Modeling the Time-to Corrosion Cracking of the Cover Concrete in Chloride Contaminated Reinforced Concrete Structures

ii Acknowledgments iii List of Figures vii List of Tables x Notations xi 1.0 Introduction 1 1.1 Background 1 1.2 Deterioration Models 1 1.3 Scope of Study 3 2.0 Review of Corrosion of Steel in Concrete 2.1 Background 5 2.1.1 Mechanism of Electrochemical Corrosion 5 2.1.2 Pourbaix Diagrams 7 2.1.3 Polarization 8 2.1.4 Passivity 11 2.1.5 Growth of Rust Film 11 2.2 Corrosion of Steel in Concrete 12 2.2.1 Concrete as an Electrolyte 12 2.2.2 Principles of Steel Corrosion in Concrete 16 2.2.3 Initiation of Steel Corrosion in Concrete 19 2.2.4 Corrosive Activity of Concrete 21 2.3 Corrosion Monitoring Techniques 25 2.3.1 Half-cell Potential 25 2.3.2 Linear Polarization Technique 26 2.3.3 AC Impedance 28 2.3.4 Gravimetric Technique (Weight Loss Method) 28 2.3.5 Techniques for Determining the Chloride Content 29 2.4 Summary 29 3.0 Review of Time to Cracking Models 32 3.1 Cady-Weyers' Deterioration Model 32 3.2 Bazant’s Mathematical Models of Time to Cracking 32 3.3 Morinaga’s Empirical Equation of Time to Cracking 34 3.4 Other Metal Loss Criteria to Cracking 35 3.5 Some Comments on Existing Model s 36