Emphasizing a conceptual understanding of concrete design and analysis, this revised and updated edition builds the students understanding by presenting design methods in an easy to understand manner supported with the use of numerous examples and problems. Written in intuitive, easy-to-understand language, it includes SI unit examples in all chapters, equivalent conversion factors from US customary to SI throughout the book, and SI unit design tables. In addition, the coverage has been completely updated to reflect the latest ACI 318-11 code.

Preface xiii

Notation xvii

Conversion Factors xxiii

**1 Introduction 1 **

1.1 Structural Concrete 1

1.2 Historical Background 1

1.3 Advantages and Disadvantages of Reinforced Concrete 3

1.4 Codes of Practice 4

1.5 Design Philosophy and Concepts 4

1.6 Units of Measurement 5

1.7 Loads 6

1.8 Safety Provisions 8

1.9 Structural Concrete Elements 9

1.10 Structural Concrete Design 10

1.11 Accuracy of Calculations 10

1.12 Concrete High-Rise Buildings 11

References 14

**2 Properties of Reinforced Concrete 15 **

2.1 Factors Affecting Strength of Concrete 15

2.2 Compressive Strength 17

2.3 Stress–Strain Curves of Concrete 18

2.4 Tensile Strength of Concrete 20

2.5 Flexural Strength (Modulus of Rupture) of Concrete 21

2.6 Shear Strength 22

2.7 Modulus of Elasticity of Concrete 22

2.8 Poisson’s Ratio 23

2.9 Shear Modulus 23

2.10 Modular Ratio 24

2.11 Volume Changes of Concrete 24

2.12 Creep 26

2.13 Models for Predicting Shrinkage and Creep of Concrete 28

2.14 Unit Weight of Concrete 64

2.15 Fire Resistance 64

2.16 High-Performance Concrete 64

2.17 Lightweight Concrete 65

2.18 Fibrous Concrete 66

2.19 Steel Reinforcement 66

Summary 70

Referecnces 72

Problems 73

**3 Flexural Analysis of Reinforced Concrete Beams 75 **

3.1 Introduction 75

3.2 Assumptions 76

3.3 Behavior of Simply Supported Reinforced Concrete Beam Loaded to Failure 76

3.4 Types of Flexural Failure and Strain Limits 80

3.5 Load Factors 84

3.6 Strength Reduction Factor φ 85

3.7 Significance of Analysis and Design Expressions 87

3.8 Equivalent Compressive Stress Distribution 88

3.9 Singly Reinforced Rectangular Section in Bending 90

3.10 Lower Limit or Minimum Percentage of Steel 101

3.11 Adequacy of Sections 102

3.12 Bundled Bars 106

3.13 Sections in the Transition Region (φ <0.9) 107

3.14 Rectangular Sections with Compression Reinforcement 109

3.15 Analysis of T- and I-Sections 120

3.16 Dimensions of Isolated T-Shaped Sections 129

3.17 Inverted L-Shaped Sections 130

3.18 Sections of Other Shapes 130

3.19 Analysis of Sections Using Tables 133

3.20 Additional Examples 134

3.21 Examples Using SI Units 136

Summary 138

References 141

Problems 142

**4 Flexural Design of Reinforced Concrete Beams 146 **

4.1 Introduction 146

4.2 Rectangular Sections with Reinforcement Only 146

4.3 Spacing of Reinforcement and Concrete Cover 149

4.4 Rectangular Sections with Compression Reinforcement 156

4.5 Design of T-Sections 163

4.6 Additional Examples 168

4.7 Examples Using SI Units 173

Summary 175

Problems 179

**5 Shear and Diagonal Tension 183 **

5.1 Introduction 183

5.2 Shear Stresses in Concrete Beams 183

5.3 Behavior of Beams without Shear Reinforcement 186

5.4 Moment Effect on Shear Strength 188

5.5 Beams with Shear Reinforcement 190

5.6 ACI Code Shear Design Requirements 193

5.7 Design of Vertical Stirrups 196

5.8 Design Summary 200

5.9 Shear Force due to Live Loads 204

5.10 Shear Stresses in Members of Variable Depth 208

5.11 Examples Using SI Units 215

Summary 217

References 218

Problems 218

**6 Deflection and Control of Cracking 222 **

6.1 Deflection of Structural Concrete Members 222

6.2 Instantaneous Deflection 223

6.3 Long-Time Deflection 229

6.4 Allowable Deflection 230

6.5 Deflection due to Combinations of Loads 230

6.6 Cracks in Flexural Members 239

6.7 ACI Code Requirements 243

Summary 248

References 249

Problems 250

**7 Development Length of Reinforcing Bars 253 **

7.1 Introduction 253

7.2 Development of Bond Stresses 254

7.3 Development Length in Tension 257

7.4 Development Length in Compression 261

7.5 Summary for Computation of Id in Tension 262

7.6 Critical Sections in Flexural Members 265

7.7 Standard Hooks (ACI Code, Sections 12.5 and 7.1) 269

7.8 Splices of Reinforcement 272

7.9 Moment–Resistance Diagram (Bar Cutoff Points) 277

Summary 282

References 283

Problems 283

**8 Design of Deep Beams by the Strut-and-Tie Method 287 **

*8.1 Introduction 287

*8.2 B– and D–Regions 287

*8.3 Strut-and-Tie Model 287

*8.4 ACI Design Procedure to Build a Strut-and-Tie Model 290

*8.5 Strut-and-Tie Method According to AASHTO LRFD 299

*8.6 Deep Members 300

References 316

**9 One-Way Slabs 317 **

9.1 Types of Slabs 317

9.2 Design of One-Way Solid Slabs 319

9.3 Design Limitations According to ACI Code 320

9.4 Temperature and Shrinkage Reinforcement 321

9.5 Reinforcement Details 322

9.6 Distribution of Loads from One-Way Slabs to Supporting Beams 323

*9.7 One-Way Joist Floor System 328

Summary 331

References 333

Problems 333

**10 Axially Loaded Columns 335 **

10.1 Introduction 335

10.2 Types of Columns 335

10.3 Behavior of Axially Loaded Columns 337

10.4 ACI Code Limitations 337

10.5 Spiral Reinforcement 339

10.6 Design Equations 341

10.7 Axial Tension 342

10.8 Long Columns 342

Summary 345

References 346

Problems 346

**11 Members in Compression and Bending 348 **

11.1 Introduction 348

11.2 Design Assumptions for Columns 350

11.3 Load–Moment Interaction Diagram 350

11.4 Safety Provisions 353

11.5 Balanced Condition: Rectangular Sections 354

11.6 Column Sections under Eccentric Loading 357

11.7 Strength of Columns for Tension Failure 359

11.8 Strength of Columns for Compression Failure 362

11.9 Interaction Diagram Example 368

*11.10 Rectangular Columns with Side Bars 369

*11.11 Load Capacity of Circular Columns 373

11.12 Analysis and Design of Columns Using Charts 378

11.13 Design of Columns under Eccentric Loading 383

*11.14 Biaxial Bending 389

*11.15 Circular Columns with Uniform Reinforcement under Biaxial Bending 391

*11.16 Square and Rectangular Columns under Biaxial Bending 394

*11.17 Parme Load Contour Method 395

*11.18 Equation of Failure Surface 400

*11.19 SI Example 403

Summary 405

References 407

Problems 407

**12 Slender Columns 412 **

12.1 Introduction 412

12.2 Effective Column Length (Klu) 413

12.3 Effective Length Factor (K) 414

12.4 Member Stiffness (EI) 415

12.5 Limitation of the Slenderness Ratio (Klu/r) 419

12.6 Moment-Magnifier Design Method 420

Summary 431

References 432

Problems 433

**13 Footings 435 **

13.1 Introduction 435

13.2 Types of Footings 437

13.3 Distribution of Soil Pressure 440

13.4 Design Considerations 441

13.5 Plain Concrete Footings 451

*13.6 Combined Footings 464

*13.7 Footings Under Eccentric Column Loads 470

*13.8 Footings Under Biaxial Moment 472

*13.9 Slabs On Ground 475

*13.10 Footings On Piles 475

13.11 SI Equations 476

Summary 476

References 479

Problems 479

**14 Retaining Walls 482 **

14.1 Introduction 482

14.2 Types of Retaining Walls 482

14.3 Forces on Retaining Walls 484

14.4 Active and Passive Soil Pressures 485

14.5 Effect of Surcharge 489

14.6 Friction on the Retaining Wall Base 491

14.7 Stability against Overturning 491

14.8 Proportions of Retaining Walls 492

14.9 Design Requirements 493

14.10 Drainage 494

14.11 Basement Walls 505

Summary 509

References 510

Problems 510

**15 Design for Torsion 515 **

*15.1 Introduction 515

*15.2 Torsional Moments in Beams 516

*15.3 Torsional Stresses 517

*15.4 Torsional Moment in Rectangular Sections 520

*15.5 Combined Shear and Torsion 521

*15.6 Torsion Theories for Concrete Members 521

*15.7 Torsional Strength of Plain Concrete Members 526

*15.8 Torsion in Reinforced Concrete Members (ACI Code Procedure) 526

*15.9 Summary of ACI Code Procedures 534

Summary 542

References 543

Problems 544

**16 Continuous Beams and Frames 547 **

16.1 Introduction 547

16.2 Maximum Moments in Continuous Beams 548

16.3 Building Frames 553

16.4 Portal Frames 555

16.5 General Frames 557

16.6 Design of Frame Hinges 559

16.7 Introduction to Limit Design 571

16.8 The Collapsec Mechanism 572

16.9 Principles of Limit Design 573

16.10 Upper and Lower Bounds of Load Factors 575

16.11 Limit Analysis 575

16.12 Rotation of Plastic Hinges 579

16.13 Summary of Limit Design Procedure 585

16.14 Moment Redistribution of Maximum Negative or Positive Moments in Continuous Beams 589

Summary 598

References 599

Problems 600

**17 Design of Two-Way Slabs 603 **

17.1 Introduction 603

17.2 Types of Two-Way Slabs 603

17.3 Economical Choice of Concrete Floor Systems 607

17.4 Design Concepts 608

17.5 Column and Middle Strips 612

17.6 Minimum Slab Thickness to Control Deflection 614

17.7 Shear Strength of Slabs 618

17.8 Analysis of Two-Way Slabs by the Direct Design Method 623

17.9 Design Moments in Columns 652

17.10 Transfer of Unbalanced Moments to Columns 653

17.11 Waffle Slabs 665

17.12 Equivalent Frame Method 673

Summary 684

References 686

Problems 686

**18 Stairs 689 **

18.1 Introduction 689

18.2 Types of Stairs 691

18.3 Examples 706

Summary 715

References 715

Problems 716

**19 Introduction to Prestressed Concrete 718 **

19.1 Prestressed Concrete 718

19.2 Materials and Serviceability Requirements 729

19.3 Loss of Prestress 731

19.4 Analysis of Flexural Members 740

19.5 Design of Flexural Members 750

19.6 Cracking Moment 756

19.7 Deflection 758

19.8 Design for Shear 761

19.9 Preliminary Design of Prestressed Concrete Flexural Members 769

19.10 End-Block Stresses 771

Summary 774

References 776

Problems 777

**20 Seismic Design of Reinforced Concrete Structures 780 **

20.1 Introduction 780

20.2 Seismic Design Category 780

20.3 Analysis Procedures 797

20.4 Load Combinations 812

20.5 Special Requirements in Design of Structures Subjected to Earthquake Loads 813

References 849

Problems 849

**21 Beams Curved in Plan 851 **

21.1 Introduction 851

21.2 Uniformly Loaded Circular Beams 851

21.3 Semicircular Beam Fixed at End Supports 858

21.4 Fixed-End Semicircular Beam under Uniform Loading 862

21.5 Circular Beam Subjected to Uniform Loading 865

21.6 Circular Beam Subjected to a Concentrated Load at Midspan 868

21.7 V-Shape Beams Subjected to Uniform Loading 871

21.8 V-Shape Beams Subjected to a Concentrated Load at the Centerline of the Beam 874

Summary 878

References 879

Problems 879

**22 Prestressed Concrete Bridge Design Based on AASHTO LRFD Bridge Design Specifications 880 **

22.1 Introduction 880

22.2 Typical Cross Sections 881

22.3 Design Philosophy of AASHTO Specificatioins 884

22.4 Load Factors and Combinations (AASHTO 3.4) 885

22.5 Gravity Loads 889

22.6 Design for Flexural and Axial Force Effects (AASHTO 5.7) 898

22.7 Design for Shear (AASHTO 5.8) 899

22.8 Loss of Prestress (AASHTO 5.9.5) 906

22.9 Deflections (AASHTO 5.7.3.6) 908

References 937

**23 Design and Analysis Flowcharts 938 **

Appendix A: Design Tables (U.S. Customary Units) 962

Appendix B: Design Tables (SI Units) 972

Appendix C: Structural Aids 980

Index 1001