441

162

3

10

0.2

(1:1)

2478

113

B120

30.1

5.4

B85

27.1

CB70 (HC)

3

–

0.2

(1:1.3)

2469

4.2

120

B90

25.9

4

CB70 (HC)

3

–

0.2

(1:1.5)

2443

4.6

118

B90

24

4.9

5

CB70 (HC)

3

–

0.2

(1:1.7)

2470

99

B75

22.3

4.4

6

CEM I 42.5 N

-

–

0.5

(1:3)

2086

49

B35

33.3

1.5

7

CEM I 42.5 N

-

–

0.45

(1:3)

2006

52

B40

33.3

1.6

8

CEM I 42.5 N

-

–

0.45

(1:3)

2179

68

B50

33.3

2.1

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V. S. Lesovik et al.

To obtain higher-strength SCC with a strength of more than 130–150 MPa (B100/110), it is advisable to reduce the ratio of binder to sand to 1:1 (reducing the area of the contact zone with the aggregate) and use composite binders with the addition of heavy concrete crushing waste. The proposed method of comparing different strength compositions, of course, does not take into account the entire range of factors, but it allows assessing quite simply and clearly the influence of the studied factors. According to the results obtained, not only the consumption of the clinker component is of great importance, but, first of all, the completeness of its implementation, which can be achieved by a balanced composition of the composite binder.

4 Conclusion 1.

2.

3.

4.

It is established that finely ground marble in the amount of 3–5%, leads to an increase in strength by 35–53%. And to ensure the economy of the clinker component and maintain a certain level of strength, it is advisable to insert finely ground marble up to 10%. It is found that the effect of self-compaction is sufficiently manifested up to the ratio of 1:1.5. With a further increase in the ratio, a decrease in the selfcompacting effect is observed, accompanied by a drop in strength in comparison with the 1:1 composition by 64%. The mineral additive in the form of finely ground heavy concrete contains a nonhydrated clinker substance, which, reacting, leads to an increase in strength in the early period, and the presence of pozzolan activity in the additive contributes to the formation of additional calcium hydrosilicates, this effect is manifested in later hardening periods. Due to this, the composition of CB70(HC) has the highest strength of 162 MPa. A method is proposed for comparing and evaluating the effectiveness of compositions based on the specific strength corresponding to 1% (wt) of the clinker component. It is found that a high amount of clinker component is not the key to the greatest strength. Compositions 1 (5.4 MPA/1% CC) and 4 (4.9 MPA/1% CC) have the greatest effect from the use of the clinker component.

Acknowledgements The work is realized in the framework of the RFBR according to the research project № 18-29-24113, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

References 1. Fanghui H, Li L, Shaomin S, Juanhong L (2017) Early-age hydration characteristics of composite binder containing iron tailing powder. Powder Technol 315:322–331

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2. Yarmakovsky VN, Pustovgar AP (2015) The scientific basis for the creation of a composite binders class, characterized of the low heat conductivity and low sorption activity of cement stone. Procedia Eng 111:864–870 3. Kharchenko AI, Alekseev VA, Kharchenko IYa, Bazhenov DA (2019) Structure and properties of fine-grained concrete based on composite binders. MGSU Bull 126:322–331 4. Amran M, Fediuk R, Vatin N, Mosaberpanah MA, Danish A, El-Zeadani M, Klyuev SV, Nikolai V (2020) Fibre-reinforced foamed concretes: a review. Materials 13(19):4323 (2020) 5. Lesovik VS, Strokova VV, Krivenkova AN, Khodykin EI (2009) Composite binder using siliceous rocks. Bull BSTU named after V.G. Shukhov 1:25–27 6. Alfimova NI, Zhernovsky IV, Yakovlev EA, Yurakova TG, Lesovik GA (2010) Influence of the genesis of a mineral filler on the properties of composite binders. Bull BSTU named after V.G. Shukhov 1:91–94 7. Tarakanov OV, Kalashnikov VI, Belyakova EA, Moskvin RN (2014) Self-compacting concretes of a new generation based on local raw materials. Reg Archit Constr 2:47–53 8. Shesternin AI, Korovkin MO, Eroshkina NA (2015) Fundamentals of self-compacting concrete technology. Young Sci 86:226–228 9. Timashev VV, Kolbasov VM (1981) Properties of cements with carbonate additives. Cement 10:10–12 10. Larsen OA, Narut VV (2016) Self-compacting concrete with carbonate filler for transport infrastructure. Eng J 68:76–85 11. Balakshin AS (2011) Properties of low-crushed concrete with an organic-mineral additive based on screenings of crushing of concrete scrap. MGSU Bull 1:253–258 12. Narut VV, Larsen OA (2020) Self-compacting concretes based on concrete scrap of demolished residential buildings. Ind Civ Eng 2:52–58 13. Klyuev SV, Klyuev AV, Khezhev TA, Pukharenko YV (2018) High-strength fine-grained fiber concrete with combined reinforcement by fiber. J Eng Appl Sci 13:6407–6412 14. Lesovik VS, Zagorodnuk LH, Tolmacheva MM, Smolikov AA, Shekina AY, Shakarna MHI (2014) Structure formation of contact layers of composite materials. Life Sci 11(12):948 15. Klyuev SV, Khezhev TA, Pukharenko YV, Klyuev AV (2018) Fiber concrete for industrial and civil construction. Mater Sci Forum 945:120–124

Belt Vibration Damping System for Closed-Type Domes A. I. Shein

and A. V. Chumanov

Abstract Studies on the damping of vibrations of closed domes under seismic influence are presented. To ensure the effect of vibration damping, a new tape system is used. The quenching effect is achieved by one-way connections of tape systems. A dynamic analysis of the dome vibrations is carried out. For a comprehensive evaluation of the damping system, numerical experiments were carried out with different locations of the belt vibration dampener and the determination of the most rational version of the belt system for different configurations of domes. The design scheme of the dome was a three-dimensional rod system consisting of rigidly fixed steel pipes of square cross-section. The design was calculated using the finite element method. When conducting a numerical experiment, the method of central differences was used to solve the differential equation of motion. It is shown that with the trapezoidal arrangement of the damper, a significant (more than 50%) decrease in the maximum amplitudes of the dome oscillations is observed. Moreover, for several peak values of displacements, the vibration damping effect reaches 80%. For flat domes, the option of cross-positioning the extinguisher belts is effective. To increase the effective volume of the dome space, it is advisable to use the option of three-point attachment of the extinguisher tapes, while the extinguishing effect increases. With this setup, there is a decrease in the values of the maximum deviations of the nodes by another 4–10%, compared to the cross arrangement. It is shown that belt dampers are an effective means of damping vibrations. Keywords Dome · Vibration · Damping · Vibration damping · Belt system of vibration damping

1 Introduction Vibration damping is one of the most important tasks in the design of buildings and structures that are subject to such natural impacts as wind and seismic. Currently, A. I. Shein (B) · A. V. Chumanov Penza State University of Architecture and Construction, Penza, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_33

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A. I. Shein and A. V. Chumanov

various types of dampers have been developed and optimized, of which the most common are Tuned Mass-Damper [1–3], Tuned Mass Column Damper [4, 5], used mainly for high-rise buildings. Domed buildings and structures are common all over the world. Examples of large-span domes are the Museum of Biosphere Ecology (Montreal, Canada), the Global Arena in Sweden, the Millennium Dome in the UK, the University of Chicago Library, the Amazon headquarters in Seattle, USA, etc. Recently, there has been a trend in the development of domed housing construction for individual housing throughout Russia. For the safe operation of such types of buildings in seismic regions should be able to prevent the development of oscillations, i.e., an effective system damping domed structures. De-Min Wei and Sheng-fu Gao analyzed the vibrations of the dome in the form of a rod mechanical system under the action of a vertically directed seismic load [6]. In [7], Francesco Tornabene and Erasmo Viola analyzed the eigenforms of the dome vibrations in the form of a shell formed by lamellar finite elements. In [8, 9], a tape vibration damping system was proposed and numerically tested for open domes. Consider the use of this damping system for closed-type domes.

2 Materials and Methods In this article, we study the oscillations of a closed-type dome, which is a cyclically symmetric structure. The design scheme of the dome is a three-dimensional rod system consisting of rigidly fixed steel pipes of square cross-section (Fig. 1). The design was calculated by the finite element method. The equation of motion of a mechanical system has the form: M · U¨ + C · U˙ + K · U = P,

Fig. 1 Finite element model of the dome

(1)

Belt Vibration Damping System for Closed-Type Domes

247

where M is the diagonal mass matrix; U is an unknown displacement vector of mechanical system nodes; C is the damping matrix; K is the stiffness matrix of the entire system; P is the load vector, the elements of which take values depending on the type of seismic loading. To compile the motion resistance matrix C, the Rayleigh damping was used: C = α · M + β · K,

(2)

where α, β are the damping coefficients, the values of which are determined from the modal analysis of the design [10]. When conducting a numerical experiment, the method of central differences was used to solve the differential equation of motion. In this case, the displacement vector at each subsequent time point was determined by the recurrent formula:  Ut+t =

M + t 2

−1   Ut−t 2 · Ut − Ut−t +C · · (Pt − K · Ut ) · t + M · , t 2 (4)

where U t+Δt , U t , U t-Δt is the displacement vector at the next, current, and previous time points; t is the time step. The methods described above are implemented in the program for calculating the vibrations of a closed-type dome, compiled in the MathCAD mathematical complex.

3 Results and Discussion During the entire period of the seismic load, the bending shape of the mechanical system vibrations is observed (Fig. 2).

Fig. 2 The shape of the dome vibrations under seismic influence (displacement scale 5:1)

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Fig. 3 Graphs of the dome pole movements

Consider the movement of the top node of the dome with the ratio f/L = 0.4 (Fig. 3). Until the time of 3 s, the amplitude of the dome pole oscillations along the x-axis does not exceed 4 cm. During the next 2 s (in the interval from 3 to 5 s), an increase in the magnitude of the amplitude to 15 cm is observed. At the final time interval, the magnitude of the amplitude reaches a maximum value of 17.2 cm (at the time of 7.29 s). A characteristic feature of the movement for all types of domes is the oscillation of the dome pole along the y axis: during the entire time, the oscillation amplitude does not exceed 1 mm. When moving the pole along the z axis, the values of amplitudes are observed, mainly up to 2 cm with three bursts (4.8 cm at the time of 2.77 s; 5.7 cm at the time of 5.94 s; 8.8 cm at the time of 7.31 s and 7.7 s). We will establish a tape vibration damping system based on the principle described in [8, 9]. We take the cross-section of the tape 200 × 4 mm, the elastic modulus of the tape E = 3 · 1010 Pa. In order to find the most rational arrangement of the belts, we will consider first three options for their installation (Fig. 4).The determination of the location of the attachment points of the dampers is based on the following principle: the coil must be installed in the support node of the rod, and the position of the second attachment point is determined by the maximum deviation of the nodes from the initial position after dynamic analysis of the movements of the system nodes (Table 1).

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249

Fig. 4 Options for installing a belt vibration damper

Table 1 Maximum deviations of the dome nodes, cm f/L

0.50

0.45

0.40

0.35

0.30

0.25

1 zone

7.11

6,92

6.20

4.66

4.27

3.38

2 zone

17.80

16.86

16.22

11.80

11.38

9.11

3 zone

25.97

23.44

24.36

17.05

16.61

13.20

4 zone

29.17

24.88

27.31

18.30

17.46

13.91

5 zone

26.61

21.97

23.60

15.24

13.89

10.57

pole

23.38

19.37

19.25

12.07

10.48

7.24

With the introduction of a vibration dampener, the swing of the pole oscillation is significantly reduced. A comparison of the dome oscillation graphs without a dampener and with a dampener is shown in Fig. 5 and in Table 2. Up to a time of 4.31 s, with relatively small displacements, a slight vibration damping (up to 15%) is observed for all three options for installing dampers. In the next time interval, with the first option of the vibration damper (the maximum displacement reaches 164 mm in 2.4 s), the amplitude gradually decreases to 36 mm; with the second (trapezoidal) option of the damper installation (here the maximum displacement value is 109 mm), there is a sharper decrease in the vibration amplitude compared to the other options; in the third, cross-installation option (the maximum amplitude of 127 mm in 2.9 s), the oscillation span gradually decreases to 8 mm. The most rational option is the second and third, since the maximum displacement

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Fig. 5 Graph of the dome pole movements along the x-axis with various options for installing the extinguisher

Table 2 Maximum deflections of dome nodes with vibration dampener, cm f/L

0.50 (2 option)

0.45 (2 option)

0.40 (2 option)

0.35 (2 option)

0.30 (3 option)

0.25 (3 option)

1 zone

13.74

14.46

10.92

11.89

6.94

4.31

2 zone

13.35

16.73

12.90

12.14

10.14

7.32

3 zone

16.76

19.60

16.16

13.27

14.99

9.06

4 zone

18.98

21.12

16.92

14.65

14.32

10.86

5 zone

22.65

18.84

14.44

13.17

11.27

9.17

pole

14.61

15.31

11.19

9.30

7.96

3.81

among all three options is minimal and the reduction of the maximum deviations of the dome nodes reaches 38%. When using the third version of the extinguisher, most of the dome space is blocked, this is not always possible. To avoid the overlap of the dome space, you can add one intermediate (roller) node, through which the tape will be held (option 4 of Fig. 4). A comparison of the calculation results for domes with 3 and 4 variants of the extinguisher arrangement is presented in Table 3.

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251

Table 3 Comparison of the maximum deviations for 3 and 4 variants of the extinguisher, cm f/L

0.30 (3 option)

0.30 (4 option)

0.25 (3 option)

0.35 (4 option)

1 zone

6.94

5.34

4.31

2 zone

10.14

9.51

7.32

6.83

3 zone

14.99

13.04

9.06

7.66

4 zone

14.32

13.48

10.86

9.59

5 zone

11.27

10.64

9.17

8.52

7.96

8.10

3.81

3.72

pole

4.15

4 Conclusion The dynamic analysis of dome vibrations is carried out and the types of natural and seismic oscillatory movements are revealed. Numerical experiments were carried out with different locations of the belt vibration dampener and the determination of the most rational version of the belt system for different configurations of domes. It is shown that the effect of dome damping is achieved by one-way connections of tape systems. In the second (trapezoidal) version of the damper arrangement for f/L > 0.25, a significant (more than 50%) decrease in the maximum amplitudes of the dome oscillations is observed. Moreover, for other peak values of displacements, the vibration damping effect reaches 80% (in the time period of 4.31–7.8 s). The effect is achieved at f/L from 0.35 to 0.5. For flat domes, the 3 option of the extinguisher arrangement is effective. To increase the effective volume of the dome space, it is advisable to use the 4 option of the location of the extinguisher, while the extinguishing effect increases. With this setup, there is a decrease in the values of the maximum deviations of the nodes by another 4–10%, compared to option 3. The results of the calculations show the high efficiency of the new belt vibration damping system for closed domes.

References 1. Giuseppe CM, Rita G, Francesco T, Bernardino C (2007) Constrained reliability-based optimization of linear tuned mass dampers for seismic control. Int J Solids Struct 44:7370–7388 2. Owji HR, Hossain Nezhad Shirazi A, Hooshmand Sarvestani H (2011) A Comparison between a New Semi-Active Tuned Mass Damper and an Active Tuned Mass Damper. Procedia Engineering 14:2779–2787 3. Sadegh E, Hojjat R (2018) Optimum design of tuned mass dampers using multi-objective cuckoo search for buildings under seismic excitations. Alexandria Eng J 57:3205–3218

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4. Christoph, A, Alberto, DM, Thomas, F, Antonina, P: Earthquake excited base-isolated structures protected by tuned liquid column dampers: design approach and experimental verification. Procedia Engineering 199, 1574 - 1579 (2017) 5. Okyay A (2017) Felix, Nolteernsting, Sebastian, Stemmler, Dirk, Abel, Sven, Klinkel: Investigations on the Performance of a Novel Semi-active Tuned Liquid Column Damper. Procedia Eng 199:1580–1585 6. Wei D-M, Gao S (2017) Seismic response analysis of K8 pattern single-layer reticulated domes under vertical rare earthquakes. Procedia Eng 210:417–424 7. Francesco T (2007) Erasmo, Viola: Vibration analysis of spherical structural elements using the GDQ method. Comput Math Appl 53:1538–1560 8. Shein AI, Chumanov AV (2019) Inertial pre-tensioning polyester-tape vibration damping system for cyclically symmetric dome-type structures. Model Mech Struct 10:1–12 9. Shein AI, Chumanov AV (2020) Tape system of radar vibration damping under seismic impacts. Constr Mech Calcul Struct 3(290):62–67 10. Barabash MS, Pikul AV (2017) Material damping in the calculation of structures for dynamic effects. Int J Comput Civ Struct Eng 2(13):13–18

Impact of the Blade Profile on the Production of the Screw Press A. S. Apachanov , E. Yu. Voronova , V. I. Grigoryev , and V. A. Evstratov

Abstract Screw presses are widely used in the production of clay bricks by a softmud process. The main drawback of screw presses is a torque transfer by the screw blade to the shaped mass so that the mass moves in a spiral. This significantly reduces the performance of screw presses. The work considered the possibility of increasing the performance of screw presses by increasing the friction force of the shaped mass as it moves along the internal surface of the tube. This is achieved by increasing the force of the normal pressure of the shaped mass on the internal surface of the tube by modifying the geometry of the screw blade so as generatrics are not oriented normally towards the screw axis, but inclined opposite to the direction of motion of the shaped mass from the axis of the screw to the periphery. The results of the study show that the performance of the screw press with a blade having an inclination from the axis of the screw to the periphery of 10–30% higher, than a press with a generatric of the blade normal towards the axis of the screw shaft, for the supply of plastic clay by increasing the forward component of the shaped mass movement in the direction of the longitudinal axis of the screw. Analysis of the results shows that the rational value of the angle of inclination for the generatric of the blade depends on the properties of the moulded mass and this value is 10–20°. Keywords Screw press · Blade · Friction force · Shaped mass · Generatric of the blade · Feed ratio · Angle of inclination

A. S. Apachanov · V. I. Grigoryev Moscow State University of Technology and Management, Moscow, Russia E. Yu. Voronova · V. A. Evstratov (B) Shakhty Automobile and Road Construction Institute (Branch) of Platov SRSPU(NPI), 1, Lenin Square, Shakhty, Rostov region 346500, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_34

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1 Introduction The main machinery for the production of clay bricks, ceramic stones and pipes is an extrusion auger (screw press) for forming different ceramic products of the required shape, size and density [1, 2]. Overflow pressure at screw outlet of press (1–1.5 Mpa) required for moulding clay bars, causes the clay mass to move in the screw channel of the press in a spiral with a significant deviation from the axis of the screw. This results in lower productivity and higher energy consumption of the machine [3, 4]. The performance of screw presses for the moulding of clay brick is defined as the product of the area of the cross-section of the screw by the projection of the material speed on the axis of the screw (Fig. 1). Q = π(R 2 − r 2 )vx ,

(1)

where R—the radius of the screw blade at the edge, m; r —the screw shaft radius, m; vx —projection of the speed of the material on the axis of the screw shaft, m/s. The maximum possible (theoretical) performance will occur if the absolute velocity of the material is directed along the screw axis. Q th = π(R 2 − r 2 )vth , Fig. 1 Velocity diagram

(2)

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where vth = ω0 Rtgα—the maximum possible (theoretical) speed of motion of the moulded mass; ω0 —angular velocity of the screw shaft, c−1 ; α—helix angle of the screw blade, rad. The ratio of actual performance Q to theoretical performance Q th describes the performance of the press and it is referred to as the screw rate [5] kβ =

1 Q vx cos α cos β = . = = Q th vth cos(β − α) 1 + tgαtgβ

(3)

where β—the angle between the direction of motion of the moulded mass and the axis (Fig. 1). Thus, Q = kβ Q th =

Q th . 1 + tgαtgβ

(4)

In screw presses, the angle of deviation of the movement of the clay mass from the axis is between 75 and 80° [6, 7], hence delivery coefficient is low kβ = 0.33 ÷ 0.42.

2 Methods and Materials Application of various design solutions aimed at increasing clay mass friction on the internal surface of the tube or at reduction of clay friction on the screw, can significantly increase the productivity of the press [8, 9]. The force of the clay mass friction against the internal surface of the tube depends on the friction coefficient of clay against this surface and the force of normal pressure. Increase in the force of the normal pressure of the moulded mass on the internal surface of the tube can be obtained by modifying the geometry of the screw blade so that the generatrics of the blade are not directed normally towards the axis, but inclined opposite to the direction of the material movement from the screw axis to the periphery, i.e. at an angle of θ to the normal to the screw axis (Fig. 2). Consider the equilibrium of the elemental volume of the clay mass cut from the channel formed by the internal surface of the tube, the shaft and the screw blade (Fig. 3). The elemental volume of clay is subject to the same forces as in the press with a blade which forms a normal direction to the axis of the screw [10] and has the following:

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Fig. 2 The screw shaft with generatric of the blade arranged at an angle θ to the shaft axis

Fig. 3 Figure diagram of elemental force in the screw channel of the press

3 Results and Discussion Force differential between back-up force and counteraction force F5 − F4 = P(R − r )2π Rtgα,

(5)

where P—Difference of pressure between the front and rear surfaces of the clay mass element under consideration, Pa. Force of friction of the shaped mass against the internal cylindrical surface of the tube F3 =

2π R 2 dϕtgαμP f h . 1 − f h cos(β − α)tgθ

(6)

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where dϕ—sector angle of the shaped mass element under consideration, rad; P—pressure of clay mass on the internal surface of the tube, Pa; μ—side thrust coefficient; f h —the coefficient of friction between the clay mass and the internal surface of the tube. Normal pressure on the screw blade by force F3 F2 =

2π R 2 dϕtgαμP f h cos(β − α) . [1 − f h cos(β − α)tgθ ] cos θ

(7)

Component of the friction force of the material against the blade of the screw by force F3 ; F f r1 =

2π R 2 dϕtgαμP f h f sch cos(β − α) . [1 − f h cos(β − α)tgθ ] cos θ

(8)

where f sch - the coefficient of friction of the clay mass against the surface of the screw shaft. Friction component of the material against pressure P F f r 2 = F f r.sh + 2F f r.bl where F f r.bl = μP f sch (R 2 −r 2 )dϕ/(2 cos α cos θ ) is the friction force of the material against the screw blade against the pressure P; F f r.sh = 2π Rr dϕtgαμf sch - the friction force of the material on the screw shaft. Condition of equilibrium of the elementary volume of material relative to the axis of the  screw after inserting force and moment values, has the form: X i = 0; −R(R − r ) − + −

dP sin α− μ

(9)

P f h f sch R 2 sin α cos(β − α)dϕ [1 − f h cos(β − α)tgθ ] cos θ

P f h R 2 osα cos(β − α)dϕ − P f sch Rr sin αdϕ 1 − f h cos(β − α)tgθ

P f h R 2 cos βdϕ P f sch (R 2 − r 2 )dϕ − = 0; π cos θ 1 − f h cos(β − α)tgθ

Having integrated (9) over dϕ in the interval from 0 up to 2π n, where n is the number of turns of the screw, we have

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Fig. 4 Delivery coefficient dependent on the inclination angle of the screw blade generators

   P0 + 2π na  R(R − r )   sin α ln −  μ P0 − + −

2π n f h f sch R 2 sin α cos(β − α) [1 − f h cos(β − α)tgθ ] cos θ

(10)

2π n f h R 2 osα cos(β − α) − 2π n f sch Rr sin α 1 − f h cos(β − α)tgθ

2π n f h R 2 cos β 2n f sch (R 2 − r 2 ) − = 0. cos θ 1 − f h cos(β − α)tgθ

Computational solution of Eq. (10) allows to determine the effect of the inclination of the generatric of the blade on the direction of the shaped mass movement and, consequently, on the performance of the screw press. Figure 4 shows the relationship of the screw delivery coefficient kβ = QQth = 1 , which characterizes the screw press efficiency, with the angle of inclination 1+tgαtgβ of the screw blades at different values of the coefficient of friction of the shaped mass against the metal of the screw and the tube and the following values of the working parameters of the press: screw blade radius R = 0.2 m; screw shaft radius r = 0.05 m; screw helix angle α = 20◦ .

4 Conclusion Quantitative results show that the performance of a screw press with a blade inclined from the screw axis to the periphery, higher than that of a press with a blade forming a normal towards the axis of the screw shaft, by 10–30% at the supply of plastic clay masses by increasing the forward component of movement of the shaped mass in the direction of the longitudinal axis of the screw. Analysis of the results shows that the rational value of the angle of inclination of the generatric of the blade depends on the properties of the shaped mass and it is 10–20°.

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References 1. Bogdanov VS, Fadin YM, Vasilenko OS, Demchenko CE, Trubaeva VA (2018) Analytical dependences of motion of working part in inertial cone crusher. IOP Conf Ser Mater Sci Eng 327(4):042113 2. Zareiforoush H, Komarizadeh MH, Alizadeh MR, Masoomi M (2010) Screw conveyors power and throughput analysis during horizontal handling of paddy grains. J Agric Sci 2(2):147–154 3. Bogdanov VS, Semikopenko IA, Vavilov DV (2018) Power calculation of grading device in disintegrator. IOP Conf Ser Mater Sci Eng 327(5):052006 4. Asli-Ardeh EA, Mohsenimanesh A (2012) Determination of effective factors on power requirement and conveying capacity of a screw conveyor under three paddy grain varieties. Sci World J 575–580 5. Khakhalev PA, Bogdanov VS, Kovshechenko VM (2018) Kinetic parameters of grinding media in ball mills with various liner design and mill speed based on DEM modeling. IOP Conf Ser Mater Sci Eng 327(4):042049 6. Owen PJ, Cleary PW (2010) Screw conveyor performance: comparison of discrete element modeling with laboratory experiments. In: Proceedings of the Seventh International Conference on CFD in the Minerals and Process Industries: Progress in Computational Fluid Dynamics 10. 5/6(327):301–307 (2010) 7. Bogdanov VS, Eltsov MY, Shirokova LY, Khakhalev PA (2017) Engineering design of mechanical equipment for the production of cement on basis of configurators. ZKG Int 70(5):64–66 8. Zareiforoush H, Komarizadeh MH, Alizadeh MR (2010) Effect of crop-screw parameters on rough rice grain damage in handling with a horizontal screw conveyor. J Food Agric Environ 8(3–4):494–499 9. Latyshev SS, Voronov VS, Bogdanov, Bazhanova OI, Maslovskaya AN (2018) Mathematical modeling of load’s movement in lifter of intramill recirculation device inside tubular mill. IOP Conf Ser Mater Sci Eng 327(2):022046 10. Rud AV, Evstratova NN, Evstratov VA, Bogdanov DV, Lozovaya SY, Lunev AS (2014) Theory of vertical auger. ARPN J Eng Appl Sci 9(11):2376–2382

Improvement of Connections Column and Beams in Wooden Houses M. V. Ariskin

and P. P. Sizov

Abstract One of the most significant indicators of the construction of houses is the construction period of the structure. In this matter, of course, fully assembled houses are the leaders, but their versatility and individuality are very limited. To add personality to the buildings, frame houses are suitable, the supporting structures of which are made of columns and beams, and the filling can be performed with various materials. Significant for such houses will be the connection of columns with beams with the help of reliable connections. One of the most technologically advanced connecting elements in low-rise buildings made of columns and beams can serve as metal connecting plates. A type of connection using steel plates is proposed. The paper presents a method for constructing a connection model on metal plates, which includes both a sequence of partitioning into a grid of finite elements, and the application of boundary conditions, and modeling the connection of a metal plate with a wooden element. The node simulation was performed in the SCAD software package. Mathematical modeling of the system allowed us to obtain a pattern of stress changes from various parameters, such as the thickness of the plate and the size of the grooves in the wooden elements. According to the results of the calculations, all the stress components were obtained, the analysis of which showed that the load distribution due to the bonding of the plates will be uniform over the entire volume of the connection, which allows us to conclude that this connection will be sufficiently reliable. The analysis of the obtained data allowed us to choose the optimal dimensions of the connecting elements. The calculated data should be confirmed by experimental studies. So, on the basis of the obtained data, a methodology for conducting experimental studies is being developed, and an experiment will be conducted, which will be presented later. Keywords Connection of wooden structures · Confidence · Metal connecting plates · Composite material · Simulation · Models

M. V. Ariskin (B) · P. P. Sizov Penza State University of Architecture and Construction, Penza, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_35

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1 Introduction In the wooden house to live comfortably and it is useful for health therefore more and more people in the cities give preference to life in the country in own wooden cottage. It should be noted that use of wood as the main construction material allows to close life cycle of construction materials in the building and to reduce the volume of use of non-renewable resources. As a result, the range of wooden designs annually increases. It is connected not only with new assessment of this construction material, but also with the improved technology of its processing [1]. The research works which are carried out for the last 55 years allowed to obtain quite exact data on physical and mechanical properties of construction wood. It gives the chance to make exact calculations of construction elements and designs from wood according to the requirements shown in each case. On the basis of research data the standards containing requirements to quality of material were developed. Thanks to these norms and the conclusions accepted on the basis of the carried-out tests the material quality control which is carried out partially on production, and partially in special facilities became possible. Now the architects and engineers applying wood as construction material can use the numerous systems of bearing structures which give an opportunity to create diverse forms. As a rule, the designer at the same time has big freedom, than during the work with steel and reinforced concrete as the tree gives in to processing in comparison with other construction materials easier. Broad application of a tree as construction material began after development of technology of pasting of wood and production of bearing structures from the stuck together packages of boards. The majority of connections represent combinations of a tree and became, for example, in the systems of framework. Type of a building construction, at which the framework from straight lines and inclined planes forms the bearing basis of the building (under various corner), of the beams executed from a powerful bar of wood of coniferous breeds, providing the high durability and durability of the building [2]. These beams are visible from the outer side of the house and give to the building a characteristic look. In the Middle Ages the space between elements of a framework was filled mixed with clay a cane, branches, straw or various construction debris; the received panels were plastered, at the same time the framework was usually left in sight. Framework elements visually dismembered white walls and gave to the image of buildings special expressiveness which became the main architectural feature a framework. In modern houses the space between a framework is filled with the brick, a tree protecting with the elements including effective heater or double-glazed windows. The medieval houses in Europe which stayed several centuries are in such a way built. This type of the frame house is widespread in Austria and Germany. Along with the German framework there were similar technologies of frame construction and in other countries. For designation of these technologies “rack-mount and frame” use the general name [3–7].

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For the purpose of cut in expenditure at construction of wooden buildings seek to use as much as possible elements and the spatial cells which are subject to fast assembly on the building site in this connection, there is a need for a certain unification and systematization of elements of a framework. The new type of connection of a system from racks and beams on metal plates is offered.

2 Methods and Materials Reliable calculation of bearing structures is a basis by their optimization. One of ways of reduction of labor input, material capacity and cost of designs of rack-mount and frame systems is application of universal connection with optimum parameters – the sizes of a metal plate. The above-stated complex of the interconnected questions defined a main objective of work which consists in development of universal nodal connection of elements of rack-mount and frame systems on steel plates and a research of his intense deformed state for improvement of constructive decisions the framework of systems and the choice of optimum parameters of elements. • For achievement of the purpose stated above it is necessary to solve the following problems: To make the analysis of the applied knots and to define the field of their rational application. • To develop knot of connection of elements of rack-mount and frame systems on steel plates. • To develop a technique of creation of settlement final and element model of the offered connection and theoretical research finite element method of nodal connection. • To carry out the analysis of the intense deformed condition of elements of nodal connection of rack-mount and frame systems on steel plates depending on their geometrical characteristics. • To execute assessment of the received results and to make practical recommendations. Calculation is executed by means of the SCAD design computer system. Method of constructing a finite element model. The scheme was manually broken down by the terminal elements in the form of parallelepipeds[8–10]. The structures of the beams connecting the plates and struts were developed separately from each other (Fig. 1), then in the assembly mode, calculation schemes were built (Fig. 2). To illustrate the results, the diagram is set at a scale of 10:1 (the dimensions in SCAD are 10 times larger than real). To achieve the best stress pattern, a grid of finite elements with a pitch of 0.1 m was adopted, which in fact corresponds to 10 mm. The present system is based on a base which is considered rigid. In this case, rigid links are introduced into the nodes that connect to the rigid base (limited movements in all possible directions).

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Fig. 1 Elements of the calculation scheme: (a) left beam;(b) right beam; (c) colon; (d) connecting plate

Fig. 2 General view of calculation schemes

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Fig. 3 Solid body connecting extreme posts and beams

Of greatest interest is the connection of the two beams above the post, therefore, in order to simplify the design scheme, the extreme posts are modeled with rod elements that coincide with the geometric axes of the corresponding posts. The connection of the beam and steel plate assemblies during assembly is defined as “hinge,” while the movements in the directions X, Y, Z, Uz are combined. The connection of the extreme posts with the beams is modeled by “three-dimensional” solid bodies (Fig. 3), combining all possible movements. A solid master node is a node that matches the geometric center of the beam cross section. All internal stresses in each volumetric final element were aligned in the direction along the axes of the general coordinate system, which provides a real picture of the processes taking place in the design under study. Loads on elements. Suppose that the total running load on the beams is 1.962 kH/m, i.e. the load of 9.81 kPa will act on the upper faces of the beams. In the considered scheme, taking into account the accepted scale, we apply a load of 9,81 MPA to the upper row of volumetric finite elements of the beams.

3 Results and Discussion The results of calculations in the SCAD program with the data described above are given in the form of stress isofields. The following are isofields of stresses in the connection elements with indication of numerical values of the required stresses under action of external load on the studied structures (Fig. 4,5). The stress isofields in the beams and the post were analyzed and graphs were plotted of the dependence of normal stresses a on the thickness of the plate t (Fig. 6), on the depth of the tie-in of the steel plate into the wooden element h, on the area t × h. As can be seen from the graphs, as the thickness of the steel plate increases, the compressive and tensile stresses in the wood elements decrease. At the depth of the tie-in of the steel plate h = 100 mm with an increase in its thickness, the stresses

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Fig. 4 Isofields of stress Nx in wood

Fig. 5 Isofields of stress Nx in steel

Fig. 6 Graphs of compressive stress dependent σ on plate thickness t

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decrease by 72–74%, and at the depth of the tie-in of the steel plate h = 200 mm by 57–59%. Thus, as the thickness of the connecting plate increases, the wood is in a more favorable mode of operation.

4 Conclusion – A method of constructing a model of a calculation scheme has been developed. – A method of theoretical investigation of the stress state of the proposed compound has been developed. – 4 types of design schemes are considered, voltage conditions are determined for them. – Dependencies of stress state on geometrical characteristics of elements of node joint are revealed. – As the thickness of the steel plate increases, the compressive and tensile stresses in the wood elements decrease. – With an optimal ratio of sizes of a steel plate with an increase in the depth of its tapping into wooden elements, normal and tangent stresses decrease. – With rational ratio of dimensions of steel plate wood is in more favorable mode of operation with increase of depth of tie-in into wooden elements and increase of plate thickness.

Reference 1. Chernykh AG (2011) Wooden house building. Architecture. Constructions. Calculation: textbook/edited by - St. Petersburg: S. Peterb. state. arkhit. builds. un-t, 342 pages 2. Sour V (2012) The main problems of low-rise house building in the Russian Federation. Part 2/B. Sour//LesPromInform 8(90):8–12 3. Khrulev VM (ed) (1983) Wooden structures and details. Handbook of the builder. Stroyizdat, 288 p. 7 4. Voevodin VM (1983) Experimental construction and testing of wooden panel houses. Voevodin VM (ed) Woodworking industry, no. 6, pp 1–3 5. Buga PG (1987) Civil, industrial and agricultural buildings. In: Buga PG (ed) Higher School, 350 p 6. Vdovin VM (1988) guidelines for conducting field tests of panel designs prefabricated wooden houses with the use of chipboards. Vdovin VM, Karpov VN, Penza CII – Penza, 36 p, Dep. VNIIIS 12.02.88, No. 8607 7. Makarova TA (2004) Architectural design of Buildings 1:46-49 8. Ariskin MV, Zagarina MS (2014) The use of wooden glued structures in construction. Sci J “Bull Magistracy” Colloquium. 12(39), t.1.:92–94 9. Ariskin MV, Zagarina MS (2017) Modeling of wooden structures by the method of finite elements. Effective building structures: theory and practice: collection of articles of the XIV International Scientific and Technical University conferences. - Penza: Volga House of Knowledge, 2014. Polytransport system materials IX International scientific-technical conference. Siberian state University of railway engineering, pp 53–56 10. Shein AI, Zavyalova OB (2012) Calculation of monolithic reinforced concrete frames taking into account the sequence of erection, physical nonlinearity and creep of concrete Construction mechanics and calculation of structures 5(244):64–69

Application of Carbon-Containing Sorption Material for Wastewater Purification from Methylene Blue Dye I. V. Starostina , D. O. Polovneva , Yu. L. Makridina , and L. V. Denisova

Abstract The equilibrium sorption of methylene blue coloring agent on carboncontaining sorption materials has been studied. As an initial sorbent the carboncontaining material, obtained by thermal processing of oil extraction industry waste kieselguhr sludge at temperature 500 ºC in conditions of lack of oxygen, notionally named TKS500 , was used. TKS500 was activated by treating it with 30% nitric acid solution and 1 M sodium hydroxide solution. It has been demonstrated that the dye’s sorption isotherms for the initial and for the activated TKS500 samples are of the S-type. In low concentrations range of the dye solution a monolayer is formed. With the further increase of the dye content, after monolayer formation the methylene blue molecules are extended to dimer molecules and the sorption becomes polymolecular, which is shown in the isotherm as a sharp increase of sorption capacity. This is characteristic for both the initial sorption material, and for the material, modified with sodium hydroxide and nitric acid solutions. In the low concentrations range of the dye solution the sorption isotherms for the initial TKS500 and for the TKS500 , modified with HNO3 solution, are described with Freundlich model’s equations, and the sorption isotherm for the TKS500 , modified with NaOH solution, is described with Temkin model’s equation. It has been determined that the maximum sorption capacity (0.244 mmol/g) is possessed by the carbon-containing sorption material TKS500 , activated with the 30% nitric acid solution. Keywords Carbon-containing sorption material · Activation · Methylene blue dye · Adsorption isotherm · Mathematical processing · Monolayer · Polymolecular adsorption · Associates

1 Introduction Synthetic dyes are one of the largest classes of chemical substances, which have found commercial application in various branches of industry. Nowadays over 100 I. V. Starostina (B) · D. O. Polovneva · Yu. L. Makridina · L. V. Denisova Belgorod State Technological University named after V. G. Shukhov, Belgorod, Belgorod Region, Russian Federation © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_36

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thousand of dyes, with the total volume about 1 mln tons, are produced globally, about 50% of which is presented with textile dyestuffs [1]. The main consumer of pigments and artificial dyes is light industry. The dyeing-and-finishing industry is characterized with complexity of processes and high water consumption. A wide range of manufactured products predetermines using a large variety of technological solutions for dyeing and finishing fabrics. This results in the generation of considerable amounts of sewage waters, which contain a broad range of pollution components—pigments, alkalis, acids, surface-active substances, suspended and colloidal particles. Wastewaters purification at textile enterprises is performed at local waste treatment plants with the usage of mechanical and physical and chemical methods, including electrochemical [2]. But the treated wastewaters are characterized with high color index, which requires additional measures for their after treatment. For neutralization of dyes various methods are used, which can be conventionally divided into destructive and non-destructive. Destructive methods are based on organic matter decomposition as a result of oxidation processes with the formation of gaseous or low-molecular reaction products. In these processes chemical, electrochemical and biochemical oxidation are used. Destruction processes of methylene blue (MB) with the usage of oxidation processes AOPs were studied in the work [3]. It has been demonstrated that MB destruction mostly occurs under the action of ozone and other active particles, which are formed in plasma. The destruction efficiency was 99–100%. In the work [4] the dyes destruction in water medium is performed with the combined action of ultraviolet and H2O2/O3 —or with Fenton’s reagent in solution. Some dyes, for example, polyaromatic—eosin, active blue and azure II, can be destructed with enzymes, produced by filamentous fungi [5]. The findings of the research, presented in the work [6], have shown the ability of Azospirillum bacterial genus (Azospirillum) for biodegradation of azoic dyes and anthraquinone dyes, exemplified by methyl orange and remazol brilliant blue (reactive 19), respectively. Non-destructive methods are based on concentrating organic substances without their decomposition [7]. Such methods include mostly physico-chemical methods (coagulation, flotation, and sorption), membrane processes and evaporation. Among the vast variety of non-destructive methods used in dyed wastewaters purification systems the adsorption processes have found wide application. This is explained by their simplicity, high efficiency, as well as the possibility of using low-cost materials and industrial or agricultural production waste as adsorbents. Besides, the usage of adsorption processes allows reducing the concentrations of organic and inorganic impurities to values significantly lower than the maximum allowable concentration. This makes possible the application of treated wastewater in the closed technological cycle. For recovering dyes of various types—anionic (acid red, direct—ordeaux) and cationic (methylene blue, crystal violet) from water media, in the work [8] the application of sorption material polyampholyte FIBAN AK-22V is considered. It is demonstrated that for direct—ordeaux dye recovery efficiency is 56%, for other dyes—up to 90–98%.

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In the work [9], as adsorption materials for purifying wastewaters from acid brown K dye, clinoptilolite, treated with polyhexamethylene guanidine chloride solution, called clinocide, and activated carbon AG-3, treated with solution of polyhexamethylene guanidine phosphate, were used. It is demonstrated that the efficiency of using modified AG-3 is by 1.9 higher than that of using clinocide. The findings have shown that the combined usage of coagulants, flocculants and aftertreatment by sorption method allows reducing the content of acid brown K in sewage waters to maximum allowable concentration. There is an experience of sorptive recovery of coloring agents from water media by using a magnetically-controlled sorption material, obtained by modifying saponite with magnetite (2% of weight) [10]. It has been determined that the modification of saponite allows not only providing the mesoporous sorbent with magnetic properties, but also improving its sorption-structural characteristics. The adsorption capacity of the magnetically-controlled sorbent for all types of dyes (anionic, cationic and non-ionogenic) is 1.5–2.5 times higher, than that of the natural saponite. The findings of the research, presented in the work [11], have demonstrated the possibility of dyed water solutions treatment by using modified sugar production sludge (sugar mud) as an adsorption material. It has been shown that the sugar mud, treated at temperature 600 ºC, is presented with calcium carbonate particles, covered with carbon layer. The efficiency of using this carbon-containing sorption material for extracting MB and Orange R dyes from test solutions has made up 94–96% and 96–98%, respectively. For purifying dyed water solutions the agricultural processing waste is also used as sorption material. Thus, the efficiency of MB extraction from water solutions by using milled apricot stones as sorption material amounted to 97.4% at the MB initial concentration 15 mg/dm3 [12]. The research in using algal biomass—of water hyacinth and water spinach in the initial and carbonized state—as adsorption materials was carried out [13]. The maximum adsorption capacity on the basis of Langmuir model for the pure and carbonized water hyacinth made up, (mg/g): 7.05 and 2.07, respectively, and for the pure and carbonized water spinach—1.25 and 5.32, respectively. The earlier research has demonstrated the possibility of obtaining a carboncontaining material (TKS500 ) by carbonization of the refined vegetable oil extraction industry waste kieselguhr sludge at temperature 500 ºC [14]. TKS500 is characterized with carbon layer on the surface of kieselguhr particles and with mesomacroporous structure. The obtained carbon-containing sorption material has ionexchange capacity due to the presence of oxygen-containing functional groups (OCFG) on its surface. The ion-exchange capacity of the obtained carbon-containing sorption material can be increased by increasing the amount of OCFG, by means of chemical modification of the material’s surface carbonic component. The purpose of this research is the acidic and alkaline modification of the carboncontaining material, as well as studying the sorption of methylene blue dye from water solutions on the obtained sorption materials.

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2 Materials and Methods The first paragraph after a heading is not indented (Bodytext style). To prepare model solutions methylene blue coloring agent was used (MB, N,N,N’, N’tetramethylthioninium chloride trihydrate)—a basic organic dye, which belongs to the group of thiazine dyes. The empirical formula of MB is C16 H18 N3 SCl. The content of oxygen-containing functional groups (OCFG) on the surface of sorption materials—TKS500 initial, TKS500 + 30% HNO3 and TKS500 + 1 M NaOH was determined by Boehm method. The sorption of methylene blue was carried out by using TKS500 —initial and modified in acidic and alkaline media. The activation of TKS500 was performed by treating it with solutions—30%-solution of nitric acid and 1 M solution of NaOH with ratio solid: solution = 1: 10 by weight, and exposed at temperature 295 ± 2 K with stirring during 24 h. The obtained materials were notionally named TKS500 + 30% HNO3 and TKS500 + 1 M NaOH, respectively. Then the sorbents were separated from the solution by filtering, washed with distilled water to the neutral pH level, and dried at temperature 105 ºC. As an initial sorbent TKS500 was used—the carbon-containing material, obtained by thermal modification of oil extraction industry waste kieselguhr sludge. The sorption equilibrium of methylene blue on the initial and modified samples of TKS500 was studied at temperature 295 ± 2 K in static conditions by alternating concentrations method. Solutions with MB concentrations from 5 to 1100 mg/dm3 were used. The weighed quantity of sorption material with weight 0.5 ± 0.0002 g was put into conical flasks, 50 cm3 of MB solution with a set concentration was added, and kept with stirring during 24 h. Then the phases were separated by centrifugation and the solution was analyzed for dye content by spectrophotometric method at wavelength 720 nm with the device KFK-3, Russia. The sorption capacity, mmol/g, was determined by the formula: A=

(ci − c f ) · V ma

(1)

where Ci and Cf —initial and final concentrations of MB coloring agent, mmol/dm3 ; V—volume of solution, dm3 ; ma —weight of adsorption material, g.

3 Results and Discussion The carbon-containing sorption material TKS500 initial consists of a carbonic and a mineral component. The mineral component is presented with diatomite—a sedimentary rock, formed of siliceous frustules of diatomic microalgae—diatoms and radiolarians. Siliceous frustules consist of morphic silica hydrates of various water content—opal varieties of the type mSiO2 ·nH2 O. Argillaceous admixtures in the amorphized state are also registered.

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By means of X-ray spectral microprobe analysis it has been determined that carbon on the surface of diatomite particles is distributed nonuniformly, and its content varies from 0 to 15.6%, i.e. the surface of the sorption material is presented with the combination of carbonic and mineral fragments. Modification of TKS500 with sodium hydroxide and nitric acid solutions increases the intensity of the bands, characteristic for C = O bond and hydroxyl groups, which indicates the increase of their content. This is confirmed by the quantitative evaluation of OCFG content on the surface of modified sorption materials (Table 1). MB sorption isotherms for the initial TKS500 and for the samples, activated with sodium hydroxide and nitric acid solutions, are presented in Fig. 1. The isotherms’ S-shape supposes the alteration of the MB sorptive bonding with the increase of its concentration in the external solution. The plateau in the isotherm in low concentrations range of the dye solution indicates monolayer formation. To identify the adsorption processes mechanisms, the obtained isotherms in their concentration range, corresponding to monolayer formation, were processed with Langmuir, Freundlich, Dubinin-Radushkevich and Temkin models, using Microsoft Office Excel [15]. Regression equations and approximation coefficients (R2 ), received as a result of mathematical processing of the obtained adsorption isotherms, are presented in Table 2. Table 1 Content of OCFG on the surface of modified sorption materials Modification conditions

Amount of OCFG, mmol-eq/g sum of carboxyl, lactone and hydroxyl

carboxyl

lactone

hydroxyl

TKS500 initial

0.137 ± 0.01

0.002 ± 0.01

0.046 ± 0.01

0.089 ± 0.01

1 M NaOH

0.163 ± 0.02

0.002 ± 0.01

0.052 ± 0.01

0.109 ± 0.01

30% HNO3

0.189 ± 0.02

0.012 ± 0.01

0.080 ± 0.01

0.097 ± 0.01

Fig. 1 MB adsorption isotherms of carbon-containing sorption materials

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Table 2 Regression equations and approximation coefficients Sorption material

Model Langmuir

Freundlich

Dubinin-Radushkevich

TKS500 initial

U = 0.1967x + 58.767

U = 0.3647x − 1.3117

y = −0.1355x − 3.7614 y = 0.0039x + 0.0291

R2 = 0.9254

R2 = 0.9968

R2 = 0.9417

TKS500 + 1 M NaOH TKS500 + 30% HNO3

Temkin

R2 = 0.9239

y = 0.5949x + y = 0.3663x − 42.117 1.3444

y = −0.0842x − 3.6808 y = 0.0049x + 0.0038

R2 = 0.8833

R2 = 0.9632

R2 = 0.5234

U = 0.1279x + 0.1279

U = 0.332x − 1.2727

y = −0.1017x − 3.5812 y = 0.0065x − 0.0031

R2 = 0.816

R2 = 0.9747

R2 = 0.8154

R2 = 0.9968

R2 = 0.957

As a fitting criterion the approximation coefficient (R2 ) was used. If the approximation coefficient value is equal to 1, this means the full accordance of the process with the model; i.e. the closer is the approximation coefficient value to 1, the better this model describes the process under study. As follows from Table 2, the MB dye sorption isotherms in the concentration range, corresponding to monolayer formation, for the initial TKS500 and for the TKS500 + 30% HNO3 solution, are best described with Freundlich model’s equations, while the sorption isotherm for TKS500 , modified with NaOH solution, is with better accordance described with Temkin model’s equation. The obtained findings indicate that on the surface of both the initial TKS500 , and modified with alkali and nitric acid, the nonuniformly distributed localized active centers are formed [16]. Adsorption centers have various energy values, and the active sorption positions with the maximal energy are filled first. Alteration of the active centers’ chemical nature and the increase of porosity are more pronouncedly demonstrated by the isotherm plateau and by the increase of MB amount, participating in monolayer formation. The maximum sorption capacity of the monolayer is characteristic for TKS500 + 30% HNO3 , which amounted to 0.04 mmol/g; the increase of sorption capacity in comparison with the initial TKS500 made up 67%. The obtained findings are in good agreement with the conclusions of the authors of the work [17], which indicates the MB ability to form dimers at dye solution concentrations over 1 · 10−3 M. With the concentration increase, the solutions can contain the dye ions and its associates, formed as a result of van der Waals interactions and hydrogen bonds. For the sorption material TKS500 + 30% HNO3 , the maximum sorption parameter value is 0.244 mmol/g, which exceeds this parameter of the initial sample by 16%.

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4 Conclusion The equilibrium sorption of MB on the initial TKS500 and on the activated samples is characterized with monolayer formation and associates formation. In the low concentrations range of MB solution the sorption isotherms for the initial TKS500 and for the TKS500 , modified with HNO3 solution are described with Freundlich model’s equations, while the sorption isotherm for the TKS500 , modified with NaOH solution, is described with Temkin model’s equation. It has been determined, that the maximum sorption capacity is possessed by the carbon-containing sorption material TKS500 , activated with the 30% nitric acid solution. Acknowledgements The work is realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V.G. Shoukhov, using equipment of High Technology Center at BSTU named after V.G. Shoukhov.

References 1. Singh K, Arora S (2011) Removal of synthetic textile dyes from wastewaters: a critical review on present treatment technologies. Crit Rev Environ Sci Technol 41:807–878 2. Sinkovich VO, Shibeka LA (2019) Optimization of purification process of sewage waters, generated at dyeing and finishing of textile fabrics. In: Proceedings of Kola scientific center of RAS, vol 10, no 1–3, pp 318–322 3. Maehara T (2008) Degradation of methylene blue by RF plasma in water. Plasma Chem Plasma Process 28(4):467–482 4. Ince NH, Gonenc DT (1997) Treatability of textile azo dye by UV/H2 O2 . Environ Technol 18:179–185 5. Khalimova LH, Petukhova NI, Lisovskaya IV, Zorin VV (2009) Research of synthetic dyes degradation with micromycetes. Bashkir Chem J 16(4):62–64 6. Vorobeva SA, Kupryshina MA, Ponomareva EG, Nikitina VE (2017) Biodegradation of synthetic dyes bacteria of the genus Azospirillum. Izv Saratov Univ (NS) Ser Chemistry Biol Ecol 17(3):328–329 7. Konkova TV, Gordienko MG, Alekhina MV, Menshutina NV, Kirik SD (2015) Catalysts on the basis of mesoporous silicon dioxide for azoic dyes oxidizing. Catal Ind 15(6):56–61 8. Soldatkina LM, Sinkova LA, Sagaidak EV, Polikarpov AP, Shunkevich AA (2008) The sorptive extraction of anionic and cationic dyes by means of fibrous polyampholyte FIBAN AK-22V. Bulletin of Odessa National University. Chemistry 13(11–12):108–113 9. Aleksandrov VI, Zakharova AA, Kruchinina NE, Bakhshieva LT (2014) Local purification of sewage waters from dyes. Des Technol 40(82):42–46 10. Makarchuk OV, Dontsova TA, Astrelin IM (2015) Magnetically-controlled argillous sorbent for removing dyes from water solutions. Scientific news of the National Technological University of Ukraine «Kiev Polytechnic Institute» 6(104):109–114 11. Elnikov DA, Sverguzova ZhA, Sverguzova SV (2011) The influence of sugar mud heat treatment on the efficiency of dyes test solutions purification. Bull BSTU VG Shukhov 2:144–147 12. Sverguzova SV, Vinogradenko YuA, Sapronova ZhA, Bomba IV (2019) Purification of solutions from methylene blue dye with apricots processing waste. Safety, protection and preservation of the natural environment: fundamental and applied research, vol 2, pp 101–108

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13. Tarawou T, Horsfall M Jr (2007) Adsorption of methylene blue dye on pure and carbonized water weeds. Bioremediat J 11(2):77–84 14. Starostina IV, Cherevatova AV, Stolyarov DV, Anischenko IV (2020) Research of textural, structural and sorption properties of carbon-containing materials on the basis of vegetable oil production sludge waste. In: Proceedings of Gubkin Russian State Oil and Gas University, vol 2, no 299, pp 119–132 15. Galimova RZ, Shaykhiev IG, Sverguzova SV (2017) Processing the research findings of adsorption processes with using Microsoft Excel software. BSTU publishing office, Belgorod 16. Denisova TR (2017) Investigation of phenol adsorption on barley husk modified by lowconcentrated sulfuric acid solutions. J Fundam Appl Sci 9(1S):1480–1490 17. Kotova DL, Sokryukina AI, Krysanova TA (2019) Sorption equilibrium of methylene blue on clinoptilolite. Sorption Chromatogr Process 19(2):174–178

Improving the Wear Resistance of Rotary-Vortex Mill Hammers A. A. Romanovich , S A. Dukhanin , M. A. Romanovich , and Amirhadi Zakeri

Abstract The method of increasing the durability of the hammers is proposed, which allows protecting the surface from rapid wear, and thereby increasing the service life of the working bodies. The results of comparative tests of traditional drill hammers, a pilot model of a rotary-vortex mill with a cylindrical shape and a drill hammer, on the working surface of which a solid surfacing and a mesh of wear-resistant material with certain cell sizes are carried out, are presented. As a result of the analytical study of the calculated scheme of force interaction in the hammer cell, an equation is obtained for determining its geometric dimensions, which allow for the pressing of the crushed material. The graphical dependence of the results of the wear value of the hammers made with surfacing of the working surface with wear-resistant material on the operating time in hours, and traditional hammers without surfacing is presented. It was found that the differences in the amount of wear of the hammers made with solid surfacing and with the cells deposited on the working surface are insignificant, this is due to the fact that the crushed material gets stuck in the cells and thus protects the surface of the hammer at the bottom of the cell from intense wear. In this case, the material contacts the area of the cells deposited with the wear-resistant material, which leads to its abrasion, at a rate equal to continuous surfacing. Keywords Hammer · Wear resistance · Rotary-vortex mills · Wear · Surfacing

1 Introduction In the modern world, rotary-vortex mills, used for fine grinding and mixing of materials with mechanical and chemical activation of their particles, are widely used in the technology of production of dry building mixes. One of the vulnerabilities in the

A. A. Romanovich · S. A. Dukhanin (B) · M. A. Romanovich Belgorod State Technological University named after V. G. Shukhov, Belgorod, Russia A. Zakeri Islamic Azad University Central Tehran Branch, Tehran, Iran © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_37

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operation of these units is the rapid wear of their working bodies—hammers, the service life of which, depending on the production technology, is up to 200 h. The use of rotary-vortex mills in practice shows that the conditions of their operation (high temperature, abrasiveness of the material, speed parameters of the unit, and others) have a significant impact on the durability of the hammers and the amount of their wear [1–3]. The most noteworthy methods are those that can significantly increase the service life of the drill hammers, which include: thermal, chemical-thermal treatment of the surface of parts or surfacing with wear-resistant materials. One of the most effective methods for achieving the durability of the working bodies of rotary-vortex mills is the surfacing of wear-resistant materials on the working surface, which allows increasing the inter-repair period, and thereby increasing the reliability of the unit [4–6]. In view of the fact that the application of wear-resistant alloys on the entire working surface of the hammer entails an increase in their cost and the unit as a whole, the search for methods to increase the durability of the hammer by applying a wear-resistant material in the form of a grid with rectangular cells on their working surface is relevant. The use of this type of surfacing on the working surface of the bill allows increasing its durability, reducing the consumption of expensive material, and also in the process of work by filling the mesh cells with particles of the crushed material will protect the non-melted part of the surface from intense wear.

2 Materials and Methods Comparative tests were carried out on a pilot model of a rotary-vortex mill, which includes a cylindrical body with a removable lining, a rotor on which traditionalshaped hammers with a hardness of 40 HRC were rigidly fixed, and two structures of the hammers, on the surface of which a solid surfacing and a mesh of wear-resistant material were made (Fig. 1). The characteristics of the surfacing material are regulated by the normative documents GOST 2246-70 and TU 1227-220-10,557,608 (Table 1). The initial material to be crushed was blast furnace slag with the following characteristics: strength 60 MPa, granule size 10–20 mm, porous structure. The chemical composition of the slag is shown in Table 2. The technical characteristics of the rotary-vortex mill are presented in Table 3. As a control sample, the traditional design of the hammer was used, and the experimental samples were the hammer with a solid surfacing and surfacing with a cell size of 15 × 15 × 5 mm (Fig. 2). The hammers were installed alternately in the two upper rows of the rotor that were subjected to the greatest wear. Control over the amount of wear of the hammers was carried out with a periodicity of mill operation equal to 20 h.

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Fig. 1 Diagram of the installation of the drill hammer on the mill rotor: a—photo; b—design diagram: 1—housing; 2—rotor; 3—lining; 4—receiving hopper; 5—finished product selection pipe, 6—bearing supports; 7—rotor drive

a)

b)

Table 1 Characteristics of welding wire SV08G2S Wire grade

Mass fraction of elements in the deposited metal, % C

Mn

Si

Cr

Ni

Hardness of the deposited metal

SV08G2S

0.05…0.0.11

1.8…2.10

0.70…0.95

≤0.2

≤0.25

180.0.210 HB

Table 2 Blast furnace slag chemical composition Mass fraction, % CaO

SiO2

A12 O3

FeO

Na2 O

K2 O

Mo

35–45

35–45

>8

0.2–1

0.5–1

1–1.5

0.5–1.1

Table 3 Technical characteristics of the mill

Name of the indicator

Value

Capacity, t/h

5

Maximum particle size, mm

25

Shaft speed, min−1

2940

Installation power, kW

2 × 45

Overall dimensions of the installation L 2150 × 1500 × 1350 × H × H, mm

a)

Rotor diameter, mm

200

Rotor height, mm

800

b)

с)

Fig. 2 View of the hammer used for comparative tests: a—traditional construction; b—with solid surfacing; c—with surfacing in the form of cells

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3 Results Depending on the size of the cell, the geometric profile, the magnitude of the elastic expansion forces of the material and the coefficient of external friction, its exit or jamming in the cell applied to the working surface of the hammer is possible. Let us assume that the force F resulting from the elastic expansion forces in the cell will be equal over its entire side surface Sside , and when surfacing the mesh surface, cells with rounded corners along the radius r are obtained (Fig. 3) [7–10] The forces acting on the elementary area of the side surface of the cell, which has a perimeter length lb and a radius at its corners r, are determined by the following expression: (1) where α—the average angle of the direction of the resulting buoyant force. dFside = cr · dα · (2nr + 2mr) · Fdα

(2)

where c—height of the side surface of the cell, mm; n—width, mm; m—cell length, mm. Taking into account the fact that the horizontally directed buoyant forces arising in the corners of the cell are mutually compensated, the vertical forces, the total component of Fside.z will affect the pushing of the material out of the cell Z, which we define by projecting them on the Z-axis: 

Fside.z = ∫ d Fside (z) · cos α = 2r2 dα(n + m)F · ∫ cos α · dα

(3)

Having integrated Eq. (3), we obtain: 

Fside.z = 2r2 (n + m)Fz · sin α

(4)

Similarly, we determine the forces acting on the spherical parts of the surface: Fig. 3 Design scheme of force interaction in a cell

Improving the Wear Resistance of Rotary-Vortex Mill Hammers



Fsph.z = πr 2 F

281

(5)

We determine the value of the buoyant force Fnorm , which acts on the normals to the lower surface of the cell with an area of Scell : Fnorm = Scell · F

(6)

Thus, the total force that provides the output from the pressed material from the cell has the form:    F= Fside.z + Fsph.z + Fnorm , (7) Based on this, it can be assumed that the output of the pressed material from the cell will be prevented by the friction forces of the material on its side surface, which consists of a spherical part formed at the corners of the cell, as well as a parallel surface along the perimeter with a height of “c”. The total projection of the friction forces acting on infinitesimal parallel sections of the side surface of the cell with a height of “c” on the Z-axis and sections of the spherical surface at the corners of the cell can be determined by the equations: Fff.side = ∫ fd Fside = −frc(n + m) · F

(8)

Fff.sph = fdFsph.z · sin α = fπr2 · F

(9)

Thus, the total force holding the material in the cells is equal to: 

Fff =



Fff.side +



Fff.sph

(10)

Based on the above, it was found that the conditions for pressing the crushed material in the cells on the working surface of the hammer will be provided if: 

Fff ≥



F

(11)

Substituting the values, we get: c≥

2r · (sin α(n + m) + 0, 5 · n · m − f · cos α(n + m)) , f · (n + m)

(12)

According to expression (12), the dimensions of the cells deposited on the working surface of the grid are determined, based on the data: f—the coefficient of external friction, depending on the properties of the material and the surface of the hammer (f = 0.5); α—the average angle of the direction of the resulting buoyant force (α = 450); r—the radius of the inscribed circle (r = 5 mm); n—the width of the mesh cell made of wear-resistant material (n = 5 mm); m—the length of the cell (m = 5 mm).

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Fig. 4 The results of the wear and tear of the hammer

According to the calculations, it can be argued that under the specified conditions, the lining of the cells deposited on the working surface of the hammer can be made with the crushed material at a height of the side surface “c” of at least 3.21 mm. According to the results of comparative studies of three samples of hammers, a graphical dependence is constructed and it is found that the most resistant to abrasion are hammers, on the surface of which a wear-resistant material is deposited, which is due to the different hardness of their working surfaces (Fig. 4). The gradual deceleration of the wear of the non-surfaced hammers after their operation for more than 80 h is associated with a decrease in the length due to wear, and, consequently, the circumferential rotation speed of the part of the hammer that is far from the center. The differences in the wear of the hammers made with solid surfacing and with the deposited cells are insignificant, this is due to the fact that the crushed material got stuck in the cells and thus prevented the wear of the surface of the hammer at the bottom of the cell. In this case, the material contacts the area of the cells deposited with the wear-resistant material, which leads to its abrasion, at a rate equal to continuous surfacing.

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An increase in the wear rate of the deposited hammers, after operating for more than 160 h, is associated with the wear of the deposited part of their surface. After that, the wear rate is carried out, as in the initial period of non-fused hammers. Thus, the proposed scheme of surfacing of the working surface of the hammer allows increasing its durability, while significantly reducing the need for expensive wearresistant material required for surfacing.

4 Discussion After analyzing the results of experimental studies, it was found that the hammers with surfacing wear out more slowly compared to the hammers made without surfacing, this is due to the different hardness of their working surfaces. As a result of an analytical study of the calculated scheme of force interaction in the hammer cell, an equation is obtained for determining its geometric dimensions, which allow for pressing the crushed material in it. The gradual deceleration of the wear value of the hammer without surfacing after their operation for more than 80 h is associated with a decrease in its length due to wear, and, consequently, the circumferential rotation speed of the part of the hammer that is removed from the center.

5 Conclusion Thus, the proposed scheme of surfacing the working surface of the hammer with the formation of cells allows increasing its durability, equal to continuous surfacing, while significantly reducing the need for expensive wear-resistant material required for surfacing the hammer. The resulting equation allows calculating the size of the cell based on the properties of the crushed material. Therefore, by applying in practice the surfacing of hammers with wear-resistant materials in the form of a mesh surface with cell sizes that meet the above design conditions, it is possible to increase the durability of the working bodies—hammers of a rotary-vortex mill and thereby increase their service life, while significantly reducing the need for expensive wear-resistant material required for continuous surfacing of hammers. Acknowledgements This work was realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V. G. Shukhov, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

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References 1. Dukhanin SA, Romanovich AA (2019) Analysis of the work and ways to increase the durability of the RVM-3000-01 mill hammers. In: Energy-resource-saving technologies and equipment in the road and construction industries: proceedings of the international scientific and practical conference. BSTU Publishing House, Belgorod, pp 51–55 2. Romanovich AA, Romanovich MA, Mamatova VV, Amini E (2018) Increase of size reduction of materials with anisotropic texture. J Phys Conf Ser 1118:012031 3. Yakushev AA, Dukhanin SA (2020) Improving the wear resistance of the working bodies of a rotary-vortex mill. In: Energy-resource-saving technologies and equipment in the road and construction industries: proceedings of the international scientific and practical conference. BSTU, Belgorod, pp 444–447 4. Romanovich AA, Amini E, Romanovich MA (2020) Improving the efficiency of the material grinding process. IOP Conf Ser Mater Sci Eng 945:12060–12065 5. Yinwei Y, Kai F, Jing X (2020) A novel control method for roll gap of roller crusher based on Fuzzy-PID with decision factor self-correction. IOP Conf Ser Mater Sci Eng 892:12–19 6. Xuemin L, Man Z, Nan H (2016) Calculation model of coal comminution energy consumption. Miner Eng 92:21–27 7. Glagolev SN, Romanovich AA (2017) New technology and energy-saving equipment for grinding materials with anisotropic texture. BSTU Publishing House, Belgorod 8. Khanin SI, Zybin RV, Mordovskaya OS (2020) Improving the efficiency of the material classification process in the classifying partition of a ball mill. Bulletin of BSTU named after V.G. Shukhov, vol 9, pp 97–107 9. Bogdanov V, Fadin YuM, Dontsova YuA, Bogdanov NE, Fyot ShK (2018) Mechanics of the crushing environment in ball mills with longitudinal and transverse motion of grinding bodies. Bulletin of BSTU named after V.G. Shukhov, vol 8, pp 117–125 10. Lang P, Rao Q, Qi YL (2013) Energy consumption analysis of single roller for disk roller crusher. Meitan Xuebao 38:249–255

Identification of the Compositions and Analysis of Changes in the Properties of Lime-Sandy Binders as a Result of Application of Petroleum Bituminous Rocks and Their Processing Waste T. K. Kuatbayeva , Z. M. Zhambakina , Zh. S. Serikbayeva , and B. K. Sarsenbayev Abstract In the paper the questions of technology of binding of silicate materials applying petroleum bituminous rocks (PBR) and waste processing, in particular: optimization of ratios of raw components of a mixture of silicate materials, the development of optimal technological parameters of production of silicate materials, technological aspects of production of these materials. The chemical-mineralogical and structural features of PBR and their processing waste are revealed. The optimal compositions of binders were studied using waste from the processing of PBR as an activating component of lime. The optimal ratio of the mixture of waste from the processing of PBR with lime and the technological parameters that allow to ensure the grade of the lime-sand binder from 400 to 500 are established. As a result, technological processes for the production of binders based on PBR and waste from their processing were justified and developed. Silicate materials based on them have high physical and mechanical properties and meet regulatory requirements. The proposed compositions and conditions for the preparation of these binders have high resistance in operating conditions. Keywords Silicate materials · Structure · Raw materials · Optimization · Mechanic and chemical activation · Solubility · Hydration · Activity

1 Introduction Binders, and products based on them, make up the main nomenclature of construction materials and products. The development of silicate materials based on them, with highly economical technological and efficient operational properties, is of great theoretical and practical importance. In Western Kazakhstan, there are huge reserves T. K. Kuatbayeva (B) · Z. M. Zhambakina · Zh. S. Serikbayeva T. Basenov Institute of Architecture and Construction, Satbayev University, Almaty, Kazakhstan B. K. Sarsenbayev M. Auezov South Kazakhstan State University, Almaty, Kazakhstan © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_38

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of petroleum bituminous rocks (PBR) (950–1000 million tons), the specific composition of which can be used for the production of silicate construction materials and products [1]. Currently, complex processing and use of PBR is carried out for the extraction of bitumen, processing and use of rocks in road construction [2]. Waste from the processing of PBR is not sufficiently disposed and it is traditionally irrational to recycle them, as this is associated with high energy costs. Previously published works do not contain specific information about the use of mineral waste from the processing of PBR for the production of binders of silicate materials. There was a need to develop scientifically based technologies for the production of silicate construction materials using the polymineral component of PBR, which will simultaneously solve the problems of creating new binding systems and technologies for their synthesis, developing production with self-sufficiency of resources, with measures for the disposal of these wastes, reducing the energy and material intensity of the production of products. Waste from the processing of PBR is a carrier of a significant amount of free energy, and therefore it is advisable to use this energy in their disposal, reducing to a minimum the energy consumption for processing, especially when implementing the technology for processing the most massive industrial products into composite materials [3]. The use of waste from the processing of PBR involves a multicomponent mixture used to produce composite materials, which is economically advantageous from an energy point of view, as the substances present in them, interacting, accelerate the synthesis (hardening) of the material. This makes it possible to use the potential energy of waste more fully in creating a perfect structure of hydrate phases with lower energy costs, conducting in-depth research to identify the mechanism of interaction of such raw materials in the process of forming hydrate phases, structural features and their interaction on the properties of composite silicate materials to achieve high quality indicators, high performance characteristics and replace traditional highenergy-intensive construction materials.

2 Materials and Methods The following raw materials were studied: natural PBR (Kulzhan field, Atyrausk region); part of the mineral processing of this rock; sand of Embinsk deposit; sand of Makat deposit; sand of Nicholaevsk deposit; lime of Sas-Tyubinsk plant, lime of Aktobe plant [4, 5]. The determination of the material composition of raw materials, the determination of optimal compositions and the study of the physical and mechanical properties of binders, their phase and structural transformations, was carried out on the basis of the results of research, involving a full range of methods of physical and chemical analysis [6, 7]. Studies were conducted on the synthesis of silicate materials—as an activating component of binders (lime) [8].

Identification of the Compositions and Analysis of Changes …

287

To develop and enhance the binding properties, mechanic and chemical activation was applied by grinding jointly the components of the mixture to a specific surface area of 300–1000 m2 /kg. Lime-sand binder is obtained by joint grinding of the sand product of PBR processing with lime to a specific surface area of 300 m2 /kg, with lime activity of 80–85% (in terms of active CaO + MgO). The hardening was carried out under hydrothermal conditions, at 175 °C, according to the regime 1.5 + 8 + 1.5 h.

3 Results and Discussion Chemical, physical and mechanical, mineralogical and structural features of PBR and mineral products of their processing are represented by two main groups—silica materials containing more than 50% SiO2 and limestone-silica materials (Tables 1, 2 and 3) containing from 20 to 50% SiO2 . Table 1 Chemical composition of raw materials Raw materials

SiO2

Al2 O3 + TiO2

Fe2 O3

CaO

MgO

K2 O

Na2 O

SO3

p.o.i

Natural PBR

71.6

8.2

1.8

1.1

0.12

1.5

0.84

0.48

15.1

PBR waste

82.6

9.3

2.0

1.3

0.3

1.8

1.2

0.8

1.4

Table 2 Physical and mechanical properties of raw materials Materials

Average density g/cm3

True density g/cm3

Specific area, m2 /kg

Fineness of grinding by the residue on the sieve N 008

Waste of PBR processing

1.290

2.30

–

–

Sand of Embinsk 1.380 deposit

2.38

–

–

Sand of Makat deposit

1.370

2.35

–

–

Sand of Nicholaevsk deposit

1.460

2.55

–

–

Lime of Aktobe plant

0.960

1.89

381

1.80

Lime of Sas-Tyubinsk plant

0.909

1.80

390

1.90

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Table 3 Granulometric composition (in %) of raw materials Raw materials

Type of residue

Size of the holes, mm 2.5

1.25

0.63

0.315

0.14

Particular

–

0.50

6.0

10.0

63.5

Total

–

0.50

6.5

16.5

80.0

Sand of Embinsk deposit

Particular

1.2

5.8

14.3

30.4

8.2

Total

1.2

7.0

22.5

52.9

61.1

Sand of Makat deposit

Particular

1.1

2.4

8.4

37.6

20.4

Total

1.1

3.5

11.9

54.1

74.2

Sand of Nicholaevsk deposit

Particular

5.1

6.4

22.4

43.4

17.9

Total

5.1

11.5

33.9

76.9

94.8

PBR waste

Table 4 Impact of the grinding time on the specific surface area of the PBR processing waste Grinding time, min

Passage through the sieve 008 mm

Grinding degree (Dg )%

PBR waste

PBR waste

Sand

Sand

10

10

6

40

24

20

17

10

68

40

40

22

20

88

80

60

24.5

22

98

88

These are dispersed systems of amorphous or submicrocrystalline structure, characterized by a significant reserve of free kinetic energy sufficient for mutual attraction of macroparticles, which identifies them as materials with potential contactcondensation properties [9]. The grinding degree (Dg ) during mechanic and chemical activation is determined by the dependence: Dg = 100 − (H 100)/M(%), where, H—residue on the sieve, g; M—material weight, g. Under the conditions of grinding, it was found that the mineral (sand) part of the PBR is better activated than natural sand, which positively affects the solubility of the aluminum-silicon components and their interaction with lime. During the grinding process, there was an increase in the specific surface area, a change in the surface properties and structure of the grains that make up the materials (Table 4). On the surface of the grains of solid crushed materials, active centers appeared, causing the hardening of mineral binders [10]. The X-ray phase analysis showed a change in the crystal structure of feldspars as a result of grinding and the formation of an amorphized layer on the surface of the grains [11]. At a specific surface area of 600 m2 /kg, the solubility of feldspars in the products of PBR processing, under hydrothermal treatment (174 °C), by SiO2 is

Identification of the Compositions and Analysis of Changes …

а)

289

b)

Fig. 1 Changes in the microstructure of the PBR under the influence of heat treatment: (a) the microstructure of the PBR before heat treatment; (b) the microstructure of the PBR after heat treatment, at 700 °C

0.31 g/l, and natural feldspars—0.23 g/l; by Al2 O3 —0.054 g/l, and natural 0.038 g/l; by R2 O—0.094, and natural 0.078 g/l. The increased solubility of PBR minerals activates their interaction with lime. When the ratio of lime and the sand part of the PBR is 0.3; 0.8; 1.0; 3.0, during autoclave treatment, at 174 °C, for 8 h, the assimilation of lime by processing waste is 11; 28.4; 30.2; 36.6% of the mass of lime inserted into the mixture. Under similar conditions, the assimilation of lime by natural feldspars is equal to 9.1; 24.2; 28.2; 30.8%. These data indicate an increase in the activity of PBR sand after mechanical grinding, compared to natural analogues. This is due to the partial melting of the surface of grains of the mineral rocks during thermal processing, where there is a widening crack in the cleavage of their crystals contributes to the rapid grinding, to improve the solubility and interaction with other components (Fig. 1). The optimal ratio of lime and PBR processing products is in the range from 0.5:1 to 1:1, at which the activity of the lime-sand binder has the highest indicators, i.e. the strength is 42–50 MPa. A further increase in lime in the mixture does not lead to an increase in strength, i.e. the activity of the binder. The reason for this is an increase in the basicity of the cementing hydrate phases, with an increase in lime in the system (Table 5) [12]. The properties of the samples of binders, depending on the composition and conditions of hardening, vary significantly (Table 6) [13]. When the composition of the binder mixture (lime is less than 30%, i.e. active CaO from 4 to 12%), lime activity is 80–85% (in terms of active CaO + MgO), the maximum strength value is observed in the composition of the mixture (with PBR waste): 88% and lime 12%—35 MPa when autoclaving, 16.4 MPa—when steaming and 12.3 MPa when hardening under normal conditions.

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Table 5 Impact of component ratios on the properties of binders Composition of mixture, % PBR waste

Lime

Ratio (lime: PBR waste)

Activity of mixture, % Limit of compressive strength, MPa

70

30

0.5:1

25

42

60

40

0.8:1

35

48

50

50

1:1

42

50

40

60

1.5:1

50

38

30

70

2:1

60

20

Table 6 Properties of lime-sand binder materials Composition of mixture% PBR waste

Sand

96

–

94 92

Hardening conditions Lime

Autoclaving at 175 °C

Steaming at 75 °C

Under normal conditions at 20 °C

4

12/1740*

3.4/1760

–

–

6

14/1730

5.1/1780

–

–

8

18/1740

10.4/1810

7.6/1778

90

–

10

28/17/50

15.2/1810

10.1/1780

88

–

12

35/1860

16.4/1780

12.3/1810

–

96

4

9.8/

2.1

–

–

94

6

10/1780

5.0/1790

–

–

92

8

14/1760

7.3/1805

5.1/1740

–

90

10

20/1800

9.6/1820

7.0/1760

–

88

12

24/1870

12/1810

9.4/1800

(*)—above the line compressive strength, MPa; below the line average density, kg/m3

The composition of mixtures of group 2 (without PBR waste) has a similar composition: sand-88%, lime-12%—24 MPa for autoclaving, 12 MPa for steaming and 9.4 MPa under normal conditions, respectively. The average density ranges from 0 to 30 kg/m3 . The linear nature of the strength dependence is noted, with an increase in the lime content in the composition of the binders. Samples that have undergone autoclave treatment have a higher strength than samples that are steamed and hardened under normal conditions. The participation of certain oxide components of PBR in the hardening reaction was revealed. Under the conditions of hydrothermal synthesis, along with silicon dioxide, aluminum oxides and alkali metals (sodium and potassium) interact with lime, which accelerate significantly the solubility of silica. The ratio of CaO/SiO2 , the basicity of calcium hydrosilicates decreases, their binding capacity increases, which positively affects the strength characteristics of silicate materials. In binders of the composition PBR waste—lime, the development of strength is more dynamic, the strength indicators are higher compared to the samples of

Identification of the Compositions and Analysis of Changes …

291

the classical composition sand-lime, which provides the required grade of lime-sand binder and silicate materials based on it have high physical and mechanical properties [14].

4 Conclusion The chemical-mineralogical and structural features of mineral waste from the processing of PBR as raw materials for the production of building materials are revealed. As a result of heat treatment of PBR, in the process of extracting organic components from it, the resulting sand is better ground and subjected to mechanical activation than natural sands: the duration of grinding is reduced; the degree of grinding is increased. This has a positive effect on the solubility of sand minerals and the degree of interaction with lime. Under the conditions of hydrothermal synthesis, the participation of certain oxide components of PBR in the hardening reaction of silicate materials was revealed, which positively affects the strength characteristics of silicate materials. The optimal ratio of the silicate mixture of PBR sand and lime and the technological parameters ensure the grade of the lime-sand binder M400—M500.

References 1. Nadirov NK (2001) High-viscosity oils and natural bitumens (History. Swimming pools. Properties) A. Science 1:256 2. Zhurinov MZh, Teltayev BB, Kalybai AA (2019) Characteristics of road bitumen modified with carbon nanopowder. News Natl Acad Sci Repub Kazakhstan Ser Geol Tech Sci 5(437):223–228 3. Yartiev AF (2012) Natural bitumen – a unique energy raw material. Bull Kazan Technol Univ 12(15):293–297 4. Ishmukhamedova NK (2016) Study of the organic fraction of the petroleum bituminous rock of the Satypaldy deposit. Oil Refin Petrochem 11:22–24 5. Imanbaev EI, Ongarbaev EK, Simakov SV, Tileuberdi E, Tuleutaev BK, Mansurov ZA (2013) Composition of the petroleum bituminous rock of the Beke field (Kazakhstan). Sci Bull 24(167):139–142 6. Tatsky LN (2005) Modern physical and chemical methods of research of building materials: a textbook. Novosibirsk State University of Architecture and Construction. NSUAC, Novosibirsk, p 80 7. Makarova IA, Lokhova NA (2011) Physical and chemical methods of research of building materials: textbook. BrSU Publishing House, Bratsk, p 139 8. Moldabayeva GZh, Metaxa GP, Alisheva ZhN (2019) Theoretical bases for the implementation of the processes to reduce viscosity in the conditions of natural reservation. News Natl Acad Sci Repub Kazakhstan Ser Geol Tech Sci 5(437):138–143 9. Sidorenko YuV (2019) Features of contact-condensation hardening of silicate building materials and products: textbook. 4th edn. Publishing House “Internauka”, Moscow, p 50 10. Prokopets V (2003) The effect of mechanical activation on the activity of binders. Constr Mater 9:28–29

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11. Khomchenko YuV (2008) Improving the efficiency of autoclave materials based on the modification of the binder: dissertation of the candidate of engineering sciences. BSTU named after V.G. Shukhov, Belgorod, p 167 12. Kuatbaeva TK, Zhambakina ZM, Nashiraliev JT, Bruyako MG, Orynova AT (2020) Use of oil and bituminous rocks and waste from their processing in creation of composite silicate materials. In: Proceedings of NAS RK. Chemistry and Technology Series, vol 2 13. Kozhukhova NI, Strokova VV, Kozhukhova MI, Zhernovsky IV (2018) structure formation in alkali activated aluminosilicate binding systems using natural raw materials with different crystallinity degree. Constr Mater Prod 1(4):38–43 14. Klyuev SV, Klyuev AV, Khezhev TA, Pukharenko YV (2018) High-strength fine-grained fiber concrete with combined reinforcement by fiber. J Eng Appl Sci 13:6407–6412

One of the Approaches to Increase the Load-Bearing Capacity of Drill-Injection Piles N. S. Sokolov

Abstract The issue of strengthening weak or overloaded bases is an important task for the development of underground space. This is especially true in the presence of alternating weak layers at the base. The paper considers a case from the geotechnical practice of strengthening the overloaded base of a reinforced concrete foundation plate of a 25-storey residential building under construction. Combined ground piles consisting of Get (type 1) ground concrete piles reinforced along the longitudinal axis with made drill-injection piles using electric discharge technology (EDT piles) are used as buried structures. This method of arrangement of a combined buried reinforced concrete structure is due to the need to increase the load-bearing capacity of the pile on the ground by two times or more. Keywords EDT drill-injection pile · Ground concrete pile · Get technology · Load-bearing capacity

1 Introduction There are increased requirements for modern geotechnical construction [1–4]. In most cases, this is justified. It is often not possible to achieve the design values of the bearing capacity of the bases using existing geotechnical technologies. Using several existing technologies together, it is possible to create a buried structure of increased load-bearing capacity. Modern geotechnical construction allows solving most of the problems that arise both during construction and during the operation of objects. The case of strengthening the base of a reinforced concrete slab foundation of a multi-storey residential building is described below.

N. S. Sokolov (B) Chuvash State University named after I. N. Ulyanov, Moskovskiy prosp., 15, Cheboksary 428015, Russian Federation NPF (LLC SPC) “FORST”, ul. Kalinina, 109a, Cheboksary 428000, Russian Federation © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_39

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2 Methods and Materials Using several existing technologies together, it is possible to create a buried structure of increased load-bearing capacity. Modern geotechnical construction allows solving most of the problems that arise both during construction and during the operation of objects. The case of strengthening the base of a reinforced concrete slab foundation of a multi-storey residential building is described below. The case of strengthening the base of a reinforced concrete slab foundation of a multi-storey residential building is described below. The studied object already during its construction (5 floors were built) began to deform at a rate of up to 2.0 mm per week. We proposed a reinforcement based on the technology proposed in, which is a synthesis of 3 geotechnical technologies: 1.Get-technology—the arrangement of soil–cement piles according to “SP 291.1325800.2017 Reinforced soil–cement structures. Design rules Moscow. 2017”; 2.SFA technology—the arrangement of drill-injection piles with the help of continuous passing screws (CPS) in the body of the soil–cement array along its axis of symmetry, usually with a diameter of no more than 300 mm; 3.Discharge-pulse technology of the arrangement of drilling-injection piles. The electrohydraulic effect that occurs when processing fine-grained concrete contributes to its insertion into the ground-cement array. Thus, there is a more complete coupling of these two structural elements. This circumstance allows constructing a fundamentally new buried reinforced concrete structure—a ground-concrete pile.

3 Results and Discussion The studied object already during its construction (5 floors were built) began to deform at a rate of up to 2.0 mm per week. We proposed a reinforcement based on the technology proposed in [1–13], which is a synthesis of 3 geotechnical technologies: 1.

2.

3.

Get-technology—the arrangement of soil–cement piles according to “SP 291.1325800.2017 Reinforced soil–cement structures. Design rules Moscow. 2017”; SFA technology—the arrangement of drill-injection piles with the help of continuous passing screws (CPS) in the body of the soil–cement array along its axis of symmetry, usually with a diameter of no more than 300.0 mm; Discharge-pulse technology of the arrangement of drilling-injection piles. The electrohydraulic effect that occurs during the processing of fine-grained concrete contributes to its introduction into the ground-cement array. Thus, there is a more complete coupling of these two structural elements [5–13].

This circumstance allows constructing a fundamentally new buried reinforced concrete structure—a ground-concrete pile. Figure 1 shows the scheme of the combined soil-concrete pile arrangement. The buried reinforced concrete structure—a ground concrete pile (GCP) shown in Fig. 1b,

One of the Approaches to Increase the Load-Bearing Capacity …

295

unlike other types, has a complex cross-section structure. The load-bearing element is an electrohydraulically treated and reinforced SFA pile (CPS) (pos. 3). Its loadbearing capacity on the outer surface depends on the friction characteristics of the soil–cement component (pos. 1) (see Fig. 2). In addition, the SFA pile (CPS), together with the cement soil array works like concrete pile friction on the lateral surface of the surrounding soil (see Fig. 3). Engineering-geological section of the amplified combined soil concrete piles of foundation is presented by bulk soils, sands from small to medium-grained, from wet to saturated and loam smooth consistency, hard and semi-hard clays. The description of engineering-geological elements (IGE) and physical–mechanical characteristics of IGE are given in the table below (Table 1). As a result of geotechnical engineering calculations grounds taking into account the actual geological conditions of the construction site, the deficiency of bearing capacity of foundation slab base. At the same time, it is up to 50.0% of the design values. It should be noted that the height of the basement is 3.3 m. Based on this, the choice of existing geotechnical technologies for strengthening the considered base is not very large. If we consider the Get technology as a base reinforcement design, then the soil– cement pile is capable of bearing up to 50.0 ts (500.0 kN) in cross-sectional strength with a diameter of ∅ 600.0 mm. At the same time, it should receive up to 120.0 ts (1200.0 kN) to overcome the design load deficit. The use of a ground concrete pile (GCP) solves the problem. Arranging a ground-concrete pile and reinforcing it with Table 1 Table of normative and calculated physical and mechanical properties of soils № of IGE

Name of soils

Bulk soil sand with the inclusion of 10% of construction debris Fine sand, medium density Fine sand, dense Fine sand, loose Sand of medium size, medium density Medium-sized sand, loose Soft-plastic loam Semi-hard clay

Calculated values of the characteristics at

Normative characteristics

, MPa

Calculated values of the characteristics at

Calculated resistance

25

1

32

1

30

-

29

38

5

36

5

34

3

33

18

-

28

-

27

-

26

28

1

33

1

32

-

31

18

-

27

-

26

-

25

18

2.00

12

23

1.98

12

22

1.96

8

21

15

1.72

75

15

1.71

75

14

1.71

50

13

Note: the numerator shows the values of the deformation characteristics at natural humidity, the denominator-at water saturation

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Fig. 1 The scheme of the device of a ground concrete pile (GCP)

drill-injection piles ∅ 250.0 mm made by electric discharge technology according to the algorithm (given in [14]), the problem of restoring the deficit of the bearing capacity of the ground base is solved. CBS piles are designed to be 14.0–19.0 m long with a bearing capacity on the ground from 110.0 (1100.0 kN) to 150.0 ts (1500.0 kN). At the same time, the coefficient of the load-bearing capacity of the reinforced base is K = 1.4.

One of the Approaches to Increase the Load-Bearing Capacity … Fig. 2 Scheme for determining the load-bearing capacity of the SFA pile (CPS) on the ground-cement base Fd1 1—ground-cement array, 2—SFA pile (CPS)

Fig. 3 Scheme for determining the load-bearing capacity of the SFA pile (CPS) together with the ground-cement array on the ground (ground-concrete piles (GCP)) 1—ground-cement array, 2—SFA pile (CPS)

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4 Conclusion The technology of reinforcement of drill-injection piles, manufactured by electric discharge technology (EDT) enables solving problems of strengthening congested grounds and piles of extra load bearing capacity.

References 1. Ilyichev VA, Mangushev RA, Nikiforova NS (2012) Experience in the development of the underground space of Russian megacities. Bases, foundations and soil mechanics, pp 17–20 2. Ulitsky VM, Shashkin AG, Shashkin KG (2010) Geotechnical support of urban development. Georekonstrukciya, Saint Petersburg, p 551 3. Razvodovsky DE, Chepurnova AA (2016) Evaluation of the effect of strengthening the foundations of buildings on the technology of jet cementation on their sediment. Ind Civil Eng 10:64–72 4. Deckner F, Viking K, Hintze S (2017) Wave patterns in the ground: case studies related to vibratory sheet pile driving. Geotech Geol Eng 35(6):2863–2878. https://doi.org/10.1016/j.soi ldyn.2017.01.039 5. Korff M, Meijers P, Wiersma A, Kloosterman F (2019) Mapping liquefaction based on CPT data for induced seismicity in Groningen. In: Earthquake geotechnical engineering for protection and development of environment and constructions-proceedings of the 7th international conference on earthquake geotechnical engineering, Rome, pp 3418–3425 6. Deckner F, Viking K, Guillemet C, Hintze S (2015) Instrumentation system for ground vibration analysis during sheet pile driving. Geotech Test J 38(6):893–905. https://doi.org/10.1520/GTJ 20140275 7. Brinkgerve RBJ (2006) Plaxis: finite element code for soil and rock analyses. Balkema 53–56 8. Denies N, Holeyman A (2017) Shear strength degradation of vibrated dry sand. Soil Dyn Earthq Eng 95:106–117. https://doi.org/10.1007/s10706-017-0285-x 9. Karol RH (2003) Chemical grouting and soil stabilization. American Society of Civil Engineers, p 536 10. Moseley MP (2004) Ground improvement. London, p 440 11. Sokolov NS, Sokolov SN, Sokolov AN (2017) Fine-grained concrete, as a structural construction material for flight augering piles-EDT. Build Mater 5:16–20 12. Sokolov NS, Viktorova SS, Smirnova GM, Fedoseeva IP (2017) Flight augering piles-EDT as a buried reinforced concrete structure. Build Mater 9:47–50 13. Sokolov NS, Viktorova SS (2017) Research and development of a discharge device for the production of a flight augering pile. Bull Chuvash Univ 3:152–159

Using Leaves and Needles of Trees as Sorption Materials for the Extraction of Oil and Petroleum Products from Solid and Water Surfaces A. V. Svyatchenko , I. G. Shaikhiev , S. V. Sverguzova , and E. V. Fomina

Abstract Due to the increase in the volume of extracted, processed and transported oil and petroleum products, emergency situations are becoming more frequent, accompanied by a spill of oil and petroleum products, which has disastrous consequences for the environment and harms human health. This review summarizes the literature data on the use of components of woody biomass of deciduous and coniferous tree species—foliage and needles as raw materials for the production of sorption materials for the removal of oil and petroleum products from the water surface and from wastewater. Interest in the development of adsorbents originating from renewable natural sources, including multi-tonnage biomass waste, is caused at the world level in solving problems of rational nature management. It is shown that it is possible to increase the hydrophobicity of sorption materials from biomass waste and their sorption capacity by modifying them with acidic chemical reagents, low-pressure high-frequency plasma, and heat treatment. The optimal modification parameters for achieving the highest adsorption parameters in terms of oil capacity and oil adsorption from solid and water surfaces, as well as the mechanisms of processes based on models of sorption isotherms, are given. The future prospects of using leaves and needles of trees as precursor materials for the creation of cost-effective and effective sorbents are noted. Keywords Leaves and needles of trees · Oil and petroleum products · Water environment · Sorbents · Purification

1 Introduction Mechanical, physical, chemical and biological methods are used to clean the surface of water environment from petroleum products. In the case of a spill on the water A. V. Svyatchenko · S. V. Sverguzova · E. V. Fomina (B) Belgorod State Technological University named after V. G. Shukhov, Belgorod, Russia I. G. Shaikhiev Kazan National Research Technological University, Kazan, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_40

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surface, oil and petroleum products are initially localized with the help of booms. This circumstance is due to the large area of hydrocarbon pollution on the water surface, for example, 1 m3 of oil contributes to the formation of an oil film on the water surface with an area of 12 km2 [1]. The collection of hydrocarbons from a large area is a certain difficulty. When the volume of spilled oil is large and the thickness of the hydrocarbon film on the surface is large, the oil products are collected using skimmers—oil collecting vessels. If the film of hydrocarbons on the water surface is thin, it is more effective to use adsorption technologies. Currently, more than 200 sorbents and sorption materials (SM) are known for the extraction of petroleum products from aqueous environment. The disadvantages of commercial SM include high cost, not always high sorption characteristics for petroleum products. Often, the urgent localization of an oil or coal-hydrogen spill on the water surface requires a long period of time for the delivery of industrial SM from storage sites to the contaminated water body. A new innovative direction in the field of environmental protection is intensively developing in the world—the use of industrial and agricultural waste [2, 3], as well as natural mineral environment [4] and components of plant and tree biomass [5] as a SM for the extraction of pollutants, including oil and its processed products, from natural and wastewater. Cellulose and lignin-containing waste from wood processing are of particular interest. It is shown that waste from wood processing (sawdust, wood chips, shavings) and components of wood biomass (leaves, needles, nut shells, tree fruits, cones, etc.) are effective methods for removing various pollutants (heavy metal ions, dyes, hydrocarbons, pesticides, etc.) from aqueous environment [6–9].

2 Methods and Materials Publications in leading Russian and foreign editions were used to collect information. Methods of system analysis, comparative criteria of efficiency of scientific results of research of biomass of leaf litter and needles of trees as raw materials in obtaining sorption materials for removal of oil and petroleum products were applied. Studies were conducted to increase the sorption activity of the leaf litter of horse chestnut (Aesculus hippocastanum L.) by thermal modification. The thermal modification was carried out by heating the average sample without oxygen access in an electric furnace of the SNOL 25/12 brand with exposure at a temperature of 250 °C for 20 min. The modified biomass was used as an adsorbent in the purification of an emulsion containing diesel fuel. The kinetics of reducing the concentration of diesel fuel from the duration of contact with the adsorbent was studied according to the method of PND F 14.1.272-2012, where the measurement of the mass concentration of petroleum products in wastewater is performed by the IR spectrophotometric method.

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301

3 Results and Discussions The multi-tonnage components of woody biomass, which are formed annually, are the foliage and needles of trees. This type of waste is practically not used in industrial production and in most cases rot at the site of formation or are burned. The use of foliage and needles of trees as a source of SM of hydrocarbons from aquatic environments is explained by the high buoyancy of the leaves, low density and good sorption characteristics. In [10], it is indicated that the maximum oil capacity of the powder of the leaves of the tree Dacryodes edulis is 3.44 g/g; acetylation with acetic anhydride makes it possible to increase this indicator to 4.99 g/g while reducing the maximum water absorption from 1.97 g/g to 1.49 g/g. When studying the removal of crude oil from the water surface, the efficiency of modifying the leaves of the oil palm (Elaeis guineensis) with lauric acid is noted [11]. Modification at a temperature of 303–323 K increases significantly the hydrophobicity (from 16.3% to 84.7%) and the pore size of SM—from 3.87 nm to 4.93 nm. The maximum adsorption capacity of the foliage for oil is 1176 ± 12.92 mg/g at 303 K, and the adsorption isotherms are more accurately described by the Freundlich model. A series of works was carried out [12] to study the leaf litter of trees—silver birch (Betula pendula), white poplar (Populus alba), pedunculate oak (Quercus robur) and mixed foliage (birch—35%, poplar—31%, linden—10%, maple—10%, other— 14%) as a SM for removing oil from the Devonian sediment from the water surface. It is determined that the best results are achieved when treating the studied SM 1 N with H2SO4 solutions at t = 75 °C (increased oil absorption compared to the original samples: poplar leaf litter—5.5%, leaf litter—4.8%, mixed leaf litter—7.4%) and CH3 COOH at t = 75 °C (increased oil absorption compared to the original samples: poplar leaf litter—3.5%, birch leaf litter—4.0%, mixed leaf litter—5.6%). At 1 N modification with HCl solution, the increase in the degree of purification is less significant (poplar leaf litter—2.2%, birch leaf litter—0.7%, mixed leaf litter—3.5%). It was found that the treatment of sheet material with acid solutions is accompanied by a change in the surface structure of the sheet material due to increase in surface area and porosity. To increase the sorption characteristics of leaf litter in relation to oil, the efficiency of low-pressure high-frequency plasma treatment is noted [13, 14]. The best result for oil recovery is observed in the case of using mixed leaf litter subjected to plasma treatment in the flow of a mixture of argon and propane gases (Table 1). It is noted in the literature that the size of the foliage of mixed leaf litter affects the sorption properties [15]. The maximum sorption capacity for oil of foliage with a size of more than 3.35 mm is 1.7 g/g, with a size of 0.85–1.7 mm—2.7 g/g. The impact of the environment parameters on the sorption characteristics is indicated in the works. Thus, when studying the foliage of nimtree or Indian lilac (Azadirachta indica), the highest oil recovery efficiency (100%) is observed at pH ≥ 10 and 25 °C. It is revealed that the adsorption isotherm is described by the Langmuir model, and the kinetics of the process obeys the pseudo-second order model [16].

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Table 1 The degree of purification of samples modified under different modes Type of leaf litter

Plasma-forming gas

Birch

Argon-propane Argon-propane

Treatment time, min

Residual oil concentration in water, g/dm3

Purification degree, %

1

1.49

98.67

30

1.47

98.69

Argon-air

1

1.65

98.53

Argon-air

30

1.51

98.65

7.0

93.75

Argon-propane

1

3.01

97.31

Argon-propane

30

2.84

97.46 97.07

Without treatment Poplar

Argon-air

1

3,28

Argon-air

30

3.27

97.08

8.3

92.59

Without treatment Mixed

Argon-propane

1

0.64

99.43

Argon-propane

30

0.65

99.42

Argon-air

1

1.44

98.71

Argon-air

30

Without treatment

1.30

98.84

9.8

91.25

The leaves of various tree species and mixed leaf litter were studied as SM and various PP. In particular, the possibility of removing the “SAE40 PETRONAS Mach 5 Mineral Engine Oil” brand by the foliage of the Senegal mahogany (Khaya senegalensis) from the water surface at the water temperature of 27 °C, 50 °C and 70 °C was investigated [17]. It is noted that with an increase in the temperature of the aqueous environment, the adsorption characteristics decrease. This circumstance is associated with the extraction of saponins and flavanoids, which are part of the leaves of Senegal mahogany and have an affinity for oils. Native (LCOinit ) and heat-treated at 250 °C (LCO250 ) leaves of horse chestnut (Aesculus hippocastanum L.) were studied as SM for the removal of diesel fuel and I-20A brand oil from model emulsions in order to simulate the treatment of water containing petroleum products. It was found that the thermal effect on the leaf litter of Aesculus hippocastanum contributes to a significant increase in the specific surface area of the SM. Thus, for LCOinit , this parameter is 2.6 m2 /g, for LCO250 -17.6 m2 /g, which is associated with a change in the shape and size of the particles and an increase in the porosity of the samples [6]. In addition, the average pore sizes of these samples were determined in SM, which are 51.4 nm for LCOinit and 142.3 nm for LCO250 . The maximum oil capacity values for I-20A oil were determined, which were 6.37 g/g for LCOinit , 7.17 g/g for LCO250 , 6.04 g/g for diesel fuel, and 6.93 g/g for LCO250 [18]. Figure 1 shows the results of the study of the effect of the LCO250 contact duration on the reduction of the initial concentration of diesel fuel.

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Fig. 1 Dependence of the decrease in the initial concentration of diesel fuel in aqueous emulsions on the duration of contact (mass LCO250 = 1 g/dm3 )

It is obvious that when using LCO250 after 10 min of contact with the sorbate, complete removal of the pollutant from the water surface is achieved. The conducted industrial tests using LCO250 allowed reducing the concentration of petroleum products in urban wastewater from 2.6 mg/dm3 to 0.33 mg/dm3 (the degree of extraction of petroleum products is 87%) [19]. The values of the maximum sorption capacity of mixed leaf litter, both native and treated with solutions of NaOH, Na2 CO3 , as well as calcination in an argon atmosphere at 250 °C, were determined. It was found that the absorption capacity for diesel fuel of native leaf litter is 1.58 g/g, heat-treated—2.75 g/g [20]. It is recommended to use the foliage of the European beech (Fagus sylvatica) as a CM for the elimination of oil spills on the example of the oil brand “Mogul M7 ADS III” on the ground and water surface [21]. A number of studies have been conducted on the use of needles of coniferous trees as a source of petroleum products from aquatic environments. In particular, the values of the maximum oil capacity of native needles of Siberian larch (Larix sibirica) in relation to oil of Devonian and Carboniferous deposits under static and dynamic conditions were determined. It is determined that the oil capacity for carbon oil is 9.09 g/g and 6.76 g/g, for Devonian oil—8.35 and 5.24 g/g [22]. In order to increase the sorption properties in relation to oil, increase hydrophobicity, oil capacity and reduce water absorption, the efficiency of modification by high-frequency lowtemperature plasma treatment is noted. In [23], the needles of Siberian fir (Abies sibírica) were treated with high-frequency plasma of low pressure. The best indicators of the maximum oil adsorption and oil capacity (Table 2), and the lowest water absorption values are observed for samples of Siberian fir needles with the following plasma treatment parameters: a mixture of argon and propane in the ratio of 70:30, Table 2 Values of the maximum oil adsorption and oil capacity and water absorption of native fir needles

Petroleum product

Maximum oil capacity, g/g Static conditions Dynamic conditions

Devonian oil 2.07

1.51

Carbon oil

2.53

1.58

Oil I-20A

2.09

1.55

Oil 5 W-40

2.19

1.63

Maximum water adsorption, g/g 2.53

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time—10 min, voltage—3 kV, current—0.3 A, pressure in the chamber of the plasma torch—26.6 Pa, gas consumption—0.06 g/s. The possibility of using needles of Scots pine (Pinus sylvestris) and Scots spruce (Picea abies) as SM for removing oil and oils from solid and water surfaces is investigated. The values of the maximum oil capacity for the oil of the Carboniferous and Devonian deposits, as well as the maximum oil capacity for the spindle oil of the “AU” brand and motor oils of the “M-63/12G” and “M10G2K” brands (Russia) are determined. The maximum water absorption values for pine needles are 8.9 g/g and for spruce—7.15 g/g. Experiments were carried out to simulate oil and oil contamination of the water surface and to remove films of petroleum products using needles of coniferous trees. The volume of petroleum products and oil was 5 cm3 per 50 cm3 of water. It was determined that the efficiency of extraction of oils and oil by pine needles was 67–93%, and by spruce needles—from 52 to 76%. The calculated sorption values were 0.107–0.192 g/g for pine needles and 0.093—0.126 g/g for spruce needles [24]. Needles of European larch (Larix decidua), white fir (Abies alba) and Scots pine (Pinus sylvestris) of different humidity were studied as SM in relation to the “10W40” brand engine oil. It was revealed that among the needles, native and air-dried larch needles have the highest oil consumption (11.1 and 19.47 g/g, respectively). It was found that drying the SM to the moisture content in the samples up to 0–2% in all cases led to a decrease in the maximum oil capacity. It was shown that natural oils (needles, tree foliage, peat) have higher oil sorption capacity values than commercial sorbents, which makes them effective and low-cost reagents for removing oil spills [25].

4 Conclusion The paper summarizes the literature data on the use of components of wood biomass –foliage and fir needles as SM for the removal of oil spills and petroleum products from the water surface and from wastewater. It is shown that alternative SM are effective and low-cost materials for the extraction of petroleum products from water and solid surfaces. It is found that it is possible to increase the hydrophobicity of SM and their sorption capacity by chemical and physico-chemical modification. Acknowledgements This work was supported by a grant from the President of the Russian Federation for state support of young Russian scientists—candidates of sciences and doctors of sciences and leading scientific schools of the Russian Federation, application number MD-1249.2020.5.; using equipment of High Technology Center at BSTU named after V.G. Shukhov.

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References 1. Ossai IC, Aziz A, Auwalu H, Fauziah SH (2020) Remediation of soil and water contaminated with petroleum hydrocarbon: a review. Environ Technol Innov 17:100526 2. Doshi B, Sillanpaa M, Kalliola S (2018) A review of bio-based materials for oil spill treatment. Water Res 135:262–277 3. Fomina EV, Sverguzova SV, Sapronova ZhA, Kozhukhova MI (2020) Obtaining sorption material from sorghum for aqueous solutions purification from heavy metals. IOP Conf Ser Mater Sci Eng 945:012016 4. Bandura L (2017) Application of mineral sorbents for removal of petroleum substances: a review. Minerals 7(37):25 5. Al-Majed AA, Adebayo AR, Hossain ME (2012) A sustainable approach to controlling oil spills. J Environ Manag 113:213–227 6. Sverguzova SV, Sapronova ZhA, Svyatchenko AV, Otiti T (2018) Adsorption of spindle oil by native and thermal modified chestnut tree waste. Constr Mater Prod 1(1):4–11 7. Sverguzova SV, Shaikhiev IG, Fomina EV, Galimova RZ (2020) Use of chestnut sheel (castánea) as adsorption material for removing pollutants from natural and sewage waters: a review. IOP Conf Ser Mater Sci Eng 945:012072 8. Shaikhiev IG, Galblaub OA, Grechina AS (2017) The use of waste from the processing of barley as a sorption material for the removal of pollutants from aquatic environments (literature review). Bull Univ Technol 20(23):110–117 9. Anastopoulos I, Robalds A, Tran H et al (2019) Removal of heavy metals by leaves-derived biosorbents. Environ Chem Lett 17:755–766 10. Nnaji NJN, Onuegbu TU, Edokwe O, Ezeh GC, Ngwu AP (2016) An approach for the reuse of Dacryodes edulis leaf: characterization, acetylation and crude oil sorption studies. J Environ Chem Eng 4:3205–3216 11. Sidik SM, Jalil AA, Triwahyono S et al (2012) Modified oil palm leaves adsorbent with enhanced hydrophobicity for crude oil removal. Chem Eng J 203:9–18 12. Alekseeva AA, Stepanova SV (2015) The use of leaf litter as a sorption material for the elimination of emergency oil spills. Environ Prot Oil Gas Ind 7:9–13 13. Fedotova AV, Dryakhlov VO, Shaikhiev IG, Garaeva GF, Nizameev IR (2018) Effect of radiofrequency plasma treatment on the characteristics of polysulfonamide membranes and the intensity of separation of oil-in-water emulsions. Surf Eng Appl Electrochem 54(2):174–179 14. Alekseeva AA, Stepanova SV (2019) Effect of plasma surface modification of mixed leaf litter on the mechanism of oil film removal from water bodies. Russ J Gen Chem 89(13):2763–2768 15. Annunciado TR, Sydenstricker THD, Amico SC (2005) Experimental investigation of various vegetable fibers as sorbent materials for oil spills. Mar Pollut Bull 5:1340–1346 16. Hassan F, Umer A, Sabri MA et al (2018) Use of Neem leaves for oil removal from waste water. Pak J Eng Appl Sci 23:86–92 17. Said Z, Alwi H (2014) SEM study of oil adsorption on the surface of Khaya senegalensis dried leaves. APCBEE Procedia 9:108–112 18. Svyatchenko AV, Chetverikov AV, Sapronova ZhA, Shaykhiev IG (2018) Investigation of the oil-containing emulsion purification process using the experimental planning method. Chem Bull 1(4):19–30 19. Sapronova ZA, Sverguzova SV, Svyatchenko AV, Fomina EV, Voitovich EV (2019) Obtaining sorption material from the leaves of Aésculus hippocastanum L. Atlantis Highlights Mater Sci Technol 1:311–315 20. Badmaeva SV, Dashinamzhilova ETs, Khankhasaeva STs (2018) Application of sorbents obtained from plant waste for absorption of petroleum products. Buryat State University Bulletin. Chemistry. Physics 4:30–35 21. Mojžiš M, Sulekova M, Slugen J, Kacikova D, Messingerova V (2017) Engine oil spills and their subsequent removal during logging. Int Multi Sci GeoConference: SGEM 17:311–315

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22. Murashko EE, Sanatullova ZT, Shaikhiev IG, Sadykova SV (2017) Influence of the pa-rameters of HF plasma treatment with low pressure on oil and water absorption of compo-nents Larix sibirica. Technol Univ Bull 20(17):121–126 23. Alekseeva AA, Stepanova SV (2019) Study of the effect of plasma modification of the surface of mixed leaf litter on the mechanism for removing oil film from water bodies. Environ Chem 28(2):88–96 24. Shaikhiev IG, Stepanova SV, Shaikhieva KI (2017) Research of pine needles as sorption materials for removing oils and oils from the water surface. Technol Univ Bull 20(3):183–186 25. Mojžiš M, Bubeníková T, Zachar M, Kaˇcíková D, Štefková J (2019) Comparison of natural and synthetic sorbents efficiency at oil spill removal. BioResourses 14(4):8738–8752

The Methodology of Risk Assessment of the Technogenic Impact of Construction Enterprises on the Environment I. A. Guschin

and O. N. Ezhova

Abstract The paper presents the results of assessing the risk of construction companies on the environment. The calculation method is proposed for a step-by-step assessment of the risk component. Failures of technological systems in the structure of fault trees are taken into account. The mechanism of the spread of pollutants to a certain point in space is considered. Principles and norms for regulation of environmental pollution have been developed to determine risk levels. Calculation formulas are given to determine the probability of disease or death in the threshold and thresholdless model. The possibility of using the proposed technique for fire and explosive situations with the release of hazardous substances into the atmosphere on the basis of regulatory documents is shown. The conclusion is made about the applicability of this technique for any models of dispersion in the environment. An assessment of the risk to public health is carried out on the example of harmful emissions of the construction industry enterprise into the air. The advantages of the dynamics of risk for a certain period in comparison with a specific amount of risk are indicated. It is concluded that the averaged probabilistic characteristics of the processes of distribution and dispersion of substances do not reduce the effectiveness of the method and allow it to be used for risk mapping. Keywords Risk · Potential risk · Construction industry · Disease · Human health · Risk mapping

1 Introduction The problem of environmental pollution is global and concerns all the humanity. Foreign studies seek to find a way to manage the risk and reduce the possible negative consequences of pollution [3–8]. Worn-out and oversaturated production increases the number of accidents and catastrophes, therefore the level of environmental risk. It is known that large construction and installation departments (SMU), trusts, and I. A. Guschin (B) · O. N. Ezhova Chuvash State University named after I.N. Ulyanov, 15, Moscow ave., Cheboksary 428015, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_41

307

308

I. A. Guschin and O. N. Ezhova

construction materials factories have an adverse impact on the environment: atmospheric air is polluted, harmful substances enter the aquatic environment through uncontrolled discharges of enterprises, and the soil loses its biological properties. Technological processes are accompanied by emissions of a significant amount of harmful substances, many of which are carcinogenic and pose a danger to the population living in residential areas. Such environmental impacts pose a potential threat to human health and reduce average life expectancy. The modern construction industry, along with other major energy-intensive biota pollutants, uses technologies that increase the risk of man-made impacts. Therefore, it is of interest to develop a method for assessing such a risk in order to predict and prevent potential hazards. In the literature, the issues of predicting emergency situations at chemically hazardous facilities and assessing the risk of hitting the population with hazardous chemicals are covered in sufficient detail. We are interested in developing a methodology for assessing the environmental risk of anthropogenic impact of pollutants on the environment and human health. To achieve this goal, it is necessary to identify potential sources of pollution at an early stage, indicating all quantitative and qualitative characteristics, to conduct a preliminary analysis of the hazards in the various operating modes of the enterprise and a quantitative risk analysis.

2 Materials and Methods of Research The territorial potential risk of exposure at any point with coordinates (x,y) was taken as the criterion of the hazard measure, which is represented as the sum of the product of three factors:  Pm (T ) · Pmn (x, y) · Pn (H ), (1) Risk(x, y) = mn

Here Pm (T) is the probability of the m-th scenario of the accident development for the year; Pmn (x, y)—the probability of implementing the mechanism of influence n according to the scenario m at this point; Pn (H)—the probability of deterioration of health or death. Finding the first factor is associated with the construction of failure trees of this technological system, the vertices of which were the event E—exceeding the emission intensity of the harmful substance of the permissible value in the m-th scenario. The final event of this tree is the failure of a specific element, which is determined by numerous statistics for certain periods. In fact, we analyze the probability of a possible accident during an abnormal operation of the facility, when a dangerous substance may be released or discharged into the environment. Such trees can be multi-leveled to account for all sorts of events leading to an incident or emergency. At the second stage, it is necessary to consider how the harmful substance gets to a given point in space. That can be a transfer in the air, and then we are interested

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in the exceeding of the actual concentration of the harmful substance in comparison with the maximum permissible concentration (MPC). This standard is widely used in environmental regulation in various environments: in air, soil, surface and underground water, and in food or plants. Another regulatory approach is related to the restriction on maximum permissible emissions (MPE) or maximum permissible discharges (MPD) for enterprises by regulatory authorities, which determine the responsibility of the employer for violating the standards. In order to stabilize the environmental situation, the company must provide for environmental protection measures in the balance sheet. In [2] the method of calculating the concentration of harmful substances in the atmospheric air OND-86, which allows determining the maximum surface concentrations at each point of the selected site, is considered as a model for the dispersion of pollutants in the atmosphere during non-standard emissions of the enterprise. The wind direction and speed are given with the normal distribution. At a certain emission intensity, a given C/MPC ratio (the multiplicity of the excess of the actual concentration to the maximum permissible concentration) is achieved at a given point. The assessment of environmental risk at fire and explosive objects, which include construction industry enterprises, has its own specifics, but the methodological approach to determining the risk value is the same. At the first stage, such objects and technologies are identified and the quantity and characteristics of the available fire-hazardous substances are determined. At the second stage, the fire safety method determines the probability of a fire (explosion), builds trees of failures (events) of production equipment, control and management systems that lead to the implementation of various fire and explosive events. Then we consider the probability of the release of the i-th harmful substance, the concentration of which exceeds the permissible value for a given exposure time: +15 Pi = P f ir e

η(M f i − Mcmi ) f n (Vx Vy )d Vx d Vy , −15

where M fi is actually located in warehouses mass of combustible material involved in the combustion with the formation of the i-th noxious substance; M cmi is the mass of combustible material. The calculation of the probability Pi is based on the method for calculating OND86 taking into account the area of combustion, the rate of burnout, the volume of combustion products and the time of the fire. The emission mass of the i-th harmful substance was determined by the formula: T M1i = 0

M˙ 1i (t)dt,

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where M˙ 1i is the intensity of the emission of combustion products; T is the fire time T  τ1 . Required mass of combustible substance M cmi , necessary so that during the combustion of a substance stored in a warehouse a harmful substance is emitted in mass M 1i : Mcmi = M1i · K i , where Ki is a coefficient determined from the equation of the chemical reaction of combustion. At the final stage, a health risk assessment is carried out. Most of the data used to characterize health status is probabilistic (concentration of a harmful substance at a given point, exposure time and dose). An important parameter is the penetration path. It follows from this that the risk of disease Pn(H) is compared with the background incidence as an additional contribution, taking into account the dependence on the dose of a harmful substance absorbed by a person over a period of life. Moreover, if during his life a person was exposed to the negative effects of the i-th harmful substance for a time not exceeding, then the danger of such exposure is characterized by the risk: Ri = 1 −

T 

(1 − Pli ) ≈ Pi T,

l=1

and for the total exposure of all substances R =1−

L 

(1 − Ri ),

i=1

where T is the average life expectancy (ALE) of a person, the spatial distribution of the i—th substance in the l-th year. Knowing the time of exposure τ1 to the i-th harmful substance with the maximum one-time concentration and SPH for a given individual at the point (x, y), we find the permissible level of environmental safety as the ratio of these parameters. For example, to obtain an acceptable risk level of ~10−6 , τ1 = 0.5 h and T = 60 years. In turn, the exposure time τ1 corresponds to the threshold value of the concentration of c1 at a given point in space. This value is determined by the values of the maximum permissible emissions (discharges) or the found permissible dose of exposure. The complexity of the problem is caused by the influence on c1 and τ1 of atmospheric changes, terrain, the presence of a certain amount of harmful substances in the source of pollution, and other influencing parameters. To assess the dose-risk relationship, we use a threshold and non-threshold model. This dependence is linear for radioactive and non-radioactive carcinogens, and for other harmful substances (toxic substances of a non-carcinogenic nature) it has a

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311

threshold value of negative effects on humans. For the threshold model, the risk calculation formula takes the form [1]: 1 R = Pn (H ) = √ 2π

pr ob   exp −x 2 /2 d x,

(2)

−∞

where prob = a + b · ln(C/MPC ms ); a, b—parameters depending on the hazard class of the substance; C—the concentration of the substance over time τ1 ; MPC ms —maximum permissible maximum one-time concentration, mg/m3 . The formula for the thresholdless model is suitable for practical calculations:   R = Pn (H ) = 1 − ex p (−0, 174/K 3 ) · (C/P DCad )β ,

(3)

MPC ad —maximum permissible average daily concentration, mg/m3 . K 3 , β—coefficients depending on the hazard class of the substance.

3 Results and Discussion As an example, this method was used to assess the health risk of the population living within the sanitary protection zone of the construction industry enterprise.The total population of 170 people is exposed to pollutants emitted by the enterprise. There are no garden plots within the SPZ. Residential buildings are equipped with centralized water supply from the water supply network. Thus, the impact of the enterprise is the inhalation effect of atmospheric air pollution. At the first stage, when identifying hazards, 4 substances representing a carcinogenic hazard were identified from the complete list of substances and groups of summations of substances released into the atmosphere: Benz(a)pyrene, Chromium(VI), Soot, Mineral oil (incompletely purified). When identifying carcinogen emissions during the inventory, the rank index of carcinogenic hazard (HRic) was calculated using the formula: H Ric = Ei W ic P/10000, where Wic is the weight coefficient of carcinogenic activity; P—population size under the influence; Ei—the value of the conditional exposure (the volume of the annual release of the i-th substance, t/year). For non-carcinogens, the rank index of non-carcinogenic hazard (HRinc) was calculated using the formula: H Rinc = Ei T W i P/10000,

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where TWi is the weight coefficient of non-carcinogenic activity; P—population size under the influence; Ei—the value of the conditional exposure (the volume of the annual release of the i-th substance, t/year). The calculation results are shown in Tables 1, 2 and 3. The analysis of the results shows that the highest value of the individual lifetime risk (Fig. 1) is observed in the substance—Chromium (VI), the highest value of the rank index of non-carcinogenic danger in the substance—Sodium hydroxide. The assessment of the dose—effect relationship made it possible to predict changes in the health status of an individual or a group of people (population) as a result of exposure to a harmful agent under the conditions of dose loads determined at the stage of exposure assessment (inhalation of air for 365 days a year and 20 h a day). To assess the carcinogenic risk, a non-threshold model was used, using the values of the carcinogenic risk potentials. The calculations were carried out using the linear model and. were calculated: individual lifetime risk, ICR, Population carcinogenic risk (annual), PCR, Total (additive) population carcinogenic risk (annual). To assess the non—carcinogenic risk in accordance with the non-carcinogenic index, a threshold model was used using the values of reference (safe) doses-RfD. For substances with the summation effect, the additive (total) risk was determined. The results of the calculations show: Table 1 Parameters of substances with a carcinogenic effect Substance

Benzapyrene

Chromium (VI) Carbon black Mineral oil

MPC ms

0.15

MPC ad , approximate safe exposure level

0.000001

0.0015

0.05

0.05

Hazard class

1

1

3

-

Inhaled carcinogenic potential, (mg/(kg day))−1

3.9

510

0.15

0.22

Weight coefficient of carcinogenic activity

10000

1000000

1000

1000

Inhalation unit risk, (mg/m3 )−1

0.0011

0.15

0.000045

0.000063

Gross emissions, t/year

0.00000007

0.0002

0.0008

0.01

The highest surface concentration 0.0000001 at the points of atmospheric air quality control, mg/m3

1.32E−05

0.0015

0.0015

Rank index of carcinogenic hazard

0.0000119

3.4

0.0136

0.17

Individual lifetime risk, ICR

1.1E−10

1.98E−06

6.75E−08

9.45E−08

Population carcinogenic risk (annual), PCR

2.67143E−10 4.81E−06

1.64E−07

2.295E−07

Total (additive) population carcinogenic risk (annual)

5.20227E−06

The Methodology of Risk Assessment of the Technogenic Impact …

313

Table 2 Parameters of substances without carcinogenic effect Substance

Iron oxide

Manganese and its compounds

MPC ad , approximate safe exposure level

0.04

MPC ms

Sodium hydroxide

Nitrogen dioxide

0.085

0.5

5

0.02

0.001

0.01

0.04

0.05

3

0.005

0.01

Sulfur dioxide (Sulphur dioxide)

Carbon monoxide

Hydrogen fluoride (gaseous fluorides)

Hazard class

3

2

–

2

3

4

2

Weight coefficient of non-carcinogenic activity

10

1000

1000

10

100

1

1000

Gross emissions, t/year

0.0294

0.0016

0.0726

0.0232

0.0046

0.1517

0.001

The highest surface concentration at the points of atmospheric air quality control, mg/m3

0.028

8.00E−04

0.0027

0.05

0.035

3.05

0.0008

Rank index of non-carcinogenic hazard

0.004998

0.0272

1.2342

0.00394

0.00782

0.00258

0.017

Average daily dose, mg/(kg*day)

0.0033333

9.52E−05

0.000321

0.00595

0.004167

0.36309

9.524E−05

Reference dose, mg/(kg*day)

0.0114286

0.0002857

0.002857

0.01143

0.014286

0.85714

0.0014286

Non-carcinogenic index

0.2916666

0.3333333

0.1125

0.52083

0.29167

0.42361

0.0666667

Table 3 Parameters of summation groups without carcinogenic effect Summation groups

NO2 + SO2

PbO + SO2

SO2 + HF

Amount of dust

Total non-carcinogenic index

0.8125

0.34722222

0.3583333

0.292292

Fig. 1 Individual lifetime risk, ICR 106

Individual lifeƟme risk, ICR106 2 1 0

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– all calculated values of the carcinogenic risk do not exceed the recommended values of 10−4 –10−6 . Thus, the carcinogenic risk to the health of the population living within the SPZ of the enterprise is quite small and it is not necessary to carry out measures to reduce it. – in the threshold model, the value of non-carcinogenic risk, including for substances with the summation effect, is zero, i.e. the dose load is less than the reference (safe) doses. Thus, the conducted risk assessment for the population living within the SPZ enterprises showed a lack of fear of ill health due to industrial emissions into the atmosphere, which allows to reduce the size of the SPZ, excluding residential area.

4 Conclusion Thus, the formulas (1–3) with all its components allows calculating the potential risk of exposure to a certain level of pollutant on the environment and human health. This risk assessment methodology is applicable for any dispersion models and allows you to build a risk field at different ratios of C/MPCms and C/MPCad, which completely solves the problem of determining the negative impact of hazardous factors of the technosphere on human health. Note that we are not interested in the value of the risk itself, but in its change over the time. Knowing the dynamics, it is possible to make management decisions at the highest level. If the results obtained are well correlated with the results of other methods that use similar principles and criteria in the dispersion models and the calculation of the concentration of harmful substances, then this methodology is quite suitable for the risk analysis and predicting the effects on biota and human health. It allows for a quantitative risk analysis and, despite the use of averaged probabilistic characteristics of process parameters, is effective in a comprehensive assessment of the impact of an industrial enterprise on the environment and, in particular, in mapping the environmental risk. Acknowledgements This study is conducted in order to attract the attention of the public and city government structures to the problem of city pollution by industrial enterprises

References 1. Gushchin I (2015) Methodology for assessing the risk of the impact of an energy enterprise on the air environment. J Chuvash Univ 3:49–51 2. Kalikhman S, Ashmarin V, Gushchin I, Stolyarov A (2000) Methodology for determining the levels of environmental risks of technogenic impact of machine-building enterprises. J Occup Saf Ind 4:32–36

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3. Science and Decisions (2008) Advancing Risk assessment. Committee on improving risk analysis approaches used by the U.S. EPA, National Research Council. Washington, D.C., p 478 4. Scientific Review of the Proposed Risk Assessment Bulletin from the Office of Management and Budget (2007) Committee to Review the OMB Risk Assessment Bulletin, National Research Council, p 302 5. Shvarts E (2015) Voluntary environmental standards in key Russian industries: a comparative analysis. Int J Sustain Dev Plan 3:1–15 6. Testa F, Rizzi F, Daddi T, Gusmerotti A, Frey N (2014) MEMAS and ISO 14001: the differences in effectively improving environmental performance. J Clean Prod 68:165–173 7. The Orange Book (2004) Management of risk - principles and concepts. HM Treasury, UK, London, p 52 8. White Paper on Risk Governance (2005) Towards an integrative approach. International Risk Governance Council, Geneva, Switzerland, p 156

The Influence of Protein-Based Foaming Agent, Obtained from Microbiological Production Mycelial Waste, on Gypsum Binders Setting I. V. Starostina , Yu. L. Makridina , L. V. Denisova , and E. V. Loktionova Abstract An essential role in forming the optimal structure and providing the required properties of foam-concrete mixes and non-autoclaved foam concretes is played by air-entraining surface-active agents. All foaming agents, used in construction technology, are divided into synthetic and protein-based. In contrast to synthetic foaming agents, which are more widely used and advertised, the application of protein-based foaming agents allows preventing the layering of foam cement systems and obtaining a stable foam cement mass. This allows producing low-density porous concretes with high physical–mechanical properties. To obtain protein-based foaming agents various vegetable-based and animal-derived materials are used as raw stuff. A protein-based foaming agent was obtained as a result of alkaline hydrolysis of citric acid microbiological production waste biomass of Aspergillus niger fungus. In the alkaline component composition, in order to reduce production costs of the obtained product, the dust from cement production calcinating kilns’ exhaust gases treatment was used. It has been demonstrated that at adding cement dust the alkaline hydrolysis of Aspergillus niger fungus biomass occurs incompletely. At adding the protein-based foaming agent to the mixing water of gypsum binders, the non-hydrolyzed protein molecules, contained in it, are adsorbed on the surface of gypsum binder’s particles, and demonstrate plasticizing action, thinning up the gypsum paste, increasing its flowability and its setting time. This allows reducing the water-gypsum ratio and improving the physical–mechanical properties of finished gypsum products. Keywords Foam concrete · Protein-based foaming agent · Alkaline component · Cement dust · Flowability · Normal consistency · Strength · Gypsum binder

I. V. Starostina (B) · Yu. L. Makridina · L. V. Denisova · E. V. Loktionova Belgorod State Technological University Named After V. G. Shukhov, Belgorod, Belgorod Region, Russian Federation © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_42

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1 Introduction Nowadays, in order to reduce energy usage at buildings and constructions operation, as well as to provide the optimal temperature conditions in premises and improve the living environment of people, more and more attention is paid to design and application of the advanced, more efficient materials with low thermal conductivity in external enclosing structures [1]. Materials are selected depending on their physical properties, structural solution, temperature and humidity conditions of the indoor air, climatological data of the construction area, as well as regulations of heat-transfer resistance, air and vapor permeability. In this regard, the most promising look the cellular-structure materials, including non-autoclaved foam concretes on both cement and gypsum binders. They possess high performance and processing characteristics: low thermal conductivity, durability, nonflammability, ecological safety, availability, relatively simple production technology, as well as possibility to be produced in non-stationary conditions. Setting up the production of non-autoclaved foam concrete requires less capital investments, than production of lightweight aggregates, or light concretes and structures, made of them. Walls of foam concrete materials are by 20–40% lighter and cheaper than large-panel walls made of haydite blocks or three-layer sandwich panels. Foam concrete is a building material with a large amount (up to 85% of the total volume) of fine and medium-sized air cells up to 1–3 mm, formed as a result of hardening of a porous mix, consisting of binders, finely-dispersed aggregate, water and foaming agent. The main problem of obtaining low-density foam concretes, used as heatinsulation materials, is the adequate selection of equipment and raw stuff [2–4]. As main raw materials the inorganic binders (gypsum, cement), finely-dispersed aggregates and fillers, water and foaming agents are used. An essential role in providing the foam-concrete mixes and non-autoclaved aerated concretes with the required properties is played by air-entraining surface-active agents. The foaming ability parameters of SAA and the properties of foam depend on the substances’ nature, their concentration, temperature, stirring intensity and other factors [5]. All the foaming agents, used in construction technologies, are divided into synthetic and protein-based. The latter, though characterized with instability of chemical composition and limited shelf life, are environmentally safe and low-cost materials. Unlike synthetic foaming agents, which are more widely used and advertised, protein-based foaming agents allow increasing the entrained air volume in the foam-concrete mix up to 80–90% [5–7], thus preventing the layering of foam cement systems, and obtaining a stable foam cement mass, which provides lowdensity porous concretes (300 kg/m3 and lower) with high physical–mechanical properties. This is explained by the fact that protein-based foaming agents, due to the special three-dimensional structure of protein SAA, form the moving, but very stable adsorption layers and foam films, which provides the foamy structure with the increased stability and resistance to some mechanical effects, for example, mixing

The Influence of Protein-Based Foaming Agent, Obtained …

319

Fig. 1 General view of Aspergillus niger fungus waste biomass a and protein-based foaming agent on its basis b

with cement mortar. As a result, the foam concrete is characterized with the more uniform distribution of pores by their sizes, and the formation of cells with smaller average size [8, 9]. As raw stuff for protein-based foaming agents, the usage of both plant raw materials (saponins, rosin, crops millcake, leguminous crop waste, lignins), and animal-derived raw materials (slaughterhouse blood, horns, hoofs, fur, feathers) is known. The protein agents production technology is based on heat polymerization or extracting from solutions, as well as on the limited alkaline hydrolysis of protein components. The earlier studies [10] have demonstrated the possibility of obtaining proteinbased foaming agents on the basis of citric acid microbiological production waste— waste biomass of Aspergillus niger fungus (Fig. 1). The foaming agent was obtained as a result of alkaline hydrolysis of proteincontaining waste in conditions of microwave field [11]. In the alkaline component composition, in order to cut production costs of the obtained substance, the dust of cement production calcinating kilns’ exhaust gases treatment from JSC «Belgorodsky Cement», Belgorod, was used. The purpose of this work was studying the influence of cement dust content in the alkaline component of protein-based foam agent production on the flowability of gypsum paste, its hardening time and physical–mechanical properties of the obtained gypsum materials.

2 Materials and Methods For the research a gypsum binder of G-5 grade, from JSC «Khabezsky gypsum plant», Russia, was taken. Cement dust in the amount 5, 10, 15 and 20% was added to the alkaline component for waste biomass hydrolysis. The chemical composition of cement dust: Fe2 O3 - 2.4–7.1, CaO - 38.5–53.5; SiO2 - 13.0–14.3; Al2 O3 - 3.1–6.2; MgO - 0.5–6.3; K2 O - 5.3–10.2; Na2 O - 0.3–0.8; SO3 - 2.1–2.3; chlorides - 2.2–3.3.

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According to the results of X-ray phase analysis, the principal minerals in cement dust are calcium carbonate, baked clay, potassium compounds (potassium sulphates and carbonates), clinker minerals and calcium hydroxide, which provide the alkaline pH of the dust aqueous extract—12.57. This has predetermined the usage of calcinating kilns cement dust instead of lime as an alkaline component in the raw mix for foaming agent production.

3 Results and Discussion The main properties of the obtained foaming agents are presented in Table 1. One of the most important properties of foaming agents, used in cellular building materials production, is the opportunity of obtaining with them a stable and durable foam, which would allow preventing the layering and slumping of foam mass, and, as a result, destruction of the finished products’ cellular structure. To increase foam stability various stabilizing additives are used, which bring the film into pseudosolid structured state, which can be either a solid substance or a solution. The most widely spread and workable are the liquid systems—heavy metal salts solutions— ferriferous, cuprous, aluminum sulphates, etc. [12]. In the process of obtaining foam from protein-based foaming agent’s water solution, air cells are formed, the adsorption layer of which contains derived proteins and heavy metal ions. In the alkaline medium metal hydroxides are formed, which increases the system’s viscosity and slows down the flowing of liquid out of foam. In this research, as a stabilizing additive for foaming agents, obtained with various content of cement dust in the alkaline component, the 15% solution of copper sulphate (CuSO4 ·5H2 O) was used, added in amount from 0.5 to 3% of the foaming agent volume. The findings, presented in Fig. 2 and in Table 2 and Table 3, have demonstrated that the increase of cement dust content in the alkaline component’s composition results in the decrease of the obtained industrial foam’s expansion ratio, but adding copper sulphate solution somewhat compensates this effect. Table 1 The influence of using cement dust instead of lime in the raw mix for foaming agent production on characteristics of the obtained industrial foam №

1

Cement dust content Critical micelle Foam expansion ratio, Foam stability, min in the alkaline concentration (CMC) units component, wt.% range, % 0

1.0–1.75

20.0

10.0

2

5

1.75–2.0

12.2

7.0

3

10

1.75–2.0

16.0

4.0

4

15

1.75–2.0

12.4

10.0

The Influence of Protein-Based Foaming Agent, Obtained …

321

Fig. 2 The influence of stabilizing solution (CuSO4 ·5H2 O) amount in foaming agent composition on the obtained industrial foam’s expansion ratio Table 2 The influence of foaming substances on gypsum paste flowability №

Cement dust content in the alkaline component, %

Water volume/gypsum weight, W/G

Spreadability of gypsum paste, mm

No water adjustment and no stabilizer 1

0, control

0.483

180

2

5

0.483

195

3

10

0.483

197

4

15

0.483

201

5

20

0.483

212

0.483

175

With water adjustment and with no stabilizer 6

0

7

5

0.483

180

8

10%

0.466

183

9

15

0.477

178

10

20

0.477

175

With water adjustment and with stabilizer CuSO4 *5H2 O 11

0

0.481

180

12 13

5

0.481

180

10

0.481

180

14

15

0.481

183

15

20

0.481

185

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Table 3 The influence of foaming agents with various compositions on gypsum binder’s setting time №

Cement dust content in the alkaline component composition, %

Initial setting

Final setting, min

1

0, control

13 min 15 s

17 min

2

5

15 min 30 s

19 min

3

10

19 min

23 min

4

15

22 min

28 min 30 s

5

20

29 min

32 min 30 s

No stabilizer

Application of stabilizer CuSO4 ·5H2 O (15% solution), 3% of the foaming agent volume 6

0, control

9 min 30 s

15 min 30 s

7

5

7 min

10 min 30 s

8

10

8 min 30 s

10 min 30 s

9

15

10 min

13 min

10

20

11 min 30 s

14 min

The most efficient stabilizing action is observed for the foaming agent, containing 5% of cement dust, which can be recommended for usage. Then the research in evaluating the influence of protein-based foaming agents, containing the 15% solution of CuSO4 •5H2 O as a stabilizing additive, on the gypsum binder’s setting time, was carried out. The foaming agents, obtained with various content of cement dust, were added to the mixing water in amount 6.65% of the gypsum binder weight. The findings, presented in Table 2, have shown that the increase of cement dust content in the alkaline component’s composition at obtaining foaming substances results in a certain increase of gypsum paste flowability, which is manifested in the increase of its spreadability from 180 mm (in the control sample—without cement dust) to 212 mm at using 20% of cement dust. It should be pointed out that the alkaline hydrolysis of Aspergillus niger fungus biomass at adding cement dust occurs incompletely. The non-hydrolyzed protein molecules, adsorbing on the surface of gypsum binder particles, demonstrate plasticizing action, thinning up the gypsum paste and increasing its flowability. So, the application of such foaming agent allows somewhat reducing water-gypsum ratio (W/G)—from 0.483 in the control sample to 0.466 at using 10% of cement dust in the alkaline component composition (Table 2). Adding copper sulphate solution as a stabilizing additive in amount 3% of the used foaming agent volume neutralizes the plasticizing action of foaming substance— the W/G value is stabilized. Non-hydrolyzed protein molecules, adsorbing on the surface of gypsum binder particles, increase the setting time. At adding the stabilizing solution this tendency persists, though the value is somewhat lower, than that without stabilizer (Table 3).

Ultimate compressive strength, МPа

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323

16 15 14 13 12 11 10 9 8 without foaming agent

0

5

10

15

20

Cement dust content in the alkaline component composition, wt. %

Fig. 3 The influence of cement dust content in the alkaline component for obtaining protein-based foaming substances on the main physical–mechanical characteristics of gypsum materials using the obtained foaming agent

The application of foaming agents of various compositions with or without stabilizer improves the physical–mechanical characteristics of finished gypsum products (Fig. 3).

4 Conclusion Based on the research findings, we can make a conclusion that adding cement dust to the alkaline component’s composition slows down the alkaline hydrolysis process of Aspergillus niger fungus biomass. Non-hydrolyzed protein molecules, adsorbing on the surface of gypsum binder particles, demonstrate plasticizing action, thinning up the gypsum paste and increasing its flowability. This allows reducing the watergypsum ratio and improving the physical–mechanical properties of finished gypsum products. Acknowledgements This work is realized in the framework of Flagship University Development Program on the base of Belgorod State Technological University named after V. G. Shukhov, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

References 1. Bazhenov YuM (2012) Development options of building materials science: new concretes. Concretes Technol 3–4:39–42 2. Baev MN, Schukina YuV (2011) Heat-insulating non-autoclaved foam concrete with advanced characteristics. Polzunovsky Bull 1:35–37

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3. Shakhova LD (2010) Foam concrete technology: theory and practice. Association of Construction Universities, Moscow, p 246 4. Palalane ZhA, Burdyugov AV, Shakhova LD (2009) Reinforcement and micro-reinforcement of foam concretes. Bulletin of BSTU named after V.G. Shukhov, vol 3, pp 20–24 5. Gorbach PS, Scherbin SA (2014) The influence of foaming agent on foam and foam concrete properties. Bull TSUAB 5:126–132 6. Shakhova LD, Burdyugov AV, Palalane ZhA (2009) Deformation properties of foam concrete at early hardening stages. Bulletin of BSTU named after V.G. Shukhov, vol 3, pp 50–54 7. Bartenyeva EA (2016) The role of foaming agents in foam concrete technology. In: Collection of papers of the IX All-Russian scientific and technical conference «Topical issues of construction». Novosibirsk State University of architecture and Civil Engineering (Sibstrin), Novosibirsk, pp 224–230 8. Kruglyakov PM, Eskerova DR (1990) Foam and foam films. Chemistry, Moscow, p 432 9. Starostina IV, Kuzina EM, Ovcharova IV, Daud R (2015) The influence of protein-based foaming agent, obtained from microbiological production waste, on hardening process of cement systems. Contemp Issues Sci Educ 2 10. Starostina IV, Sverguzova SV, Ovcharova IV, Besedin PV, Pendurin EA, Kuzina EM (2015) Recycling of microbiological industry waste with the obtaining of foaming agents for building industry. Int J Appl Eng Res 10(21):42701–42706 11. Patent RF № 2552396 Protein-based foaming agent and its production method: Starostina IV, Ovcharova IV, Pendurin EA, Kuzina EM, Besedina IN. Application № 2014115919 of 21.04.2014. Publ. 10.06.2015. Bul.16 12. Gurova EV, Nadykto GI (2018) Effect of a stabilizer on the properties of a foaming agent for foam concrete. In: Collection of scientific papers of the national scientific and practical conference «Education. Transport. Innovation. Construction». Siberian State Automobile and Highway University, Omsk, pp 452–455

The Role of Water Management Technologies in the Sustainable Development of Water-Deficient Territories A. Ya. Gaev , I. V. Kudelina , T. V. Leontyeva , and M. V. Fatyunina

Abstract The technical and economic development of Orenburg region, especially its eastern part, is hindered by the shortage of drinking water quality, the widespread processes of pollution, salinization and increased radiation. The regional government has put forward the task of providing the region with drinking water. To solve it, it is proposed to develop and implement new technologies for the region, replenishing water intake reserves by partial accumulation of runoff in floods and protecting water from pollution, salinization and increased radiation, using original barrier technologies. Difficult situation in the economic and drinking water supply of the population has developed in the south-east of the region in the settlement Svetly and in the city Yasny. Water supply here is carried out at the expense of the waters of the Kumak reservoir, where the water does not meet the drinking quality. By draining these volumes of water with the planned underground water intake near the Kumak reservoir, it is possible to provide the population of the settlement Svetly and city Yasny with water of good quality. It is possible to protect the water intake from pollution by creating a complex barrier structure, the effectiveness of which is proved experimentally. Keywords Mining areas · Water management problems · Barrier technologies · Pollutants · Groundwater replenishment

1 Introduction With the economic development of territories, the processes of their pollution increase. There is a growing shortage of water resources not only of drinking quality, but also of water necessary for the development of industrial and civil construction. If to the mid-twentieth century, the possibility of applying water technologies is determined solely by the natural features of the site factors that affect the quality of waters, in the process of urbanization and the extension of the processes of pollution A. Ya. Gaev · I. V. Kudelina (B) · T. V. Leontyeva · M. V. Fatyunina Orenburg State University, Orenburg, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_43

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the water situation has become very difficult. The volume of water resources suitable for economic activity has decreased and the need for environmental engineering measures to ensure the sustainable development of productive forces has increased. In the context of increasing water consumption, elements of new water management technologies and, above all, the use of artificial replenishment of underground water reserves have been introduced in the world and domestic practice for two centuries [1–3]. In areas with arid and semi-arid climates, the incoming part of the water balance is mainly provided by a short period of snowmelt. The flood waters drain into the water areas, bringing almost no benefit to the water sector, except for the areas of reservoirs, from which a significant part of the water is lost to evaporation [4].

2 Materials and Methods In the course of the research, the analysis of stock and literary sources was used. Chemical analyses were carried out to determine the composition of water in underground and surface water intakes and reservoirs. We used data on natural sources of pollution of natural waters, as well as on the impact of technogenic objects on them. In order to reduce water losses due to evaporation in the southern regions, it is proposed to use reservoirs not only of alluvium, but also of fractured-karst limestone massifs, as well as Mesozoic weathering crusts, which are widely developed in the Trans-Urals. The region has the richest mineral resources, the development of which is constrained by water scarcity caused by both natural and technogenic factors. Water management technologies have been developed for the Orenburg agglomeration with one of the largest oil and gas complexes in Europe and in the low-water areas of the Eastern Orenburg region, which exceeds many European states by area, amounting to more than 30 thousand km2 [5]. Underground water here is formed under the influence of natural and technogenic factors. In their study, modeling methods and barrier technologies were used [6, 7].

3 Results and Discussion The inflow of water into the alluvial horizon is the input item of the balance, and the outflow or intake of water is the expenditure item. In an artificial reservoir, the incoming balance items (A) are atmospheric precipitation (X), the amount of condensation (K), as well as inflows from adjacent horizons (P): A=X+K+P

(1)

The expenditure items of the balance sheet (B) include the values of evaporation (Z) and water runoff: underground (f) and surface (V):

The Role of Water Management Technologies …

B = V + Z + f.

327

(2)

During the dry period, the expenditure item (B) decreases sharply, and the water balance equation takes on a different form: X + K + P = V + Z + f ± W.

(3)

Where—W i + W—consumption or accumulation of moisture. The comparison of the arrival and flow of water for an artificial pool over time, taking into account technogenic and natural factors, is determined using instruments. These parameters include: changes in depth and pressure, well productivity, water intake resources, water filtration rate, water mineralization, temperature and composition. The features of landscape-climatic, hydrological, structuralgeological and paleohydrogeological conditions are also taken into account. Regime hydrogeological observations were carried out on the well network. The demand for water in low water period rises sharply, causing the depletion of the aquifer. Substandard water is drawn to the water intake from adjacent complexes. In high water, water resources are replenished with an improvement in their quality. This indicates that it is possible to stabilize the situation by replenishing groundwater reserves. Orenburg has the highest water level in the Urals 842 cm set in 1942 with an average long-term 460 cm. In water intake wells, the difference between the dynamic and static levels is even greater [6]. Within the Syrtov Artesian basin, observations of the formation of underground waters of the main hydrogeological divisions (aQ, P2 ur-P3 v, P2 kz,) were carried out in natural and disturbed conditions (Table 1). According to the results of long-term observations, it is found that the levels of underground water are decreasing. The maximum values of the groundwater level are observed in May–June, the minimum—in January-December (Fig. 1, Fig. 2). In order to stabilize the operation of wells both in terms of productivity and water quality, it is proposed to build a cascade of small dams on the river, raising the water level by no more than 3 m [6] (Fig. 3). Then the high floodplain will not be flooded, and the volume of water (Q, m3 /day), will be: Q = Kf ·F·

h = K f · F · I, L

(4)

where F—flow area, in m2 ; h—difference in the pressure of the two specified sections, in m; L—percolation path, in m; I = H/L –hydraulic gradient. In Ivanovo water intake calculated water balance elements based on materials of “Votemiro” Company and data of long-term operation of water wells [8]. The volume of water in m3 /day, filtered in the low water to the wells, will be:

23.9–52

DWS

DWS

(P2 ur-P3 v) Aquifer Urzhum-Vyatka complex

(P2 kz) Kazan aquifer complex

41.65

8.3

(N2 -Q) DWS Aquifer Pliocene–Quaternary complex

90.92–92.66

89.08–166.26

91.38

55.96–91.51

DWS

(aQ) Aquifer Quaternary alluvial horizon

7.5–14.0

Purpose Power, m Absolute mark of the underground water level, m

Index and name of the aquifer

0.5–0.7

0.43–1.4

5.0–8.0

0.74

–

Fe, Br

Hydrocarbonate

–

–

–

–

increased content of Na, No3 ,Mn

Components Note whose content exceeds the MPC

Chloride-hydrocarbonate, Fe sulfate–chloride

Hydrocarbonate

Sulphate-hydrocarbonate

Mineralization, g/dcm3 Type of chemical composition

12.85–131.56 0.43–0.46

49.4

–

Pressure of the water above the roof, m

Table 1 Characteristics of the main aquifers of Syrtov Artesian basin

328 A. Ya. Gaev et al.

The Role of Water Management Technologies …

329

Fig. 1 Average values of the fluctuations of the groundwater level of Urzhum-Vyatka aquifer complex

Fig. 2 Average monthly values of fluctuations in the underground water level of the Kazan aquifer complex

profile

plan

Fig. 3 A section of the Ural river valley with reservoirs that partially accumulate flood waters: a—valley profile; b—its plan: 1—sand-gravel-pebble alluvium; 2—clay waterproof layer; 3—river level up to and 4—after backwater; 5—artificial reservoirs; 6—hydropost of Orenburg; 7—Ural “open” water intake; 8—Ural underflow water intake; 9—Ivanovsky water intake; 10—South Ural water intake

Q 1 = K f · F1 ·

H = K f · F1 · I = 422 · 17000 · 0.0013 = 9326 m3 /day L

where F1 = l · h 1 = 2500 · 6.8 = 17000 m2

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I =

H1 − H2 85.3 − 84.5 H = = = 0.0013 L L 600

where profile width, l = 2500 m; hydroisohypses at the water intake, H1 and H2, respectively 85.3 m and 84.5 m; the segments between hydroisohypses L = 600 m. The volume of water filtered from reservoirs will be: Q 2 = K f · F2 ·

H = K f · F2 · I = 422 · 24500 · 0.0013 = 13440 m3 /day L F2 = l · h 2 = 2500 · 9.8 = 24500 m2

where the reservoir capacity after the rise of the water level will be h2 = 9.8 m. Then water flows (Q) to wells near the reservoir, will be. Q = 1, 366 ·

K f · (h 2 − h 2d ) , lg 2L − lg r

(5)

where hd —the value of the dynamic water level, m; L—distance between water intake and reservoir, m; r—radius of water intake wells, m. The production capacity of each well during operation averaged 1,200 m3 /day. After the construction of the dam and the rise of the underground water level, the productivity of wells will increase to 2057 m3 /day, that is, it will increase by 1.5–2 times. That is, when replenishing the water reserves of existing water intakes, it is possible to avoid water depletion, and there will be no need to build additional wells. It is found that the rise of the water level in the river by 2–3 m, due to artificial reservoirs, provides replenishment of water reserves, increasing the productivity of water intake and obtaining drinking water quality without flooding the high floodplain and the need to drill new wells. In the Eastern Orenburg region, the situation is more complicated due to the proximity of the arid zone. On the example of the Kumak reservoir site, the effectiveness of the application of the technologies developed by us is obvious. Here, in addition to a natural reduction of module water flow and deterioration of water quality in a south-east direction, shown significantly the processes of secondary salinization of water due to the relics of the salt sea in the Miocene-lower Pleistocene and Paleogene sediments. In addition, hydrogeological massifs of granitoids with radon and radioactive products of its decay are widely developed on the territory [5]. Due to the low capacity of alluvium for the accumulation of flood waters in the Eastern Orenburg region, it is recommended to use poorly studied types of reservoirs in karst limestone and in the Mesozoic weathering crust. For this territory, the fundamental possibility of applying the technology of replenishment of reserves in all areas, including the most arid Svetlinsky district, is justified. Currently, the economic and drinking water supply of the population of the settlement Svetly and the city Yasny is carried out at the expense of the waters of the Kumak reservoir. This is sufficient in volume, but does not correspond to the drinking quality.

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Fig. 4 The nature of the relation between alluvial and river waters in the zone of their mutual influence on the example of the Kumak reservoir: 1—alluvial deposits; 2—Mesozoic weathering crust; 3—alluvium, which provides self-purification of water when it is flooded; 4—wall made of adsorption material; 5—pipe for drainage of polluted water; 6—hydrodynamic barrier. Water intake wells—1, 2, 3 and their depth. Water levels in the reservoir: 7—NRL 291; 8—MLWD 283; 9 –pumping station; 10—static level at MLWD; 11—static level at NRL; 12—dynamic level at NRL; 13—dynamic level at NRL. The absolute elevation marks are given in meters

At the pumping station of the Kumak reservoir, according to the company Votemiro and in accordance with the regional program “Clean Water” [9–11], we built a profile and developed a model of an integrated barrier to protect underground and surface water from pollution (Fig. 4). The expenses of water intake wells at the normal retaining level (NRL 291 m) and the maximum level of water discharge in the reservoir (MLWD 283 m) are calculated. At MLWD one of the three wells is able to provide water in the volume of 546·m3 /day, and three wells—1639·m3 /may, or —598341·m3 /year. At NRL 291 m the flow rate of one of the two wells will be 923·m3 /day, both—1847·m3 /day, and for the year they will provide 674129·m3 of water [5]. When alluvial water is replenished near the reservoir due to the partial accumulation of flood runoff formed outside the granitoids, the standard level of water radiation is provided, as evidenced by modeling. Original integrated barriers protect the water from pollution.

4 Conclusion For the first time, for various conditions within the Orenburg region, the issue of localization of pollution, salinization and increased radiation of water in the process of replenishing the reserves of operated water intakes has been resolved. This will ensure the necessary amount of water and its drinking quality. Within the Orenburg

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urban agglomeration, the construction of small dams in the Ural River valley will partially accumulate flood waters and improve the quality of underground water in water intakes. The construction of an underground water intake near the Kumak reservoir will provide the population with the necessary amount of water. Filtering this water through alluvium will give the water a drinking quality. The creation of a complex barrier structure, the effectiveness of which is experimentally justified, will protect water intakes from pollution.

References 1. Jódar-Abellán A, Albaladejo-García J, Prats-Rico D (2017) Artificial groundwater recharge. review of the current knowledge of the technique. Revista de la Sociedad Geológica de España 30(1):85–96 2. Mukherjee D (2016) A Review on Artificial Groundwater Recharge in India. SSRG Int J Civ Eng (SSRG – IJCE) 3(1):57–62 3. Zektser IS, Karimova OA, Chetverikova AV (2015) Resources of fresh underground waters of Russia and their use in emergency situations Water resources 42(4):351–366 4. Sivokhip ZhT (2014) Analysis of the ecological and hydrological specifics of the transboundary basin of the Ural River in connection with the regulation of runoff. Bulletin of the VSU. Series: Geography. Geoecology 3:87–94 5. Leontyeva TV (2019) To the analysis of the water supply system of the population in the Eastern Orenburg region. Sci New Technol Innov Kyrgyzstan 4:240–243 6. Kudelina IV (2018) On the possibility of stabilizing the operation mode of water intakes in the Orenburg urban agglomeration. Sci New Technol Innov Kyrgyzstan 2:68–72 7. Babushkin VD, Gaev AYa, Gatskov VG, et al (2013) Scientific and methodological bases of protection from pollution of water intakes for household and drinking purposes. Perm Institute, Perm 267 8. Baktorova NI, Koltunova OF (2009) Geological exploration works with the calculation of operational reserves of underground water at the site of the Ivanovsky water intake (as of 01.10.2008). Book 1. JSC “Votemiro Company”, Orenburg, 152 9. Regional program “Clean Water” Ministry of Construction, Housing and Communal Services and Roads of the Orenburg Region. https://minstroyoren.orb.ru/trades/ecology/o-proekte. Accessed 04 Nov 2019 10. Resolution of the Government of the Orenburg Region of 30.08.2013 No. 739-pp on improving the quality of drinking water of the regional program within the framework of the federal project “Clean Water” in the period for 2019–2024. Orenburg 60 (2013) 11. Tsvetkova NV, Zatsepina AA (2015) Analytical review of the state of the subsoil of the Orenburg Region. JSC “Company Votemiro”, Orenburg 138

Pneumatic Mixer with a Spiral Energy-Carrying Tube Yu. M. Fadin , O. M. Shemetova , V. P. Voronov , and E. G. Shemetov

Abstract This article explores blending equipment and reveals advantages and disadvantages of blenders for production of dry building mixes. This analysis results in highlighting a pneumatic blender as one of the most challenging and poorly explored blenders to blend dry mixes. Such blenders fully comply with ecological and production regulations, do not deal any harm to employee’s health, and its technical characteristics are in no way worse than those of mechanical blenders. After examining challenging directions of their improvement we offer a new design of such a pneumatic blender, which aims to enhance the quality of final product through increasing product uniformity by intensifying the blending process. Its main concept is based on blending dry building mixes in air turbulence flow. Additionally, this article deals with the method of calculation design and technological parameters of such a pneumatic blender. A graphical comparison of experimental and theoretical dependences of the coefficient of inhomogeneity on time is presented. Main parameters, that define blender’s geometric and utility features, are pressure, gas consumption, material lifting range. The results of this article can be used in the design of pneumatic mixers for mixing dry building mixtures, as well as in the educational process of bachelors and masters. Keywords Pneumatic mixer · Mixing · Building mixtures · Vortex mixing · Mixer · Improvement

1 Introduction Dry building mixes have been taking leading positions as most demanded construction branch for years. Construction productivity can be essentially boosted with the help of such mixes, make it more efficient and improve the result of using traditional mixes [1, 6, 8].

Yu. M. Fadin · O. M. Shemetova (B) · V. P. Voronov · E. G. Shemetov Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_44

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To produce high-quality multi-component mixes, it is necessary to pick a proper blender. A proper blend ere defines the quality of mixing process. After am in indifferent blender models, as well their pros and cons, we can draw conclusion, that mechanical blenders (paddle blenders, gravity blenders and so on) have a wide range of advantages. And still, despite fall their positive features, they have unfavorable features, that we cannot ignore, such as-big power requirement, metal intensity and necessity to protect moving parts from dust [2, 10, 14, 15]. On the basis of this analysis, we played attention to the innovations concerning pneumatic blending, with such advantages as—lower metal intensity, absence of any moving parts and high efficiency. Such blenders fully comply with ecological and production regulations, do not deal any harm to employee’s health, and its technical characteristics are in no way worse than those of mechanical blenders [3, 7, 12]. This article examines the design of a pneumatic blender, which aims to enhance the quality of final product through increasing product uniformity by intensifying the blending process, as well as the way of defining its geometrical parameters is explored.

2 Materials and Methods In respect of e merging potential to use pneumatic mixer we can mark several directions of their development [4, 6, 9]. We can refer following aspects to forward-looking directions of pneumatic blenders development: • Achievement of new technological possibilities of blending equipment by designing and effective blending chamber; • Introduction of high-tech ways to treat (process) components of dry mixes; • Improving the quality of mix homogenization; • Reduction of metal intensity of blending equipment. Based on the above-mentioned development opportunities, we offer a new design of such a pneumatic blender, which aims to enhance the quality of final product through increasing product uniformity by intensifying the blending process. The main concept of a pneumatic blender with a spiral energy-carrying tube (Fig. 1) for fine grade material is based on blending dry building mixes in air turbulence flow. Components for blending are delivered in chamber 1 of the blender with a spiral energy-carrying tube for fine grade material through a loading pipe 6. The material in chamber 1 is gripped by utility product, for example by pressed air, flowing out of a spiral energy-carrying tube 4, which is adjusted with holders 5, and such utility product is simultaneously delivered with the material. A shoals in thespian leerycarry in grub are located proportionally and in a check board order and directed upward at an angle of 30–35° against a vertical plane of a spiral energy-carrying tube 4. Chaotically-turbulent air flow appears in chamber 1, that’s why components get blended intensively. Un load in gates place at the conical bottom, and after a

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Fig. 1 Pneumatic mixer with a spiral energy-carrying tube

blending cycle final mix goes out through the undo adding pipe 3 into the precipitator (not shown). Such solution contributes to increased uniformity of final product by intensifying the blending process, what enables to improve the quality and produce dry mixes with high grade of diffusion of the key component.

3 Results and Discussion Let’s handle the calculation method of design and technological parameters of a pneumatic blender (Fig. 2). Main parameters that define blender’s geometric and utility features are gas consumption, pressure and material lifting range. As stable pneumatic blending requires definite hovering velocity, air flow velocity must remain within the range, given in this equation vr ≈ 1.5 ÷ 2vvit [11], and the tube’s diameter is calculated based on specified air consumption: dt =

Qr ρr · vr

(1)

It is worth mentioning, that increase in gas flow velocity vvit.c > 2 · vvit results in impractical energy loss. Flow pressure loss in the motive nozzle can be calculated only when gas flow in the formula remains incoercible:   Sc ρr · vr2 1 (2) · 1− Pc = 2 1 St

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Fig. 2 Calculation scheme

Operating pressure in the supple main and exhaust area are defined by the ratio [13]:  dc =

4Q r π · vc

Pp = Pc + Ppp

(3) (4)

Pressure loss at vertical blending depends on specified values, like tube’s diameter and height, as well as air consumption, particle concentration consumption, and is calculated by the following formula (ratio): P pp =

Qm Q m (u r − u t ) (γm − γr )L t St + ρm · ur · Sr St

(5)

Blender’s efficiency can be calculated by the following ratio: Q m = μ · Qr

(6)

Knowing blender’s efficiency, period of time tk that it requires to achieve the necessary mixture heterogeneity index vc = 5%, or the amount of cycles of material blending N = ttchk , depends on particles’ residence time distribution for the full cycle of material motion.

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To enhance the efficiency of the averaging process, i.e. the minimum amount of material motion with the mass N, it is necessary, that the residence time distribution value remains between 2.2 and 3.5: L 1 + H2 sinα vmax tmax = · tmin L min vmin

(7)

This condition is met, when the blender’s receiver chamber geometry corresponds the values of the geometric similarity test: h1 =

h max h min

(8)

h2 =

h min dt

(9)

If all the above mentioned conditions are fulfilled, time necessary to create homogenous mix is calculated the following way: tmx = N ·

M Qm

(10)

In order to test this calculation of the mixer, after the experiment, the distribution density curves of the particles of the key component for the full cycle were obtained, which allow calculating the change in the heterogeneity coefficient of the mixture during the mixing process. Based on the results of the experiment, a response curve was built for a full cycle of displacements of the entire initial amount of the key component in the mixer. Figure 3 shows the response curves of the system at the corresponding values of the load volume V and the intensity of the circulation movement. The average residence time of the particles of the key component over a full cycle is determined by the formula: tcp =

V Q ob

(11)

where Q ob -is the volumetric consumption of material (Tables 1 and 2). According to the distribution density curve of the residence time (Fig. 3), the average time is found as the mathematical expectation of the value t in the interval 0 < t < t max .

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Fig. 3 Comparison of experimental and theoretical time dependences of the inhomogeneity coefficient

Table 1 Change in the inhomogeneity of the mixture over the mixing time

Table 2 Change in the distribution of the key component over time

№

Material

1

dry mix

Mixing time, t

Material heterogeneity, %

60

14

2

120

10

3

150

5

4

240

2

№

Material

1

dry mix

Mixing time, t

Key component distribution

60

0.15

2

120

0.1

3

150

0.05

4

240

0.01

4 Conclusion Nowadays, more scientists pay attention to the opportunity of using pneumatic blenders. Creating spiral motion and stress state in such blenders allows to review the process of blending in a different way. This is especially vital for production of dry building mixes, where the quality of homogenization directly affects the quality of final product. The above-mentioned enables us to conclude about the relevancy of this subject.

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Acknowledgements This work was realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V. G. Shukhov, using equipment of High Technology Center at BSTU named after V. G. Shukhov.

References 1. Bolshakov EL, et al (200) Current state and development prospects of production of dry building mixtures in Russia. Sat. articles of the International Scientific and Technical Conference “Modern technologies of dry mixes in construction". Stroimaterialy, St. Petersburg, 3–5 2. Korneev VI (2010) Dry mixes. Stroimaterialy, St. Petersburg 3. Orekhova TN, Agarkov AM, Golubyatnikov AA (2015) Directions of constructive and technological improvement of pneumatic mixers for the production of building materials. Sci Almanac 3:124–127 4. Dergunov SA, Orekhov SA (2012) Dry building mixtures (composition, technology, properties): a tutorial. OSU, Orenburg 5. Orekhova TN (2013) Continuous pneumatic mixer for the production of dry building mixtures. Belgorod 6. LNCS. https://studfile.net/preview/7493544/page:15/. Accessed 20 Oct 2020 7. Bogdanov VS (1996) Mechanical equipment for enterprises of the building materials industry. BelGTASM, Belgorod (1996) 8. Orekhova TN, Krasnov VV, Demushkin NP (2018) Trends in the development of modern technology and technologies for mixing bulk materials. News Sci Educ 4:17–20 9. Weinekotter R, Gericke H (2000) Mixing of solids. Kluwer academic publishers 10. Dury CM, Ristow GH (1999) Competition of mixing and segregation in rotating. Physics of fluids 1387–1394 11. Berthiaux H, Mizonov V (2004) Applications of Markov chains in particulate process. Can J Chem Eng 6:1143–1168 12. Orekhova TN (2011) Determination of the performance of a pneumatic mixer of dry building mixtures, taking into account the analysis of the devices of mixing units. Bulletin of BSTU named after V.G. Shukhov (3):65–68 13. Orekhova TN, Kachaev AE, Goncharov EI (2017) Aerodynamic features of pneumatic mixers for the production of dry building mixtures. Bulletin of BSTU named after V.G. Shukhov (11):149–155 14. Orekhova TN, Kachaev AE, Okushko VV, Shestakov YuG (2020) Suspended bed mechanics with polydisperse particles in continuous pneumatic mixers. Bulletin of BSTU named after V.G. Shukhov (3):121–127 15. Fadin YuM, Shemetova OM (2020) Dry building mixtures and mixing equipment for production. Bulletin of BSTU named after V.G. Shukhov (12):145–150

Calculation of the Walls of Beams Under the Action of Local Stress in the Places where the Load is Applied to the Sole S. A. Makeev , A. A. Komlev , P. A. Korchagin , and S. V. Savelyev

Abstract In modern Russian standards, the calculation of the strength of the wall of a beam, welded or rolled, not reinforced with webbing, under the action of local stress in the places where the load is applied to the upper sole is made according to the formula of the centrally compressed element. It is assumed that the extreme values of local stresses in the wall act at a distance of 2–3 thicknesses of the beam flanges and are distributed evenly. Finite element calculations show that stress concentrations and significant non-linearity of the distribution are observed near the places where loads are applied in the beam walls. The paper presents the results of finite element modeling of the overlap beam grillage, where special attention is paid to the support zones of beams with a floor-by-floor scheme of co-extension. The results of calculations are presented, which show the zones of nonlinear stress distribution, as well as their values. The obtained stress values in the finite element model are compared with the values obtained by the standard calculation. Keywords Overlap structure · Beam grillage · I-Beam · Beam wall · Tension

1 Introduction Steel beam overlaps, today, are one of the most common structural overlap systems [1]. Their wide distribution is facilitated by the simplicity of structures, high loadbearing capacity and cost-effectiveness. The main direction in the study of beam overlaps, to date, is to reduce the metal consumption of structures, which is achieved through parametric optimization of beam grillages [2, 3], the use of thin-walled cold-bent elements as load-bearing elements of beam grillages [4, 5], the use of perforated [6, 7], corrugated [8, 9] and sprengel beams. The study of the stress–strain state of welded, and even more so rolled beams, is practically not performed, as it is believed that this issue has already S. A. Makeev (B) · A. A. Komlev · P. A. Korchagin · S. V. Savelyev Federal State Budget Educational Institution of Higher Education, The Siberian State Automobile and Highway University, Omsk, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_45

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been sufficiently worked out, the calculation methods are given in the regulatory documents [10, 11], and the standard units in the series [12]. To date, there are many options for connecting beams in beam grillages, but the most common option is when the secondary beams rest directly on the upper sole of the main beams. Such a coupling is called floor-by-floor [1]. In accordance with Russian standards, it is assumed that during floor-to-floor coupling, the normal stresses in the main beam wall are distributed evenly over the lef section, and the maximum stress values are located at a distance h from the upper face. Preliminary calculations in the LIRA-CAD software package with modeling of beams with plate elements showed that an extremely nonlinear stress distribution in the walls of the beams is observed at the junctions of the beams. In this case, the normal stresses in the walls of the coupled beams can exceed the values of the stresses obtained according to the norms by two or more times. The aim of the study is to identify the real picture of the stress distribution in the walls of beams that are not reinforced with webbing at the places where the load is applied to the soles.

2 Methods and Materials Let us check the strength of the beam wall under the action of local stress in the following example. On the main overlap beam with a calculated span of 6000 mm, made of I-beam 50B1 [13] (Fig. 1) according to the floor scheme, secondary twospan with spans of 5000 mm continuous beams made of I-beams 20B1 [13] are supported. Secondary beams are placed in increments of 1500 mm. The supports of all the beams around the perimeter of the grillage are hinged.

Fig. 1 Structural diagram of the overlap fragment

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Table 1 Table for collecting loads on the beam wall Name of load

Normal value, kN/m2

γf

Calculated value, kN/m2

Agp , m2

F n , kN

F p , kN

1.1

1.15

1) W.up. of secondary beam

1.05

2) W.up. of slab 3.75

1.1

4.12

7.5

28.12

30.93

3) W.up of floor 1.25

1.1

1.37

7.5

9.37

10.31

4) Useful

1.3

2.60

7.5

15.00

19.50

F n kN = 53.6

F p kN = 61.90

2.00

The overlap beam grillage is made of C245 steel. The overlap is represented by a monolithic reinforced concrete slab with a thickness of 150 mm, on which a cementsand screed with a thickness of 50 mm is arranged. The overlap is affected by a temporary evenly distributed load with an intensity of q = 2 kN/m2 [14]. Checking the strength of the beam wall is carried out according to the formula [10]:   σloc = F/ le f · tw ≤ R y · γc ; where, le f = 100 + 2 · (12 + 21) = 166 mm, conditional length of load distribution on the wall of the main overlap beam (50B1), t w = 8.8 mm [13] beam wall thickness; le f = 200 + 2 · (8, 5 + 12) = 241 mm, conditional length of the load distribution on the wall of the secondary beam (20B1), t w = 5.6 mm [13] wall thickness; F—the value of the concentrated force acting on the wall of the overlap beam, kN. The calculated value of the concentrated force F p is obtained as a result of the collection of loads and is given in tabular form (Table 1). For the convenience of calculations according to the standard methodology, the calculated load value is rounded to F p = 62 kN. It is known that the reaction on the intermediate support of two-span continuous beams is 25% greater than in split schemes. We calculate the values of local normal stresses in the wall of the main beam: σloc = 62/(0.166 · 0.0088) · 1.25 ≈ 53125 kN/m2 = 53.125 MPa < 240 · 1 MPa The calculation showed that the wall strength of the main floor beam is provided with a load-bearing capacity utilization factor of 0.22. Accordingly, the local normal stresses in the walls of the secondary beams will be equal to: σloc = 62/(0.241 · 0.0056) · 1.25 ≈ 57400 kN/m2 = 57.4 MPa < 240 · 1 MPa.

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The calculation showed that the strength of the walls of secondary beams is provided with a load-bearing capacity utilization factor of 0.24. Consequently, in accordance with the norms [9], in the walls of the elements of the considered beam grillages, when loads are applied to the soles, the level of local normal stresses σloc does not exceed 24% of the calculated resistance.

3 Results and Discussion To reveal the real picture of the distribution of local normal stresses in the walls of the beams, a finite element simulation of the overlap beam grillage was performed in the LIRA-CAD software package with plate elements (Fig. 2). The elements of the beam grillage are made using 41 EE (universal rectangular end element, plate) with dimensions of 10 × 10 mm with stiffness characteristics corresponding to the parameters: main beam 50B1, secondary beams 20B1. The flanges of the secondary beams are supported on the flange of the main beam by means of two-node finite elements with a one-way elastic coupling with a friction of 264 EE. Loading of the beam grillage is performed by a linear load applied to the upper sole of secondary beams q = 62/5 = 12.4 kN/m (Table 1, Fig. 2). As a result of the calculation of the finite element model of the beam grillage (Fig. 3), the maximum normal stresses at a distance of h = 33 mm from the upper face of the upper sole in the wall of the main beam were 80 MPa, which is 1.51 times more than the stresses obtained by the standard method. The stress distribution along the length of the lef is extremely uneven. At the ends of the lef section, the stresses do not exceed 10 MPa. In the secondary beam, the stress distribution pattern is similar. However, the values of the maximum normal stresses are greater, despite the fact that the lef zone is longer, as the wall is thinner. The value of the maximum stresses was 145 MPa, which is 2.5 times more than the stresses obtained by the standard method. The stress Fig. 2 Fragment of a finite element model of a beam grillage in LIRA-CAD

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Fig. 3 Diagram of the distribution of vertical stresses in the walls of beams when a load is applied to the soles: a—the main beam; b—the secondary one

distribution over the length of the lef is also extremely nonlinear. At the ends of the l ef section, the stresses do not exceed 5 MPa. Detailed pictures of the distribution of normal stresses in the walls of the beams at the interface points are shown in Fig. 3.

4 Conclusion As a result of the study, it was found that the maximum values of normal stresses in the walls of beams at a distance h from the sole (local normal stresses σloc ) obtained by finite element modeling exceed the stresses obtained by the standard method by 1.5–2.5 times. To perform adequate calculations of the stress–strain state of the elements of the beam coupling nodes, it is recommended to perform verification calculations in finite element complexes with modeling of beams with plate elements.

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In this case, there is a risk of exceeding the maximum normal stresses of the calculated resistance of steel with the formation of local zones of plastic deformation. In this case, calculations should be performed taking into account the physical nonlinearity of the deformation of the applied steels in accordance with SP 16.13330.2017.

References 1. Moskalev NS, Pronozin YaA (2007) Metal structures. Textbook. Publishing house Association of Construction Universities, Moscow, p 344 2. Serpik IN, Alekseytsev AV, Shvyryaev MV (2013) Parametric optimization of steel beam grillage. Constr Reconstr 4(48):43–50 3. Chernyaev AA (2018) Alternative engineering of steel girder cages by geometrical methods. Mag Civil Eng 2(78):3–15 4. Kretinin AN (2008) Thin-walled beams made of bent galvanized profiles: composite belts of box section and corrugated walls. Autoref. diss ... Cand. of Eng. Sciences: Novosibirsk: NSACE 24 5. Aktuganov AA, Aktuganov AN (2016) Stability of thin walls in beams with soils made of LSTK. Innovations in the educational process. Materials of the XIII Final Scientific and Practical Conference. Cheboksary: Cheboksary Institute (branch) of Moscow Polytechnic University, pp 68–71 6. Brudka Ya, Lubinski M (1974) Light steel structures. Stroyizdat, Moscow, p 345 7. Ganeman GA, Kikot AA (2017) Analysis of metal beams with a perforated wall. Polzunovsky almanac. Altai State Technical University named after I.I. Polzunov 4-2, Barnaul, pp 49–52 8. Makeev SA, Silina NG (2020) Development of a methodology for the refined calculation of corrugated beams for general stability. Ind Civil Constr 12:52–60 9. Dmitrieva TL, Ulambayar H (2017) Comparative analysis of beams with a corrugated wall in relation to beams with a straight wall. Actual problems of the construction industry development. In: Materials of the international scientific and practical conference. Irkutsk National Research Technical University, Irkutsk, pp 43–51 10. SP 16.13330.2017 “Steel structures. Updated version of SNiP II-23-81*” 11. SP 294.1325800.2017 Steel structures. Design rules 12. Series 2.440-2 Units of steel structures of industrial buildings of industrial enterprises 13. GOST 26020-83 Hot-rolled steel I-beams with parallel flange faces 14. SP 20.13330.2016 Loads and impacts. Updated version of SNiP 2.01.07-85*

Improved Surface Water Treatment Technology in the Kyrgyz Republic T. Kh. Karimov , N. Baygazy kyzy , Zh. I. Osmonov , and M. T. Karimova

Abstract The paper considers the use of local quartz sand for cleaning the surface natural waters of drinking water supply. The Department of “Water Supply, Water Disposal and Hydro-technical construction” of the KG UCTA named after N. Isanov for two years conducted a study on the use of cheap local raw materials for the filter loading of fine water filters. Sand from Kyrgyz deposits was used as a loading. The aim of the experiments was to consider the physical picture of the process of water clarification by filtration and the factors characterizing it, to study the features of the filter layers in terms of the loading height and depending on the grain diameter, as well as to determine the parameters of technological modeling for subsequent optimization of the process. The results obtained on the “short” columns were tested on a pilot plant, which is a conventional column with a full height of the filter load, calculated on the basis of technological modeling data. The operating conditions of the pilot plant generally corresponded to the operating conditions of the process simulation plant. The task is to create a simple and affordable device for use in national conditions, in which it would be possible to use a filter load from a natural non-toxic material for the human body, which does not have high operational qualities, for a sufficiently long time to purify drinking water. All technological schemes for the treatment of drinking water quality from surface sources using a rapid non-pressure filter are several times cheaper than similar schemes with filter loads from the Russian Federation. Keywords Natural water · Surface sources · Filters · Filter loading · Local natural materials · Water clarification · Switchgear

T. Kh. Karimov (B) · N. Baygazy kyzy · Zh. I. Osmonov · M. T. Karimova Kyrgyz State University of Construction, Transport and Architecture named after N. Isanov, Bishkek, Kyrgyz Republic e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_46

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1 Introduction Obtaining drinking water in sufficient quantity and of the required quality is a complex and urgent problem of a universal nature. To do this, it is necessary to make sure that all systems and structures for water treatment work in the appropriate norm and meet the requirements of the SNiP. In connection with the further development of the economy, the consumption of water for industrial, agricultural and household needs increases sharply. Therefore, the tasks of integrated and rational use of water resources and strengthening the fight against pollution of water supply sources are gaining more and more attention. Providing the population with water that meets specific sanitary and hygienic requirements is one of the main tasks of water supply. Water supply systems are a complex of engineering structures and devices designed to obtain water from natural sources, transport it and supply it to consumers under the necessary pressure, in the right volume and of the right quality [1, 2, 5, 8]. The paper analyzes the current state of surface water quality in Kyrgyzstan and the use of new non-traditional filters for water treatment. Water is the main vital natural resource in the entire globe, and it is the main carrier of infectious diseases and all kinds of chemical compounds in the human body. Drinking water in terms of quality indicators must meet the requirements of GOST 2874-82 “Drinking water”. And the water used for the technological needs of industrial enterprises must meet the requirements of the technological processes produced in them. Natural waters in terms of their quality indicators in almost all cases (on a global scale), and in Kyrgyzstan, do not meet the above-mentioned requirements. Therefore, in the system of drinking and industrial water supply, engineering structures for water treatment are provided. Water treatment is carried out using a special technology [8]. In the technology of water treatment for drinking and industrial water supply in practice, the vast majority of cases use granular filters, which in SNiP 2.04.02-84 – “Water supply. Outdoor networks and structures” has a special section. In filters, the main working element is the filter loading filter material. According to experts, 70–75% of the existing water supply networks are in poor condition, require restoration, repair and replacement, as most of this water supply system was built before 1970. There are no funds to install additional and necessary equipment for water treatment and purchase reagents for existing water disinfection facilities. To control the quality of drinking water in the water supply system in rural areas, only 10% of the staff work in many areas, which is a 75% reduction in employees. Almost 90% of all drinking water supplied through centralized water supply networks, as well as most of the water for industrial use, is provided by underground water.

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2 Research Methods Studies of sand from local deposits in order to use it as a raw material base for the production of filter material were carried out by the Department of “Water Supply, Sanitation and Hydro-technical construction” of the KGB UCTA and were of a complex nature. They included a survey of deposits, taking samples from various sites, determining the most suitable quarries for development, analyzing and summarizing the results obtained. On the territory of the Kyrgyz Republic, quartz sand deposits are widely known in the south of the republic in the areas of the Kok-Yangak, Sulyukta, and Markay coal deposits. And in the Chuysk region, quartz sand – Ivanovsky, Vasilievsky quarries in the Issyk-Ata district. Studies of the parameters and properties of the filter material from quartz sand can be carried out on the basis of an integrated approach to the evaluation of filter materials according to the following program: 1) 2) 3) 4)

Determination of indicators and properties of quartz sand: physical and mechanical, chemical resistance, sanitary and toxicological; Determination of the parameters of the granular layer: geometric structure, hydraulic characteristics, tangential stresses on the surface of the grains; Determination of technological parameters of the filter layer: filtration speed, filter cycle duration, dirt capacity; Conducting production tests of the filter material.

Tests and analyses were carried out in the laboratory of the Department “Water supply, Sanitation and Hydraulic Engineering” [1, 2, 8]. In this work, the main filter material is quartz sand. In the Kyrgyz Republic, quartz sand deposits are widely known: Ivanovsky, Vasilievsky quarries in the Chuysk region. These studies were carried out in the laboratory of the department “WSSHE” KG UCTA. Water from the Ala-Archa River was taken for purification. The main filter loads are sand from the Ivanovsky and Vasilyevsky quarries and river sand. The experiment was performed on a model of a filter made in this laboratory (Fig. 1).

3 Research Results In the laboratory unit, in the filter, three experiments were carried out, three cycles each. The sands of the Ivanovsky and Vasilyevsky deposits and the river sand of the Ala-Archa River were used, and crushed stone with a granulometric composition of 8–9 mm and 12–15 mm, respectively, was also used. The experiments were carried out as follows. Firstly, we prepare the investigated river water in a bowl. Then this prepared water is passed through a filter with the appropriate design of the filter layer.

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Fig. 1 Rapid pressure-free filter with optimized drainage system

The first experiment – the main filter material was the sand of the Ivanovsky deposit, crushed stone, coarse sand. The design of the filter layer consists of: – crushed stone (6–8 mm), h = 12 cm; – coarse sand (4–6 mm), h = 15 cm; – large crushed stone (12–13 mm), h = 20 cm;

Htotal = 47cm. We took 5 test tubes of the test water passed through the filter, every 2 min, at room temperature 18 °C. On the device, the photoelectric concentration colorimeter KFEK-2, we check the water contained in each tube separately for turbidity, i.e. the concentration of the test water. The initial concentration remains constant, and the final concentration changes. After determining the turbidity on the device “pH-meter”, we determine the acidity of the water in the test tube. The permissible acidity is normal in the range of pH = 7.5–9.0. At the end of the experiment, we determine the dry residue. Based on the obtained data, we make the curves, determine the concentration and dry residue of the test water for each experiment separately. We set the sampling time (min) on the horizontal axis t, and the concentration of C (mg/l) of the solution on the vertical axis. The results of the first experiment are shown in Fig. 2. The second experiment - the sand of the Vasilyevsky deposit, crushed stone, coarse sand were used. The design of the filter layer consists of: – crushed stone (6–8 mm), h = 12 cm; – coarse sand (4–6 mm), h = 15 cm; – large crushed stone (12–13 mm), h = 20 cm;

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Fig. 2 I – Lightening curve on the sand of the Ivanovsky deposit

Htotal = 47cm. The results of the second experiment are shown in Fig. 2. The third experiment - river sand of the Ala-Archa river, crushed stone, coarse sand were used. The design of the filter layer consists of: – crushed stone (6–8 mm), h = 12 cm; – coarse sand (4–6 mm), h = 15 cm; – large crushed stone (12–13 mm), h = 20 cm;

Htotal = 47cm. Similarly, all the same operations are performed as in the first experiment, the graphs of the curves of the second and third experiments are made, respectively, in Fig. 2, 3, 4, 5. Based on the results of the research, a simulation of the operation of a rapid filter with local loading of quartz sands from the Ivanovsky and Vasilevsky deposits of the Kyrgyz Republic was found (Table 1). Fig. 3 II – Lightening curve on the sand of the Vasilevsky field

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Fig. 4 III – Lightening curve on the sand of the Ala-Archa river

Fig. 5 Graph of water lightening in three filter cycles on quartz sand of the Ivanovsky field

The improvement of water supply and sanitation systems will create additional water resources. As a result of the research, it was revealed that the duration of the filter cycle is doubled, and the water quality meets all the requirements of GOST and SES of the Kyrgyz Republic. For surface water treatment, a “Filter” is proposed that can purify up to 85% of water and up to 92% of suspended solids. To solve the problem of preparing water of drinking quality, the technology of water purification from surface sources, which corresponds to GOST “Drinking water”, is proposed.

4 Conclusion Recently, the program of the Asian Development Bank and the World Bank for the supply of clean drinking water to rural settlements has been implemented. When designing water supply systems in these places, all design institutes of the Kyrgyz Republic use old standard projects developed in the 70 s and 80 s by design institutes of the USSR, which were designed without taking into account local conditions and on the raw materials of the Russian Federation. For example, rapid pressure-free filters were designed for the Volgograd and Astrakhan quartz sand, which has good

14.6

9.8

11.0

9.8

14.0

7.1

6.9

6.0

3.7

1

2

3

4

5

6

7

8

9

Average values

C0 , mg/l

Filter cycles

9.9

9.4

8.2

7.0

5.6

4.6

3.1

2.6

2.3

tv , °C

1.6

1.8

2.0

2.0

1.7

1.6

1.5

1.2

1.0

1.2

0.6

0.7

0.6

0.7

0.7

0.7

0.6

0.5

0.5

0.4

0.4

0.5

0.5

0.5

0.6

0.5

0.4

0.4

0.3

0.3

0.4

0.4

0.4

0.4

0.4

0.4

0.4

0.4

0.5

0.5

0.4

0.4

0.4

0.4

0.4

0.4

0.4

0.4

0.5

0.5

2

0.4

0.4

0.4

0.4

0.4

0.4

0.4

0.4

0.5

0.5

3

1

3

1

2

Ultimate porosity

Maximum hydraulic slope

1.0

1.1

1.1

1.2

1.1

1.0

1.0

0.9

0.8

0.9

1

0.64

0.64

0.65

0.67

0.69

0.68

0.66

0.61

0.62

0.56

2

0.55

0.56

0.57

0.58

0.65

0.59

0.58

0.51

0.48

0.46

3

Maximum tangential stresses, Pa

Table 1 Technological modeling according to the “fast filter” scheme Summary indicators

1.5

1.1

0.7

1.2

0.8

2.2

2.1

1.7

1.2

2.7

1

0.6

0.4

0.3

0.4

0.3

0.7

0.9

0.7

0.5

0.9

2

0.1

0.1

0.1

0.1

0.1

0.3

0.1

0.2

0.1

0.2

3

Dirt capacity, kg/m2

2.2

1.6

1.1

1.7

1.2

3.2

3.1

2.6

1.8

3.8

total

14.9

16.9

17.5

18.3

16.9

15.9

14.6

12.0

11.0

10.6

Ppp , kPa

18

31

14

19

13

16

21

16

13

18

tc , h

Improved Surface Water Treatment Technology in the Kyrgyz Republic 353

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Fig. 6 1 – water intake; 2 – microhydroelectric power plant; 3 – sump; 4 – filter; 5 – decontamination device; 6 – clean water tank

sorption properties, or for the anthracite loading of Russian deposits. But despite this, design institutes develop schemes using these very loads, which lead to a multiple increase in the cost of drinking water for the rural population. The Department of “Water Supply, Sanitation and Hydraulic Engineering” of KGUCTA for two years conducted a study on the use of cheap local raw materials for the filter loading of fine water filters. Sand from Kyrgyz deposits was used as a loading. As a result of the study, it turned out that the duration of the filter cycle is doubled; the water quality meets all the requirements of GOST “Drinking Water” and the Sanitary Code of the Kyrgyz Republic. The proposed technological scheme for the preparation of drinking water quality from surface sources using a rapid non-pressure filter is several times cheaper than similar schemes with filter loads from the Russian Federation (Fig. 6). Acknowledgements These studies were funded under the state budget topic No. DN-34-0007589

References 1. Ayukaev RI (1981) Production and application of local filter materials in municipal and industrial water supply. Express-Inform 3(6) 25 Moscow 2. Ayukaev RI, Vorobyev VA, Kivran VK, Koryakin VP (1976) Application of computers in the study of physical and structural properties of porous materials. KISI, Kuibyshev 3. Karimov TKh, Rakhmanbekov BR (2018) Monitoring of the Chu River and its main tributaries. Bull KGUCTA 61(3):109–114

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4. Karimov TK, Karimova MT, Baigazy kyzy N, Maatkulova J, Abdykalykov AA (2019) Analysis of groundwater resources in the Kyrgyz Republic. J Environ Manage Tourism. vol. X, Fall 5(37): 984–990 5. Kastalsky AA, Mints DM (1982) Preparation of water for drinking and industrial water supply. Moscow (1982) 6. Korenev YuI (1980) Research of air washing of fast filters: Research in the field of water supply of LICI. Leningrad 7. Kurgaev EF (1972) Modeling of clarifiers and granular filters. Proc Inst Central Res Inst Transport 48:25–38 8. Mints DM, Shubert SA (1961) APU filters and Calculation of Filter Washing. MKH RSFSR, Moscow 9. Noskov MD, Zaytseva MS, Istomin AD, Lukashevich OD (2008) Mathematical modeling of the operation of fast filters. TSACE Bulletin 2:126–137 10. Petrov EG, Levitin SM (1985) Filter materials for non-reagent treatment of natural waters New research on networks and structures of water supply systems LISI, Leningrad

Use of Weak Foundations in the Construction of Highways N. S. Sokolov

and P. Yu. Fedorov

Abstract The actively developing world is developing more and more new territories that were previously economically unattractive. Often, such areas have features in the form of weak foundations that are beginning to be built up. Ensuring the reliability and durability of the foundations of the embankments of urban main roads is an important geotechnical task. To ensure the smooth movement of urban transport, the issues of increasing their load-bearing capacity and stability are relevant. The modern geotechnical industry has various technologies and materials that can solve this problem. To do this, they can use methods of reinforcing the soil embankment, strengthening the base with a pile field of reinforced concrete piles, crushed stone piles, or use combined methods. Each of the methods increases either stability or load-bearing capacity, so it is more expedient to use combined methods based on technical and economic analysis, which give a win in several positions at once. Keywords Urban highways · Pile field · Geosynthetic materials (woven geotextiles geogrids) · Reinforced embankment · Crushed stone piles

1 Introduction In connection with the increase in the volume of construction and the development of new territories, tasks that were previously tried to avoid become relevant again. In rapidly developing cities, new neighborhoods are being built up. Often, there are only areas where weak or collapsing soils lie at the base, as well as to build on ravines that were filled with a large capacity of various technogenic soils, also not characterized by high load-bearing capacity [1–12].

N. S. Sokolov (B) Chuvash State University named after I. N. Ulyanov, Moskovskiy prosp., 15, Cheboksary 428015, Russian Federation N. S. Sokolov · P. Yu. Fedorov NPF (LLC SPC) “FORST”, ul. Kalinina, 109a, Cheboksary 428000, Russian Federation © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_47

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All the new neighborhoods are in need of transport communications with the center and other residential districts of the city. Main roads perform just this function. The main problem in the construction of engineering structures in complex engineering and geological conditions is to ensure the strength, stability of the foundations, as well as the maximum permissible values of deformation. For clarity and concretization, we will consider one of the projects under development: “Construction of a highway on Nikolay Rozhdestvensky Street in Cheboksary”.

2 Methods and Materials It is possible to increase the speed of consolidation and increase the stability and loadbearing capacity of the foundation of the embankment of fine-grained sand by using modern rolled geosynthetic materials. The stability of the embankment is achieved by laying the material in the form of casting or semi-casting with turns of 3.0 m. The result is reinforced layers that work on transverse tension. The tensile strength of the material is applied from 300 in the upper layers to 600 kN/m in the lower layers of the embankment. Replacing the weak layer in the base is also a good way to increase the stability of the embankment. But in the conditions of existing buildings, the use of this geotechnical technology is not always possible. At the same time, it is almost impossible to develop open pits. The use of drainage piles allows removing excess moisture from the waterlogged base of the embankment. However, when performing such works, it is necessary not to forget about the geotechnical monitoring of the zone of influence from construction works, it is necessary to take into account the presence of closely located buildings. It is known that uneven lowering of the ground water level can lead to uneven deformations of their foundations.

3 Results and Discussion The site under consideration is a territory significantly changed by technogenic construction activities, as a result of full or partial filling of ravines, laying of storm and drainage sewers. The terrain of the projected road is also very complex, with significant differences in absolute marks from 95.4 to 107.1 m on the bottoms of ravines and 108.6–105.1 m on the accumulative-denudation surface. Also on this site there are dangerous engineering and geological processes in the form of: 1. Landslide processes along the sides of ravines; 2. Suffusion with the formation of local dips; 3. Ravine erosion; 4. Self-sealing of non-compacted interlayers in bulk soils; 5. Technogenic flooding of built-up areas; 6. Bulk soil creep; 7. Subsidence of soils during soaking. Characteristics of roads: road category—the highway of regional significance with pedestrian sidewalks, type of pavement—major on SP 34.13330.2014 “Roads”. (The

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Table 1 Road surface construction Name of the layer

Material of the layer

Thickness of the layer, m

Top coat of covering

Hot dense fine-grained asphalt concrete of type B grade I

0.05

Bottom layer of covering

Hot porous coarse grained grade II asphalt concrete

0.07

Top layer of the base

Black crushed stone

0.30

Bottom layer of the base

Fractional crushed stone (fr. 40–70) 0.30 M800 with small crushed stone (fr. 10–20)

Technological layer

Geotextile material “Dornit”

An additional layer of the base Fine sand with Cf > 1 m/day

– 0.50

Compacted base soil Note the total thickness of the structural layers of the road surface is 1.22 m

updated edition of SNiP 2.05.02-85*), the width of the roadway 16.0 m (to 23.0 m on exitings); width of the subgrade at the top of 27.0–35.0 m; the maximum height of the embankment to 23.4 m axis and of 27.0 m to the bottom of the slope; the inception of slopes: −1:1.5 (m to 6.0 m from the top); −1:1.75 (up to 12.0 m from the top); −1:2.0 (up to 18.0 m from the top); −1:2.5 (more than 18.0 m from the top) according to SP 78.13330.2012 “Highways”. (Updated version of SNiP 3.06.03-85) (Table 1). Numerical analysis of the deformations and stability of the embankment was performed using the PLAXIS 2D software package for geotechnical calculations using the finite element method (hereinafter referred to as FEM). The use of numerical calculation methods (FEM) is regulated by such documents as: SP 16.13330.2012 “Engineering protection of territories, buildings and structures from dangerous geological processes. Basic provisions” (Updated version of SNiP 22-02-2003) and ODM 218.2.006-2010 “Recommendations for calculating the stability of landslide-prone slopes (downhills) and determining landslide pressures on engineering structures of highways”. When creating a geometric model, the ground array is divided into a network of 6 nodal triangular isoparametric finite elements (FE), in which the displacements are determined at all nodes, and the stresses (calculated by the method of K. Terzaghi)— at three points. The transport load taken into account in the calculations of the stability of the embankment—45.0 kN/m2 , adopted according to GOST R 52,748-2007 “Standard loads, calculated loading schemes and approach dimensions”, is evenly distributed over the width of the roadway. According to paragraph 4.3.2 GOST 32,960-2014 “Automobile roads of general use. Standard loads, design loading schemes” when calculating the embankment sediment, the load AK, reduced to the equivalent evenly distributed load qAK intensity, kPa, should be taken as a temporary mobile load:

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(1) where n—number of lanes; BZP—the width of the ground surface, m; K—AK load grade. The relief of the Chuvash Republic is heavily indented by ravines due to the incessant erosion processes. In this regard, there is a huge lack of soil in the Republic for the construction and construction of embankments, so most often sand is used for filling the embankments, which is extracted in huge quantities on the banks of the Volga. Filling of embankments of variable height (from 0 to 23.0 m) is a complex and lengthy process. The filling should be made in layers with the compaction of each layer. It is also necessary to take into account the additional compaction and deformation of the lower layers from the increasing load of the embankment itself. The period of consolidation of this embankment can be estimated up to one year. Which long for this object is unacceptably, due to the need to put it into operation as soon as possible. It is also impossible to achieve complete sedimentation and deformation of the embankment during the consolidation period. The payload from the passing transport is dynamic and it is almost impossible (they need a word, “take into account” is not quite suitable) during the construction period. Figures 1 and 2 show the estimated deformation of the embankment as a result of loading.

Fig. 1 Plots of horizontal deformations of the embankment base on a slope

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Fig. 2 Total deformation of a high embankment

The reinforcement of the embankment with semi-casing provides for the reinforcement of the roadbed with the help of geosynthetic materials (woven geotextile, geogrid, flat geogrid and their compositions) with a maximum tensile load of at least 30.0 kN/m. Reinforcing the embankment with layers of composite materials of various types and compacted soil, we get—reinforcement soil. Figure 3 shows the scheme of layer-by-layer reinforcement, the transverse profile is built in the IndorCAD software package, which allows laying and calculating the amount of required material for the construction of this structure.

Fig. 3 Reinforcement embankment

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This design is much more effective in taking the load from its own weight and passing vehicles and pedestrians, evenly distributing it over the entire body of the embankment. It is possible to increase the speed of consolidation and increase the stability and load-bearing capacity of the foundation of the embankment of fine-grained sand by using modern rolled geosynthetic materials. The stability of the embankment is achieved by laying the material in the form of casing or semi-casings with turns of 3.0 m. The result is reinforced layers that work on transverse tension. The tensile strength of the material is applied from 300 in the upper layers to 600 kN/m in the lower layers of the embankment. Replacing the weak layer in the base is also a good way to increase the stability of the embankment. But in the conditions of existing buildings, the use of this geotechnical technology is not always possible. At the same time, it is almost impossible to develop open pits. The use of drainage piles allows removing excess moisture from the waterlogged base of the embankment. However, when performing such works, it is necessary not to forget about the geotechnical monitoring of the zone of influence from construction works, it is necessary to take into account the presence of closely located buildings. It is known that uneven lowering of the ground water level can lead to uneven deformations of their foundations. It is rational to combine the use of crushed stone piles with the reinforcement pile (Fig. 4), due to which it becomes possible to use less durable geotextiles or increase the reinforcement step, due to which savings are possible.

Fig. 4 Model of the calculated precipitation of an armoured embankment and a ground base with crushed stone piles in the form of a network of GE

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Fig. 5 The total sediment of a reinforced embankment with concrete piles in the form of isofields of two-dimensional deformations at the operational stage (mm)

Another combined variant the option of using an reinforced embankment together with concrete piles (Fig. 5), can be considered. However, due to the high cost of the pile field device, this method is the least attractive from an economic point of view.

4 Conclusion 1.

2.

Modern geotechnical methods allow the construction of large and critical structures on weak foundations with minimal deformation after the commissioning of the object. The most preferred option for each individual site should be chosen based on the feasibility study and the tasks that this design should perform.

References 1. Il’ichev VA, Mangushev RA, Nikiforova NS (2012) Development of underground space in large Russian cities. Bases Found Soil Mech 2:17–20 2. Ulitsky VM, Shashkin AG, Shashkin KG (2010) Geotechnical maintenance of urban development. Georeconstruction. St. Petersburg 551

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3. Ter-Martirosyan ZG (2009) Mechanic of soil. M.: ASV, 550 4. Ulickiy VM, Shashkin AG, Shashkin KG (2015) Guide to geotechnical engineering (Guide to the grounds, foundations and underground structures). Second edition, additional. Saint Petersburg, vol 284 5. Mangushev RA, Gursky AV (2016) Assessment of the impact of sheet pile indentation on additional precipitation of neighboring buildings. Geotechnics 2:2–7 6. Mangushev RA, Sapin DA (2015) Taking into account the rigidity of the “wall in the ground” on the draft of neighboring buildings. Housing Constr 9:3–7 7. Mangushev RA, Gursky AV, Sapin DA (2017) Taking into account the technological sediment of existing structures in the construction of new buildings around them with a developed underground expanse. Engineering-geological surveys, design and construction bases, foundations and underground structures. Sat. Tr. All-Russian scientific. -tech. Conf. 1–3 9–22 February 2017 8. Mirsayapov IT, Hasanov RR, Safin DR (2017) Results of geotechnical monitoring of carriers building structures during reconstruction. Engineering-geological surveys, design and construction of foundations and underground structures. Sat. Tr. All-Russian scientific. -tech. Conf. 1–3 February 2017 pp 164–169 9. Nikiforova NS, Vnukov DA (2011) Geotechnical cut-off screens for the protection of buildings in the device of communication collectors. III Academic reading them. Professor A. A. Bartholomew. The foundations of the deep laying and problems of underground expanse development. Mat. intl. Conf. Perm, October 18–19 2011. Perm: publishing house of Perm national research. Polytech. UN-TA pp 413–422 10. Sokolov NS, Ryabinov VM (2016) The technology of appliance of continuous flight augering piles with increased bearing capacity. Housing Constr 9:11–14 11. Sokolov NS (2017) Criteria of economic efficiency of use of drilled piles. Housing Constr 5:34–38 12. Sokolov NS (2018) Determination of the type of buried structure of the reinforcement of the base under the embankment of high-speed rail line, vol 9, pp 62–66

Correction of the Test Method for Ladders with Removable Steps V. A. Antonova , K. V. Zherdev , and A. Ya. Barvina

Abstract This paper discusses ladder for overhead power line supports, and those that can be part of machinery and equipment. The design and installation of the ladder should be subject to the same requirements as the machine for which it is intended, including special circumstances such as adverse atmospheric conditions, vibrations. Selected types of structures are made of metal and have removable lower steps. All ladder and its elements must be sufficiently rigid and firm to support the structure to ensure the safety of users under normal operating conditions. There is no test method for removable steps in existing standards. The established safety requirements must be controlled by calculation and/or testing, which must be carried out in accordance with the procedure described in Sect. 5 of GOST R ISO 141224-2019. The purpose of this work is to develop safety criteria for the operation of vertical ladders with removable steps. Tests for static characteristics were carried out under normal climatic conditions on a stand for testing personal protective equipment against falls from a height. The tests were carried out on a vertical ladder to solve this problem, the test method was adjusted and approved to eliminate the error due to the technological bias set by the manufacturer. Keywords Safety · Ladder · Steps · Removable steps · Tests of stairs · Deflection · Deformation

1 Introduction The operation of any type of ladder is associated with the risk of falling and injury. To prevent accidents, it is necessary to comply with the safety requirements for ladder [5, 6]. The safety of using ladder in construction or industry is ensured by knowledge of safety standards [7, 8]. An important factor is the material from which the ladder is made. As part of this work, we are considering metal ladder. This material is by far V. A. Antonova (B) · K. V. Zherdev · A. Ya. Barvina TL IISC NRU MGSU, Moscow, Russia e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_48

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the most popular. Here it is important to pay attention to the protection of materials from corrosion, the condition of welded seams. Ladders are divided into mobile and stationary, that is, permanent. The second are less dangerous and provide maximum stability. In general, these structures are used for lowering/lifting personnel, for towers of overhead power lines, and can be part of machinery and equipment. After installation, during the commissioning of the facility, all ladders are tested. Load-bearing structural elements must withstand the loads given in GOST R ISO 14122-4-2009. During transportation and storage of ladder, conditions must be provided that protect them from mechanical damage, heating, direct sunlight, precipitation, moisture, and aggressive environments. In order to avoid unauthorized entry of undesirable persons, the construction of stationary ladder provides for removable steps at a height of 3–4 m from the ground level. For the possibility of attaching the lower steps to the rack, the manufacturer provides a technological tolerance in size. There is no method in the existing regulatory documents that allows testing degrees, including the inherent parameters of technological displacements. The purpose of this work is to develop safety criteria for the operation of vertical ladders with removable steps. To achieve the goal, the following tasks were solved: analysis of the existing test procedure; identification of inconsistencies and gaps in the test method; solving emerging problems by adjusting the existing method; approbation of results; conclusion and recommendations.

2 Materials and Methods of Research Tests for static characteristics were carried out under normal climatic conditions on a stand for testing personal protective equipment against falls from a height [1–4, 9–16]. The tests were carried out on a vertical ladder with a single strut inclined from 75° to 90° as defined in EN ISO 14122-1, clause 3.2, the steps of which are attached to both sides of the strut. The load is absorbed by the vertical rack (Fig. 1). The established safety requirements are controlled by calculation and/or tests, which should be performed in accordance with the methodology described in Sections 5 of GOST R ISO 14122-4-2009. When tested, ladder elements shall meet the requirements of the following subclauses of EN 131-2:—ladder bending test (EN 131-2, clause 4.3);—stage torsion test (EN 131-2, clause 4.7).

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Fig. 1 Vertical ladder less than 3000 mm high with one upright: 1—vertical rack; 2—stage; 3—bend against slipping at the end of the step; 4—mounting bracket

Fig. 2 Scheme of testing stairs for bending: F—the point of application of the test load; 1— structure for installing and testing stairs; 2—ladder post, rigid anchor line of the T-shaped profile; 3—fastening element; 4—screw M20 × 200; 5—connector of rail segments

2.1 Bend Test of a Stain Member The distance L, which is taken into account in the strength and bending test, shall be the largest distance between two consecutive anchorage points of the ladder. The acceptance criterion for the bend test (EN 131-2, clause 4.3) is modified as follows: the maximum allowable deflection under a load of 750 N should be no more than 5 * L2 * 10–6 mm, but should not exceed 30 mm. Application of a test load for more than 1 min (Figs. 2, 3 and 4).

2.2 Step Strength The bend test of one-strut stair treads should be carried out as shown in the Fig. 5.

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Fig. 3 Scheme of bending tests of ladders with radius type: F—the point of application of the test load; 1—structure for installing and testing stairs; 2—ladder post, rigid anchor line of the T-shaped profile; 3—fastening element; 4—screw M20 × 200

Fig. 4 Testing scheme for composite stairs with a profile of 2 m and more, including stairs: F—the point of application of the test load; 1—structure for installing and testing stairs; 2—ladder post, rigid anchor line of the T-shaped profile; 3—fastening element; 4—screw M20 × 200; 5—connector of rail segmentswith removable bending steps Fig. 5 Scheme of testing stairs of ladder with one stand for bending: F—the point of application of the test load; L—step length; 1—construction for the installation and testing of ladders; 2—ladder post, rigid anchor line of the T-shaped profile; 3—stage

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Fig. 6 Scheme of torsion testing of ladders: F—points of application of the test load; 1—structure / structure for installing and testing ladders; 2—ladder post, rigid anchor line of the T—shaped profile; 3—fastening element; 4—connector of rail segments; 5—steps

A preload of 200 N was applied vertically perpendicular to the surface of the steps for 1 min. The position of the stage under the action of the preload was considered as the initial position during the test under the main load. The direction of preload and base load of 2.6 kN was the same. Preload and main load are evenly distributed over a length of 100 mm around the anti-slip bends at the ends of the steps. The deflection of the steps at the place of load application should be no more than 0.3% relative to the length L of the step. The measurement point was 50 mm from the side fold at the end of the steps. The measurement was carried out along the line of application of the test load. The application of the test load lasted for at least 1 min. No residual deformation was observed.

2.3 Torsion Test of Ladder A torsion test was carried out for vertical ladders with one post. The ladder must be loaded with two forces (Fig. 6). The direction of both test loads of 400 N was perpendicular to the surface of the ladder, the length of the test ladder was slightly more than 4 m. The ladder was mounted on a horizontal surface at the anchorage points. Test loads were applied to the points considered most unfavorable. The bend of the ladder should not exceed 20 mm under test load. The measuring points on the steps to which the test loads were applied were 50 mm from the anti-slip bends at the ends of the steps. The direction of measurement shall be along the line of application of the test loads. The application of the test load lasted for at least 1 min.

3 Results and Discussion The insertion of an ash microsphere into the magnesia mixture is accompanied by a decrease in the density of the composite material (Table 1). The strength of the compositions depends on the fraction of the ash microsphere and decreases as the structure is saturated with hollow particles, which is obvious for the systems under

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Table 1 Bending test of stairs according to EN 131-2: 2010 + A1: 2012, point 5.3, on its own supports № of scheme

Permissible deflection, 5L2 * 10-6 mm

Deflection after testing, mm

Conclusion

In diagram 2 (see Fig. 2)

11.25

2.6

All values are valid

In diagram3 (see Fig. 3)

12.8

1.4

In diagram 4 (see Fig. 4)

20

2.4

In diagram 5 (see Fig. 5)

0.2

2.6

study. The properties of the compositions are largely determined by the composition of the mixed binder. The content of the ash microsphere should be limited to 20%, as an increase in the proportion of porous particles causes a shortage of binder for binding the microsphere (Tables 2 and 3). Table 2 Torsion test of the stage according to EN 131-2: 2010 + A1: 2012, point 5.7 Stapes name

Permissible deflection, 0.3% relative to the step length L

Step deflection during the application of the main load

Deflection of a step after applying the main load

Note

Screw M 20*200

0.6

4

0.3

Stage mobile 1

0.6

2.5

0.3

There are structurally embedded step displacements

Table 3 Torsion test of stairs according to EN 131-2: 2010 + A1: 2012, point 4.4 № of scheme

Amendment

Permissible bending, mm

Ladder of stairs, mm

In diagram 1 (see Fig. 6)

-

20

18.7

In diagram 2 (see Fig. 6)

There are structurally 20 embedded step displacements in the area of connection with respect to the rack. The displacement of the step after applying a preload equivalent to 0.5 kg was 42.2 mm

15

Correction of the Test Method for Ladders with Removable Steps

371

4 Conclusion As you can see, in GOST R ISO 14122-4-2009 there is no method that allows testing for removable steps due to the gap provided by the manufacturer. A solution to this problem can be achieved by applying an initial load to remove the present structurally embedded step displacements in the area of the joint relative to the strut. The preliminary load can be taken equal to no more than 0.5 kgf. After that, the main load is applied. The preload position of the stage was considered as the starting position for the main load test. Since the designation and name of the relevant national standards for this GOST R ISO 14122-4 are absent. It should be noted that in the appendix of this guest there is a recommendation to use the translation into Russian of the European standard EN 131-2, but the version to which you can refer is not indicated. As a result, it turns out that from a legal point of view it is impossible to carry out tests according to this standard. Therefore, for the current edition, it is possible to carry out tests according to the above-mentioned GOST only within the framework of control test protocols with correction of test methods, even with regard to standard solutions. At the same time, we consider it important to note the need to introduce solutions with removable steps into this regulatory document.

References 1. Stupakov AA, Lelikov GD, Semonov PA, Vasilenko VV (2015) Inspection and repair of highrise objects work including industrial alpinism. Mech Constr 2(848):48–52 2. Stupakov AA, Kapyrin PD, Lelikov GD, Semenov PA, Vasilenko VV (2015) Stands for studies of personal protection equipment for people against falling from a height. MGSU Bulletin 8:130–139 3. Pham NT, Vasilenko VV, Korolchenko DA (2017) Actualization of the dynamic test methods to be systemized for temporary edge protection systems. Fire Explos Saf 12(26):35–44 4. Senchenko VA, Kaverzneva TT, Rumyantseva NV, Skripnik, IL, Lelikov GD (2018) Implementation of stationary anchor devices for safe operation at the height of support of air communication lines and electric transmission lines. Fire Expl. Saf 1 (2)7:58–67 5. Head to the stairs. Senchenko V, A., Lelikov G. D. and Glumov E.A. The patent for utility model RU 184480 U1, 29.10.2018. Applicator number: 2018131525. Registration date: 03.09.2018 6. Patent RU 196601 U1 No. 2019127419. Head to the stairs with anchor device / Senchenko V.A., Lelikov G. D.and Sencheno O.A.; Registration date: 30.08.2019; Publication date: 06.03.2020, Buhl. 7. 7. Korolchenko DA, Korolchenko AD (2019) Definition Marginal States of Irrigated Firefighting Barriers. IOP Conf Ser Mater Sci Eng 471:112017 8. Gorev VA, Korolchenko AD (2020) Impact of the idle run of a rotating easily dumped structure on pressure in the room. IOP Conf Ser Mater Sci Eng 869:052069 9. Pham NT, Vasilenko VV, Korolchenko DA (2018) Test and certification procedures of pulleys as a part of personal fall arrest system. IOP Conf Ser Mater Sci Eng 365(4):042057 10. Vasilenko VV (2017) Updating the methodology of dynamic testing of shock absorbers as personal protection equipment against falling from a height. Constr creating a living environment, pp 439–441

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11. Lelikov GD, Vasilenko VV (2017) Analysis of the use of safety slings made of synthetic ropes as PPE against falling from a height. Construction - creating a living environment pp 475–477 12. Korolchenko DA, Vasilenko VV, Lelikov GD (2018) Problems of the dynamic test method for individual protection equipment (shock absorbers). MATEC Web Conf 193:05034 13. Vasilenko VV, Korolchenko DA, Pham NT (2018) Definition of the inspection criteria for personal protective equipment (for work at heights) on example of full body harnesses. MATEC Web Conf 251:02042 14. Prostakishin DA, Pham NT (2020) Dynamic test method for full body harnesses exploited in cold climates. Lecture Notes in Civil Engineering, p 012027 15. Zherdev K, Korolchenko O, Gadzhiyev R (2020) Polyspast - personal fall protection equipment. Features of certification and certtification tests. Integration, partnership and innovation in construction science and education, vol 83 16. Pham NT, Lelikov GD, Korolchenco DA (2018) Improvement of the safety systems for working at heights on transmission towers. In: Pham NT, Lelikov GD, Korolchenco DA (eds.) Construction - the formation of living environment 042-054

Implementation of Environmental Tasks of Waste-Free Biotechnological Industries Using the Fly Hermetia Illucens Larvae Zh. A. Sapronova , I. G. Shaikhiev , S. V. Sverguzova , and E. V. Fomina

Abstract Biotechnology is a promising area of science that studies the possibilities of using living organisms, systems or products of their vital activity to solve technological problems. The larvae of the fly Hermetia illucens are effectively used for the bioconversion of organic waste, providing a reduction in the load on natural ecosystems and economic feasibility. An increase in the bioconversion of organic substrates using the Hermetia illucens fly contributes to an increase in the amount of insect biomass that requires effective areas of larvae application to solve the problems of creating waste-free circulation. The larvae can be a promising raw material for use in the production of feed. The protein composition of the larvae contains a large amount of amino acids, the composition of which is similar in many ways to fish and soy proteins, due to which in many studies there are good results have achieved when feeding fish and poultry with the larvae. This type of insect also has a good tolerance for mycotoxins, which allows them to thrive on substrates consisting of various wastes. The pathogenic environment has led to the development of the ability to produce antibacterial peptides for protective purposes in the insects, which can be used in medicine and agriculture. The composition of the fat fraction is represented by various fatty acids, such as lauric, oleic, stearic, etc., which makes it possible to consider it as an alternative to industrial cosmetic oils. Keywords Waste-free biotechnology · Resource conservation · Waste · Hermetia Illucens · Feed

1 Introduction On our planet, of all known multicellular living things, the largest number of known species is represented by insects [1], therefore, the growing interest of science and Zh. A. Sapronova · S. V. Sverguzova · E. V. Fomina (B) Belgorod State Technological University named after V. G. Shukhov, Belgorod, Russia I. G. Shaikhiev Kazan National Research Technological University, Kazan, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_49

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Fig. 1 Hermetia illucens: a adult insect, b larvae

society in their use in agriculture, fodder and food industries has become a natural phenomenon. The fly of the Hermetia Illucens species (Fig. 1) or the black soldier fly is a large insect from the Stratiomyidae (Diptera) family, a natural inhabitant of the tropics, subtropics and warm temperate zones of North and South America, which in recent decades has been introduced by humans to all inhabited continents [2]. This type of insects is one of the most frequently used in human economic activities, since it has a number of valuable biological qualities [3]: – simplicity of breeding and fast reproduction rate; – the ability to feed on almost all types of food and agricultural waste, including manure; – harmless to humans: adult insects are inactive, do not feed and do not spread disease. Only insect eggs, which, if swallowed, can cause myiasis, pose a relative hazard; – rich chemical composition of the protein and fat parts of the larvae.

2 Methods and Materials To collect information, we used publications in leading Russian and foreign publications. Methods of system analysis, comparative criteria for the effectiveness of scientific results were used. As objects of research, the authors analyzed the use of such protein sources as a feed additive as Hermetia Illucens larvae—for feeding birds, in particular, chickens; insect meal—as part of the feed for farm animals. As a method for assessing the effect of Hermetia Illucens larvae on animal feed, we used a method for assessing the degree of Cd, Pb, and Zn cumulation ions for the development of larvae and pupae of the black soldier fly. These metals were added to the substrate that was used as chicken feed. Also, within the framework of this review, we analyzed the study of the antimicrobial properties of extracts of Hermetia Illucens larvae. A review was also conducted on the isolated food additive as a bioactive polysaccharide, which has immunomodulatory activity in mammals. To prepare the extract, the larvae were washed, dried with filter paper, frozen, and ground together with a solution of methanol/water/acetic acid in a ratio of 90/9/1 (by volume). Also, a

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method for its preparation is presented, which is as follows: the extract was separated by centrifugation, then methanol was evaporated in a rotary evaporator under reduced pressure.

3 Results and Discussions Fodder Production. Insects are natural food for many species of poultry and fish, so their use as a protein supplement in feed production is a logical step [4]. The protein of the larvae contains a large amount of amino acids (Table 1), the composition of which is similar in many respects to soy and fish proteins [5]. However, many researchers note that dietary adjustments need to be made in terms of protein, fat and fiber to ensure optimal nutrient content. In this regard, it may be more convenient to use the larvae not entirely, but in the form of separate fractions: protein, fat, and chitin, which will facilitate the development of fodder mixtures [6]. Meal from larvae can replace fishmeal without serious losses in weight gain, feed utilization and protein retention up to 50%. Although the growth rates of the rainbow trout that received the highest level of larval meal were the lowest, there were no signs of nutritional deficiencies or higher mortality rates. The reason for the decrease in productivity may be the content of chitin in larvae, since this component of the exoskeleton of invertebrates can adversely affect the absorption of nutrients [7]. Despite the general positive results of experiments on the use of a feed product made from larvae, the authors note that research is needed on a longer fish rearing [8]. All authors agree that the black soldier fly larvae are a valuable and economically beneficial addition to the poultry diet, but differ in the optimal amounts of this component: from 10 to 33% of the total protein content [9]. The authors found Hermetia illucens to be a promising protein source for bird nutrition. The addition of Hermetia illucens (50%) or complete replacement in the Table 1 The composition of essential amino acids of the protein fraction of Hermetia Illucens larvae in comparison with soy and fish protein [5]

Amino acids

Content (%), raw protein H. illucens larvae

Fish

Soy protein

Arginine

4.80

5.81

7.42

Histidine

3.28

2.82

2.77

Isoleucine

4.16

4.08

4.56

Leucine

6.56

7.20

7.81

Lysine

5.92

7.62

6.26

Methionine

1.6

2.81

1.45

Phenylalanine

3.60

3.99

5.26

Threonine

3.92

4.19

3.99

Valine

5.68

4.81

4.72

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fodder for laying hens does not affect the health or productivity of the hens and practically does not affect the eggs [10]. Insect protein is a good alternative to soybean meal and fishmeal when feeding other farm animals [11]. Toxic Resistant of Hermetia Illucens Larvae. In many countries, the cultivation of the Black Lion’s larvae is practiced on various wastes, since this allows solving several problems at once: to process organic waste and obtain a valuable protein product [12]. Waste and manure are subject to decomposition and contain many pathogenic microorganisms, mycotoxins, etc., which together is a rather aggressive environment [13]. Hermetia illucens larvae are known to be able to tolerate high levels of mycotoxins, either individually or in mixture, without compromising overall survival and growth rate. Aflatoxins are a group of mycotoxins that are mainly produced by Aspergillus flavus and Aspergillus parasiticus molds. The four main aflatoxins are B1, B2, G1 and G2, which can be found in various foods such as peanuts and corn. Aflatoxins are carcinogenic to humans and pose a serious economic and health problem worldwide. It was found that the larvae are highly resistant to aflatoxin B1 in an amount of up to 0.5 mg/kg of dry food and do not accumulate it in tissues [14]. Antibiotics are often found in poultry and livestock waste. It was established in [15] that the larvae of Hermetia Illucens can tolerate sulfonamide concentrations up to 1 mg/kg in the substrate without harm. The degree of Cd, Pb and Zn cumulation for the development of larvae and pupae of the black soldier fly was studied. These metals were added to the substrate, which was used as chicken feed. It was found that the accumulation factor of cadmium in pupae (the concentration of metal in the body divided by the concentration of metal in fodder) varied from 2.32 to 2.94. The coefficient of zinc bioaccumulation in fly pupae decreased with increasing zinc concentration in food from 0.97 to 0.39. With regard to lead, it was revealed that its concentration in larvae and pupae of flies remained significantly lower than its initial concentration in fodder. The authors concluded that none of the three elements of heavy metals had a significant effect on the determinants of the life cycle (pupal weight, developmental time, sex ratio) of larvae [16]. Extraction of Valuable Components from Larvae. Many studies have studied the antimicrobial properties of extracts of Hermetia illucens larvae [17], which are due to the natural necessity of survival in a bacteriogenic and toxicogenic aggressive environment. In work [18], a bioactive polysaccharide was isolated from larvae, which has immunomodulatory activity in mammalian organisms. Content of antimicrobial peptides varies depending on the feed used, which opens up great opportunities for the use of larval extracts in the medical field. To prepare the extract, the larvae were washed, dried with filter paper, frozen, and ground together with a solution of methanol/water/acetic acid in a ratio of 90/9/1 (by volume). The extract was separated by centrifugation, then methanol was evaporated in a rotary evaporator under reduced pressure. The obtained extracts demonstrated obvious inhibition of the growth of bacteria of the species Escherichia coli BL21 (DE3), Micrococcus luteus, Pseudomonas fluorescens BL915, and Bacillus subtilis [19]. Methanol

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extracts have shown antibacterial action against the proliferation of Klebsiella pneumoniae, Neisseria gonorrhoeae and Shigella sonnei. However, antibacterial effects have not been observed against gram-positive bacteria such as Bacillus subtilis, Streptococcus mutans and Sarcina lutea [20]. A similar study [21] was aimed at studying the pharmacological activity of new antibacterial peptides isolated from the larvae of Hermetia illucens against Klebsiella pneumoniae and Shigella dysenteriae. These results demonstrate that the peptides induced by Hermetia illucens exhibit strong antibacterial activity against gram-negative bacteria, indicating the great potential of larval-derived peptides for the development of new antibacterial drugs. The addition of feed containing the product from Hermetia illucens larvae led to an increase in the resistance of broiler chickens to Salmonella Gallinarum in the experiment [22]. The high fat content in larvae makes it possible to obtain biodiesel fuel as one of the products of their processing. Chitin is another valuable product that can be obtained from larvae [23]. At a university in Germany, studies were carried out to obtain a fatty product from the larvae of Hermetia illucens [24]. The killed and dried larvae were processed using a screw press to extract oil from oilseeds. For the experiment, the larvae were reared in rye flour and water for 10–14 days. The larvae were then dried in a paddle vacuum dryer (40 °C, 200 mbar) to a moisture content of 14.7%. Further drying to 8.7% moisture was achieved in a fluidized bed dryer at 70 °C. The dried larvae were crushed and then squeezed out in an oil press. The following parameters were used: press head diameter: 6 mm, rotation speed: 40 rpm, productivity: 2.2 kg/h. The press head was heated to 90 °C in order to drain the fat, which was completely cleaned in the laboratory, including the steps of degumming, chemical neutralization, bleaching and deodorization. The protein content in the cake was 42% of dry matter. The extracted fat fraction had an interesting composition of fatty acids with the predominant representatives of lauric (48%), myristic (11%) and palmitic acids (16%); very similar to the fat of palm coconut oils. The content of tocopherols and tocotrienols was low (64.7 mg/kg), while the total amount of sterols (3557 mg/kg) is comparable or higher to commonly used vegetable fats and oils. The sterols are dominated by campesterol (889.7 mg/kg) and β-sitosterol (1866 mg/kg). Refined oil from Hermetia illucens larvae is proposed as a suitable alternative to palm and palm kernel oil in the cosmetic industry (Table 2) [25]. Protein hydrolyzate is a complex mixture of peptides and amino acids that can be obtained from various biomass sources, including insects such as the larvae of Hermetia illicens flies, due to its relatively high protein content. The protein hydrolyzate from the black soldier larvae contains a large amount of hydrophobic essential amino acids, in particular, lysine (8.0%), leucine (7.7%), and valine (7.3%) [26].

378 Table 2 Composition of fatty acids in refined fat of black soldier fly larvae in comparison with industrial oils

Zh. A. Sapronova et al. Fatty acid

Content [%] Refined larval Industrial palm Industrial palm fat oil kernel oil

Caprylic

–

–

3.5

Lauric

28.8

0.2

47.8

Myristic

5.4

1.1

16.3

Palmitic

21.6

44.0

8.5

Stearic

2.4

4.5

2.4

–

–

Palmitoleic 3.2 Oleic

23.4

39.2

15.4

Linoleic

11.1

10.1

2.4

Linolenic

0.4

0.4

–

Others

–

0.1

3.6

4 Conclusion The larvae of the fly Hermetia Illucens is one of the most promising species for various types of organic waste bioconversion; subject to general hygiene rules they are not dangerous to humans and can serve as a source of many useful products. The use of insects is an effective stage in the agriculture development. Larval protein is quite nutritious and can successfully replace soy and fish meal in the manufacture of feed for poultry, fish and farm animals. An interesting line of research is the production of antimicrobial peptides from Hermetia Illuicens larvae, which are effective against many gram-negative bacteria. The Black Soldier fly larvae contain a large amount of fat, similar in composition to coconut oil, so it seems possible to use refined fat in the cosmetic industry. Thus, the environmental problems of reducing the volume of generated organic waste are being solved with the economic efficiency of obtaining the protein component in demand in various fields of industry, which ensures the creation of waste-free biotechnological industries. Acknowledgements This work was financially supported by the Ministry of Science and Higher Education of the Russian Federation under agreement No. 075-11-2019-070 of November 29, 2019, using equipment of High Technology Center at BSTU named after V.G. Shukhov.

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3. Sholikin MM, Alifian MD, Jayanegara A, Ramli N (2019) Optimization of the Hermetia illucens larvae extraction process with response surface modelling and its amino acid profile and antibacterial activity. IOP Conf Ser Mater Sci Eng 546:062030 4. Spranghers T, Ottoboni M, Klootwijk C, Ovyn A (2017) Nutritional composition of black soldier fly (Hermetia illucens) prepupae reared on different organic waste substrates. J Sci Food Agric 97:2594–2600 5. Tschirner M, Simon A (2015) Influence of different growing substrates and processing on the nutrient composition of black soldier fly larvae destined for animal feed. J Insects Food Feed 1(4):249–259 6. Sogari G, Amato M, Biasato I, Chiesa S, Gasco L (2019) The potential role of insects as feed: a multi-perspective review. Animals 9(119):15 7. Stamer A, Wesselss S, Neidigk R, Hoerstgen-Schwark G (2014) Black soldier fly (Hermetia illucens) larvae-meal as an example for a new feed ingredients’ class in aquaculture diets. In: Proceedings of the 4th ISOFAR Scientific Conf. «Building Organic Bridges» pp 1043–1046 8. Stadtlander T, Stamer A, Buser A, Wohlfahrt J, Leiber F, Sandrock C (2017) Hermetia illucens meal as fish meal replacement for rainbow trout on farm. J Insects Food Feed 3(3):165–175 9. Pieterse E, Erasmus SW, Uushona T, Hoffman LC (2019) Black soldier fly (Hermetia illucens) pre-pupae meal as a dietary protein source for broiler production ensures a tasty chicken with standard meat quality for every pot. J Sci Food Agric 99:893–903 10. Secci G, Bovera F, Nizza S, Baronti N, Gasco L, Conte G, Serra A, Bonelli A, Parisi G (2018) Quality of eggs from Lohmann Brown Classic laying hens fed black soldier fly meal as substitute for soya bean. Animal 12(10):2191–2197 11. Chia ShY, Tanga ChM, Osuga IM, Alaru AO, Mwangi DM, Githinji M, Subramanian S, Fiaboe KKM, Ekesi S, Loon JJA, Dicke M (2019) Effect of dietary replacement of fishmeal by insect meal on growth performance, blood profiles and economics of growing pigs in Kenya. Animals 9(705):19 12. Jucker C, Erba D, Leonardi MG, Lupi D, Savoldelli S (2017) Assessment of vegetable and fruit substrates as potential rearing media for Hermetia illucens (Diptera: Stratiomyidae) larvae. Environ Entomol 46(6):1415–1423 13. Meijer N, Stoopen G, Fels-Klerx HJ, Loon JJA, Carney J, Bosch G (2019) Aflatoxin B1 conversion by black soldier fly (Hermetia illucens) larval enzyme extracts. Toxins 11(9):11 14. Schrogel P, Watjen W (2019) Insects for food and feed-safety aspects related to mycotoxins and metals. Foods 8:28 15. Gao Q, Deng W, Gao Z, Li M, Liu W, Wang X, Zhu F (2019) Effect of sulfonamide pollution on the growth of manure management candidate Hermetia illucens. Pub Libr Sci 14(5):12 16. Diener S, Zurbrügg C, Tockner K (2015) Bioaccumulation of heavy metals in the black soldier fly, Hermetia illucens and effects on its life cycle. J Insects Food Feed 1(4):261–270 17. Park S, Yoe SM (2017) A novel cecropin-like peptide from black soldier fly, Hermetia illucens: isolation, structural and functional characterization. Entomol Res 47:115–124 18. Ali MF, Ohta T, Ido A, Miura C, Miura T (2019) The Dipterose of black soldier fly (Hermetia illucens) induces innate immune response through toll-like receptor pathway in mouse macrophage RAW264.7 cells. Biomolecules 9(677):15 19. Vogel H, Muller A, Heckel DG, Gutzeit H, Vilcinskas A (2018) Nutritional immunology: diversification and diet-dependent expression of antimicrobial peptides in the black soldier fly Hermetia illucens. Dev Comp Immunol 78:141–148 20. Choi W, Yun J, Chu J, Chu K (2012) Antibacterial effect of extracts of Hermetia illucens (diptera: stratiomyidae) larvae against Gram-negative bacteria. Entomological Res 42:219–226 21. Choi WH, Choi H, Goo TW, Quan F (2018) Novel antibacterial peptides induced by probiotics in Hermetia illucens (Diptera: Stratiomyidae) larvae. Entomol Res 48:237–247 22. Lee J, Kim Y, Park Y, Yang Y, Jung B (2018) Black soldier fly (Hermetia illucens) larvae enhances immune activities and increases survivability of broiler chicks against experimental infection of Salmonella Gallinarum. J Vet Med Sci 80(5):736–740 23. Joly G, Nikiema J (2019) Global experiences on waste processing with black soldier fly (Hermetia illucens): from technology to Business: research program on water, land and ecosystems CGIAR. Resour Recov Reuse Ser 16:66

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Mechanical-Empirical Model for Predicting the Faulting on Concrete Pavements A. A. Fotiadi , S. A. Gnezdilova , and V. V. Silkin

Abstract A special feature of road pavement with a concrete pavement is the presence of deformation joints. Over time, vertical displacements are observed in the compression joints, leading to the formation of faulting, which impairs the comfort and safety of movement on such pavements. This paper examines the reasons for the occurrence of faulting on concrete pavements. In order to develop a mechanical and empirical model for predicting faulting, full-scale surveys of existing concrete pavements were performed. The surveys allowed obtaining data on the actual values of the faulting in various conditions by climate and traffic composition. Based on the statistical analysis of the data and theoretical assumptions, a cumulative mechanicalempirical model was developed for predicting faulting over time, taking into account changes in the parameters of traffic intensity, as well as seasonal changes in climate parameters. The basis of the mechanical-empirical model for predicting faulting is proposed to use the energy spent on the deformation of the structure in the area of the transverse compression joint. The proposed mechanical-empirical model allows determining the size of the faulting in any period of time, depending on the design features of the road pavement, for example, such as the base material, the distance between the compression joints, the presence of bowel bar connections. Keywords Concrete pavement · Faulting · Joints · Dowel bar · Load

1 Introduction The main criterion for calculating road surfaces with a concrete pavement is the condition under which the strength, taking into account the fatigue of the material, should be greater than or equal to the total stress from the impact of the load and the stress from daily temperature fluctuations [1]. The structural feature of the concrete A. A. Fotiadi · V. V. Silkin Moscow Automobile and Road Construction State Technical University (MADI), Moscow, Russia S. A. Gnezdilova (B) Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russia © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. V. Klyuev and A. V. Klyuev (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1_50

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pavement is the presence of deformation joints. These joints have a great influence on the work of rigid pavement and during operation provide the ability of the pavement to deform without its destruction under the influence of seasonal temperature fluctuations [2]. However, the use of concrete as a pavement shows that during operation, vertical displacements of concrete slabs are formed on such surfaces relative to each other, that is, faulting are formed [3, 4]. This type of damage to the concrete pavement affects negatively the convenience and comfort of driving cars and, to the greatest extent, the longitudinal evenness of the pavement. In Russia, the size of the offset at the end of the service life of the concrete pavement should not exceed 3 mm. In order to study and control the process of formation of faulting on concrete pavements, road communities conduct scientific research to determine the causes of this phenomenon and create special models for their prediction over time [1, 5–8]. From the moment of the installation of the pavement of concrete, a gradual process of formation of faulting from the influence of air temperature and loads from passing cars begins. With significant traffic intensity and the presence of heavy trucks as part of the traffic flow, dowel bar connections are inserted into the body of the future joint when laying the pavement in the structure along the entire length of the joint, with a certain step between them. However, this only slows down the process of formation of faulting, but does not eliminate their occurrence. The inefficiency or inability of the dowel bar joints and the natural engagement of the material on the fracture surface of the crack to transfer the load from slab to slab leads to the accumulation of residual deformations in the layers of the road pavement bases. The material of the base layers plays a significant role not only in the accumulation of residual deformations, but also in the absence of a sealing material in the grooves of the deformation joints, it leads to the penetration of water into the seam zone and contributes to the gradual leaching of soil particles [9–11]. This manifests itself in the form of splashes of liquefied soil and base material through the seams and edges of concrete slabs (Fig. 1).

Fig. 1 Faulting on a concrete pavement

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2 Methods and Materials L.I. Goretsky, A.N. Zaschepin, G.Ya. Klyuchnikov, V.P. Nosov, M.S. Koganzon, V.K. Apestin and many others were engaged in research in the field of the state of concrete pavements and their performance. V.P. Nosov made a significant contribution to the prediction of damage to concrete pavements using mathematical modeling [1, 5]. We consider a section of concrete pavement in the joint area consisting of two adjacent slabs, one of which has a load P applied to it (Fig. 2). The load P causes the loaded edge of the slab to deflect in the Wload joint area. Also, the load P causes the deflection of the unloaded adjacent Wunload slab.This is achieved due to the natural engagement of the material on the fracture surface of the crack under the joint and the presence of dowel bar in the joints. The effect of temperature curling, depending on the time of day, will increase or decrease the total displacement, deflections of the edge sections of the slabs. In addition, the amount of deflections in the joint area will significantly depend on the width of the opening of the joints L. The energy expended on the deformation of the structure is defined as: E=

1 ·P·W 2

(1)

where P—load on the surface of the slab, MPa; W—slab deflection, mm. From the calculation of slabs on an elastic base according to the Fuss-Winkler model with the coefficient of subgrade reaction, we have: K =

P W

(2)

Fig. 2 Calculation scheme for determining the deflections of concrete slabs from the load and temperature curling

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where k− coefficient of subgrade reaction, MPa/cm; Substituting the formula (2) in the expression (1), we get: E=

1 · K · W2 2

(3)

The work of the concrete pavement in the joint zone is accompanied by mutual movements of adjacent slabs, which allows taking as the main criterion for determining the growth of faulting, the amount of energy spent on the mutual displacement of slabs in the cross-joint zone. Due to the fact that the loaded slab in the zone of the edge section involves and forces the adjacent slab to move, causing it to move, the expression for determining the amount of energy spent on deforming the structure will have the form: W =

1 1 2 2 · k · Wload. − · k · Wunload. 2 2

(4)

where Wload. —deflection of the loaded angle of the slab, cm; Wunload. —deflection of the unloaded corner of the slab, cm; k—coefficient of subgrade reaction, MPa/cm. As a result, taking into account the movements of the slabs from transport loads, horizontal movements and movements from temperature curling, the deformation energy in the cross-joint zone during each hour can be determined by the formula: E D =

A  i=1

Ni · (k ·

(Wunload. .PA ,L ± Wcurl.t )2 (Wload. .PA ,L ± Wcurl.t )2 −k· ) 2 2

(5)

where ED – hourly increment of the deformation energy in the zone of the transverse compression joint, J/cm2 ;Wload. —deflection of the loaded angle of the slab, cm; Wunload. —deflection of the unloaded corner of the slab, cm; Wcurl.t —deflection of the slab angle from temperature curling for hour t, cm; km —coefficient of subgrade reaction for the month M, MPa/cm; A– the number of considered groups of cars in the traffic; Ni —the number of axial impacts of cars A per hour; PA —design load for group A, kN; L—width of opening of the compression joint, mm.

3 Results and Discussions Using formula 5, for a highway located in Moscow with a service life of 20 years, the dependence of the energy spent on the deformation of the structure in the zone of transverse compression joints was obtained as a function of the response time of the joint, that is, the formation of a technological crack under the cut joint groove. Most often, a technological crack is formed immediately after cutting the joint groove, but it should be noted that the process of building a concrete pavement lasts for several months during the construction season. This relationship explains well the different

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500 400 300 200 100 0 January February March April May June July August September October November December January February March April May June July August September October November December

Deformation energy, J/cm2

values of the faulting found on the concrete pavement, even with a uniform quality of construction within a small section of the highway, on which the same number of cars moved over a certain period of time. Thus, the size of the faulting is a random value, which is also subject to random processes occurring in nature. The intensity of the formation of the offset in each specific compression joint will depend on the time at which the compression joint will be triggered, and how the temperature of the concrete slab will change during its operation (Fig. 3). To create a model for predicting faulting, work was carried out on the survey of existing roads with concrete pavements located in Moscow, Kaluga, Vologda regions and the Krasnodar Territory. Figure 4 shows a histogram of the distribution of faulting on the Moscow-Kiev highway—r.st. Zikeevo-Polyudovo.

Months

May

Аugust

Оctober

Relative frequency, %

Fig. 3 The deformation energy of the structure in the zone of the transverse compression joint, depending on the month of its operation

20 15 10 5 0 0-1

1-2

2-3

3-4

4-5

5-6

6-7

Faulting, mm

7-8

8-9

9-10 10-11 11-12 12-13

Fig. 4 Histogram of the distribution of faulting on the highway “Moscow-Kiev”—ZikeevoPolyudovo station

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Fig. 5 Influence of dowel bar in joints on the intensity of faulting

4 Conclusion Based on the large array of statistical data obtained during the survey, calibration parameters were determined for various functions of the distribution of the values of the faulting. Figure 5 shows the dependence of the influence of dowel bars in compression joints on the intensity of the formation of faulting, with a small diameter of dowel bars equal to 18 mm. The developed mechanical-empirical model for predicting faulting in time based on the strain energy in the zone of transverse compression joints refers to interval, cumulative models, where the prediction period is represented as the sum of time intervals. In this case, the time interval is adopted in such a way that it can be assumed that within this interval, the main influencing factors that depend on time would not change significantly. One hour is taken as such an interval, taking into account the significant changes in the temperature of the slab and the intensity of movement during the day [6]. h f aulting (T ) = [A ·

T  12  30  24 

E D (H ) + B] · T

(6)

Y =1 M=1 D=1 H =1

where hfaulting —faulting height, mm; A, B—calibration parameters; Y—year; M—month; D—day; H—hour; T—predicting period. The parameters A and B for the graphs shown in Fig. 7 are A = 0.00004 B = 0.04348. The use of a mechanical-empirical model for predicting the faulting of concrete pavements will allow determining the parameters of the structure with less intensive formation of faulting during the design service life of the road pavement at the stage of designing road pavement. Acknowledgements This work was realized in the framework of the Program of flagship university development on the base of the Belgorod State Technological University named after V.G.Shukhov,

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using equipment of High Technology Center at BSTU named after V.G.Shukhov, and on the base of the Moscow Automobile and Road Construction State Technical University (MADI).

References 1. Nosov V (2013) Concrete road pavement. Damage prediction based on mathematical modeling. Moscow Automobile and road construction state technical university Press, Moscow (2013) 2. Fotiadi A (2013) The main areas of research in the field of concrete pavement and ways to solve them. Constr Equip Technol 6:92–95 3. Nosov V, Fotiadi A (2008) Reasons for the formation of faulting on concrete road pavement. Sci Technol Road Ind 3:20–22 4. Caltrans (2006) Maintenance Technical Advisory Guide – Rigid Pavements 217 5. Nosov V, Dobrov E, Chistyakov I, Borisiuk N, Fotiadi A (2017) Mathematical modelling of cracking process in concrete pavement highways. Int J Appl Eng Res 12(23):13158–13164 6. Fotiadi A, Gnezdilova S, Strekha I (2020) Remote method for predicting damage to cement concrete pavements. Lecture notes in civil engineering, no 95, pp 333–339 7. Nosov V, Gnezdilova S (2010) Taking in to account the regional natural features while calculating the characteristics of soils for pavements design. Bulletin of BSTU named after V.G. Shukhov (1):18–22 8. Morosiuk, G.: HDM-4. Modelling road deterioration and works effects. Designer’s Guide. Birmingham (2001) 9. Radovsky B (2015) Cement concrete pavements in the USA - structures. Car roads 2:48–60 10. Farooq A, Lechner B, Khan Y, Schmerback R (2015) Effect of changing support conditions by erosive attacks in jointed plain concrete pavements. IJEDR 3(4):157–174 11. Caltrans A (2014) Highway Design Manuel 7(765)

Author Index

A Abdullaev, A. R., 37 Afonin, V. I., 117 Akishev, U. K., 169 Al Shemali, Ali, 1 Annenko, D. M., 31 Apachanov, A. S., 253 Ariskin, M. V., 261 B Babkin, M. S., 131 Badalyan, N. P., 117 Balamirzoev, A. G., 37 Bardin, I. N., 109 Baygazy kyzy, N., 347 Belyaev, D. A., 161 Breslavceva, I. V., 153 Buldyzhova, E. N., 183 Buryanov, A. F., 183 C Chashchina, E. E., 117 Chernikova, I. S., 175 Chernositova, E. S., 45 Chernova, T. P., 101 Chernysheva, N. V., 23 Chetverikov, B. S., 31, 67, 131 Chumanov, A. V., 245 D Degtev, I. A., 207 Denisova, J. V., 45, 207 Denisova, L. V., 15, 147, 269, 317 Dmitrienko, V. G., 191

Donchenko, O. M., 207 Drebezgova, M. Yu., 23 Dryakhlov, V. O., 15 Duhanin, S. A., 139 Dukhanin, S A., 277 E Elistratkin, M. Yu., 237 Evstratov, V. A., 153, 253 Ezhova, O. N., 307 F Fadin, Yu. M., 333 Fatyunina, M. V., 325 Fedorov, P. Yu., 215, 357 Filippov, V. V., 101 Fomina, E. V., 299, 373 Fotiadi, A. A., 381 G Gaev, A. Ya., 325 Galtseva, N. A., 183 Glagolev, E. S., 23 Gnezdilova, S. A., 381 Gorodov, A. I., 51 Grigoryev, V. I., 253 Guschin, I. A., 307 I Inozemtcev, S. S., 59 K Kalinina, A. A., 229 Karimov, T. Kh., 347

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. Klyuev et al. (eds.), Environmental and Construction Engineering: Reality and the Future, Lecture Notes in Civil Engineering 160, https://doi.org/10.1007/978-3-030-75182-1

389

390 Karimova, M. T., 347 Karnauhov, A. A., 51 Komlev, A. A., 341 Korchagin, P. A., 341 Kosogov, I. V., 229 Kovalev, S. V., 93 Kozyukova, N. V., 169 Kuatbayeva, T. K., 169, 285 Kudelina, I. V., 325 L Labudin, B. V., 101 Leontyeva, T. V., 325 Lesovik, V. S., 237 Linnik, V. Yu., 153 Loktionova, E. V., 317 Lubimyi, N. S., 31, 67, 139 Lyapin, D. M., 109 Lymar, I. A., 67, 139 M Makeev, S. A., 341 Makridina, Yu. L., 269, 317 Maslakova, G. V., 117 Melekhov, V. I., 101 Mikhailova, O. P., 83 Mishin, D. A., 93 Morozov, I. V., 183 Motorykin, D. A., 23 N Nazarova, N. P., 83 O Osmonov, Zh. I., 347

Author Index S Salnikova, A. S., 237 Sapronova, Zh. A., 147, 373 Sarsenbayev, B. K., 285 Savelyev, S. V., 341 Selimkhanov, D. N., 37 Semikopenko, I. A., 161 Shaikhiev, I. G., 15, 299, 373 Sharapov, R. R., 125 Shein, A. I., 245 Shemetov, E. G., 191, 333 Shemetova, O. M., 191, 333 Silkin, V. V., 381 Sirota, V. V., 223 Sizov, P. P., 261 Slavkova, N. N., 131 Smal, D. V., 93 Sokolov, N. S., 215, 293, 357 Sopilov, V. V., 109 Starostina, I. V., 269, 317 Sverguzova, S. V., 15, 299, 373 Svyatchenko, A. V., 147, 299 T Tarasenko, V. N., 75, 207 Tikhonov, A. A., 31, 67, 139 Toan, D. T., 59 Tsaritova, N. G., 229 Tumasov, A. A., 229 U Unkovskiy, A. N., 131 V Volodchenko, A. A., 9 Voronov, V. P., 191, 333 Voronova, E. Yu., 153, 253

P Polovneva, D. O., 269 Popov, E. V., 109 Pospelova, E. A., 175, 237 Prokhorenkov, D. S., 223 Prokopenko, V. S., 125

Y Yakubovich, A. N., 199 Yakubovich, I. A., 199 Yastrebinskaya, A. V., 51 Yastrebinsky, R. N., 51, 223

R Rakhimbaev, Sh. M., 175 Romanovich, A. A., 277 Romanovich, M. A., 277

Z Zaitsev, S. V., 223 Zakeri, Amirhadi, 277 Zhambakina, Z. M., 169, 285