Corrosion Of Reinforcement In Concrete (efc 25): Monitoring, Prevention And Rehabilitation (european Federation Of Corrosion Publications)

The results of research info and application of various prevention, protection and remedial methods are discussed, together with aspects of the understanding of the mechanisms of the processes that are involved. Experience in the field with the application of electrochemical methods for protection and restoration and procedures for monitoring the protection are described. Front Matter 1 Series Introduction 3 Preface 5 Table of Contents 6 Part I. Corrosion Mechanisms 10 1. Effect of Potential Drop in Migration Testing of Chloride Diffusivity in Concrete 10 1.1 Introduction 10 1.2 Theoretical Background 10 1.3 Experimental 12 1.3.1 Materials and Specimen Preparation 12 1.3.2 Test Procedures 13 1.4 Results and Discussion 13 1.5 Conclusions 16 References 17 2. Results From Laboratory Tests and Evaluation of Literature on the Influence of Temperature on Reinforcement Corrosion 18 2.1 Introduction 18 2.2 Theoretical Background 18 2.2.1 General 18 2.2.2 Electrochemical Corrosion Process 19 2.2.3 Simplified Electrical Circuit Model 19 2.2.4 Basic Influencing Parameters 20 2.2.5 Influence of Temperature 21 2.3 Results from Laboratory Tests 21 2.3.1 General 21 2.3.2 Laboratory Investigations Based on Macrocell-Measurements 22 2.3.2.1 General 22 2.3.2.2 Test Set-Up and Materials 22 2.3.2.3 Testing Programme 23 2.3.2.4 Test Results and Discussion 23 2.3.3 Results from Other Laboratory Tests 26 2.3.3.1 Influence of Temperature on the Electrical Resistivity of Concrete 26 2.3.3.2 Influence of Temperature on the Corrosion Rate 27 2.3.3.3 Influence of Temperature on the Cathodic Process 27 2.4 Results from Measurements On-Site 27 2.5 Conclusions 27 2.6 Further Outlook 28 References 28 3. Corrosion Induced Cracking of Reinforcing Steel 30 3.1 Introduction 30 3.2 Stress Corrosion Cracking SCC 30 3.3 Corrosion Fatigue 34 References 37 Part II. Reference Electrodes, Supplementary Protection Measures 39 4. Junction Potentials at a Concrete/Electrolyte Interface 39 4.1 Introduction 39 4.1.1 What is a 'True Potential'? 40 4.2 Experimental 40 4.2.1 Diffusion Potentials 40 4.2.2 Streaming Potentials 42 4.2.3 A Good Solution 45 4.3 Discussion 46 References 47 5. Manganese Dioxide Reference Electrodes for Use in Concrete 48 5.1 Introduction 48 5.2 Experimental 50 5.2.1 Uniformity of MnO_2 -Electrodes 50 5.2.2 Short-Term Stability of Embedded Electrodes 50 5.2.3 Long-Term Stability of Embedded Electrodes 51 5.2.4 Polarisation Behaviour 52 5.2.5 Temperature Response 52 5.2.6 Dynamic Tests 56 5.3 Field Experience 59 5.4 Discussion 60 References 60 6. Corrosion Inhibitors for Steel in Concrete 62 6.1 Introduction 62 6.2 Corrosion Inhibitors for Use in Concrete 63 6.3 Mechanism 63 6.4 Inhibitors as Repair Strategy 64 6.5 Short Literature Review 65 6.5.1 Nitrites 65 6.5.2 Stannous Chloride 66 6.5.3 Sodium Benzoate 66 6.5.4 MFP Sodium Monofluoro Phosphate, Na_2 PO_3 F 66 6.5.5 Alkanolamines and Amines 67 6.5.6 Organic Based Admixtures 68 6.6 Laboratory Study with Migrating Corrosion Inhibitors 69 6.6.1 Experiments in Solution 69 6.6.2 Surface Analysis 70 6.6.3 Mortar Experiments 71 6.6.4 Field Tests 72 6.7 Critical Evaluation of Corrosion Inhibitors 73 6.7.1 Concrete Properties - Environment 73 6.7.2 Concentration Dependence 73 6.7.3 Measurement and Control of Inhibitor Action 74 6.7.4 Durability of the Inhibitor Action 74 6.8 Concluding Remarks 74 References 75 Part III. Corrossion Rate Measurement 79 7. Performance Testing of Corrosion Inhibitors for Concrete Using Mortar Samples 79 7.1 Introduction 79 7.2 Experimental 81 7.3 Results and Discussion 83 7.4 Conclusions 87 References 88 8. Dependence of Corrosion Rate of Rebars on Climatic Parameters in Outdoor Concrete Structures Contaminated with Chlorides 89 8.1 Introduction 89 8.2 Experimental 90 8.3 Results 91 8.3.1 Chloride-Containing Structure 91 8.3.2 Carbonated Structure 94 8.4 Discussion 95 8.5 Conclusions 97 References 97 9. Corrosion Rate of Steel in Concrete - From Laboratory to Reinforced Concrete Structures 98 9.1 Introduction 98 9.1.1 Location of Corroding Areas - Half-Cell Potential Mapping 98 9.1.2 Corrosion Rates 99 9.1.3 Determination of the Polarisation Resistance R_p 99 9.2 Corrosion Rate Measurements On-Site 101 9.2.1 Current Distribution 101 9.2.2 Determination of the Ohmic Resistance 104 9.2.3 Determination of Localised Corrosion Rates 106 9.2.4 Variation of i_corr with Time 107 9.3 Conclusions 107 9.4 Glossary 108 References 108 10. Field and Laboratory Experience with Potentiostatic Polarisation and Potentiokinetic Scans to Assess the Severity of Corrosion of Steel in Concrete 110 10.1 Introduction 110 10.2 Experimental Technique 111 10.3 Results 111 10.3.1 Potentiodynamic Scans and Cyclic Voltammetry 111 10.3.2 Potentiostatic Polarisation 115 10.4 Discussion 119 10.4.1 Polarisation Resistance Obtained by Potentiodynamic Polarisation 119 10.4.2 Polarisation Resistance Obtained by Potentiostatic Polarisation 123 10.4.3 The Origin of the Polarisation Induced Changes of the Electrodes 124 10.4.4 The Relationship Between Polarisation Resistance and Corrosion Rate 124 10.5 Conclusions 126 References 126 Part IV. Electrochemical Realkalisation and Chloride Removal 129 11. Repair of Reinforced Concrete Structures by Electrochemical Techniques - Field Experience 129 11.1 Introduction 129 11.2 Fundamentals 130 11.2.1 Ion Migration 131 11.3 Laboratory Results 132 11.4 Results from Field Application 135 11.4.1 Condition Assessment 135 11.4.1.1 Electrochemical Realkalisation [13] 136 11.4.1.2 Electrochemical Chloride Removal [6,12] 136 11.4.2 Electrochemical Treatment 137 11.4.3 Checking the Effectiveness of the Treatment 137 11.4.3.1 Half-Cell Potential Measurements 137 11.4.3.2 Total Charge Flow 141 11.4.3.3 Sodium Content 141 11.4.3.4 Chloride Content 142 11.5 Durability of the Treatment 142 11.6 Application to Post-Tensioned Structures 142 11.7 Conclusions 143 11.8 Acknowledgements 143 References 143 12. The Perception of the ASR Problem with Particular Reference to Electrochemical Treatments of Reinforced Concrete 145 12.1 Introduction 145 12.1.1 Presence of Alkali Reactive Aggregates 146 12.1.2 Presence of Moisture 146 12.1.3 Alkali Metal Ions 146 12.1.4 Temperature 147 12.1.5 pH Value 149 12.2 Effect of Desalination on ASR 150 12.3 Effect of Realkalisation on ASR 150 12.4 Other Considerations 151 12.5 Concluding Remarks 152 References 152 13. Experience on Accuracy of Chloride and Sodium Analysis of Hardened Concrete 154 13.1 Introduction 154 13.2 Nordic Round Robin Test 155 13.2.1 Experimental 155 13.2.2 Results 155 13.2.2.1 Quantab Test 155 13.2.2.2 Chloride Selective Electrode Potentiometry 156 13.2.2.3 Volhard Titration 157 13.3 Dutch Round Robin Test 157 13.4 Sodium Analysis 159 13.5 Concluding Remarks 160 References 161 Part V. Cathodic Protection 163 14. Principles of Cathodic Protection and Cathodic Prevention in Atmospherically Exposed Concrete Structures 163 14.1 Introduction 163 14.2 Beneficial Effects 165 14.3 Behaviour of Steel in Chloride-Contaminated Concrete 165 14.4 The Initiation of Corrosion and Its Prevention 166 14.5 The Propagation of Corrosion and Its Control 167 14.6 Cathodic Protection in Carbonated Concrete 169 14.7 Hydrogen Embrittlement 170 14.8 The Throwing Power 171 14.9 Conclusions 172 References 172 15. Cathodic Protection of Reinforced Concrete Structures in The Netherlands - Experience and Developments 174 15.1 Introduction 174 15.2 Cantilever Beams in Two Apartment Blocks, Tilburg 175 15.2.1 History 175 15.2.2 Design and Execution 175 15.2.3 Conventional Repairs 177 15.2.4 Performance During Six Years 177 15.3 Gallery Slabs and Frames, Groningen 178 15.3.1 History and Preliminary Investigation 178 15.3.2 Design and Execution 178 15.3.3 Repair Mortar Compatibility 179 15.3.4 Performance 180 15.4 Abutments of a Post-Tensioned Bridge, River Dommel 181 15.4.1 History 181 15.4.2 Design and Execution 182 15.4.3 Performance 182 15.4.4 Further Results 183 15.5 Discussion of Evaluation Procedures 183 15.6 Concluding Remarks 183 15.7 Acknowledgement 184 References 184 16. Ten Years of Cathodic Protection in Concrete in Switzerland 186 16.1 Introduction 186 16.2 Cathodic Protection Procedure and Criteria of Protection 187 16.3 Survey 187 16.4 Checking the Efficiency 188 16.5 Experiences 188 16.5.1 Foreign Countries 188 16.5.2 Switzerland 189 16.5.3 Rodi Bridge 189 16.5.4 Intschi Bridge 192 16.5.5 Further, Recently Installed Systems 195 16.6 Conclusions 198 References 199 17. Cathodic Protection of Buried Reinforced Concrete Structures 200 17.1 Introduction 200 17.2 Design Constraints and Considerations 201 17.2.1 Anode Design 201 17.2.2 Design Life and Design Current Density 202 17.3 Monitoring Results 202 17.3.1 Potential Shift 202 17.3.2 Potential Decay 202 17.4 Discussion 203 17.5 Conclusions 206 References 206 List of Abbreviations 208 Index 209 A 209 B 209 C 210 D 212 E 212 H 213 I 214 L 215 M 215 O 216 P 216 Q 218 R 218 S 219 T 219 V 220 Plate Section 222 Content: • Front Matter • Series Introduction • Preface • Table of Contents •Part I. Corrosion Mechanisms 1. Effect of Potential Drop in Migration Testing of Chloride Diffusivity in Concrete 2. Results From Laboratory Tests and Evaluation of Literature on the Influence of Temperature on Reinforcement Corrosion 3. Corrosion Induced Cracking of Reinforcing Steel •Part II. Reference Electrodes, Supplementary Protection Measures 4. Junction Potentials at a Concrete/Electrolyte Interface 5. Manganese Dioxide Reference Electrodes for Use in Concrete 6. Corrosion Inhibitors for Steel in Concrete •Part III. Corrossion Rate Measurement 7. Performance Testing of Corrosion Inhibitors for Concrete Using Mortar Samples 8. Dependence of Corrosion Rate of Rebars on Climatic Parameters in Outdoor Concrete Structures Contaminated with Chlorides 9. Corrosion Rate of Steel in Concrete - From Laboratory to Reinforced Concrete Structures 10. Field and Laboratory Experience with Potentiostatic Polarisation and Potentiokinetic Scans to Assess the Severity of Corrosion of Steel in Concrete •Part IV. Electrochemical Realkalisation and Chloride Removal 11. Repair of Reinforced Concrete Structures by Electrochemical Techniques - Field Experience 12. The Perception of the ASR Problem with Particular Reference to Electrochemical Treatments of Reinforced Concrete 13. Experience on Accuracy of Chloride and Sodium Analysis of Hardened Concrete •Part V. Cathodic Protection 14. Principles of Cathodic Protection and Cathodic Prevention in Atmospherically Exposed Concrete Structures 15. Cathodic Protection of Reinforced Concrete Structures in The Netherlands - Experience and Developments 16. Ten Years of Cathodic Protection in Concrete in Switzerland 17. Cathodic Protection of Buried Reinforced Concrete Structures • List of Abbreviations • Index • Plate Section This volume in the European Federation of Corrosion series brings together the full papers presented in the successful session ""Corrosion of Steel in Concrete"" at EUROCORR '99 held in Aachen, Germany. The papers, grouped under the two headings ""Corrosion Mechanisms and Corrosion Measurements"" and ""Corrosion Protection of Reinforced Concrete Structures"" provide a bridge between theory and practice and will be of value to both scientists and engineers 'Published for the European Federation of Corrosion.''Book number 710'--T.p. versoIncludes bibliographical references and indexElectronic reproduction.Norwich, N.Y. :Knovel,2007.System requirements: Adobe Acrobat Reader.Available via the World Wide Web.Access restricted to users at licensed institutions.Includes interactive index