The Issues and Discussion of Modern Concrete Science

This book is devoted to two primary objectives. The first is to present the errors, inadaptability, and mistakes arising when the current theory on concrete is applied to explaining practical construction of concrete; the second is to put forward viewpoints in modern concrete science.Taking a number of engineering cases as examples, we experimentally studied and theoretically analyzed the errors, inadaptability, and mistakes when the current theory on concrete is applied to explaining practical construction of concrete. Moreover, we investigated the use of mixing ratios, aggregates, cement, high-performance concrete and fibers, as well as the frost resistance, cracking behavior, durability, dry shrinkage and autogenous healing to address and remedy the shortcomings in today’s concrete science, put forward new proposals, and make a number of innovative achievements in the field, particularly in modern theory on concrete science. The results and topics which will be of particular interest to engineers and researchers include: corrections to several one-sided, even mistaken views on concrete construction in the field and a new theory that can be adopted to improve the durability of concrete projects, to control and improve the implementation quality of concrete projects, and to guide teaching in universities.**Wenke Yang** is a distinguished senior engineer at China Airport Construction Group Corporation, General Administration of Civil Aviation of China (CAAC). Foreword 5 Preface 6 Contents 8 About the Author 14 1 Sole of Concrete---Mix Proportion 15 1.1 Theoretical Foundation for Past Mix Proportion 16 1.1.1 Specific Surface Area Method 16 1.1.2 Maximum Density Method 18 1.1.3 Weymouth Grap Grading Method 19 1.2 Inadaptability Between Old Mix Proportion and Modern Concrete 21 1.3 Reasons and Puzzles 25 1.4 Thinking About Establishing the Modern Concrete Mix Proportion Theory 27 A.1. Others 33 A.1.1 Different Opinions 33 References 37 2 Important Raw Material---Coarse Aggregate 38 2.1 Aggregate Varieties and Causes Overview 38 2.2 Effects of Different Rock Aggregate on Performance of Concrete 43 2.2.1 Effects on Strength 43 2.2.2 Effects of Rock Mechanical Property on Other Performances of Concrete 45 2.3 Two Different Opinions 45 2.3.1 Different Opinions About Rock Strength Requirement in Specification 45 2.3.2 Utilization of Gravel 46 References 47 3 Core Raw Material---Cement 48 3.1 Effects of Cement Property Indexes on Concrete Performance 48 3.2 Overview of Cement Production Process 52 3.3 Effect of Modern Cement Production Process on Quality of Concrete 53 3.4 Where Is the Correct Direction of Cement Production Technology? 56 3.5 Ending Words 58 References 58 4 Alkali-Aggregate Reaction, Where Are You? 59 References 64 5 Is Air-Entraining Agent a Panacea for Solving Frost Resistance Problem? 65 5.1 Freeze&hx2013;Thaw Damage on Engineering 65 5.2 World-Recognized Measure for Enhancing Frost Resistance---Adding Air-Entraining Agent 68 5.3 Overview of Freeze&hx2013;Thaw Damage Theory 71 5.4 Research on Method and Measure for Enhancing Frost Resistance of Practical Engineering 72 5.5 What is the Correct Using Method and Range of Air-Entraining Agent (AEA) 74 5.6 Ending Words 79 References 80 6 Breeding and False Setting, Which Is Better? 81 6.1 Reasons for Breeding 82 6.2 Reasons for False Setting 88 6.3 Detriment of Breeding and False Setting 93 6.4 Prevention Method for Breeding and False Setting 94 References 95 7 Fiber, When Is Useful? 96 7.1 Fate and Experience with Fiber-Reinforced Concrete 96 7.2 Experimental Method and Conclusion 97 7.3 Reason Analyzing 100 7.4 Ending Words 102 References 102 8 Cancer of Modern Concrete---Cracks 104 8.1 General Remarks 104 8.2 Cause Analysis 107 8.2.1 Fine Questions Which Field Engineers Are Unable to Solve 107 8.2.2 Seven Problems Which Field Engineers Are Different to Solve 109 8.2.3 Eleven Problems Which Field Engineers Can Solve 110 8.3 Category of Cracks 112 8.3.1 Dehydration Cracks 112 8.3.2 Temperature Crack 112 8.3.3 Drying Shrinkage Crack 113 8.3.4 Stress Cracks 113 8.3.4.1 Generation Cause 114 8.3.4.2 Generation Time 115 8.3.4.3 Crack Scale 115 8.3.4.4 Detriment 115 8.4 Cause, Detriment, and Prevention of Dehydration Crack 115 8.4.1 Cause for Dehydration Crack 116 8.4.2 Harmfulness of Dehydration Crack 116 8.4.3 Prevention and Cure for Dehydration Crack 117 References 118 9 Fly Ash, Really Only Advantages? 119 9.1 Problems Unsolved in the Utilization of Fly Ash 119 9.1.1 Problems Unsolved Theoretically 119 9.1.2 Unsolved Technological Problems in Engineering 120 9.2 Several Practical Projects 121 9.2.1 The Concrete Surface of a Parking Apron in South China 121 9.2.2 The Concrete Surface of a Parking Apron in North China 124 9.2.3 Universal Harmless Cracks Phenomena in the Construction of Airport 125 9.2.4 The Floorslab of Terminal Buildings in an Airport in North China 125 9.2.5 Floor in a Plant in Southwest China 127 9.2.6 Other Cases 129 9.3 Summary 131 References 132 10 Admixtures: All Medicines Have Their Own Side Effects 133 10.1 Understanding on Negative Effects of Several Main Chemical Admixtures of the Author 133 10.1.1 Water Reducer 133 10.1.2 Air-Entraining Agent 134 10.1.3 Expansive Agent 135 10.1.4 Early-Strength Agent 135 10.2 Serious Quality Accident Cause by Improper Chemical Admixture Dosage 136 10.2.1 Water Reducer 136 10.2.2 Retarding Agent 137 10.2.3 Early-Strength Agent 139 10.2.4 Others 139 10.3 What Is the Correct Using Method of Chemical Admixture?2026? 140 10.4 Conclusion 140 References 141 11 Fatal Factor for Durability: Drying Shrinkage 142 11.1 Generating Process of Drying Shrinkage Crack 142 11.2 Harmfulness of Dehydration Crack 143 11.2.1 Drying Shrinkage Crack has Great Effect on Flexural Strength and Directly Threatens Safety of Concrete Structure 146 11.2.2 Destroying Structure Directly in Some Individual Severe Regions 148 11.2.3 Reducing Frost Resistance and Impermeability of Pavement Concrete in Cold Regions 151 11.2.4 Thin-Walled Structure and Reinforced Concrete Structure with Small Protection Layer Direct Impact on Their Durability and Usage Security 151 11.2.5 In Partial Regions in the South and North, Drying Shrinkage Crack is also Manifested as a Kind of Shallow and Harmless Crack Which has no Practical Effect on Security and Durability of Engineering 155 11.3 Cause for Drying Shrinkage Crack 156 11.4 Ending Words 158 References 159 12 Doctor of Concrete---Self-healing 160 12.1 Discovery of Self-curing Phenomenon 160 12.2 Cause Analysis 169 12.3 Application of Self-curing Principle During Practical Engineering 170 12.4 Ending Words 173 13 High-Performance Concrete, Really High Performance? 175 13.1 Difference Between Normal Concrete and High-Performance Concrete 175 13.2 Comparison of Application Effect During Practical Engineering 178 13.3 Ending Words 179 References 180 14 Where Is the Correct Idea for Durability Research? 181 14.1 Reason for Poorer Durability and Research Mistakes 181 14.2 Correct Method to Solve Durability Problem 183 14.3 Ending Words 187 References 187 15 Scientific Foundation of Modern Concrete 188 15.1 Discovery of the Problem 189 15.2 Conception of the Second-Period Concrete 192 15.3 Proposing of the ``Three-Stage Hypothesis'' 195 15.4 Cause Analysis 202 15.5 Scientific Meaning of Three-Period Theory Toward Modern Concrete 205 15.6 Ending Words 207 References 208 16 Summary Report of Experimental Study on Dehydration Crack Appearing in the Construction of Turpan Civil Airport Cement Concrete Pavement 210 16.1 Experimental Meaning and Purpose 210 16.1.1 Experimental Meaning 211 16.1.2 Experimental Purpose 212 16.2 Experimental Program 213 16.2.1 Emerging Time, Size, Shape, and Character of Dehydration Crack 213 16.2.2 Harmfulness of Dehydration Crack 214 16.2.3 Cause for Generation of Dehydration Crack 216 16.2.4 Experimental Program 219 16.2.5 Formation and Labor Division of Institutional Framework 224 16.3 Experimental Process 227 16.3.1 Preparation of Materials, Crews, and Machines 227 16.3.2 Concrete Mix Proportion 227 16.3.3 Process Controlling 230 16.3.4 Process of Curing and Observing 242 16.3.5 Experiment on Penetration Speed 245 16.3.6 Experiment on Water-to-Cement Ratio (W/C) 248 16.4 Experimental Summary and Conclusion 251 16.4.1 Introduction 251 16.4.2 Summary on Environment Climate Influence 252 16.4.3 Summary on Raw Material 253 16.4.4 Summary on Concrete Mix Proportion 256 16.4.5 Summary on Adding Polyester Fiber 259 16.4.6 Summary on Map Crack 261 16.4.7 Summary on Construction Technology 263 16.4.8 General Conclusions 265 16.5 Total Requirements for Construction of Concrete Used in Turpan Airport 266 16.5.1 Requirements for Construction Preparation 266 16.5.2 Controlling of Construction Process 267 Reference 271 Appendix A 272 Appendix B 279 Appendix C 283 This book is devoted to two primary objectives. The first is to present the errors, inadaptability, and mistakes arising when the current theory on concrete is applied to explaining practical construction of concrete; the second is to put forward viewpoints in modern concrete science. Taking a number of engineering cases as examples, we experimentally studied and theoretically analyzed the errors, inadaptability, and mistakes when the current theory on concrete is applied to explaining practical construction of concrete. Moreover, we investigated the use of mixing ratios, aggregates, cement, high-performance concrete and fibers, as well as the frost resistance, cracking behavior, durability, dry shrinkage and autogenous healing to address and remedy the shortcomings in today’s concrete science, put forward new proposals, and make a number of innovative achievements in the field, particularly in modern theory on concrete science. The results and topics which will be of particular interest to engineers and researchers include: corrections to several one-sided, even mistaken views on concrete construction in the field and a new theory that can be adopted to improve the durability of concrete projects, to control and improve the implementation quality of concrete projects, and to guide teaching in universities. Wenke Yang is a distinguished senior engineer at China Airport Construction Group Corporation, General Administration of Civil Aviation of China (CAAC). Front Matter....Pages i-xv Sole of Concrete—Mix Proportion....Pages 1-23 Important Raw Material—Coarse Aggregate....Pages 25-34 Core Raw Material—Cement....Pages 35-45 Alkali-Aggregate Reaction, Where Are You?....Pages 47-52 Is Air-Entraining Agent a Panacea for Solving Frost Resistance Problem?....Pages 53-68 Breeding and False Setting, Which Is Better?....Pages 69-83 Fiber, When Is Useful?....Pages 85-92 Cancer of Modern Concrete—Cracks....Pages 93-107 Fly Ash, Really Only Advantages?....Pages 109-122 Admixtures: All Medicines Have Their Own Side Effects....Pages 123-131 Fatal Factor for Durability: Drying Shrinkage....Pages 133-150 Doctor of Concrete—Self-healing....Pages 151-165 High-Performance Concrete, Really High Performance?....Pages 167-172 Where Is the Correct Idea for Durability Research?....Pages 173-179 Scientific Foundation of Modern Concrete....Pages 181-202 Summary Report of Experimental Study on Dehydration Crack Appearing in the Construction of Turpan Civil Airport Cement Concrete Pavement....Pages 203-264 Back Matter....Pages 265-279