Systematic Approach of Characterisation and Behaviour of Recycled Aggregate Concrete (eBook)

Chakradhara Rao M is an associate professor at the Civil Engineering Department at the Institute of Technology, Guru Ghasidas Vishwavidyalaya (a Central University), Bilaspur, Chhattisgarh, India. He holds a Ph.D. degree from the Indian Institute of Technology Kharagpur (IIT Kharagpur), an M.Tech. (Structural Eng.) from the National Institute of Technology (NIT), Surathkal, Karnataka and a B.Tech. (Civil Eng.) from Nagarjuna University, Guntur, Andhra Pradesh (A.P.). His research interests are sustainable construction materials and microstructure of concrete. He has published more than 20 papers in leading national/international journals and conferences.Sriman K. Bhattacharyya is currently the Deputy Director of the Indian Institute of Technology Kharagpur (IIT Kharagpur). Formerly he was the Director of Council of Scientific & Industrial Research (CSIR)-Central Building Research Institute at Roorkee. He is a senior professor and Ex-head of Civil Engineering at IIT Kharagpur. His research interests include fluid–structure interactions, structural health monitoring, sustainability of materials and fibre-reinforced polymer (FRP)-Concrete composite systems. He is a fellow of the Indian National Academy of Engineering, Institution of Engineers (India) and Institution of Structural Engineering. He has travelled to various countries in connection with his research.Sudhirkumar V. Barai holds B.E. (Civil) and M.E. (Civil) degrees with specialisation in Structural Engineering from Maharaja Sayajirao (M.S.) University of Baroda and a PhD (Eng.) from the Indian Institute of Science, Bangalore. He is a professor of Structural Engineering at the Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India. His research interests include computational intelligence applications, structural health monitoring and concrete technology. He has published more than 200 papers in leading national/international journals and conferences. He is a fellow of the Association of Consulting Civil Engineers (India) and Institution of Engineers (India). He is also the co‐author (with Shailendra Kumar) of the book Concrete Fracture Models and Applications, which has recently been published by Springer.

Foreword 8
Preface 10
Acknowledgements 13
Contents 15
About the Authors 19
Symbols and Abbreviations 21
List of Figures 25
List of Tables 35
1 Introduction 39
1.1 Introduction 39
1.2 Applications of Recycled Aggregates 43
1.3 Benefits of Recycled Aggregates 46
1.3.1 Economic Aspects 47
1.3.2 Reducing Environmental Impacts 48
1.3.3 Saving Resources 48
1.4 Constraints of Recycled Aggregate Concrete 49
1.4.1 Management Problems (Tam and Gao 2003) 49
1.4.1.1 Lack of Suitable Regulations 49
1.4.1.2 Lack of Codes, Specifications, Standards and Guidelines 49
1.4.1.3 Lack of Experience 49
1.4.2 Technology Problems 49
1.4.2.1 Cement Mortar Attached to Aggregate 50
1.4.2.2 Poor Grading 50
1.4.2.3 High Porosity of Recycled Aggregates 50
1.4.2.4 Weak Interfacial Transition Zone 50
1.4.2.5 Transverse Cracks Generated 50
1.4.2.6 Variations in Quality 51
1.4.2.7 High Impurity 51
1.4.2.8 Low Quality 51
1.5 Classification of Recycled Aggregates 52
1.6 Current Global Scenario 52
1.6.1 Japan 52
1.6.2 Germany 56
1.6.3 United Kingdom 58
1.6.4 Hong Kong 61
1.6.5 Australia 63
1.6.6 China 63
1.6.7 Spain 66
1.6.8 RILEM Specifications 68
1.6.9 India 68
1.7 Summary 72
References 73
2 Demolition Techniques and Production of Recycled Aggregate 77
2.1 Introduction 77
2.2 Methods of Demolition 78
2.2.1 Non-engineering Demolition 79
2.2.2 Engineering Demolition Techniques 80
2.2.2.1 Mechanical Methods 80
2.2.2.2 Demolition by Implosion or Explosion 84
2.2.2.3 Deconstruction 84
2.2.3 Top-Down demolition 85
2.3 Production Technology of Recycled Aggregates 85
2.3.1 Mobile Plants 89
2.3.2 Stationary/Fixed Plants 92
2.4 Process of Recycling Technology 93
2.4.1 Jaw Crusher 93
2.4.2 Impact Crusher 93
2.4.3 Gyratory Crushers 94
2.4.4 Pre-crushing Separation 96
2.5 Summary 98
References 99
3 Properties of Recycled Aggregates 102
3.1 Introduction 102
3.2 Physical Properties of Recycled Aggregates 103
3.2.1 Grading, Shape and Surface Texture 103
3.2.2 Density and Specific Gravity 105
3.2.3 Water Absorption 108
3.2.4 Flakiness and Elongation Indices 112
3.3 Mechanical Properties of Recycled Aggregates 113
3.3.1 Aggregate Crushing Value 113
3.3.2 Los Angeles Abrasion Resistance Value 114
3.4 Summary 116
References 117
4 Properties of Recycled Aggregate Concrete 119
4.1 Introduction 119
4.2 Workability 119
4.2.1 Factors Influencing the Workability 119
4.2.1.1 Effect of Water Requirement on Workability 120
4.2.1.2 Influence of Moisture State of Recycled Aggregate 122
4.2.1.3 Influence of Strength of Parent Concrete 126
4.3 Mechanical Properties 129
4.3.1 Compressive Strength 129
4.3.1.1 Effect of Amount of Recycled Aggregate 130
4.3.1.2 Effect of Method of Curing 135
4.3.1.3 Effect of Strength of Parent Concrete 136
4.3.1.4 Effect of W/C Ratio 142
4.3.1.5 Effect of Moisture State of RA 143
4.3.2 Static Modulus of Elasticity 146
4.3.3 Split Tensile Strength 152
4.3.4 Flexural Strength 162
4.3.5 Density 166
4.3.6 Ultrasonic Pulse Velocity (UPV) 170
4.4 Interrelationships Among Mechanical Properties 175
4.4.1 Relationship Between Compressive Strength and Split Tensile Strength 177
4.4.2 Compressive Strength and Flexural Strength or Modulus of Rupture Relationship 179
4.4.3 Compressive Strength and Static Modulus of Elasticity Relationship 181
4.4.4 Compressive Strength and Ultrasonic Pulse Velocity (UPV) Relationship 183
4.4.5 Compressive Strength and Density Relationship 184
4.5 Summary 185
References 188
5 Long-Term and Durability Properties 194
5.1 Introduction 194
5.2 Shrinkage 195
5.2.1 Influence of Amount of Recycled Aggregate 195
5.2.2 Effect of Quality of Recycled Aggregate 197
5.2.3 Effect of Mineral Admixtures 201
5.2.4 Effect of Source Concrete, Crushing Method, and Age of Crushing 203
5.2.5 Effect of Method of Curing 205
5.2.6 Effect of Method of Mixing 206
5.3 Creep 208
5.3.1 Effect of Water to Cement (w/c) Ratio 209
5.3.2 Effect of Mineral Admixtures 210
5.3.3 Effect of Method of Curing and Period of Curing 212
5.3.4 Estimation of Creep of RAC 213
5.4 Durability Performance of RAC 214
5.4.1 Permeability 214
5.4.2 Chloride Penetration 222
5.4.3 Carbonation Depth 231
5.5 Summary 236
References 239
6 Microstructure of Recycled Aggregate Concrete 243
6.1 Introduction 243
6.2 Sample Preparation for Microscopic Study 245
6.3 Scanning Electron Microscope (SEM) 246
6.4 Image Acquisition 246
6.5 Image Analysis 247
6.6 Vickers Microhardness (HV) 248
6.7 Characteristics of Interfacial Transition Zone (ITZ) 248
6.7.1 Hydration Compounds, Anhydrous Cement, and Porosity 254
6.7.2 Distribution of Hydration Compounds, Anhydrous Cement, and Porosity Across the Width of ITZ 257
6.7.3 Effect of Aggregate 265
6.8 Compressive Strength–Porosity Relationship 266
6.9 Microhardness of ITZ 268
6.10 Compressive Strength–ITZ Microhardness Relationship 271
6.11 Influence of Binder on ITZ 272
6.12 Influence of the Water–Binder Ratio, Quality and Quantity of Adhesion Mortar 274
6.13 Influence of Strength of Source Concrete 278
6.14 Influence of Treatment of RCA on ITZ 279
6.15 Summary 279
References 280
7 Structural Behavior of RAC 282
7.1 Introduction 282
7.2 Impact Behavior 283
7.2.1 Instrumented Drop Hammer Impact Test Setup and Devices 285
7.2.2 Impact Test Results 287
7.2.2.1 Accelerations 287
7.2.2.2 Displacement 293
7.2.2.3 Strains 294
7.2.2.4 Support Reactions 297
7.2.2.5 Failure Pattern 299
7.3 Flexural Behavior of RAC 300
7.4 Shear Behavior of RAC 304
7.5 Other Structural Aspects 306
7.6 Summary 307
References 307
8 Quality Improvement Techniques 309
8.1 Introduction 309
8.2 Quality Improvement Techniques for Recycled Aggregate 309
8.2.1 Mechanical Treatment 310
8.2.2 Thermal Treatment 312
8.2.3 Chemical Treatment (Tam et al. 2007a, b) 314
8.2.4 Three-Step Method (Gao et al. 2013) 322
8.3 Impregnation Techniques 323
8.3.1 Silica Fume Impregnation 323
8.3.2 Ultrasonic Cleaning 324
8.3.3 Polymer Emulsion Impregnation 329
8.3.4 Surface Treatment with Nanomaterials 331
8.4 New Mixing Techniques 334
8.4.1 Two-Stage Mixing Approach 334
8.4.2 Diversifying Two-Stage Mixing Approach 338
8.4.3 Self-healing 340
8.5 Summary 340
References 342
Appendix A: Additional Results of Microstructure of Concrete 344
A.1 Introduction 344