Durability of Concrete Design and Construction

Mark Alexander, Arnon Bentur, and Sidney Mindess

~ ~~r~Fr~~i~Z~up ~ Boca Raton London New Yori<

CRC Press is an imprint of the Taylor & Francis Group, an lnforma business

Contents

Preface xvu Acknowledgments XIX

Authors XXI

1 Introduction 1

References 9

2 Concrete as a modern construction material 11

2.1 Overview 11 2.2 Hydration, microstructure, and pore solution composition 14

2.2.1 Range of binder compositions 14 2.2.2 Microstructure and pore solution composition 18

2.3 Control of the rheology of fresh concrete 23 2.4 Control of density and concrete microstructure 26

2.5 Deformations and crack control 32 References 34

3 Materials for concretes in relation to durability 37

3.1 Introduction 37 3.2 Portland cements and other binders 37

3.2.1 Chemical attack 38 3.2.1.1 Alkali-aggregate reaction 39 3.2.1.2 Sulfate attack 39 3.2.1.3 Acid attack 40 3.2.1.4 Other considerations 40 3.2.1.5 Fineness 41 3.2.1.6 C3A content 41

3.2.2 Physical attack 42 3.2.2.1 Thermal effects 42

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Contents

3.3 Aggregates 43 3.3.1 Physical mechanisms 44

3.3.1.1 Thermal ef fects 44 3.3.1.2 Moisture effects 45 3.3.1.3 Freezing and thawing 4 5 3.3.1.4 Abrasion and erosion 45 3.3.1.5 Maximum aggregate size 46 3.3.1.6 Recycled concrete aggregates 46

3.3.2 Chemical mechanisms 47 3.4 Water 47 3.5 Admixtures 48

3.5.1 Supplementary cementing materials 49 3.5.2 Chemical admixtures 49

3.6 Fibers 49 References 50

Concrete deterioration

4.1 Introduction 53 4.2 Concrete properties relevant to deterioration 56

4.2.1 Transport properties of concrete 56 4.2.1.1 Permeation 56 4.2.1.2 Absorption 56 4.2.1.3 Diffusion 57 4.2.1.4 Migration 58

53

4.2.1.5 Transport properties of cracked concrete 58 4.2.1.6 Summary of transport processes 59

4.2.2 Mechanical, physical, and chemical properties of concrete in relation to deterioration 59 4.2.2.1 Mechanical and physical properties 59 4.2.2.2 Chemical properties 60

4.2.3 Cracking of concrete and its in"f/.uence on deterioration 62

4.3 Mechanisms of deterioration 66 4.3.1 Introduction 66 4.3.2 Mechanical and physical

deterioration mechanisms 77 4.3.3 Chemical deterioration mechanisms 77

4.3.3.1 Exchange reactions between external aggressive medium and components of hardened cement paste (ion exchange or substitution) 77

Contents xi

4.3.3.2 Hydro/ysis and dissolution of the products of cement hydration (ion removal) 79

4.3.3.3 Expansive stresses caused by conversion of the products of hydration by agents (external or internal) (ion addition) 79

4.3.4 Other factors to consider in chemical deterioration 82 4.3.5 Steel corrosion in reinforced concrete 82

4.3.5.1 Mechanism of steel corrosion in concrete 83

4.3.5.2

4.3.5.3 4.3.5.4 4.3.5.5 4.3.5.6 4.3.5.7 4.3.5.8

Steel passivation and depassivation in concrete 84 Corrosion products 84 Corrosion initiation 85 Chloride binding in concrete 87 Corrosion rate in concrete 87 Corrosion of steel in cracked concrete 87 Electrochemical corrosion and nondestructive testing techniques 89

4.4 Design and construction considerations to minimize concrete deterioration 89 4.4.1 Concrete mix design and materials selection 89 4.4.2 Reinforcement cover 91 4.4.3 Curing of concrete 91

4.5 Concluding comments 92 Ref erences 92 Further reading 94

5 Durability specifications, limit states, and modeling

5.1 Basic concepts 97 5.1.1 Performance versus prescriptive specifications 98 5.1.2 Predictive models of service life 100 5.1.3 Service life design codes and standards 102 5.1.4 Equivalent performance concept 104 5.1.5 Durability tests 106

5.2 Limit state approach 108 5.2.1 Ultimate limit states 109 5.2.2 Serviceability limit states 109

5.3 Probabilistic limit state approach 112 5.4 Partial factor design approach 118

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xii Contents

5.5 Application of the limit state design methods 119 5.5.1 Limit states for corrosion of steel 120

5.5.1.1 Carbonation-induced corrosion 123 5.5.1.2 Chloride-induced corrosion 130 5.5.1.3 Residual service life-cycle estimation 142

5.5.2 Frost-induced internal damage 143 5.5.3 Chemical attack 146

5.6 Deemed-to-satisfy approach 146 5.7 Life-cycle cost analysis 152 References 15 3

6 Durability indicators (indexes) and their use in engineering practice

6.1 I ntroduction 15 5 6.1.1 Durability problems in concrete

structures; need for a new approach 155 6.1.2 Traditional approach to concrete durability 157 6.1.3 fib Model Code (2010) 159

6.2 Durability indicators; durability indexes 160 6.2.1 Philosophy of durability indicators or indexes 161

6.2.1.1 Material indexing 162 6.2.1.2 Direct durability testing 163 6.2.1.3 Structural performance 164 6.2.1.4 Fundamental mechanistic studies 164 6.2.1.5 Correlations 164

6.2.2 Need for an integrated sch~me 165 6.2.3 "Material potential„ versus "as-built quality„ 166

6.2.3.1 Differences between material potential and as-built quality 166

6.3 Materialparameters suitable as durability indicators 169 6.3.1 Physical parar.teters {physical

microstructure of the material) 169 6.3.1.1 Permeability to liquids andlor gases 169 6.3.1.2 Water absorption and sorptivity 169 6.3.1.3 Porosity; pore spacing parameters 170

6.3.2 Mechanical parameters 170 6.3.2.1 Abrasion resistance 171

6.3.3 Chemical parameters 171 6.3.3.1 Calciumhydroxide content 171 6.3.3.2 Degree of hydration 171

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Contents xiii

6.3.4 Physicochemical and electrochemical parameters 171 6.3.4.1 Diffusivity and conductivity 171 6.3.4.2 Resistivity 172 6.3.4.3 Electrical migration 172 6.3.4.4 Rapid chloride permeability test 173

6.3.5 Other parameters 173 6.4 Performance-based durability design and

specification: Link with durability indicators 174 6.4.1 Prescriptive versus performance-based design

and specification 174 6.4.1.1 Performance-based approach

to durability design 174 6.4.2 Durability indicators and performance­

based durability design 176 6.4.2.1 South African experience:

Durability indexes and a performance-based approach 176

6.5 Use of durability indicators: Contemporary approaches and examples of implementation 178 6.5.1 Approaches in different countries 178

6.5.1.1 Canada 178 6.5.1.2 6.5.1.3 6.5.1.4 6.5.1.5 6.5.1.6 6.5.1.7

6.6 Closure 202 Ref erences 203 Further reading 208

France 182 The Netherlands 184 Norway 186 Spain 190 Switzerland 193 South Africa 194

7 Durability testing: Transport properties

7.1 Introduction 209 7.2 Penetration tests 210

7.2.1 Nonreactive penetrating fiuids 210 7.2.2 Reactive penetrating fiuids 211

7.3 Penetration tests based on transport of water 212 7.4 Penetration tests based on transport

of nonreactive gaseous fiuids 217 7.5 Chloride penetration 225

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7.6 Penetration of C0 2 and carbonation 234 Ref erences 23 7

8 Durability testing: Degradation mechanisms

8.1 Introduction 241 8.2 Tests identifying and quantifying

degradation processes of concrete 241 8.2.1 Alka/i-aggregate reaction tests 242 8.2.2 Sulfate resistance tests 245 8.2.3 Freeze-thaw resistance 247

8.3 Corrosion of steel in concrete 248 8.3.1 Introduction 248 8.3.2 Electrochemical corrosion and

nondestructive testing techniques 249 8.3.3 Half-cell potential method 251 8.3.4 Concrete resistivity 254 8.3.5 Linear polarization resistance 256 8.3.6 Electrochemical impedance spectroscopy 259

References

9 Design of concrete mixtures for durability

9.1 Introduction 263 9.2 Fundamentals of mix design 264

9.2.1 Design procedures 265 9.2.2 Freezing and thawing 266 9.2.3 Sulfate attack 267 9.2.4 Alkali-aggregate reactions 270

9.2.4.1 Mitigation of AAR 271 9.2.4.2 Use of a low alkali cement 271 9.2.4.3 Use of a low wie 271 9.2.4.4 Use o; SCMs 271 9.2.4.5 Other chemical additions 272

9.2.5 Abrasion and erosion 272 9.2.6 Concrete exposed to sea water 272

9.2.6.1 Fresh concrete 273 9.2.6.2 Hardened concrete 273

9.2.7 Acid attack 274 9.2.8 Corrosion of steel in concrete 275

9.3 Concluding remarks 276 References

241

261

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Contents xv

10 Durability and construction

10.1 Introduction 279 10.2 Concrete manufacture 280

10.2.1 Batcbing of concrete mixes 280 10.2.1.1 Contra/ of mixing water content 282 10.2.1.2 Quality control of concrete

279

constituents and concrete production 283 10.2.2 Concrete mixing 284

10.3 Site construction: Cballenges and site practices 285 10.3.1 Concrete bandling, placing, and compaction 286 10.3.2 Protection and curing 292 10.3.3 Cover control and cover measurement 297

10.3.3.1 Specification of cover and cover measurement 298

10.3.3.2 Spacers or spacer blocks 301 10.4 Concreting in cold and bot conditions 303

10.4.1 Concreting in cold weatber 303 10.4.2 Concreting in bot weatber 304

10.5 Quality control for durability 306 10.5.1 Evaluating material potential quality 306 10.5.2 Evaluating as-built concrete quality 307

10.6 Gase studies of durable construction 308 10.6.1 Concrete bridge, 0resund Link 309

10.6.1.1 Background and design 309 10.6.1.2 Concrete materials, mix designs,

and otber relevant information 310 10.6.1.3 Construction and quality management 311 10.6.1.4 Inspection and maintenance 313 10.6.1.5 Summary 313

10.6.2 Construction of tbe new Panama Canal 314 10.6.2.1 Introduction: background,

structures, and environment 314 10.6.2.2 Concrete design pbilosopby and basis 314 10.6.2.3 Durability aspects and

critique of specification 315 10.6.2.4 Construction, testing, and verification 316

References 317 Furtber reading 319

Index 321