Passivation and Corrosion of Black Rebar with Mill Scale

Description

The passivation and corrosion of metal are significantly affected by its surface state and chemical characteristics. In practical engineering, the reinforcement is with mill scale or rust stains. Its passivation and corrosion are obviously different from the descaled one. This book briefly discusses the pseudo-passivation behavior and corrosion mechanisms of hot-rolled rebars with mill scale and provides the corresponding protection measures, which can be used as a reference for corrosion or civil engineers. Preface About This Book Contents 1 Passivation of Iron 1.1 Discovery and Explanation of Passivation 1.2 E-pH 1.3 Passive Films of Iron 1.4 Summary References 2 Determination Methods of Passivation 2.1 Passivatability and Self-Passivity 2.2 Determination of Passivity 2.2.1 Potentiodynamic Polarization Method 2.2.2 Other Methods 2.3 Summary References 3 Passivation of Rebars Without Mill Scale 3.1 Potentiodynamic Polarization of Rebars Without Mill Scale 3.2 Passive Films of Rebars Without Mill Scale 3.2.1 Produced by Anodic Polarization 3.2.2 Produced by Natural Immersion 3.3 Passivation Characteristics of Descaled Rebars 3.4 Summary References 4 Mill Scale of Hot-Rolled Rebars 4.1 High-Temperature Oxidation of Iron 4.2 Formation of Mill Scale 4.2.1 Oxidation Process 4.2.2 Rolling Defects 4.3 Microstructure of Rebar Mill Scale 4.3.1 Surface Morphology 4.3.2 Section Morphology 4.4 Semiconductive Properties of Mill Scale 4.4.1 Conductivity of Iron Oxide 4.4.2 Semiconductive Properties of Scale-Solution System 4.5 Summary References 5 Passivation of Hot-Rolled Rebars 5.1 Passivation of Hot-Rolled Rebars 5.1.1 HPB235 5.1.2 HRB335 5.1.3 HRB400 5.2 Oxidation of Mill Scale 5.2.1 HRB335 5.2.2 HRB400 5.3 Pseudo-Passivation Mechanisms of Rebar 5.4 Summary References 6 Redox Reactions of Hot-Rolled Rebars 6.1 Electrode Reactions of Fe in Water 6.2 Reactions of Fe and Descaled Rebar in Alkaline Solutions 6.3 Cyclic Voltammetry of Rebar with Mill Scale 6.3.1 HRB335 6.3.2 HRB400 6.4 Oxidation and Reduction of Mill Scale 6.4.1 Reduction of Mill Scale 6.4.2 Redox Reaction Mechanisms of Mill Scale 6.5 Summary References 7 Corrosion of Hot-Rolled Rebars 7.1 Existing Theories 7.2 Effect of Mill Scale on Metallic Corrosion Resistance 7.3 Corrosion Resistance of Rusty Rebar 7.3.1 Rusty Rebar 7.3.2 Fresh Mortar 7.3.3 Cement Hydration Solution 7.3.4 Simulated Concrete Pore Solution 7.4 Corrosion Under Trace Chloride Ions 7.5 Galvanic Corrosion 7.6 Effect of Dissolved Oxygen Concentration 7.7 Carrier Analysis 7.8 Corrosion Mechanisms of Hot-Rolled Rebars 7.9 Unified Model for the Passivation and Corrosion of Rebar 7.10 Summary References 8 Protection of Hot-Rolled Rebars 8.1 General Principles 8.2 High-Temperature Phosphating of Hot-Rolled Rebars 8.3 Cathodic Protection 8.4 Change the Rebar Interfacial Environment 8.5 Physical Isolation or Substitution 8.6 Summary References 9 Further Work Needs to Do 9.1 Carriers’ Problem 9.2 Influence of Adsorption Films 9.3 Influence of Stress References Epilogue Appendix A Chemical Stability of Metals Appendix B Iron Compounds Appendix C Experimental Materials Index