Reinforced concrete design 9780190269807, 9780190647049, 9780190269852, 0190269804

Citation preview

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REINFORCED CONCRETE DESIGN

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REINFORCED CONCRETE DESIGN CHU-​K IA WANG CHARLES G. SALMON JOSÉ A. PINCHEIRA GUSTAVO J. PARRA-​M ONTESINOS University of Wisconsin–​Madison EIGHTH EDITION

New York  Oxford OXFORD UNIVERSITY PRESS

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Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark of Oxford University Press in the UK and certain other countries. Published in the United States of America by Oxford University Press 198 Madison Avenue, New York, NY 10016, United States of America. © 2018 by Oxford University Press © 2007 by John Wiley & Sons, Inc. © 1997 by Addison Wesley Publishing Company For titles covered by Section 112 of the US Higher Education Opportunity Act, please visit www.oup.com/​us/​he for the latest information about pricing and alternate formats. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, by license, or under terms agreed with the appropriate reproduction rights organization. Inquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above. You must not circulate this work in any other form and you must impose this same condition on any acquirer. Library of Congress Cataloging-​in-​Publication Data Names: Wang, Chu-Kia, 1917–author. Title: Reinforced Concrete Design / Chu-Kia Wang, Charles G. Salmon, José A. Pincheira,   Gustavo J. Parra-Montesinos. Description: New York: Oxford University Press, [2018] |   Includes bibliographical references and index. Identifiers: LCCN 2017000252 | ISBN 9780190269807 (hardcover) |   ISBN 9780190647049 (looseleaf) | ISBN 9780190269852 (eISBN) Subjects: LCSH: Reinforced concrete construction. Classification: LCC TA683.2 .W3 2018 | DDC 624.1/8341—dc23 LC record available at https://lccn.loc.gov/2017000252 987654321 Printed by Edwards Brothers Malloy, United States of America

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CONTENTS IN BRIEF Preface  xxi About the Authors  xxv Conversion Factors  xxvii

  1 INTRODUCTION, MATERIALS, AND PROPERTIES    2 DESIGN METHODS AND REQUIREMENTS 

1

31

  3 FLEXURAL BEHAVIOR AND STRENGTH OF BEAMS    4 T-​S ECTIONS IN BENDING 

43

94

  5 SHEAR STRENGTH AND DESIGN FOR SHEAR    6 DEVELOPMENT OF REINFORCEMENT 

110

176

  7 ANALYSIS OF CONTINUOUS BEAMS AND ONE-​WAY SLABS  239   8 DESIGN OF ONE-​WAY SLABS 

254

  9 DESIGN OF SLAB–​B EAM–​G IRDER AND JOIST FLOOR SYSTEMS  266 10 MEMBERS IN COMPRESSION AND BENDING 

321

11 MONOLITHIC BEAM-​C OLUMN CONNECTIONS  12 SERVICEABILITY 

403

13 SLENDERNESS EFFECTS ON COLUMNS 

463

380

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14 STRUT-​A ND-​T IE MODELS—​D EEP BEAMS, BRACKETS, AND CORBELS  528 15 STRUCTURAL WALLS 

569

16 DESIGN OF TWO-​WAY FLOOR SYSTEMS  17 YIELD LINE THEORY OF SLABS  18 TORSION 

622

720

748

19 FOOTINGS 

799

20 INTRODUCTION TO PRESTRESSED CONCRETE  21 COMPOSITE MEMBERS AND CONNECTIONS  Index  949

844

897

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CONTENTS Preface  xxi About the Authors  xxv Conversion Factors  xxvii

1 INTRODUCTION, MATERIALS, AND PROPERTIES  1.1

Reinforced Concrete Structures  1

1.2

Historical Background  2

1.3 Concrete 4 1.4 Cement 5 1.5 Aggregates 6 1.6 Admixtures 6 1.7

Compressive Strength  9

1.8

Tensile Strength  12

1.9

Biaxial and Triaxial Strength  14

1.10 Modulus of Elasticity  14 1.11 Creep and Shrinkage  16 1.12 Concrete Quality Control  18 1.13 Steel Reinforcement  19 1.14 Fiber-​Reinforced Concrete 

25

1.15 Units  26 Selected References  26

2 DESIGN METHODS AND REQUIREMENTS  2.1

Structural Design Process—​General  31

2.2

ACI Building Code  31

31

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2.3

Strength Design and Working Stress Methods  32

2.4

Working Stress Method  33

2.5

Strength Design Method  33

2.6

Safety Provisions—​General 

2.7

Safety Provisions—​ACI Code Load Factors and Strength Reduction Factors  36

2.8

Serviceability Provisions—​General 

2.9

Serviceability Provisions—​ACI Code  39

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2.10 Handbooks and Computer Software  39 2.11 Dimensions and Tolerances  40 2.12 Accuracy of Computations  41 Selected References  41

3 FLEXURAL BEHAVIOR AND STRENGTH OF BEAMS 

43

3.1

General Introduction  43

3.2

Flexural Behavior and Strength of Rectangular Sections  44

3.3

Whitney Rectangular Stress Distribution  47

3.4

Nominal Flexural Strength Mn—​Rectangular Sections Having Tension Reinforcement Only  48

3.5

Balanced Strain Condition  51

3.6

Tension-​and Compression-​Controlled Sections  52

3.7

Minimum Tension Reinforcement  58

3.8

Design of Rectangular Sections in Bending Having Tension Reinforcement Only  60

3.9

Practical Selection for Beam Sizes, Bar Sizes, and Bar Placement  64

3.10 Nominal Flexural Strength Mn of Rectangular Sections Having Both Tension and Compression Reinforcement  72 3.11 Design of Beams Having Both Tension and Compression Reinforcement  78 3.12 Nonrectangular Sections  84 3.13 Effect of As, As′ , b, d, fc′ , and fy on Flexural Behavior  86 Selected References  88 Problems  88

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4 T-​S ECTIONS IN BENDING 

94

4.1 General 94 4.2

Comparison of Rectangular and T-​Sections  95

4.3

Effective Flange Width  95

4.4

Nominal Moment Strength Mn of T-​Sections 

4.5

Design of T-​Sections in Bending  105

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Selected References  108 Problems  108

5 SHEAR STRENGTH AND DESIGN FOR SHEAR 

110

5.1 Introduction 110 5.2

Shear Stresses Based on Linear Elastic Behavior  111

5.3

Combined Normal and Shear Stresses  113

5.4

Behavior of Beams without Shear Reinforcement  114

5.5

Shear Strength of Beams without Shear Reinforcement—​ACI Approach  119

5.6

Function of Web Reinforcement  122

5.7

Truss Model for Reinforced Concrete Beams  125

5.8

Shear Strength of Beams with Shear Reinforcement—​ACI Approach  128

5.9

Deformed Steel Fibers as Shear Reinforcement  129

5.10 ACI Code Design Provisions for Shear  130 5.11 Critical Section for Nominal Shear Strength Calculation  135 5.12 Shear Strength of Beams—​Design Examples  136 5.13 Shear Strength of Members under Combined Bending and Axial Load  146 5.14 Deep Beams  151 5.15 Shear Friction  152 5.16 Brackets and Corbels  157 Selected References  168 Problems  172

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6 DEVELOPMENT OF REINFORCEMENT 

176

6.1 General 176 6.2

Development Length  177

6.3

Flexural Bond  179

6.4

Bond Failure Mechanisms  180

6.5

Flexural Strength Diagram—​Bar Bends and Cutoffs  182

6.6

Development Length for Tension Reinforcement—​ACI Code  185

6.7

Modification Factors ψt, ψe , ψs, and λ to the Bar Development Length Equations—​ACI Code  190

6.8

Development Length for Compression Reinforcement  194

6.9

Development Length for Bundled Bars  195

6.10 Development Length for a Tension Bar Terminating in a Standard Hook  195 6.11 Bar Cutoffs in Negative Moment Region of Continuous Beams  198 6.12 Bar Cutoffs in Positive Moment Region of Continuous Beams  201 6.13 Bar Cutoffs in Uniformly Loaded Cantilever Beams  202 6.14 Development of Positive Reinforcement at Simple Supports and at Points of Inflection  209 6.15 Development of Shear Reinforcement  211 6.16 Tension Lap Splices  213 6.17 Welded Splices and Mechanical Connections in Tension  215 6.18 Compression Lap Splices  216 6.19 End Bearing Connections, Welded Splices, and Mechanical Connections in Compression  217 6.20 Splices for Members under Compression and Bending  217 6.21 Design Examples  217 Selected References  234 Problems  236

7 ANALYSIS OF CONTINUOUS BEAMS AND ONE-​WAY SLABS  239 7.1 Introduction 239

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7.2

Analysis Methods under Gravity Loads  240

7.3

Arrangement of Live Load for Moment Envelope  241

7.4

ACI Code—​Arrangement of Live Load and Moment Coefficients  246

7.5

ACI Moment Diagrams  247

7.6

Shear Envelope for Design  250 Selected Reference  252 Problems  252

8 DESIGN OF ONE-​WAY SLABS 

254

8.1 Definition 254 8.2

Analysis Methods  254

8.3

Slab Design  255

8.4

Choice of Reinforcement  258

8.5

Bar Details  264 Selected References  265 Problems  265

9 DESIGN OF SLAB-​B EAM-​G IRDER AND JOIST FLOOR SYSTEMS  266 9.1 Introduction 266 9.2

Size of Beam Web  267

9.3

Continuous Frame Analysis for Beams  270

9.4

Choice of Longitudinal Reinforcement in Beams  274

9.5

Shear Reinforcement in Beams  285

9.6

Details of Bars in Beams  287

9.7

Size of Girder Web  294

9.8

Continuous Frame Analysis for Girders  297

9.9

Choice of Longitudinal Reinforcement in Girders  300

9.10 One-​Way Joist Floor Construction  306 9.11 Design of Joist Floors  307

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9.12 Redistribution of Moments—​Introduction to Limit or Plastic Analysis  312 Selected References  317 Problems  318

10 MEMBERS IN COMPRESSION AND BENDING 

321

10.1 Introduction 321 10.2

Types of Columns  322

10.3

Behavior of Columns under Pure Axial Load  322

10.4

Safety Provisions for Columns  325

10.5

Concentrically Loaded Short Columns  326

10.6

Strength Interaction Diagram  326

10.7

Slenderness Effects  328

10.8

Lateral Ties  329

10.9

Spiral Reinforcement and Longitudinal Bar Placement  330

10.10 Limits on Percentage of Longitudinal Reinforcement  332 10.11 Maximum Strength in Axial Compression—​ACI Code  333 10.12 Balanced Strain Condition  333 10.13 Nominal Strength of a Compression-​Controlled Rectangular Section  336 10.14 Nominal Strength of a Rectangular Section with Eccentricity e Greater than That at the Balanced Strain Condition  340 10.15 Design for Strength—​Region I, Minimum Eccentricity  342 10.16 Design for Strength—​Region II, Compression-​Controlled Sections (emin < e < eb )  345 10.17 Design for Strength—​Region III, Transition Zone and Tension-​Controlled Sections (e > eb )  351 10.18 Circular Sections Under Combined Compression and Bending  354 10.19 Combined Axial Tension and Bending  357 10.20 Combined Axial Force and Biaxial Bending  359 10.21 Design for Shear  368 Selected References  370 Problems  374

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11 MONOLITHIC BEAM-​C OLUMN CONNECTIONS  11.1 Introduction 380 11.2

Beam-​Column Joints Actions  381

11.3

Joint Transverse Reinforcement  383

11.4

Joint Shear Strength  387

11.5

Column-​to-​Beam Moment Strength Ratio  389

11.6

Anchorage of Reinforcement in the Joint Region  390

11.7

Transfer of Column Axial Forces through the Floor System  391

11.8 Examples 391 11.9

Additional Remarks  399 Selected References  399 Problems  401

12 SERVICEABILITY 

403

12.1 Introduction 403 12.2

Fundamental Assumptions  403

12.3

Modulus of Elasticity Ratio, n  404

12.4

Equilibrium Conditions  404

12.5

Method of Transformed Section  407

12.6

Deflections—​General  410

12.7

Deflections for Linear Elastic Members  411

12.8

Modulus of Elasticity  414

12.9

Effective Moment of Inertia  414

12.10 Instantaneous Deflections in Design  417 12.11 Creep Effect on Deflections under Sustained Load  428 12.12 Shrinkage Effect on Deflections under Sustained Load  431 12.13 Creep and Shrinkage Deflection—​ACI Code Method  435 12.14 Creep and Shrinkage Deflection—​Alternative Procedures  436 12.15 ACI Minimum Depth of Flexural Members  439

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12.16 Span-​to-​Depth Ratio to Account for Cracking and Sustained Load Effects  441 12.17 ACI Code Deflection Provisions—​Beam Examples  446 12.18 Crack Control for Beams and One-​Way Slabs  451 12.19 Side Face Crack Control for Large Beams  455 12.20 Control of Floor Vibrations—​General  456 Selected References  457 Problems  459

13 SLENDERNESS EFFECTS ON COLUMNS 

463

13.1 General 463 13.2

Buckling of Concentrically Loaded Columns  465

13.3

Effective Length Factor  468

13.4

Moment Magnification—​Members with Transverse Loads—​Without Joint Lateral Translation (i.e., No Sidesway)  470

13.5

Moment Magnification—​Members Subject to End Moments Only—​Without Joint Lateral Translation (i.e., No Sidesway)  472

13.6

Moment Magnification—Members with Sidesway—Unbraced (Sway) Frames  477

13.7

Interaction Diagrams—​Effect of Slenderness  479

13.8

ACI Code—​General  480

13.9

ACI Code—​Moment Magnifier Method for Columns in Nonsway Frames  482

13.10 ACI Code—​Moment Magnifier Method for Columns in Sway Frames  485 13.11 Alignment Charts for Effective Length Factor k  490 13.12 Second-​Order Analysis—​ACI Code  493 13.13 Minimum Eccentricity in Design  493 13.14 Biaxial Bending and Axial Compression  494 13.15 ACI Code—​Slenderness Ratio Limitations  494 13.16 Amplification of Moments in Beams  495 13.17 Examples  495 Selected References  523 Problems  526

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14 STRUT-​A ND-​T IE MODELS—​D EEP BEAMS, BRACKETS, AND CORBELS  528 14.1 Introduction 528 14.2

Deep Beams  542

14.3

Brackets and Corbels  559

14.4

Additional Remarks  565 Selected References  566 Problems  567

15 STRUCTURAL WALLS 

569

15.1 General 569 15.2

Minimum Wall Dimensions and Reinforcement Requirements—​ACI Code  569

15.3

Design of Nonbearing Walls  573

15.4

Design of Bearing Walls  573

15.5

Design of Shear Walls  576

15.6

Lateral Support of Longitudinal Reinforcement  596

15.7

Retaining Structures  597 Selected References  619 Problems  620

16 DESIGN OF TWO-​WAY FLOOR SYSTEMS 

622

16.1

General Description  622

16.2

General Design Concept of the ACI Code  624

16.3

Total Factored Static Moment  625

16.4

Ratio of Flexural Stiffnesses of Longitudinal Beam to Slab  633

16.5

Minimum Slab Thickness for Deflection Control  637

16.6

Nominal Requirements for Slab Thickness and Size of Edge Beams, Column Capital, and Drop Panel  639

16.7

Direct Design Method—​Limitations  644

16.8

Direct Design Method—​Longitudinal Distribution of Moments  645

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16.9

Direct Design Method—​Effect of Pattern Loadings on Positive Moment  647

16.10 Direct Design Method—​Procedure for Computation of Longitudinal Moments  647 16.11 Torsion Stiffness of the Transverse Elements  651 16.12 Transverse Distribution of Longitudinal Moment  656 16.13 Design of Slab Thickness and Reinforcement  662 16.14 Size Requirement for Beam (If Used) in Flexure and Shear  669 16.15 Shear Strength in Two-​Way Floor Systems  671 16.16 Shear Reinforcement in Flat Plate Floors  676 16.17 Direct Design Method—​Moments in Columns  686 16.18 Transfer of Moment and Shear at Junction of Slab and Column  687 16.19 Openings and Corner Connections in Flat Slabs  697 16.20 Equivalent Frame Method for Gravity Load Analysis  698 16.21 Equivalent Frame Models  710 16.22 Equivalent Frame Method for Lateral Load Analysis  711 Selected References  711 Problems  718

17 YIELD LINE THEORY OF SLABS 

720

17.1 Introduction 720 17.2

General Concept  720

17.3

Fundamental Assumptions  723

17.4

Methods of Analysis  724

17.5

Yield Line Analysis of One-​Way Slabs  725

17.6

Work Done by Yield Line Moments in Rigid Body Rotation of Slab Segment  728

17.7

Nodal Forces at Intersection of Yield Line with Free Edge  729

17.8

Nodal Forces at Intersection of Three Yield Lines  732

17.9

Yield Line Analysis of Rectangular Two-​Way Slabs  736

17.10 Corner Effects in Rectangular Slabs  742

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17.11 Application of Yield Line Analysis to Special Cases  743 Selected References  747 Problems  747

18 TORSION 

748

18.1 General 748 18.2

Torsional Stress in Homogeneous Sections  749

18.3

Torsional Stiffness of Homogeneous Sections  751

18.4

Effects of Torsional Stiffness on Compatibility Torsion  752

18.5

Torsional Moment Strength Tcr at Cracking  755

18.6

Strength of Rectangular Sections in Torsion—​Skew Bending Theory  757

18.7

Strength of Rectangular Sections in Torsion—​Space Truss Analogy  761

18.8

Strength of Sections in Combined Bending and Torsion  765

18.9

Strength of Sections in Combined Shear and Torsion  767

18.10 Strength Interaction Surface for Combined Bending, Shear, and Torsion  768 18.11 Torsional Strength of Concrete and Closed Transverse Reinforcement—​ACI Code  770 18.12 Combined Torsion with Shear or Bending—​ACI Code  772 18.13 Minimum Requirements for Torsional Reinforcement—​ACI Code  773 18.14 Examples  775 Selected References  791 Problems  796

19 FOOTINGS 

799

19.1

Purpose of Footings  799

19.2

Bearing Capacity of Soil  799

19.3

Types of Footings  800

19.4

Types of Failure  800

19.5

Shear Strength  802

19.6

Flexural Strength and Development of Reinforcement  803

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19.7

Proportioning Footing Areas for Equal Settlement  804

19.8

Investigation of Square Spread Footings  804

19.9

Design of Square Spread Footings  809

19.10 Design of Rectangular Footings  814 19.11 Design of Plain and Reinforced Concrete Wall Footings  818 19.12 Combined Footings  822 19.13 Design of Combined Footings  823 19.14 Pile Footings  841 Selected References  841 Problems  842

20 INTRODUCTION TO PRESTRESSED CONCRETE 

844

20.1 Introduction 844 20.2

Historical Background  844

20.3

Advantages and Disadvantages of Prestressed Concrete Construction  845

20.4

Pretensioned and Post-​tensioned Beam Behavior  846

20.5

Service Load Stresses on Flexural Members—​Tendons Having Varying Amounts of Eccentricity  849

20.6

Three Basic Concepts of Prestressed Concrete  853

20.7

Loss of Prestress  856

20.8

Nominal Strength Mn of Flexural Members  866

20.9

Cracking Moment  871

20.10 Shear Strength of Members without Shear Reinforcement  873 20.11 Shear Reinforcement for Prestressed Concrete Beams  881 20.12 Development of Reinforcement  883 20.13 Proportioning of Cross Sections for Flexure When No Tension is Permitted  885 20.14 Additional Topics  894 Selected References  894 Problems  895

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21 COMPOSITE MEMBERS AND CONNECTIONS  21.1 Introduction 897 21.2

Composite Action  897

21.3

Concrete Composite Flexural Members  901

21.4

Concrete-​Steel Composite Columns  916

21.5

Concrete-​Encased Steel Composite Columns  918

21.6

Concrete-​Filled Tube Columns  934

21.7

Moment Connections with Composite Columns  943 Selected References  944 Problems  947

Index  949

897

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PREFACE The eighth edition of this textbook has been substantially updated to incorporate the changes introduced by the publication of the 2014 American Concrete Institute (ACI) Building Code and Commentary for Structural Concrete, as well as to reflect changes in construction and design practices that have occurred in the last few years.

APPROACH This new edition follows the same philosophical approach that has gained wide acceptance of users since the first edition was published in 1965. Herein, as in past editions, consider­ able emphasis is placed on presenting to the student, as well as to the practicing engineer, the basic principles of reinforced concrete design and the concepts necessary to understand and properly apply the provisions of the ACI Building Code. Numerous examples are presented to illustrate the general approach to design and analysis. The material is incorporated into the chapters in a way that permits the reader to either study in detail the concepts in logical sequence or obtain a qualitative explanation and proceed directly to the design process using the ACI Code.

NEW TO THIS EDITION The eighth edition of this book incorporates the changes arising from the publication of the 2014 American Concrete Institute Building Code and Commentary (ACI 318-​14). While past editions of the ACI Code were largely structured around member actions (e.g., flexure, shear, and axial load), ACI 318-​14 is organized primarily by structural elements (e.g., beams, columns, walls). As a result, virtually all design provisions have changed in format and number, and are located under a new chapter designation in the  Code. Accordingly, all chapters and example problems have been revised to conform to the format and reorganization of the 2014 ACI Building Code (ACI 318-​14). In addition, content has been reorganized within existing chapters, moved to other chapters, or relocated as new, stand-​alone chapters for better continuity and presentation of the material. Main revisions, updates, and new material include the following. 1. A new chapter on Structural Walls (Chapter 15) has been added. This chapter includes the design of Non-​Bearing and Bearing Walls, as well as the design of Shear Walls. The design of Cantilever Retaining Walls (formerly Chapter 12) has been revised and is included at the end of the new Chapter 15. 2. The chapter on composite construction (Chapter 21) has been substantially revised and renamed “Composite Members and Connections” to better reflect its new scope. The first part covers the design of concrete-​concrete composite flexural members, including calculation of deflections for shored and unshored construction. In addition, the chapter now includes sections on Concrete-​Encased Steel Columns and Concrete-​Filled Tubes, along with a new section on Moment Connections between Composite Columns and Steel Beams.

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3. The material on the Strut and Tie Method and its application to the design of Deep Beams, Brackets, and Corbels (previously included in Chapter 5, Shear Strength) has been updated and is now presented as a stand-​alone, separate chapter (Chapter 14). 4. The material on Rectangular Sections in Bending under Service Load Conditions (formerly Chapter 4) and Deflections (formerly Chapter 14) was revised and combined into a single chapter dealing with Serviceability (new Chapter 12). 5. The design of T-​Sections in Bending (formerly Chapter 9) was relocated as Chapter 4, immediately after Chapter 3, Flexural Behavior and Strength of Beams, for better flow and continuity of the material on beam design. 6. The chapter on Slenderness Effects on Columns, now Chapter  13 (formerly Chapter 15) has been revised to include additional content and example problems for better understanding of the ACI Code procedures established to account for second-​ order effects in column design. 7. The alternative provisions of Appendix B and the alternative load factors of Appendix C included in past editions of the ACI Code have been removed from the Code. Accordingly, discussion and example problems corresponding to these appendices are not included in this edition of the textbook. 8. All sections have been revised to improve the flow and continuity of the material in accordance to the changes in ACI 318-​14. In addition to the content revisions indicated above, all the examples and the problems at the end of each chapter have been revised and updated to conform to the current ACI Code. Examples and problems have also been updated, and new examples have been added to reflect the strengths of the materials most commonly used in current practice. A  few examples, however, use less common values in order to emphasize specific aspects of the design process that students might otherwise overlook. To aid instructors, a solutions manual has been prepared for the end-​of-​chapter problems. Many problems are solved in Mathcad®, allowing alternative solutions to be easily arrived at by modifying a few parameters, either as suggested in this textbook or at the choice of the instructor.

COURSE SUGGESTIONS Depending on the proficiency required of the student, this book may provide material for two courses of three or four semester-​hours each. It is suggested that the beginning course in concrete structures for undergraduate students contain all or most of the material in Chapters 1 through 6, and Chapters 8 through 10. The second course may begin with Chapter 10, using that topic (members in compres­ sion and bending) to review many of the subjects in the first course, followed by Chapter 12 on serviceability, Chapter 13 on slenderness effects on columns, and Chapter 16 on two-​ way slab systems. In addition, one or two of the following may be included in a second course:  the remaining sections of Chapter  5 on shear strength affected by axial force; Chapter 15 on structural walls; Chapter 18 on torsion; Chapter 14 on strut-​and-​tie models, deep beams, brackets, and corbels; and Chapter 20 on prestressed concrete. Chapters on beam-​ column connections (Chapter  11), yield line theory of slabs (Chapter 17), footings (Chapter 19), and composite members and connections (Chapter 21) may serve as contents for a third course.

UNITS This edition continues the modest treatment of SI units used in previous editions. The 2014 ACI Code has an SI version (known as ACI 318-​14M), and the SI versions of the ACI Code equations appear in this book as footnote equations with the same equation number. According to the ACI Code, the designer must use in its entirety either the Inch-​Pound units version (ACI 318-​14) or the SI version (ACI 318-​14M), although the

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PREFACE

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Inch-​Pound units version is the official version of the Code. The authors believe that sufficient metrication should be included in a text on reinforced concrete to permit the reader to gain some familiarity with SI units, but suspect that too much would interfere with learning the basic concepts of concrete design; constant conversion back and forth between Inch-​Pound and SI units is more confusing than using either one exclusively. The text provides data on reinforcing bars in accordance with the American Society for Testing and Materials Inch-​Pound units, and also ASTM SI units (the “soft” conversion of the bar sizes and strengths approved in 1996). Some design tables are provided for bars and material strengths in SI units, a few numerical examples are given in SI units, and some problems at the ends of chapters are given with an SI alternate in parentheses at the statement concluding the problem. In all parts of this book that use metric units, force is expressed in the newton (N) or kilonewton (kN) unit. The SI unit of stress is the pascal (Pa), or newton per meter squared, which because of its typically large numerical value is usually expressed in megapascals (MPa): that is, 106 pascals. A few diagrams show, along the stress axis, the kilogram force per centimeter squared (kgf/​cm2) in addition to Inch-​Pound and SI units. For the convenience of the reader, some conversion factors for forces, stresses, uniform loading, and moments are provided on a separate page following this Preface. It is noted that throughout the textbook, conversion factors (for forces, stresses, and dimensions) used in example problems (when needed) are shown with a smaller font so as to not interfere with the values of the parameters actually involved in the calculations and to facilitate understanding of the problem solution.

ACKNOWLEDGMENTS The authors continue to be indebted to students, colleagues, and other users of the first seven editions of this book, who have suggested improvements of wording, identified errors, and recommended items for inclusion or omission. The authors are pleased to acknowledge the following reviewers, to whom they owe special thanks:  Mohammad Azarbayejani, University of Texas–​Pan American; Abdeldjelil Belarbi, University of Houston; Sergio F.  Breña, University of Massachusetts–​ Amherst; Norbert Delatte, Cleveland State University; Apostolos Fafitis, Arizona State University; Susan Faraji, University of Massachusetts Lowell; Catherine French, University of Minnesota; David Garber, Florida International University; Roberto Leon, Virginia Tech University; John B. Mander, Texas A&M University; Fatmir Menkulasi, Louisiana Tech University; Gregory K. Michaelson, Marshall University; Levon Minnetyan, Clarkson University; Ayman M. Okeil, Louisiana State University; Nima Rahbar, Worcester Polytechnic Institute; Michael Seek, Old Dominion University; Ahmed Senouci, University of Houston; Lisa Spainhour, FAMU–​ Florida State University; Andreas Stavridis, University at Buffalo; Jale Tezcan, Southern Illinois University–​Carbondale; Robin Tuchscherer, Northern Arizona University; Baolin Wan, Marquette University; Paul Ziehl, University of South Carolina. Their comments and suggestions have been carefully considered and the results of our review are reflected in this complete revision. Users of this eighth edition are urged to communicate with the authors regarding all aspects of this book, particularly on identification of errors and suggestions for improvement. We are indebted to late Professors Chu-​Kia (CK) Wang and Charles (Chuck) G. Salmon, who originated this textbook and entrusted us to carry on their legacy. Much of the new and expanded material presented in this eighth edition would not have been possible without their work in earlier editions of this book. Special thanks are due to the Higher Education Group, Oxford University Press—​in particular, Dan Kaveney, Executive Editor, Christine Mahon, Associate Editor, Claudia Dukeshire, Production Editor, Megan Carlson, Assistant Editor, and Nancy Blaine, former Senior Acquisitions Editor. We acknowledge the long-​time continuing patience and encouragement from our families and especially from our wives, Rebeca and Connie, throughout the preparation of this edition of the book. Nicole and Gabriel Parra, with their frequent smiles and unbounded

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love, were a continuous source of inspiration to their father. We also owe a special recognition to our parents, Paulina Peña, Hernán Pincheira, Gustavo Parra Pardi and Yolanda Montesinos Soteldo, who instilled in us from an early age the importance of learning, education, and hard work. To all of them we wholeheartedly dedicate this book. José A. Pincheira Gustavo J. Parra-​Montesinos

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ABOUT THE AUTHORS CHU-​KIA WANG* was Professor of Civil Engineering at the University of Wisconsin–​ Madison for more than 30 years. A devoted teacher throughout his career, he was the author or coauthor of many textbooks in the field of structural engineering as the outgrowth of lectures he prepared for his classes. The University of Wisconsin–​Madison recognized his contribution to the education of future engineers with the College of Engineering’s Benjamin Smith Reynolds Award for Excellence in Teaching. A fellow and lifetime member of the American Society of Civil Engineers, Professor Wang was also a member of the American Concrete Institute (ACI), the American Society for Engineering Education (ASCE), and other professional societies. CHARLES G. SALMON* was Professor Emeritus of Civil Engineering at the University of Wisconsin–​Madison. An accomplished author, educator, researcher, and professional structural engineer, Professor Salmon received numerous honors in recognition of his contributions to the field, including the Western Electric Award for excellence in teaching from the American Society for Engineering Education, the University of Wisconsin’s Emil H. Steiger Distinguished Teaching Award, and the American Concrete Institute’s Joe W. Kelly and Delmar L. Bloem Awards. He was a long-​time member of the ACI Building Code Committee for Structural Concrete (ACI 318), Committee 340 (Design Aids), and Committee 435 (Deflections of Concrete Structures). Professor Salmon was also an honorary member of ACI, an honorary member of the American Society of Civil Engineers; and a life member of the American Society for Engineering Education. *Deceased JOSÉ A.  PINCHEIRA is Associate Professor of Civil and Environmental Engineering at the University of Wisconsin–​Madison. His main research interests include the behavior and design of reinforced concrete structural systems subjected to earthquakes, as well as the seismic rehabilitation of concrete structures. Dr. Pincheira is a fellow of the American Concre