Properties of concrete / Adam Matthew Neville.

CONTENIDO
1 Portland Cement 1
Historical note 1
Manufacture of Portland cement 2
Chemical composition of Portland cement 8
Hydration of cement 12
Calcium silicate hydrates 14
Tricalcium aluminate hydrate and the action of gypsum 17
Setting 19
False set 19
Fineness of cement 20
Structure of hydrated cement 25
Volume of products of hydration 26
Capillary pores 31
Gel pores 32
Mechanical strength of cement gel 34
Water held in hydrated cement paste 35
Heat of hydration of cement 37
Influence of the compound composition on properties of cement 40
Effects of alkalis 46
Effects of glass in clinker 48
Tests on properties of cement 49
Consistency of standard paste 49
Setting time 50
Soundness 51
Strength of cement 53
References 56
2 Cementitious materials of different types 62
Categorization of cementitious materials 62
Different cements 65
Ordinary Portland cement 69
Rapid-hardening Portland cement 71
Special very rapid-hardening Portland cements 72
Low heat Portland cement 75
Sulfate-resisting cement 76
White cement and pigments 77
Portland blastfurnace cement 79
Supersulfated cement 82
Pozzolanas 83
Fly ash 84
Pozzolanic cements 86
Silica fume 86
Fillers 88
Other cements 88
Which cement to use 90
High-alumina cement 91
Manufacture 91
Composition and hydration 92
Resistance to chemical attack 93
Physical properties of high-alumina cement 93
Conversion of high-alumina cement 95
Refractory properties of high-alumina cement 102
References 103
3 Properties of aggregate 108
General classification of aggregates 108
Classification of natural aggregates 109
Sampling 111
Particle shape and texture 112
Bond of aggregate 117
Strength of aggregate 119
Other mechanical properties of aggregate 122
Specific gravity 125
Bulk density 127
Porosity and absorption of aggregate 128
Moisture content of aggregate 132
Bulking of fine aggregate 134
Deleterious substances in aggregate 136
Organic impurities 136
Clay and other fine material 137
Salt contamination 139
Unsound particles 140
Soundness of aggregate 142
Alkali-silica reaction 144
Tests for aggregate reactivity 145
Alkali-carbonate reaction 147
Thermal properties of aggregate 148
Sieve analysis 149
Grading curves 154
Fineness modulus 155
Grading requirements 156
Practical gradings 163
Grading of fine and coarse aggregates 166
Oversize and undersize 168
Gap-graded aggregate 171
Maximum aggregate size 174
Use of plums 175
Handling of aggregate 176
Special aggregates 176
References 177
4 Fresh concrete 182
Quality of mixing water 182
Definition of workability 184
The need for sufficient workability 185
Factors affecting workability 186
Measurement of workability 189
Slump test 189
Compacting factor test 191
ASTM flow test 193
Remoulding test 193
Vebe test 194
Flow test 195
Ball penetration test 196
Nasser's K-tester 196
Two-point test 197
Comparison of tests 198
Stiffening time of concrete 200
Effect of time and temperature on workability 201
Segregation 204
Bleeding 206
The mixing of concrete 207
Concrete mixers 207
Uniformity of mixing 209
Mixing time 211
Hand mixing 214
Ready-mixed concrete 214
Retempering 216
Pumped concrete 217
Concrete pumps 217
Use of pumping 219
Requirements for pumped concrete 219
Pumping lightweight aggregate concrete 223
Shotcrete 224
Underwater concrete 226
Preplaced aggregate concrete 227
Vibration of concrete 228
Internal vibrators 229
External vibrators 230
Vibrating tables 230
Other vibrators 231
Revibration 231
Vacuum-dewatered concrete 232
Permeable formwork 234
Analysis of fresh concrete 235
References 237
5 Admixtures 243
Benefits of admixtures 243
Types of admixtures 244
Accelerating admixtures 245
Retarding admixtures 249
Water-reducing admixtures 252
Superplasticizers 255
Nature of superplasticizers 256
Effects of superplasticizers 257
Dosage of superplasticizers 259
Loss of workability 259
Superplasticizer-cement compatibility 262
Use of superplasticizers 262
Special admixtures 263
Waterproofing admixtures 263
Anti-bacterial and similar admixtures 264
Remarks about the use of admixtures 265
References 265
6 Strength of concrete 269
Water/cement ratio 269
Effective water in the mix 273
Gel/space ratio 274
Porosity 277
Cement compacts 284
Influence of properties of coarse aggregate on strength 284
Influence of aggregate/cement ratio on strength 287
Nature of strength of concrete 289
Strength in tension 289
Cracking and failure in compression 291
Failure under multiaxial stress 293
Microcracking 298
Aggregate-cement paste interface 300
Effect of age on strength of concrete 302
Maturity of concrete 304
Relation between compressive and tensile strengths 308
Bond between concrete and reinforcement 311
References 311
7 Further aspects of hardened concrete 318
Curing of concrete 318
Methods of curing 323
Tests on curing compounds 326
Length of curing 327
Autogenous healing 328
Variability of strength of cement 328
Changes in the properties of cement 332
Fatigue strength of concrete 335
Impact strength 343
Electrical properties of concrete 346
Acoustic properties 350
References 353
8 Temperature effects in concrete 359
Influence of early temperature on strength of concrete 359
Steam curing at atmospheric pressure 366
High-pressure steam curing (autoclaving) 370
Other thermal curing methods 374
Thermal properties of concrete 374
Thermal conductivity 374
Thermal diffusivity 377
Specific heat 377
Coefficient of thermal expansion 378
Strength of concrete at high temperatures and resistance to fire 385
Modulus of elasticity at high temperatures 388
Behaviour of concrete in fire 388
Strength of concrete at very low temperatures 390
Mass concrete 394
Concreting in hot weather 398
Concreting in cold weather 401
Concreting operations 403
References 405
9 Elasticity, shrinkage, and creep 412
Stress-strain relation and modulus of elasticity 412
Expressions for stress-strain curve 417
Expressions for modulus of elasticity 418
Dynamic modulus of elasticity 420
Poisson's ratio 421
Early volume changes 423
Autogenous shrinkage 425
Swelling 425
Drying shrinkage 426
Mechanism of shrinkage 426
Factors influencing shrinkage 429
Influence of curing and storage conditions 435
Prediction of shrinkage 437
Differential shrinkage 438
Shrinkage-induced cracking 441
Moisture movement 442
Carbonation shrinkage 443
Shrinkage compensation by the use of expansive cements 446
Types of expansive cements 446
Shrinkage-compensating concrete 448
Creep of concrete 449
Factors influencing creep 452
Influence of stress and strength 454
Influence of properties of cement 456
Influence of ambient relative humidity 457
Other influences 461
Relation between creep and time 465
Nature of creep 469
Effects of creep 472
References 474
10 Durability of concrete 482
Causes of inadequate durability 482
Transport of fluids in concrete 483
Influence of the pore system 483
Flow, diffusion, and sorption 484
Coefficient of permeability 485
Diffusion 485
Diffusion coefficient 486
Diffusion through air and water 486
Absorption 487
Surface absorption tests 488
Sorptivity 489
Water permeability of concrete 490
Permeability testing 494
Water penetration test 495
Air and vapour permeability 495
Carbonation 497
Effects of carbonation 498
Rates of carbonation 499
Factors influencing carbonation 501
Carbonation of concrete containing blended cements 503
Measurement of carbonation 504
Further aspects of carbonation 505
Acid attack on concrete 506
Sulfate attack on concrete 508
Mechanisms of attack 509
Factors mitigating the attack 511
Tests on sulfate resistance 512
Efflorescence 513
Effects of sea water on concrete 514
Salt weathering 516
Selection of concrete for exposure to sea water 517
Disruption by alkali-silica reaction 517
Preventive measures 519
Abrasion of concrete 521
Tests for abrasion resistance 521
Factors influencing abrasion resistance 523
Erosion resistance 523
Cavitation resistance 524
Types of cracking 525
References 529
11 Effects of freezing and thawing and of chlorides 537
Action of frost 537
Behaviour of coarse aggregate particles 542
Air entrainment 544
Air-void system characteristics 546
Entrained-air requirements 548
Factors influencing air entrainment 550
Stability of entrained air 553
Air entrainment by microspheres 554
Measurement of air content 554
Tests of resistance of concrete to freezing and thawing 556
Further effects of air entrainment 559
Effects of de-icing agents 561
Chloride attack 563
Mechanism of chloride-induced corrosion 563
Chlorides in the mix 566
Ingress of chlorides 567
Threshold content of chloride ions 569
Binding of chloride ions 569
Influence of blended cements on corrosion 571
Further factors influencing corrosion 572
Thickness of cover to reinforcement 574
Tests for penetrability of concrete to chlorides 574
Stopping corrosion 574
References 576
12 Testing of hardened concrete 581
Tests for strength in compression 581
Cube test 582
Cylinder test 583
Equivalent cube test 583
Effect of end condition of specimen and capping 584
Non-bonded caps 586
Testing of compression specimens 587
Failure of compression specimens 589
Effect of height/diameter ratio on strength of cylinders 591
Comparison of strengths of cubes and cylinders 593
Tests for strength in tension 594
Flexural strength tests 595
Splitting tension test 598
Influence on strength of moisture condition during test 600
Influence of size of specimen on strength 601
Size effects in tensile strength tests 603
Size effects in compressive strength tests 605
Specimen size and aggregate size 609
Test cores 611
Use of small cores 612
Factors influencing strength of cores 613
Relation of core strength to strength in situ 616
Cast-in-place cylinder test 617
Influence of rate of application of load on strength 618
Accelerated-curing test 619
Direct use of accelerated-curing strength 623
Non-destructive tests 623
Rebound hammer test 624
Penetration resistance test 627
Pull-out test 629
Post-installed tests 630
Ultrasonic pulse velocity test 631
Further possibilities in non-destructive testing 633
Resonant frequency method 634
Tests on the composition of hardened concrete 635
Cement content 635
Determination of the original water/cement ratio 636
Physical methods 636
Variability of test results 637
Distribution of strength 637
Standard deviation 640
References 641
13 Concretes with particular properties 649
Concretes with different cementitious materials 649
General features of use of fly ash, ggbs, and silica fume 650
Durability aspects 651
Variability of materials 652
Concrete containing fly ash 653
Influence of fly ash on properties of fresh concrete 654
Hydration of fly ash 655
Strength development of fly ash concrete 657
Durability of fly ash concrete 660
Concretes containing ground granulated blastfurnace slag (ggbs) 661
Influence of ggbs on properties of fresh concrete 662
Hydration and strength development of concrete containing ggbs 662
Durability aspects of concrete containing ggbs 665
Concrete containing silica fume 666
Influence of silica fume on properties of fresh concrete 667
Hydration and strength development of the Portland cement-silica fume system 669
Durability of concrete containing silica fume 672
High performance concrete 674
Properties of aggregate in high performance concrete 676
Aspects of high performance concrete in the fresh state 677
Compatibility of Portland cement and superplasticizer 678
Aspects of hardened high performance concrete 680
Testing of high performance concrete 683
Durability of high performance concrete 684
The future of high performance concrete 687
Lightweight concrete 688
Classification of lightweight concretes 688
Lightweight aggregates 689
Natural aggregates 689
Manufactured aggregates 692
Requirements for aggregates for structural concrete 694
Effects of water absorption by lightweight aggregate 696
Lightweight aggregate concrete 698
Aspects of the fresh state 698
Strength of lightweight aggregate concrete 699
Lightweight aggregate-matrix bond 702
Elastic properties of lightweight aggregate concrete 703
Durability of lightweight aggregate concrete 704
Thermal properties of lightweight aggregate concrete 706
Cellular concrete 708
Autoclaved aerated concrete 709
No-fines concrete 711
Nailing concrete 714
Remark about specialized concretes 715
References 715
14 Selection of concrete mix proportions (mix design) 724
Cost considerations 725
Specifications 725
The process of mix selection 727
Mean strength and 'minimum' strength 729
Variability of strength 732
Quality control 738
Factors governing the selection of mix proportions 739
Durability 740
Workability 743
Maximum size of aggregate 744
Grading and type of aggregate 744
Cement content 745
Mix proportions and quantities per batch 745
Calculation by absolute volume 747
Combining aggregates to obtain a type grading 748
American method of selection of mix proportions 751
Example 755
Mix selection for no-slump concrete 756
Mix selection for flowing concrete 757
Mix selection for high performance concrete 758
Mix selection for lightweight aggregate concrete 759
Example 761
British method of mix selection (mix design) 762
Example 768
Other methods of mix selection 769
Concluding remarks 769
References 770