Recycling of Building Materials: Generation - Processing - Utilization 3658346086, 9783658346089

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Anette Müller · Isabel Martins

Recycling of Building Materials Generation – Processing – Utilization

Recycling of Building Materials

Anette Müller · Isabel Martins

Recycling of Building Materials Generation – Processing – Utilization

Anette Müller Weimar, Germany

Isabel Martins Lisboa, Portugal

ISBN 978-3-658-34608-9 ISBN 978-3-658-34609-6  (eBook) https://doi.org/10.1007/978-3-658-34609-6 Translated and expanded version from the German language edition: Baustoffrecycling by Anette Müller © Springer Fachmedien Wiesbaden 2018. Published by Springer Fachmedien Wiesbaden. All Rights Reserved. © Springer Fachmedien Wiesbaden GmbH, part of Springer Nature 2022 This work is subject to copyright. All rights are reserved 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. Responsible Editor: Frieder Kumm This Springer Vieweg imprint is published by the registered company Springer Fachmedien Wiesbaden GmbH part of Springer Nature. The registered company address is: Abraham-Lincoln-Str. 46, 65189 Wiesbaden, Germany

Preface

The term “sustainability” is the key word for the responsible handling of the environment. For the construction sector, this means, among other things, the consistent implementation of material cycles. The immediate goal is to reduce the volume of waste while at the same time conserving increasingly scarce resources. Compared with the energy sector, there is still a lot to be done here – starting with the clear definition of certain terms and key figures, through the clear formulation of objectives and requirements, to the development of the necessary technologies and products from recycled materials. In addition, the corresponding contents must be established in the engineering education. In this context, "recycling science" could be interpreted as an extension of building materials science or as a sub-field of process engineering. It would also be possible to assign it to waste or resource management. However, such a division does not do justice to the complex tasks to be solved. Only if – as in this book – all three contents are treated in context interrelationships can really be recognized and a useful basis created for students, engineers and players in the recycling industry. Perhaps this approach can also help to overcome, or at least question, the way of looking at recycled building materials, which has been focused on the pollutant aspect for decades. The starting point of this book were the scripts of my lectures on building materials recycling, which I held at the Bauhaus-University Weimar. I also used the scripts created during my stays at the University of Illinois in Urbana-Champaign and the Universidade de Sao Paulo. The results of research projects and master's theses written by my students served as additional sources. I have also included the initially still rare technical literature, which I have supplemented with current material. Compared to the 1990s, the number of publications on the recycling of building materials has grown exponentially in recent years. Some of these has significant contribute to the increase of knowledge and are incorporated into the English version. The contact with representatives of the recycling industry was also always important to me. Plant visits and discussions often made the challenges of recycling more clear to me as considerations at my desk. Writing a book in one's mother tongue is already a challenge. Of course, this is much more true for a book in a foreign language. But I was happy to take on this challenge because I expect that it will significantly increase the reach of my book. I was supported v

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Preface

in this by my colleague Isabel Martins from Portugal, who critically reviewed and supplemented the manuscript. Regarding the collaboration, she expressed that it was a very fruitful experience resulting in this successful outcome and an asset to boost the market for secondary raw materials in the construction. Thank you Isabel! Mrs. Margaret-Ann Schellenberg helped me with the correction of the English text. I would also like to thank her for the always speedy correction of the texts. I hope that the book will find a wide, critical readership. If it helps to achieve better products and higher recovery rates in building materials recycling, its purpose would be more than fulfilled. Anette Müller

Contents

1

Material Cycles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Examples from the Natural Environment . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Developments and Drivers of Recycling. . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Typification of Material Cycles in the Construction Industry. . . . . . . . . 10 1.4 Material Balance and Anthropogenic Building Material Stock. . . . . . . . 14 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2

Material Flow Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.1 Basic Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.2 Classification of Construction and Demolition Waste. . . . . . . . . . . . . . . 26 2.3 Construction- Specific Key Figures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2.3.1 Quantities and Types of Waste Generated During the Construction and Renovation of Structures. . . . . . . . . . . . . . . . 31 2.3.2 Quantities and Types of Waste from Demolition and Dismantling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2.4 Waste Management Key Figures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

3

Regulations for the Handling of Construction and Demolition Waste. . . . . 51 3.1 Legal Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.2 Environmental Regulations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.3 Building Regulations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

4

Processing of Construction and Demolition Waste . . . . . . . . . . . . . . . . . . . . 65 4.1 Size Reduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.1.1 Basic Concepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.1.2 Performance of Crushers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 4.1.3 Effects of Comminution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

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4.2 Screening. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4.2.1 Basic Concepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4.2.2 Types of Screening Machines . . . . . . . . . . . . . . . . . . . . . . . . . . 94 4.2.3 Selection of the Suitable Screening Machine . . . . . . . . . . . . . . 98 4.3 Sorting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 4.3.1 Basic Concepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 4.3.2 Dry Sorting Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 4.3.3 Wet Sorting Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 4.3.4 Sorting Methods for Ferrous and Non-Ferrous Metals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 5

Plants for the Treatment of Construction and Demolition Waste . . . . . . . . 127 5.1 Overview of System Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 5.2 Building Rubble Treatment Plants in Germany. . . . . . . . . . . . . . . . . . . . 130 5.2.1 Stationary Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 5.2.2 Mobile Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

6

Recycling of Reclaimed Asphalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 6.1 Basic Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 6.2 Statistics on Consumption of Primary Material and Waste Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 6.3 Properties of Reclaimed Asphalt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 6.4 Recycling Technologies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 6.4.1 Recycling in Place. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 6.4.2 Recycling in Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 6.4.3 Recycling of Materials Containing Tar Pitch. . . . . . . . . . . . . . . 170 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

7

Recycling of Concrete Rubble. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 7.1 Basic Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 7.2 Developments, Produced Quantities and Existing Stock. . . . . . . . . . . . . 178 7.3 Specific Properties of Recyclates and Recycled Concretes. . . . . . . . . . . 182 7.3.1 Heterogeneity of Recycled Aggregates. . . . . . . . . . . . . . . . . . . 182 7.3.2 Reaction Potential of Recycled Aggregates. . . . . . . . . . . . . . . . 185 7.3.3 Concretes from Recycled Aggregates as Composites. . . . . . . . 188 7.4 Properties of Recycled Aggregates of Concrete Rubble . . . . . . . . . . . . . 194 7.5 Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 7.5.1 Utilization in Earthworks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 7.5.2 Utilization in Road Construction. . . . . . . . . . . . . . . . . . . . . . . . 209 7.5.3 Utilization as Aggregate for the Production of Concrete. . . . . . 214 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228

Contents

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8

Recycling of Masonry Rubble. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 8.1 Basic Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 8.2 Developments, Produced Quantities and Existing Stock. . . . . . . . . . . . . 239 8.3 Features of Masonry Building Materials. . . . . . . . . . . . . . . . . . . . . . . . . 242 8.3.1 Typology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 8.3.2 Properties of Unmixed Components of Masonry Rubble . . . . . 245 8.4 Properties of Recycled Building Materials from Masonry Rubble. . . . . 250 8.5 Utilization of the Pure Components of Masonry Rubble. . . . . . . . . . . . . 254 8.5.1 Pure Clay Brick Aggregates. . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 8.5.2 Pure Aggregates of Calcium Silica Bricks. . . . . . . . . . . . . . . . . 263 8.5.3 Pure Aggregates of Aerated Autoclaved Concrete. . . . . . . . . . . 266 8.5.4 Pure Aggregates of Lightweight Concrete. . . . . . . . . . . . . . . . . 268 8.6 Application of Mixed Masonry Rubble. . . . . . . . . . . . . . . . . . . . . . . . . . 270 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271

9

Recycling of Other Types of Construction Waste . . . . . . . . . . . . . . . . . . . . . 277 9.1 Track Ballast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 9.1.1 Characteristics of Primary Material and Waste. . . . . . . . . . . . . 277 9.1.2 Recycling Technologies and Products. . . . . . . . . . . . . . . . . . . . 279 9.2 Gypsum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 9.2.1 Characteristics of Primary Material and Waste. . . . . . . . . . . . . 283 9.2.2 Recycling Technologies and Products. . . . . . . . . . . . . . . . . . . . 287 9.2.3 Downcycling of Gypsum Waste. . . . . . . . . . . . . . . . . . . . . . . . . 289 9.3 Fiber Cement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 9.3.1 Characteristics of Primary Material and Waste. . . . . . . . . . . . . 290 9.3.2 Recycling Technologies and Products. . . . . . . . . . . . . . . . . . . . 292 9.4 Mineral Wool. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 9.4.1 Characteristics of Primary Material and Waste. . . . . . . . . . . . . 293 9.4.2 Recycling Technologies and Products. . . . . . . . . . . . . . . . . . . . 297 9.5 Glass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 9.5.1 Characteristics of Primary Material and Waste. . . . . . . . . . . . . 299 9.5.2 Recycling Technologies and Products. . . . . . . . . . . . . . . . . . . . 301 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305

10 Advanced Recycling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 10.1 Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 10.1.1 Comminution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 10.1.2 Sorting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 10.1.3 Plant Concepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 10.2 Raw Material Recycling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345

About the authors

Professor Dr.-Ing. habil. Anette Müller’s  professional roots go back to her diploma in building materials engineering at the the University of Architecture and Civil Engineering Weimar (now Bauhaus-University of Weimar). This was followed by the doctorate and the habilitation in the field of chemistry and engineering of cement as a result of her many years of research in this sector. From 1995 to 2011, she held the professorship “Processing of Building Materials and Recycling” at the Bauhaus-University in Weimar. Visiting professorships took her to the University of Illinois in Urbana Champaign and at the Universidade de Sao Paulo. Since April 2011 she has been an employee of the IAB – Institut für Angewandte Bauforschung Weimar gGmbH with the vision to bring the recycling of building materials in practice. Dr Isabel Martins graduated in Chemical Engineering Applied Chemistry at Instituto Superior Técnico of Universidade Técnica de Lisboa, Portugal, and completed her PhD on Valorisation of wastes in cementitious based building materials: environmental assessment and contaminants release mechanisms at the University of Leeds, United Kingdom. Dr Isabel Martins is a Researcher of Laboratório Nacional de Engenharia Civil developing activity centred in cementitious building materials at the Concrete, Stone and Ceramics Unit. For the last 15 years have been focused on the reuse of materials and waste recycling aiming their secondary use to improve circularity in the construction sector. Furthermore, the long term performance of materials in the built environment and their mechanisms of degradation, along with the development of sustainable binders, are relevant areas of interest. xi

List of Figures

Fig. 1.1 Fig. 1.2 Fig. 1.3

Fig. 1.4 Fig. 1.5

Fig. 1.6 Fig. 2.1 Fig. 2.2

Fig. 2.3 Fig. 2.4 Fig. 2.5 Fig. 2.6 Fig. 2.7 Fig. 2.8 Fig. 2.9

Material cycle in the lithosphere [1] . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Scheme of a rubble processing plant in Germany after the Second World War [6]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Concretes with crushed bricks as aggregates taken from a building constructed in the 1950s (Image source: Sylvia Stuermer, Vanessa Milkner, HTWG Konstanz). . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Comparison of building construction without and with recycling of building materials [11] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Simplified cost comparison of traditional demolition and construction of a building with linked demolition, processing of building rubble and construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Material balance of the building material cycle in Germany for 2014. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Selective deconstruction of a residential building and the components that have to be dismantled [1]. . . . . . . . . . . . . . . . . . . . . . 22 Material separation during selective demolition (top) and examples of components separated by mechanical sorting on-site (bottom). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Examples of small parts after crushing of concrete rubble. . . . . . . . . . 24 Definitions of harmful substances and impurities in construction and demolition waste. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Example for the calculation of the gross volume of a building and supplements for the enclosed space . . . . . . . . . . . . . . . . . . . . . . . . 25 Correlation between the gross floor area and the gross volume (Data from [5, 6]). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Number codes of the European List of Waste. . . . . . . . . . . . . . . . . . . . 27 Building rubble: Concrete (top) and masonry (bottom) . . . . . . . . . . . . 28 Construction site waste from construction (top) or renovation (bottom). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

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xiv

Fig. 2.10 Fig. 2.11

Fig. 2.12 Fig. 2.13 Fig. 2.14 Fig. 2.15

Fig. 2.16 Fig. 2.17 Fig. 2.18 Fig. 2.19 Fig. 2.20

Fig. 2.21

Fig. 3.1

Fig. 3.2

Fig. 4.1

Fig. 4.2

List of Figures

Material types and their assignment to LoW codes using the example of a hypothetical average building (Adapted from [8]). . . . . . 29 Dependence of the volumes of construction site waste generated during the construction of buildings on the size of the building (Data from [9], comparative data from [10]). . . . . . . . . . . . . . . . . . . . . 32 Composition of waste generated during construction and renovation (Data from [9, 11–25]). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Comparison of the mass and the volume composition of construction site waste. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Influence of the building size on the building material volume with various examples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Dependence of the specific building rubble quantity on building size for residential buildings (Data from [6, 26–42], comparative data from [10, 48]). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Dependence of the specific building rubble quantity on building size for industrial buildings (Data from [29, 43–47]). . . . . . . . . . . . . . . . . . 38 Dependence of the specific quantity of building rubble on the structure of the building [35] . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Time series on waste generation in Germany, broken down by type of waste (Data from [49, 50]). . . . . . . . . . . . . . . . . . . . . . . . . . 40 Recycling rates of the different types of construction and demolition waste in Germany. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Per capita mass of construction and demolition waste excluding excavated soil in European countries for 2004 resp. as the average value for 2010 to 2016 (Data from [53–55]). . . . . . . . . . . . . . . . . . . . . 45 Dependence between population density and amount of construction and demolition waste per capita on an European scale and beyond (Data from [48, 53–57]) . . . . . . . . . . . . . . . . . . . . . . 46 Procedure for eluate recovery from recycled building materials: Shaking batch test (top) as a static procedure, column percolation (bottom) as a dynamic test (Adapted from [8]) . . . . . . . . . 57 Simplified illustration of the influences on the release of pollutants from recycled building materials and on the transport of pollutants up to the point of entry into groundwater . . . . . . . . . . . . . . . . . . . . . . . 58 Simplified process flow diagrams of a mobile treatment plant for mineral construction and demolition waste (left) and a stationary treatment plant (right). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Rest of a reinforced concrete chimney block with crushed concrete and deformed reinforcing steel. . . . . . . . . . . . . . . . . . . . . . . . 69

List of Figures

Fig. 4.3

Fig. 4.4 Fig. 4.5

Fig. 4.6 Fig. 4.7

Fig. 4.8

Fig. 4.9 Fig. 4.10 Fig. 4.11 Fig. 4.12 Fig. 4.13

Fig. 4.14 Fig. 4.15 Fig. 4.16 Fig. 4.17 Fig. 4.18

Fig. 4.19

Fig. 4.20

xv

Fracture pattern after an impact loading of a glass or a concrete ball. (Left: Schematic fracture pattern of a glass sphere (Adapted from [2]); Middle: Fracture pattern of a concrete ball at a loading speed of 15 m/s; Right: Simulation of the crushing of the concrete ball (Adapted from [3])). . . . . . . . . . . . . . . . . . . . . . . . 70 Proportions of particles of different sizes produced by the impact comminution of a 150 mm concrete sphere [4]. . . . . . . . . . . . . . . . . . . 70 Cumulative distribution curve or screen passing curve (left) and relative frequencies of particle fractions (right) of a recycled building material 0/45 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Energy flow chain for coarse crushing. . . . . . . . . . . . . . . . . . . . . . . . . . 74 Increase in surface energy as a function of the kinetic energy of the impact tests with concrete spheres according to the diagram shown on the left [4] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Specific technical crushing work required for coarse crushing as a function of the product particle size at a screen passing of 80 mass-%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Schematic of a single-toggle jaw crusher . . . . . . . . . . . . . . . . . . . . . . . 77 Schematic of an impact crusher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Geometry of a jaw crusher feed and discharge opening . . . . . . . . . . . . 79 Relationship between the gap and the area of the jaw crusher feed opening (Data from [5]). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Throughput, drive power demand and crusher mass for jaw crushers (left) and impact crushers (right) depending on the feed opening (Data from [5]). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Schematic (left) and feed opening of an impact roll crusher (right). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Schematics of a cone crusher (left) and a rotor granulator (right). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Feed material concrete rubble (left) and produced recycled aggregates 0/45 mm (right). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Screen passing curves of recycled aggregates and calculated GGS distribution functions (Data from quality control protocols). . . . 85 Influence of the particle density of the feed material on the crushing ratio achieved during crushing in the jaw crusher (Data from [9, 10]). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Influence of the content of bricks in the feed material on the content of the fraction  2 mm for concrete production [89]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 Formulations and properties of concretes with recycled aggregates used in selected projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 Loss on ignition and oxide composition of pure masonry blocks (Data from [4–15], unpublished data). . . . . . . . . . . . . . . . . . . . . . . . . . 246 Absolute powder density, particle density and calculated particle porosity of pure masonry blocks (Data from [5, 13, 15–18], unpublished data). . . . . . . . . . . . . . . . . . . . 247 Loss on ignition and oxide composition of recycled aggregates of masonry rubble (Data from [5, 14], unpublished data). . . . . . . . . . . 251 Absolute powder density, particle density and calculated particle porosity of recycled aggregates of masonry rubble (Unpublished data) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 Guide values for the specific material consumption for mineral surfaces or vegetation applications at a bulk density of 1200 kg/m3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 Quality parameters for clay brick residues for the production of new clay brick [46, 47]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 Quality parameters for residues of calcium silica brick for the production of new calcium silica brick [60] . . . . . . . . . . . . . . . 265 Overview of impurities and contaminations of used track ballast . . . . 278 Mineral phases and modifications in system CaSO4–H2O. . . . . . . . . . 283 Quality parameters for recycled gypsum [14, 15]. . . . . . . . . . . . . . . . . 289 Oxide composition and loss on ignition (LOI) of pure fiber cements [21]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292

xxx

Table 9.5 Table 9.6 Table 9.7

List of Tables

Physical parameters of fiber cement particles [22]. . . . . . . . . . . . . . . . 292 Oxide composition of pure rock and glass wool [23–28]. . . . . . . . . . . 294 Selected maximum foreign and off-color components as quality parameters for glass recyclates [36]. . . . . . . . . . . . . . . . . . . 303 Table 9.8 Important physical parameters of foam glass and expanded glass. . . . 305 Table 10.1 Comparison of different processing methods for the production of recycled aggregates with low content of hardened cement paste [42]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Table 10.2 Sensor technology, separation characteristics and application areas for sensor-based sorting [44]. . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 Table 10.3 Degree of hydration of cements containing brick powder. (Adapted from [72]) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335

1

Material Cycles

1.1 Examples from the Natural Environment Material cycles are essential to maintain the stable state of nature. The chemical elements circulate in different binding forms and aggregate states between the different reservoirs of the biosphere, hydrosphere, lithosphere, pedosphere and atmosphere, thus ensuring stability and compensating for changes over longer periods of time. The cycles of matter fundamentally important for life on earth are the cycles of the elements carbon, oxygen, nitrogen, phosphorus and sulphur, as well as the hydrological cycle. Presently, there is an increasing effort to quantitatively record the material flows and to describe their interactions, resulting in an improvement in knowledge about the processes taking place. The aim is to create model concepts and to identify influencing variables in order to be able to forecast the future developments and to derive control mechanisms. The category of natural material cycles includes the rock cycle (Fig. 1.1), in which new formations, transformations or dissolutions of rocks occur as a result of physical and chemical processes. Although this cycle moves in completely different temporal and spatial dimensions, certain conclusions can be applied to cycles of mineral wastes such as construction and demolition waste. Erosion and weathering can be regarded as stress during the use of buildings and also as demolition and mechanical processing at the end of use. Sedimentation represents the recovery of mineral material in bound or unbound form. Up to this stage, recycling of construction waste as recycled aggregates for pavement base layers or for concrete production is carried out today. Only when – triggered by increased temperatures and/or pressures – the structure of the rocks is progressively dissolved up to complete melting, new rocks with completely altered mineral composition and physical properties can form. This stage of return to the material cycle has so far only been achieved for certain mineral wastes such as waste glass.

© Springer Fachmedien Wiesbaden GmbH, part of Springer Nature 2022 A. Müller and I. Martins, Recycling of Building Materials, https://doi.org/10.1007/978-3-658-34609-6_1

1

2

1  Material Cycles

Weathering and erosion Deposition on land or sea

SEDIMENT

Uplift

Uplift

Uplift

IGNEOUS ROCK

Burial, compaction, cementation

SEDIMENTARY ROCK

Temperature, pressure

Heat, pressure

METAMORPHIC ROCK

Cooling Melting MAGMA

Fig. 1.1  Material cycle in the lithosphere [1]

As a result of the intensification and rise of industrial as well as agricultural activities and the growth of the world population, there is an increased human impact on natural material cycles. The best-known example is the human influence on the carbon cycle, in which the state of equilibrium is increasingly being shaken by the combustion of fossil fuels, deforestation, land use and other influences with the consequence of increasing CO2 emissions in the atmosphere. In order to reduce the interference in the natural material cycles, “saving strategies” can be applied; for example, by effectively reducing consumption or by dematerialization. Another way is through the establishment of closed material cycles in the technosphere. However, it should be mentioned that the creation of such closed material cycles is only at the beginning stage, even though the term “recycling” is a word frequently used. In Germany, for example, the construction sector is faced with an annual extraction of sand, gravel, natural stone and other mineral raw materials of around 500 million tons, with a recycling of 60 to 70 million tons of construction and demolition waste processed into recycled construction materials. So the substituted amount of natural raw materials is between 10 and 15%. Primary raw materials are therefore still required in considerable

1.2  Developments and Drivers of Recycling

3

quantities. Higher recycling rates occur for materials such as glass, paper and metals. On the one hand, this is technologically justified because the recycling technologies for these materials involve a melting or a suspension process, completely dissolving the original structure. The properties of the resulting product are only slightly influenced by the source material. On the other hand, at least for metals, the high price, as well as the energy savings achieved in metal production from scrap instead of ore, are the decisive factors for the recycling of these materials.

1.2 Developments and Drivers of Recycling Recycling as the return of used products and materials into the material cycle is not a phenomenon of our time. Collecting and recycling materials such as scrap metal, rags, clothing, paper, bones and ashes has been a common practice since the late Middle Ages. Reith [2], for example, reports on the recycling of rags used in paper production: “In the early modern period, rag collecting districts were already formed on the basis of official privileges. The instrument of the export ban was also used, and ‘rag smuggling’ signals this was a scarce good”. As a result of technological developments, rags were no longer needed in paper production from the end of the nineteenth century onwards, so that this material cycle disappeared. In addition to such technical reasons, the level of economic development and the social environment also determine the development and the disappearance of material cycles. In terms of economic development, material cycles can in some way be regarded as “shortage indicators". According to Reith, in the Federal Republic of Germany, scrap metal, rags and paper could be sold for profit in the scrap trade until the 1960s. Later this was no longer possible, which brought collecting to a standstill. In the German Democratic Republic, collected waste materials were also remunerated. In developing and emerging countries, entire families still live from searching waste for recyclable components. There is currently a renaissance in the collection of waste materials, such as plastics, metals and composites, which are now called recyclables. Waste paper and waste glass are important raw materials from which profits can once again be made. With regard to the recycling of building materials, most of the surviving structures from antiquity to the Middle Ages can be proven to have incorporated the material of older buildings. Only after the industrial revolution made the mass production of building materials possible did recycling lose its significance and was only necessary in crisis situations when the need for building materials could not be met by other means. The most frequently cited example is the recycling in large German cities after the Second World War. Large quantities of rubble, consisting mainly of bricks, had to be processed. Three recycling methods were preferred:

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1  Material Cycles

• The undamaged bricks were sorted and cleaned so that they could be reused as wallbuilding material. The cleaning was carried out manually by women or by machine, for which, for example, a type of thickness planer was used. • Damaged bricks were processed into brick chippings and used as aggregate in crushed-brick concrete. Their production and use were subject to a standard [3]. Conflicting statements were made regarding the serviceability of such concretes. On the one hand, there are reports of damage when such crushed-brick concrete was used, even the collapse of an eight-story building. The cause was the insufficient and uneven compaction of the concrete [4]. On the other hand, buildings from the postwar period, which are still used today without restrictions, prove the durability of crushed-brick concrete [5]. • Mixed rubble was used for things like fillings and backfillings. In cities with a rather flat terrain such as Cologne or Berlin, hills were created that still exist today as part of park areas. An example of a technological solution going beyond these methods was the complex processing and recycling plant operated by the “Trümmer-Verwertungs-Gesellschaft” in Frankfurt/Main from 1945 to 1964 [6]. The coarse rubble was sorted by hand, crushed in several stages, classified into fractions and then used for the production of concrete products. The unsortable, fine debris was processed as raw material in an induced draught sintering plant (Fig. 1.2). The feed material consisted of the debris fraction  1500  kg/m3

 > 2000  kg/m3

 > 2400  kg/m3

Water absorption

  150  kg/m2. The maintenance requirements are similar to those of plantings on grown soil. For field applications, a compromise must be found between the load-bearing capacity of the layers applied and the vegetation requirements. Despite the necessary porosity, which ensures the air and water balance important for the plant growth, sufficient particle strength must be guaranteed so that no deformation occurs under the defined traffic loads. The entire mixture of aggregates produced during comminution can be used, although certain particle size distributions and restrictions on proportions 150 kg/m2

Single layer, low loads, 200 mm layer thickness

240 kg/m2

Double layer, high loads, 400 mm layer thickness

480 kg/m2

Tree pit with 20 m3 root space

2.4 t

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8  Recycling of Masonry Rubble

material composition is thus no longer necessary. The precautionary, complete exclusion of bricks as components of the aggregates in layers of road construction resulting from this uncertainty is circumvented. On a test section containing recycled building materials with graded brick contents of up to 40 mass-% in the frost protection layer and in the base course, it was determined that the bearing capacity and particle refinement were not critical [35, 36]. However, the moisture content of the frost protection layer increased with the increase of the brick content, if a corresponding water supply was available. This can result in uplifts. It is proposed to produce the lower part of the frost protection layer from natural aggregates in order to prevent the recycled aggregates placed on top of it from getting wet. Use as a component of recycled aggregates for the production of concrete Aggregates made from processed, sorted bricks are suitable for the production of concrete. The lower particle densities compared to natural aggregates cause a decrease in strength with an increasing proportion of recycled bricks (Fig. 8.19). If more than 20 mass-% of the natural aggregates are replaced by recycled bricks, the decrease in strength is greater than when using recycled concrete aggregates. With lower proportions, sometimes strengths result which are higher than those of concrete with recycled concrete aggregates. The cause can be the pozzolanicity of the bricks, which compensates for the decrease in strength due to the lower particle density. Regardless of the decrease in strength, brick aggregates can be used for the production of structural concrete. According to the current regulations, type 2 recycled

Fig. 8.19  Related 28-day strength of concretes in dependence of the proportion of recycled clay brick aggregates (Data from [13, 37–42])

8.5  Utilization of the Pure Components of Masonry Rubble

259

aggregates, known as mixed recycled aggregates, may contain up to 30 mass-% of wall building materials made of burnt clay, calcium silica aggregates brick and non-floating aerated autoclaved concrete. The addition of the type 2 aggregates in concrete is limited to 35 vol.-%. The total aggregate then contains about 10 vol.-% clay brick, calcium silica brick or aerated autoclced concrete. If this limit is observed and the fine aggregates consist of natural sand, the effects on the mechanical properties of the concretes are minimal. How recycled aggregates with the allowed maximum brick content of 30 mass-% can be produced depends on the available starting material: • If the starting materials are an almost brick-free recycled concrete and a pure recycled brick, the permissible contents can be set either by means of dosing devices or by means of the weighing devices of the wheel loaders. • If a recycled building material with brick contents between 30 and 100% by mass is used as the “brick supplier”, the brick content must first be determined and the possible amount of brick to be added calculated from this. In addition to the brick content, the secondary components of the added material must be taken into account in order to produce a mixture that meets the requirements. So far, the possibility of using recycled bricks in concrete production, which is covered by the regulations, has only rarely been used actively. Brick-containing recycled aggregates are used more widely in Switzerland, where interior walls and other building components, but also a complete building, have been constructed from brick-containing recycled aggregates [43]. In the case of the building, it was found that wet mechanical cleaning and classification of the recycled aggregates directly from the demolition process using a log washer is recommended. In this way, problematic foreign matter contained in the fine fraction is removed and the quality fluctuations of the recycled aggregates are reduced. In concrete production, 75 mass-% of the aggregates were replaced by recycled aggregates. The processability of the concretes was adjusted with the aid of superplasticizers. Based on the measured compressive strengths, the concrete can be classified in the strength class C30/37. An example for the suitability of recycled bricks for the production of precast concrete elements is the production of MAbA Ziegelit® walls. However, experience has shown that brick aggregates from processed demolition material are subject to quality defects due to impurities such as bitumen, concrete or mortar residues. Additional processing steps for quality improvement were not taken. Instead, only processed material from the production of roof tiles and wall bricks is now being used [44]. Masonry blocks made of brick aggregates and cement are subject of research since years. One industrially manufactured product, for example, is the “Buhl storage brick”, which has been in the product assortment of an Austrian manufacturer for over 15 years [45]. It consists of 70 mass-% of brick aggregates, 10 mass-% of expanded clay, 7 mass-% of gravel and 13 mass-% of cement. Its characteristics are a high degree of

260

8  Recycling of Masonry Rubble

sound insulation and a high storage mass as well as a low primary energy input and easy workability. The same manufacturer also produces concrete blocks in which a part of the aggregates is replaced by brick aggregates. Application as a raw material component for the brick production Pure clay brick recycled materials, which occur in the form of burnt brick scrap, can be fed into the new brick production after grinding. They act as a leaning agent and reduce the drying and possibly also the firing shrinkage, but also the strength. The leaning effect and the resulting reduction in drying shrinkage and total shrinkage can be an advantage. The resulting decrease in strength is rather undesirable, but can be compensated by increasing the firing temperature. A return is also possible for pure brick rubble from demolition. Bricks of satisfactory quality have been produced from raw mixtures in which up to 50 mass-% of the clay has been replaced by pure, processed bricks [7]. Table 8.6 provides an orientation on the requirements for brick powder from the “red” fraction of construction waste, which can be used as a secondary raw material for brick production. The comparison of the mean values of the chemical composition of unmixed bricks (Table 8.1) with the requirements confirms the suitability of brick rubble without secondary constituents. In the case of rubble from masonry (Table 8.3), exceeding values already occur at the loss on ignition. The calcium carbonate content may also be above the permissible value. A direct recycling of masonry rubble into brick production is therefore not possible or only possible to a very limited extent.

Table 8.6  Quality parameters for clay brick residues for the production of new clay brick [46, 47] Provisional requirement

Reasons/effects

Particle size