Steel-Reinforced Concrete Structures: Assessment and Repair of Corrosion

by El-Reedy, Ph.D; Mohamed Abdall

• ISBN13: 9781420054309
• ISBN10: 1420054309
• Format: Hardcover
• Copyright: 2007-10-22
• Publisher: CRC Press

Summary

Carrying a billion-dollar price tag, corrosion of reinforced concrete is the enemy of every country's investment in real estate. The widespread and long-term use of reinforced concrete makes its correct and proper examination, maintenance, and repair paramount. Steel-Reinforced Concrete Structures: Assessment and Repair of Corrosion explains the corrosion of reinforced concrete from a practical point of view, highlighting protective design and repair procedures.The book begins with a discussion of the corrosion phenomena, the effect of concrete properties on corrosion, and the precautions available in the construction stage to mitigate corrosion. It covers the theoretical and practical methods in evaluating the concrete structures and new, practical methods to protect steel reinforcement. The book also includes methods established in the last decade that provide new ways of protecting steel-reinforced bars and the traditional and advanced repairing methods. The author explains the importance of implementing an integrity management system to provide a comprehensive maintenance strategy and concludes with coverage of the traditional, time-tested, and advanced repair techniques. A special feature is a chapter focusing on the advance maintenance plan philosophy and risk-based maintenance for reinforced concrete structures.The author examines economic analysis procedures and the probability of structural failures to define structure risk assessment. He covers precautions and recommendations for protecting the reinforced concrete structures from corrosion based on codes and specifications. He uses case histories from all over the world to demonstrate the widespread application and range of advanced repair techniques and presents a practical guide to the maintenance of concrete structures. The book provides procedures for corrosion diagnosis and determining the appropriate methods for repair, as well as economic models for on-site decision making.

Table of Contents

Preface	p. xiii
The Author	p. xv
Introduction	p. 1
Reference	p. 3
Corrosion of Steel in Concrete	p. 5
Introduction	p. 5
The Corrosion Process	p. 7
Black Corrosion	p. 9
Pit Formation	p. 9
Bacterial Corrosion	p. 10
Corrosion Rate	p. 10
Summary	p. 13
References	p. 13
Causes of Corrosion and Concrete Deterioration	p. 15
Introduction	p. 15
Carbonation	p. 16
Spread of Carbonation inside Concrete	p. 19
Parrott's Determination of Carbonation Rates from Permeability	p. 21
Chloride Attack	p. 21
Chloride Movement inside Concrete	p. 22
Corrosion Rates	p. 23
Statistical Analysis for Initiation of Corrosion and Corrosion Rate	p. 23
Effect of Age on Concrete Strength	p. 24
Statistical Analysis of Longtime Concrete Strength	p. 26
Code Recommendations	p. 26
Available Statistical Parameters for Concrete Strength Considering Age	p. 27
Corrosion's Effect on Spalling of Concrete Cover	p. 27
References	p. 32
Assessment Methods for Reinforced Concrete Structures	p. 33
Introduction	p. 33
Preliminary Inspection	p. 34
Detailed Inspection	p. 34
Methods of Structure Assessment	p. 35
Visual Inspection	p. 36
Plastic Shrinkage	p. 36
Settlement	p. 37
Shrinkage from Drying	p. 37
Thermal Stresses	p. 38
Chemical Reaction	p. 39
Concrete Test Data	p. 44
Core Test	p. 44
Rebound Hammer	p. 48
Ultrasonic Pulse Velocity	p. 51
Load Test for Concrete Members	p. 56
Comparison between Different Tests	p. 59
Sources of Concrete Failure	p. 60
Example for Structure Evaluation	p. 61
Example for Structure Assessment	p. 63
Test Methods for Corroded Steel in Concrete	p. 65
Manual Method	p. 65
Concrete Cover Measurements	p. 67
Half-Cell Potential Measurements	p. 69
Electrical Resistivity Measurement	p. 71
Measurement of Carbonation Depth	p. 74
Chloride Tests	p. 74
Building Assessment	p. 75
References	p. 76
Codes and Specification Guides	p. 79
Introduction	p. 79
Allowable Chloride Content in Concrete	p. 80
Concrete Cover Specifications	p. 81
British Standards	p. 82
American Codes	p. 82
European Code	p. 83
Specifications for Structures Exposed to Very Severe Conditions	p. 85
Egyptian Code	p. 85
Executing Concrete Cover	p. 87
Maximum Crack Width	p. 91
Recommended Reinforcement Details of Crack Control	p. 92
Design Precautions in Cases of Carbonation	p. 93
Design Precautions for Chloride Effects	p. 95
Effect of the Diffusion Factor on Chloride Permeability	p. 97
Effect of Chloride Concentration on Surface	p. 98
Effective Chloride Concentration	p. 99
Calculating Structure Lifetime	p. 99
General Design Considerations	p. 101
References	p. 102
Controlling Corrosion in Steel Bars	p. 105
Introduction	p. 105
Carbonation Process Control	p. 106
Effect of Environmental Conditions	p. 106
Components of Concrete Mix	p. 109
Curing	p. 110
Chloride Control	p. 112
Weather Factors Affecting Corrosion	p. 112
Composition of Concrete Mix	p. 113
Curing for Chloride Attack	p. 114
Execution of Curing	p. 116
The Curing Process in ACI	p. 119
British Standard for Curing	p. 120
Protecting Special Structures	p. 121
References	p. 122
Methods for Protecting Steel Reinforcements	p. 123
Introduction	p. 123
Corrosion Inhibitors	p. 124
Anodic Inhibitors	p. 124
Cathodic Inhibitors	p. 125
Epoxy Coating of Steel Reinforcement	p. 126
Galvanized Steel Bars	p. 127
Stainless Steel	p. 129
Fiber Reinforcement Bars	p. 130
Protecting the Concrete Surface	p. 131
Sealers and Membranes	p. 132
Coating and Sealing	p. 132
Pore Lining	p. 133
Pore Blocking	p. 133
Cathodic Protection by Surface Painting	p. 134
Cathodic Protection System	p. 135
Cathodic Protection	p. 135
Cathodic Protection Components and Design Consideration	p. 137
Source of Impressed Current	p. 138
Anode System	p. 138
Conductive Layer	p. 140
Precautions in Designing the Anode	p. 140
Follow-Up Precaution	p. 142
Comparison between Cathodic Protection and Other Types of Protection	p. 142
Cathodic Protection for Prestressed Concrete	p. 143
Bond Strength in Cathodic Protection	p. 144
Concrete with Silica Fume	p. 146
References	p. 146
Repair of Reinforced Concrete Structures	p. 149
Introduction	p. 149
Main Steps to Executing Repair	p. 150
Structure Strengthening	p. 150
Removing Concrete Cracks	p. 151
Manual Method	p. 152
Pneumatic Hammer Methods	p. 152
Water Jet	p. 153
Grinding Machine	p. 155
Clean Concrete Surfaces and Steel Reinforcements	p. 155
Concrete	p. 155
Clean Steel Reinforcement Bars	p. 156
New Patch Concrete	p. 160
Polymer Mortar	p. 160
Cement Mortar	p. 161
Execution Methods	p. 161
Manual Method	p. 161
Grouted Preplaced Aggregate	p. 162
Shotcrete	p. 163
Repair Steps	p. 165
New Methods for Strengthening Concrete Structures	p. 165
Using Steel Sections	p. 166
Fiber-Reinforced Polymer (FRP)	p. 169
CFRP	p. 170
Application On-site	p. 171
General Precautions	p. 172
References	p. 173
Risk-Based Maintenance Strategy	p. 175
Introduction	p. 175
Basic Rules of Cost Calculation	p. 176
Present Value Method	p. 176
Repair Time	p. 176
Capacity Loss in Reinforced Concrete Sections	p. 178
Example	p. 180
Required Time to Start of Corrosion	p. 181
Time Required to Start of Deterioration	p. 182
Cost Analysis for Different Protection Methods	p. 183
Repair and Inspection Strategy and Optimization	p. 185
Repair	p. 186
Expected Total Cost	p. 186
Optimization Strategy	p. 187
Maintenance Plan	p. 190
Assessment Process	p. 190
Risk-Based Inspection Maintenance Plan	p. 193
References	p. 195
Index	p. 197
Table of Contents provided by Ingram. All Rights Reserved.