Limit State Design of Reinforced Concrete Structural Elements

Preface

This text on the limit state design of reinforced concrete elements was developed out of my class notes, prepared for teaching and training undergraduate students studying Civil engineering and related disciplines, the design of reinforced concrete structures. The book intends to provide introduction and solid foundation to the students in the principles of limit state design, especially in Nigeria where there is a dearth of indigenous books in the area.

Though the book is primarily aimed at students of civil and structural engineering degree and diploma courses, other students in allied professions such as architects, builders and surveyors may also find it suitable. Practicing professionals in all these areas, without the knowledge of the limit state design who require introduction to it, will doubtless find the book useful. However, prior or parallel courses in structural analysis is necessary for complete and integrated understanding of the subject of this book.

Dr. C. A. Fapohunda had BSc., MASc. and PhD degrees in Civil Engineering respectively at University of Ife (now Obafemi Awolowo University), Nigeria, University of Toronto, Canada and the University of Lagos, Nigeria, specializing in Structural Engineering. He is a registered engineer and a member of the Nigerian Institution of Structural Engineers. He has previously lectured at the Polytechnic Ibadan, Osun State College of Technology Esa-Oke, and Caleb University, Imota, all in Nigeria. He presently lectures in the Department of Civil Engineering, Federal University, Oye-Ekiti, Nigeria.

Contents

Preface....................................................................................................................ix

Acknowledgment ................................................................................................... x

List of Some Symbols............................................................................................ xi

Chapter 1 - Introduction.......................................................................................1

1.1 Structure..................................................................................................................................1

1.2 The Goal of Structural Design ................................................................................................4

1.3 Design Process.................................................................................................................4

1.4 Considerations in Design........................................................................................................7

1.5 Structural Design Principles/Philosophies ..............................................................................7

1.6 What are Design Codes in Reinforced Concrete?...................................................................9

1.7 Reinforced Concrete Design Practice in Nigeria – BS 8110 and the Eurocodes .................11

Chapter 2 - Structural Elements and Systems in Reinforced Concrete ......... 13

2.1 Reinforced Concrete - Background ......................................................................................13

2.2 Structural Concrete ...............................................................................................................16

2.3 Structural Elements...............................................................................................................16

2.4 Forms of Structural Elements in Reinforced Concrete .........................................................17

2.5 Classification of Concrete Structural Elements ....................................................................24

2.6 Structural Systems for Reinforced Concrete.........................................................................27

2.7 System of Reinforced Concrete Building Structures ............................................................28

2.8 Structural Systems for Low/Medium Storey Buildings ........................................................29

2.9 Structural Systems of Tall Buildings ....................................................................................29

Chapter 3- Properties of Materials for Structural Concrete...........................30

3.1 Introduction ..........................................................................................................................30

3.2 Concrete................................................................................................................................30

3.3 Reinforcement Steel..............................................................................................................36 3.4 Loading.................................................................................................................................37

3.5 Load Estimation in Practice..................................................................................................42

Chapter 4- Analysis of Reinforced Concrete Structures ................................. 45

4.1 Introduction ..........................................................................................................................45

4.2 Stiffness of a Member...........................................................................................................45

4.3 Structural Analysis................................................................................................................46

4.3.1 Determinate Structures - Beams and Slabs ...................................................................46

4.3.2 Indeterminate Structures - Beams and Slabs.................................................................49

4.3.3 Analysis of Framed Structures ......................................................................................55

Chapter 5 - Limit State Design Method.......................................................................................74

5.1 Introduction ..........................................................................................................................74

5.2 Limit State Requirement.......................................................................................................74

5.3 Serviceability Limit State and Reinforcement Details..........................................................76

Chapter 6 - Design of Reinforced Concrete Beams ....................................................................86

6.1 Introduction ..........................................................................................................................86

6.2 Design of Singly-Reinforced Beams (Ultimate Strength of Section in Flexure/Bending) ...88

6.3 Shear in Reinforced Concrete Beam...................................................................................101

6.4 Doubly Reinforced Beams..................................................................................................114

6.5 Flanged Beam Sections.......................................................................................................119

6.6 Detailing and Curtailment of Reinforcement......................................................................138

Chapter 7 - Design of Reinforced Concrete Slabs ....................................................................143

7.1 Introduction ........................................................................................................................143

7.2 One-way Spanning Solid Slab ............................................................................................143

7.3 Two-way Spanning Solid Slab ...........................................................................................155

Chapter 8 - Design of Reinforced Concrete Stairs....................................................................179

8.1 Introduction ........................................................................................................................179

8.2. Common Stairs ..................................................................................................................179

8.3 Special Types of Stairs .......................................................................................................182

8.4 General Functional Requirements for Stairs.......................................................................183

8.5 Design of Stairs ..................................................................................................................185

Chapter 9- Design of Reinforced Concrete Columns ...............................................................199

9.1 Definitions ..........................................................................................................................199

9.2 Classifications of Columns .................................................................................................199

9.3 Reinforcement detailing in Columns ..................................................................................207

9.4 Design of Short Braced Columns .......................................................................................208

9.5 Design of Slender Columns ................................................................................................216

Chapter 10- Design of Reinforced Concrete Foundations .......................................................218

10.1 Introduction ......................................................................................................................218

10.2 Importance of Soil Investigations in Structural Design of Foundations ...........................219

10.3 Strip Foundation ...............................................................................................................219

10.4 Pad Foundation .................................................................................................................225

10.5 Combined Foundation ......................................................................................................238

10.6 Design of others Types of Foundation..............................................................................249

Chapter 11– Design of Reinforced Concrete Retaining Walls.................................................255

11.1 Introduction ......................................................................................................................255

11.2 Free Standing Retaining wall............................................................................................255

11.3 Soil Pressures in Retaining Walls .....................................................................................258

11.4 Bending Moments and Shear Force Calculation in Retaining Wall .................................259

11.5 Structural Design of Retaining Walls ...............................................................................260

11.6 Stability Analysis in Retaining Wall.................................................................................261

11.7 Construction Consideration ..............................................................................................264

11.9 Design of Counterfort Retaining Wall ..............................................................................277

Chapter 12 – Presentation and Documentation of Results of Structural Design Process .....293

12.1 Introduction ......................................................................................................................293

12.2 Design Calculation sheets.................................................................................................293

12.3 Structural detailing............................................................................................................294

12.4 Bar bending schedule........................................................................................................295

Chapter 13 – Preventing Early Deterioration and Failures in Concrete Structures .............297

13.1 Introduction ......................................................................................................................297

13.2 Measures for strong and durable Concrete Structures ......................................................297

References.....................................................................................................................................302

Bibliography .................................................................................................................................303

Index .............................................................................................................................................304