Table Of ContentSeismic Retrofit of Existing Reinforced
Concrete Buildings
Seismic Retrofit of Existing Reinforced
Concrete Buildings
Stelios Antoniou
Seismosoft ltd.
Pavia
Italy
This edition first published 2023
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Hardback ISBN: 9781119987321
Cover Design: Wiley
Cover Image: Courtesy of Dr. Stelios Antoniou
Set in 9.5/12.5pt STIXTwoText by Straive, Pondicherry, India
To Eleni, Lydia and Miley
vii
Contents
Foreword by Rui Pinho xvii
Acknowledgments xix
1 Introduction 1
1.1 General 1
1.2 Why Do Old RC Buildings Need Strengthening? 3
1.3 Main Differences Between Assessment and Design
Methodologies 4
1.4 Whom Is this Book For? 7
1.5 Main Standards for the Seismic Evaluation of Existing Structures 8
References 12
2 Know Your Building: The Importance of Accurate Knowledge of the Structural
Configuration 15
2.1 Introduction 15
2.2 What Old RC Buildings Are Like 16
2.2.1 Lack of Stirrups 17
2.2.2 Unconventional Reinforcement in the Members 18
2.2.3 Large, Lightly Reinforced Shear Walls or Lack of Shear Walls 19
2.2.4 Lap Splices 22
2.2.5 Corrosion 22
2.2.6 Geometry: Location of Structural Members 25
2.2.7 Geometry: Bad Alignment of the Columns 25
2.2.8 Geometry: Arbitrary Alterations During Construction or During the Building’s
Lifetime 26
2.2.9 Bad Practices with Respect to the Mechanical and Electrical Installations 26
2.2.10 Soft Ground Stories 28
2.2.11 Short Columns 28
2.2.12 Different Construction Methods 30
2.2.13 Foundation Conditions 30
2.2.14 Discussion 32
2.2.15 One Final Example 34
viii Contents
2.3 How Come Our Predecessors Were So Irresponsible? 34
2.4 What the Codes Say – Knowledge Level and the Knowledge Factor 36
2.5 Final Remarks 39
References 39
3 Measurement of Existing Buildings, Destructive and Nondestructive
Testing 41
3.1 Introduction 41
3.2 Information Needed for the Measured Drawings 41
3.3 Geometry 44
3.4 Details – Reinforcement 46
3.5 Material Strengths 52
3.6 Concrete Tests – Destructive Methods 54
3.7 Concrete Tests – Nondestructive Methods, NDT 55
3.7.1 Rebound Hammer Test 56
3.7.2 Penetration Resistance Test 56
3.7.3 Pull- Off Test 57
3.7.4 Ultrasonic Pulse Velocity Test, UPV 57
3.8 Steel Tests 58
3.9 Infill Panel Tests 58
3.10 What Is the Typical Procedure for Monitoring an Existing Building? 59
3.11 Final Remarks 61
References 62
4 Methods for Strengthening Reinforced Concrete Buildings 63
4.1 Introduction 63
4.2 Literature Review 64
4.3 Reinforced Concrete Jackets 67
4.3.1 Application 67
4.3.2 Advantages and Disadvantages 74
4.3.3 Design Issues: Modeling, Analysis, and Checks 76
4.4 Shotcrete 77
4.4.1 Introduction 77
4.4.2 Dry Mix vs. Wet Mix Shotcrete 79
4.4.3 Advantages and Disadvantages of Shotcrete 80
4.4.4 What Is It Actually Called – Shotcrete or Gunite? 81
4.4.5 Materials, Proportioning, and Properties 81
4.4.5.1 Cement 81
4.4.5.2 Pozzolans 82
4.4.5.3 Silica Fume 82
4.4.5.4 Aggregates 82
4.4.5.5 Water 83
4.4.5.6 Fiber Reinforcement 83
4.4.5.7 Chemical Admixtures and Accelerators 85
4.4.5.8 Reinforcing Steel 85
