Science and technology of concrete admixtures

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Science and technology of concrete admixtures

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Science and Technology of Concrete Admixtures Related titles Advances in Asphalt Materials (ISBN 978-0-08-100269-8) Acoustic Emission and Related Non-destructive Evaluation Techniques in the Fracture Mechanics of Concrete (ISBN 978-1-78242-345-4) Handbook of Alkali-activated Cements, Mortars and Concretes (ISBN 978-1-78242-276-1) Understanding the Rheology of Concrete (ISBN 978-0-85709-028-7) Woodhead Publishing Series in Civil and Structural Engineering: Number 59 Science and Technology of Concrete Admixtures Edited by Pierre-Claude Aïtcin and Robert J Flatt Knowing is not enough: we must apply Willing is not enough: we must –Goethe AMSTERDAM • BOSTON • CAMBRIDGE • HEIDELBERG LONDON • NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Woodhead Publishing is an imprint of Elsevier Woodhead Publishing is an imprint of Elsevier 80 High Street, Sawston, Cambridge, CB22 3HJ, UK 225 Wyman Street, Waltham, MA 02451, USA Langford Lane, Kidlington, OX5 1GB, UK Copyright © 2016 Elsevier Ltd All rights reserved No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein) Notices Knowledge and best practice in this field are constantly changing As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein ISBN: 978-0-08-100693-1 (print) ISBN: 978-0-08-100696-2 (online) British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library Library of Congress Control Number: 2015952093 For information on all Woodhead Publishing publications visit our website at http://store.elsevier.com/ Contents About the contributors Woodhead Publishing Series in Civil and Structural Engineering Preface Acknowledgments Introduction Terminology and definitions Glossary Historical background of the development of concrete admixtures Part One Theoretical background on Portland cement and concrete The importance of the water–cement and water–binder ratios P.-C Aïtcin 1.1 Introduction 1.2 The hidden meaning of the w/c 1.3 The water–cement and water–binder ratios in a cement paste made with a blended cement 1.4 How to lower the w/c and w/b ratios 1.5 Conclusion References xiii xv xix xxiii xxv xxxi xxxvii xli 3 11 12 13 Phenomenology of cement hydration P.-C Aïtcin 2.1 Introduction 2.2 Le Chatelier’s experiment 2.3 Powers’ work on hydration 2.4 Curing low w/c ratio concretes 2.5 Conclusion References 15 Portland cement P.-C Aïtcin 3.1 Introduction 3.2 The mineral composition of Portland cement clinker 3.3 The fabrication of clinker 3.4 Chemical composition of Portland cement 27 15 15 16 22 24 24 27 28 31 33 vi Contents 3.5 3.6 3.7 3.8 3.9 3.10 The grinding of Portland cement The hydration of Portland cement Hydrated lime (portlandite) Present acceptance standards for cements Side-effects of hydration reaction Conclusion Appendices References 36 39 43 44 44 45 45 50 Supplementary cementitious materials and blended cements P.-C Aïtcin 4.1 Introduction 4.2 Crystallized and vitreous state 4.3 Blast-furnace slag 4.4 Fly ashes 4.5 Silica fume 4.6 Calcined clays 4.7 Natural pozzolans 4.8 Other supplementary cementitious materials 4.9 Fillers 4.10 Ground glass 4.11 Blended cements 4.12 Conclusion References 53 Water and its role on concrete performance P.-C Aïtcin 5.1 Introduction 5.2 The crucial role of water in concrete 5.3 Influence of water on concrete rheology 5.4 Water and cement hydration 5.5 Water and shrinkage 5.6 Water and alkali/aggregate reaction 5.7 Use of some special waters 5.8 Conclusion References 75 Entrained air in concrete: rheology and freezing resistance P.-C Aïtcin 6.1 Introduction 6.2 Entrapped air and entrained air 6.3 Beneficial effects of entrained air 6.4 Effect of pumping on the air content and spacing factor 6.5 Entraining air in blended cements 6.6 Conclusion References 87 53 54 57 60 62 65 66 67 67 69 70 72 72 75 75 77 78 78 83 83 84 85 87 87 88 93 93 94 94 Contents vii 97 Concrete rheology: a basis for understanding chemical admixtures A Yahia, S Mantellato, R.J Flatt 7.1 Introduction 7.2 Definition of rheology 7.3 Different rheological behaviours 7.4 Micromechanical behaviour of suspensions 7.5 Factors affecting concrete rheology 7.6 Thixotropy of concrete 7.7 Conclusions Terminology and definitions Acknowledgements References Mechanisms of cement hydration D Marchon, R.J Flatt 8.1 Introduction 8.2 Hydration of C3A 8.3 Hydration of alite 8.4 Hydration of ordinary Portland cement 8.5 Conclusions Acknowledgments References Part Two 10 Chemistry and working mechanisms 97 98 101 104 110 116 120 121 122 122 129 129 130 131 138 141 141 141 147 Chemistry of chemical admixtures G Gelardi, S Mantellato, D Marchon, M Palacios, A.B Eberhardt, R.J Flatt 9.1 Introduction 9.2 Water reducers and superplasticizers 9.3 Retarders 9.4 Viscosity-modifying admixtures 9.5 Air-entraining admixtures 9.6 Shrinkage-reducing admixtures 9.7 Conclusions Acknowledgements References 149 Adsorption of chemical admixtures D Marchon, S Mantellato, A.B Eberhardt, R.J Flatt 10.1 Introduction 10.2 Adsorption and fluidity 10.3 Adsorption isotherms 10.4 Molecular structure and adsorption 10.5 Dynamic exchanges between surface and solution 219 149 150 171 175 182 197 207 207 207 219 220 221 226 232 viii Contents 10.6 10.7 10.8 10.9 11 12 13 14 Consumption (ineffective adsorption) Surfactant adsorption at the liquid–vapor interface Experimental issues in measuring adsorption Conclusions Acknowledgments References 234 239 241 248 248 248 Working mechanisms of water reducers and superplasticizers G Gelardi, R.J Flatt 11.1 Introduction 11.2 Dispersion forces 11.3 Electrostatic forces 11.4 DLVO theory 11.5 Steric forces 11.6 Effect of superplasticizers 11.7 Conclusions Acknowledgements References 257 Impact of chemical admixtures on cement hydration D Marchon, R.J Flatt 12.1 Introduction 12.2 Mechanisms of retardation 12.3 Retardation by superplasticizers 12.4 Retardation by sugars 12.5 Conclusions Acknowledgment References 279 Working mechanisms of shrinkage-reducing admixtures A.B Eberhardt, R.J Flatt 13.1 Introduction 13.2 Basic principles of the shrinkage of cementitious systems 13.3 Impact of SRAs on drying shrinkage 13.4 Dosage response of SRA on drying shrinkage 13.5 Conclusions References 305 Corrosion inhibitors for reinforced concrete B Elsener, U Angst 14.1 Introduction 14.2 Corrosion mechanisms of reinforcing steel in concrete 14.3 Corrosion inhibitors for steel in concrete 14.4 Critical evaluation of corrosion inhibitors 321 257 257 258 262 266 268 275 275 275 279 281 287 290 299 299 299 305 306 311 315 318 318 321 322 326 334 Contents ix 14.5 Concluding remarks References Part Three 15 Formulation of commercial products S Mantellato, A.B Eberhardt, R.J Flatt 15.1 Introduction 15.2 Performance targets 15.3 Cost issues 15.4 Conclusions Acknowledgments References Section One 16 17 Admixtures that modify at the same time the properties of the fresh and hardened concrete 341 343 343 343 346 347 347 347 351 Superplasticizers in practice P.-C Nkinamubanzi, S Mantellato, R.J Flatt 16.1 Introduction 16.2 Application perspective on superplasticizers and their use 16.3 Impact of superplasticizers on rheology 16.4 Unexpected or undesired behaviors 16.5 Conclusions Acknowledgments References 353 Air entraining agents R Gagné 17.1 Introduction 17.2 Mechanisms of air entrainment 17.3 Principal characteristics of a bubble network 17.4 Production of a bubble network 17.5 Stability of the network of entrained bubbles 17.6 Conclusion References 379 Section Two 18 The technology of admixtures 335 336 Admixtures that modify essentially the properties of the fresh concrete Retarders P.-C Aïtcin 18.1 Introduction 18.2 Cooling concrete to retard its setting 18.3 The use of retarders 353 354 357 362 371 372 372 379 379 380 381 388 390 390 393 395 395 396 397 ... considerations of the principles governing the formulation of commercial admixtures, we present the technology of four categories of concrete admixtures: • • • • Admixtures Admixtures Admixtures Admixtures... result of a massive research effort that has created a true science of concrete and a true science of admixtures It is the prime objective of this book to present the current state of the art of. .. The future of admixtures Conclusions and outlook on the future of concrete admixtures R.J Flatt 28.1 Chemical admixtures are to concrete, what spices are to cooking 28.2 Of good and bad concrete

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  • Front Cover

  • Related titles

  • Science and Technology of Concrete Admixtures

  • Copyright

  • Contents

  • About the contributors

  • Woodhead Publishing Series in Civil and Structural Engineering

  • Preface

    • References

  • Acknowledgments

  • Introduction

    • References

  • Terminology and definitions

    • Introduction

    • Cement, cementitious materials, binders, fillers

    • Binary, ternary, and quaternary cements (or binders)

    • Cementitous material content

    • Specific surface area

    • Alite and belite

    • Hemihydrate

    • Water–cement, water–cementitious materials, water–binder ratios

    • Saturated surface-dry state for an aggregate (SSD state)

    • Water content, absorption, moisture content of an aggregate

    • Specific gravity

    • Superplasticizer dosage

    • Eutectic

    • Reference

  • Glossary

  • Historical background of the development of concrete admixtures

    • Early developments

    • The development of the science of admixtures

    • The use of admixtures

    • The use of synthetic molecules and polymers

    • An artificially complicated terminology

    • Classification of admixtures

    • The importance of cement particles dispersion

    • References

  • One - Theoretical background on Portland cement and concrete

    • 1 - The importance of the water–cement and water–binder ratios

      • 1.1 Introduction

      • 1.2 The hidden meaning of the w/c

      • 1.3 The water–cement and water–binder ratios in a cement paste made with a blended cement

        • 1.3.1 Case of a blended cement containing a supplementary cementitious material

        • 1.3.2 Case of a blended cement containing some filler

        • 1.3.3 The relative importance of the w/c and w/b ratios

      • 1.4 How to lower the w/c and w/b ratios

      • 1.5 Conclusion

      • References

    • 2 - Phenomenology of cement hydration

      • 2.1 Introduction

      • 2.2 Le Chatelier's experiment

      • 2.3 Powers' work on hydration

        • 2.3.1 Hydration of a cement paste having a w/c ratio equal to 0.42

          • 2.3.1.1 Hydration in a closed system

          • 2.3.1.2 Hydration under water

        • 2.3.2 Hydration of a cement paste having a w/c ratio equal to 0.36 cured under water

        • 2.3.3 Hydration of a cement paste having a w/c ratio equal to 0.60 cured in a closed system

        • 2.3.4 Hydration of a cement paste having a w/c ratio of 0.30

          • 2.3.4.1 Hydration in a closed system

          • 2.3.4.2 Hydration under water

      • 2.4 Curing low w/c ratio concretes

        • 2.4.1 Different types of shrinkage

        • 2.4.2 Curing concrete according to its w/c ratio

      • 2.5 Conclusion

      • References

    • 3 - Portland cement

      • 3.1 Introduction

      • 3.2 The mineral composition of Portland cement clinker

      • 3.3 The fabrication of clinker

      • 3.4 Chemical composition of Portland cement

      • 3.5 The grinding of Portland cement

        • 3.5.1 Influence of the morphology of the cement particles

        • 3.5.2 Why is calcium sulphate added when grinding Portland cement?

      • 3.6 The hydration of Portland cement

      • 3.7 Hydrated lime (portlandite)

      • 3.8 Present acceptance standards for cements

      • 3.9 Side-effects of hydration reaction

      • 3.10 Conclusion

      • Appendices

        • Appendix 1

          • Tricalcium aluminate

        • Appendix 2

          • Ettringite

      • References

    • 4 - Supplementary cementitious materials and blended cements

      • 4.1 Introduction

      • 4.2 Crystallized and vitreous state

      • 4.3 Blast-furnace slag

      • 4.4 Fly ashes

      • 4.5 Silica fume

      • 4.6 Calcined clays

      • 4.7 Natural pozzolans

      • 4.8 Other supplementary cementitious materials

      • 4.9 Fillers

      • 4.10 Ground glass

      • 4.11 Blended cements

      • 4.12 Conclusion

      • References

    • 5 - Water and its role on concrete performance

      • 5.1 Introduction

      • 5.2 The crucial role of water in concrete

      • 5.3 Influence of water on concrete rheology

      • 5.4 Water and cement hydration

      • 5.5 Water and shrinkage

        • 5.5.1 General considerations

        • 5.5.2 How to eliminate the risk of plastic shrinkage

        • 5.5.3 How to mitigate autogenous shrinkage

        • 5.5.4 How to provide an internal source of water

        • 5.5.5 How to eliminate drying shrinkage

      • 5.6 Water and alkali/aggregate reaction

      • 5.7 Use of some special waters

        • 5.7.1 Seawater

        • 5.7.2 Wastewaters from ready-mix operations

      • 5.8 Conclusion

      • References

    • 6 - Entrained air in concrete: rheology and freezing resistance

      • 6.1 Introduction

      • 6.2 Entrapped air and entrained air

      • 6.3 Beneficial effects of entrained air

        • 6.3.1 The beneficial effect of entrained air on the workability of fresh concrete

        • 6.3.2 The beneficial action of entrained air against the propagation of cracks

        • 6.3.3 The beneficial action of entrained air on the absorptivity and permeability of concrete

        • 6.3.4 Trapping expansive products

        • 6.3.5 The beneficial effect of entrained air on the resistance to freezing and thawing cycles

      • 6.4 Effect of pumping on the air content and spacing factor

      • 6.5 Entraining air in blended cements

      • 6.6 Conclusion

      • References

    • 7 - Concrete rheology: a basis for understanding chemical admixtures

      • 7.1 Introduction

      • 7.2 Definition of rheology

        • 7.2.1 Shear laminar flow

        • 7.2.2 Shear stress

        • 7.2.3 Shear rate

        • 7.2.4 Flow curve

      • 7.3 Different rheological behaviours

        • 7.3.1 Newtonian fluids

        • 7.3.2 Bingham fluid

        • 7.3.3 Shear-thinning and shear-thickening fluids with yield stress

      • 7.4 Micromechanical behaviour of suspensions

        • 7.4.1 Yield stress

        • 7.4.2 Viscosity

        • 7.4.3 Thixotropy

        • 7.4.4 Concrete: A visco-elasto-plastic material

        • 7.4.5 Bleeding and segregation

      • 7.5 Factors affecting concrete rheology

        • 7.5.1 General considerations

        • 7.5.2 Effect of processing energy on concrete rheology

        • 7.5.3 Effect of solid concentration on viscosity and yield stress

        • 7.5.4 Effect of paste/aggregate and mortar/aggregate ratio on the rheology of concrete

        • 7.5.5 Effect of paste composition

          • 7.5.5.1 Effect of water content

          • 7.5.5.2 Effect of cement

          • 7.5.5.3 Effect of mineral admixtures

          • 7.5.5.4 Clays

        • 7.5.6 Effect of air content on rheology of concrete

      • 7.6 Thixotropy of concrete

        • 7.6.1 Consequences of thixotropy on concrete processing

        • 7.6.2 Experimental methods to quantify thixotropy

          • 7.6.2.1 Hysteresis curves

          • 7.6.2.2 Structural breakdown curves

          • 7.6.2.3 Structural build-up at rest

      • 7.7 Conclusions

      • Terminology and definitions

      • Acknowledgements

      • References

    • 8 - Mechanisms of cement hydration

      • 8.1 Introduction

      • 8.2 Hydration of C3A

      • 8.3 Hydration of alite

        • 8.3.1 Chemistry and stages of alite hydration

        • 8.3.2 Stages 0 and I: initial dissolution

          • 8.3.2.1 Protective membrane

          • 8.3.2.2 Dissolution control

        • 8.3.3 Stage II: the induction period

        • 8.3.4 Stage III: the acceleration period

          • 8.3.4.1 Structure of CSH

        • 8.3.5 The deceleration period

      • 8.4 Hydration of ordinary Portland cement

        • 8.4.1 Stages of cement hydration

        • 8.4.2 Silicate–aluminate–sulfate balance

      • 8.5 Conclusions

      • Acknowledgments

      • References

  • Two - Chemistry and working mechanisms

    • 9 - Chemistry of chemical admixtures

      • 9.1 Introduction

      • 9.2 Water reducers and superplasticizers

        • 9.2.1 Introduction

        • 9.2.2 Natural polymers

          • 9.2.2.1 Lignosulphonates

          • 9.2.2.2 Casein

        • 9.2.3 Linear synthetic polymers

          • 9.2.3.1 Polynaphthalene sulphonates (PNS)

          • 9.2.3.2 Polymelamine sulphonates

          • 9.2.3.3 Phosphonate-terminated PEG brushes

          • 9.2.3.4 Vinyl copolymers

        • 9.2.4 Comb-shaped copolymers

          • 9.2.4.1 Chemical nature of the backbone

          • 9.2.4.2 Chemical nature of side chains

          • 9.2.4.3 Characterization of comb-shaped superplasticizers

          • 9.2.4.4 Conformation of PCEs in solution

      • 9.3 Retarders

        • 9.3.1 Introduction

        • 9.3.2 Carbohydrates

          • 9.3.2.1 Monosaccharides

          • 9.3.2.2 Disaccharides

          • 9.3.2.3 Oligosaccharides

          • 9.3.2.4 Polysaccharides

      • 9.4 Viscosity-modifying admixtures

        • 9.4.1 Introduction

        • 9.4.2 Natural polymers

          • 9.4.2.1 Welan gum and diutan gum

        • 9.4.3 Semi-synthetic polymers

          • 9.4.3.1 Cellulose-ether derivatives

          • 9.4.3.2 Guar gum derivatives

          • 9.4.3.3 Modified starch

        • 9.4.4 Synthetic polymers

          • 9.4.4.1 Polyethylene oxide

          • 9.4.4.2 Polyacrylamides

        • 9.4.5 Inorganic powders

      • 9.5 Air-entraining admixtures

        • 9.5.1 Introduction

        • 9.5.2 General features of surfactants

          • 9.5.2.1 Basic structural features

          • 9.5.2.2 The concept of hydrophile-lipophile balance

        • 9.5.3 Sources for air-entraining admixtures

        • 9.5.4 Anionic surfactants

          • 9.5.4.1 Carboxylic acid salts

          • 9.5.4.2 Sulphonic acid salts

          • 9.5.4.3 Sulphuric acid ester salts

          • 9.5.4.4 Taurates

        • 9.5.5 Cationic surfactants

        • 9.5.6 Amphoteric surfactants

        • 9.5.7 Non-ionic surfactants

      • 9.6 Shrinkage-reducing admixtures

        • 9.6.1 Introduction

        • 9.6.2 History and working mechanism of SRAs

        • 9.6.3 General features and overview of surfactants used in SRAs

        • 9.6.4 Classes of compounds used in SRAs

          • 9.6.4.1 Monoalcohols

          • 9.6.4.2 Glycols

          • 9.6.4.3 Polyoxyalkylene glycol alkyl ethers

          • 9.6.4.4 Polymeric surfactants

          • 9.6.4.5 Other SRAs

      • 9.7 Conclusions

      • Acknowledgements

      • References

    • 10 - Adsorption of chemical admixtures

      • 10.1 Introduction

      • 10.2 Adsorption and fluidity

        • 10.2.1 Initial fluidity

        • 10.2.2 Fluidity retention

      • 10.3 Adsorption isotherms

        • 10.3.1 Basic phenomenology of adsorption

        • 10.3.2 Simple adsorption isotherm models

        • 10.3.3 Linear zone of adsorption isotherms of superplasticizers

        • 10.3.4 Specific issues in studying adsorption on cementitious systems

      • 10.4 Molecular structure and adsorption

        • 10.4.1 General features

        • 10.4.2 Adsorption of superplasticizers

        • 10.4.3 Surfactant adsorption at the solid–liquid interface

          • 10.4.3.1 Adsorption of ionic surfactants

          • 10.4.3.2 Adsorption of nonionic surfactants

      • 10.5 Dynamic exchanges between surface and solution

        • 10.5.1 Reversibility of adsorption

        • 10.5.2 Competitive adsorption

      • 10.6 Consumption (ineffective adsorption)

        • 10.6.1 Precipitation

        • 10.6.2 Organoaluminates

        • 10.6.3 Change of specific surface

        • 10.6.4 Adsorption on clay minerals

      • 10.7 Surfactant adsorption at the liquid–vapor interface

        • 10.7.1 Driving force for adsorption of surfactants and micelle formation

        • 10.7.2 Surfactant adsorption at the liquid–air interface1

      • 10.8 Experimental issues in measuring adsorption

        • 10.8.1 Suspension preparation

        • 10.8.2 Separation of the liquid phase

        • 10.8.3 Stabilization of the liquid phase after extraction

        • 10.8.4 Analysis of the liquid phase

        • 10.8.5 Indirect measurement of adsorption using zeta potential

        • 10.8.6 Measurement of the specific surface

      • 10.9 Conclusions

      • Acknowledgments

      • References

    • 11 - Working mechanisms of water reducers and superplasticizers

      • 11.1 Introduction

      • 11.2 Dispersion forces

      • 11.3 Electrostatic forces

      • 11.4 DLVO theory

      • 11.5 Steric forces

      • 11.6 Effect of superplasticizers

        • 11.6.1 Role of electrostatic repulsion

        • 11.6.2 Role of electrosteric repulsion

        • 11.6.3 Role of steric hindrance

        • 11.6.4 Specific role of the PCE molecular structure

      • 11.7 Conclusions

      • Acknowledgements

      • References

    • 12 - Impact of chemical admixtures on cement hydration

      • 12.1 Introduction

      • 12.2 Mechanisms of retardation

        • 12.2.1 Complexation of calcium ions in solution

        • 12.2.2 Inhibition of the dissolution of anhydrous phases

        • 12.2.3 Inhibition of nucleation and/or growth of hydrates

        • 12.2.4 Perturbation of the silicate–aluminate–sulfate balance

      • 12.3 Retardation by superplasticizers

        • 12.3.1 Role of the molecular architecture of PCE superplasticizers

        • 12.3.2 Role of the chemical composition

      • 12.4 Retardation by sugars

        • 12.4.1 Overview

        • 12.4.2 General observations

        • 12.4.3 Role of molecular structure

        • 12.4.4 The role of complexation and stability

        • 12.4.5 The role of adsorption

          • 12.4.5.1 Adsorption on portlandite

          • 12.4.5.2 Adsorption on calcium silicates

          • 12.4.5.3 Adsorption on calcium aluminates

        • 12.4.6 Other issues

      • 12.5 Conclusions

      • Acknowledgment

      • References

    • 13 - Working mechanisms of shrinkage-reducing admixtures

      • 13.1 Introduction

      • 13.2 Basic principles of the shrinkage of cementitious systems

        • 13.2.1 Capillary pressure theory

        • 13.2.2 Disjoining force theory

        • 13.2.3 A thermodynamic framework of shrinkage

          • 13.2.3.1 Deformation energy

          • 13.2.3.2 Interfacial energy

          • 13.2.3.3 Variation in the total Helmholtz free energy

      • 13.3 Impact of SRAs on drying shrinkage

        • 13.3.1 Macroscopic changes

          • 13.3.1.1 Pore saturation

          • 13.3.1.2 Creation of internal surface in the course of drying

          • 13.3.1.3 Shrinkage strain

        • 13.3.2 Working mechanism of shrinkage reduction

      • 13.4 Dosage response of SRA on drying shrinkage

      • 13.5 Conclusions

      • References

    • 14 - Corrosion inhibitors for reinforced concrete

      • 14.1 Introduction

      • 14.2 Corrosion mechanisms of reinforcing steel in concrete

        • 14.2.1 Initiation phase

          • 14.2.1.1 Depassivation due to chloride ions

          • 14.2.1.2 Depassivation due to carbonation

        • 14.2.2 Propagation phase

          • 14.2.2.1 Chloride-induced corrosion

      • 14.3 Corrosion inhibitors for steel in concrete

        • 14.3.1 Mechanism

        • 14.3.2 Laboratory studies on admixed corrosion inhibitors

          • 14.3.2.1 Calcium nitrite

            • Mechanism

            • Long-term efficiency

          • 14.3.2.2 Alkanolamines and amines

            • Pure compounds

            • Proprietary blends

        • 14.3.3 Mechanistic action of the organic inhibitor blends

      • 14.4 Critical evaluation of corrosion inhibitors

        • 14.4.1 Testing corrosion inhibitors

        • 14.4.2 Concentration dependence

        • 14.4.3 Measurement and control of inhibitor action

      • 14.5 Concluding remarks

      • References

  • Three - The technology of admixtures

    • 15 - Formulation of commercial products

      • 15.1 Introduction

      • 15.2 Performance targets

        • 15.2.1 Slump retention

        • 15.2.2 Environmental conditions

        • 15.2.3 Setting and hardening control

        • 15.2.4 Defoamers

        • 15.2.5 Co-surfactants and hydrotropic compounds

        • 15.2.6 Biocides

      • 15.3 Cost issues

      • 15.4 Conclusions

      • Acknowledgments

      • References

    • One - Admixtures that modify at the same time the properties of the fresh and hardened concrete

      • 16 - Superplasticizers in practice

        • 16.1 Introduction

        • 16.2 Application perspective on superplasticizers and their use

          • 16.2.1 Main types of superplasticizers

          • 16.2.2 Practical benefits of dispersion by superplasticizers

          • 16.2.3 Rheological tests for superplasticizers in cementitious systems

        • 16.3 Impact of superplasticizers on rheology

          • 16.3.1 Yield stress

          • 16.3.2 Plastic viscosity

          • 16.3.3 Shear thickening

          • 16.3.4 The importance of mixing protocol

          • 16.3.5 Fluidity retention

          • 16.3.6 Delayed fluidification

        • 16.4 Unexpected or undesired behaviors

          • 16.4.1 General considerations

          • 16.4.2 Inadequacy of standard tests to identify incompatibilities

          • 16.4.3 Robustness of cement/superplasticizer combinations in concrete

          • 16.4.4 Role of cement composition

            • 16.4.4.1 Soluble alkalis and their relation with aluminates

            • 16.4.4.2 Surface mineralogy

          • 16.4.5 Role of superplasticizers

            • 16.4.5.1 PNS and PMS

            • 16.4.5.2 Different sensitivity of PCEs

          • 16.4.6 Interaction with other admixtures

        • 16.5 Conclusions

        • Acknowledgments

        • References

      • 17 - Air entraining agents

        • 17.1 Introduction

        • 17.2 Mechanisms of air entrainment

        • 17.3 Principal characteristics of a bubble network

        • 17.4 Production of a bubble network

          • 17.4.1 Influence of formulation parameters

            • 17.4.1.1 Cement

            • 17.4.1.2 Consistence and superplasticizer

            • 17.4.1.3 Supplementary cementitious materials

            • 17.4.1.4 Aggregates

            • 17.4.1.5 Admixtures

            • 17.4.1.6 Fibers

          • 17.4.2 Influence of the mixing procedure parameters

            • 17.4.2.1 Type of mixer

            • 17.4.2.2 Temperature

        • 17.5 Stability of the network of entrained bubbles

          • 17.5.1 Influence of the transportation of the fresh concrete

          • 17.5.2 Influence of vibration and pumping

        • 17.6 Conclusion

        • References

    • Two - Admixtures that modify essentially the properties of the fresh concrete

      • 18 - Retarders

        • 18.1 Introduction

        • 18.2 Cooling concrete to retard its setting

        • 18.3 The use of retarders

          • 18.3.1 Different chemicals used to retard concrete setting

          • 18.3.2 Different retarders standardized in North America

          • 18.3.3 Sugar as a retarder

          • 18.3.4 Dosage

        • 18.4 Addition time

        • 18.5 Some case history of undue retardations

          • 18.5.1 Cracking of prefabricated slabs just after the removal of the forms

          • 18.5.2 A particularly hard-working aggregate trucker

          • 18.5.3 An accidental overdosage of retarder

          • 18.5.4 Slipforming the gravity base of an offshore platform

        • 18.6 Conclusion

        • References

      • 19 - Accelerators

        • 19.1 Introduction

        • 19.2 Different means to accelerate concrete hardening

          • 19.2.1 The use of high-strength cement

          • 19.2.2 Decreasing w/c or w/b

          • 19.2.3 Heating of concrete

          • 19.2.4 Insulated forms

          • 19.2.5 Use of an accelerator

        • 19.3 Different types of accelerators

        • 19.4 Calcium chloride as an accelerator

          • 19.4.1 Mode of action

          • 19.4.2 Mode of addition

          • 19.4.3 Rules concerning the use of calcium chloride

        • 19.5 Shotcrete accelerators

        • 19.6 Conclusions

        • References

      • 20 - Working mechanism of viscosity-modifying admixtures

        • 20.1 Introduction

        • 20.2 Performance of VMAs

          • 20.2.1 Mechanisms of action of VMAs

          • 20.2.2 Impact of VMAs on the rheology of cementitious systems

          • 20.2.3 Performance of VMAs in the presence of superplasticizers

            • 20.2.3.1 Impact of VMAs on the rheological properties in the presence of superplasticizers

            • 20.2.3.2 Compatibility of polymeric VMAs with superplasticizers

        • 20.3 Working mechanisms of water retention agents

        • 20.4 Influence of polymeric VMAs on hydration of cement

        • 20.5 Use of VMAs in SCC formulation

        • 20.6 Conclusions

        • Acknowledgments

        • References

      • 21 - Antifreezing admixtures

        • 21.1 Introduction

        • 21.2 Winter concreting in North America

        • 21.3 Antifreeze admixtures

        • 21.4 The construction of high-voltage power lines in the Canadian North

        • 21.5 The use of calcium nitrite in Nanisivik

        • 21.6 Conclusion

        • References

    • Three - Admixtures that modify essentially the properties of the hardened concrete

      • 22 - Expansive agents

        • 22.1 Introduction

        • 22.2 Principle

        • 22.3 Expansion mechanisms

          • 22.3.1 Expansion due to the formation of ettringite

          • 22.3.2 Expansion due to the formation of portlandite

        • 22.4 Measurement of free and restrained expansion

          • 22.4.1 Free expansion

          • 22.4.2 Restrained expansion

        • 22.5 Factors affecting the expansion

          • 22.5.1 Expansive agent dosage

          • 22.5.2 Curing conditions

          • 22.5.3 Temperature

          • 22.5.4 Test method: restrained versus free expansion

        • 22.6 Field applications of concretes containing expansive agents

          • 22.6.1 Bridge decks

          • 22.6.2 Slabs on ground

          • 22.6.3 Bonded concrete overlays

        • 22.7 Conclusion

        • References

      • 23 - Shrinkage-reducing admixtures

        • 23.1 Introduction

        • 23.2 Principal molecules used as shrinkage-reducing admixtures

        • 23.3 Typical dosages

        • 23.4 Laboratory studies on the use of shrinkage-reducing admixtures

          • 23.4.1 Autogenous shrinkage

            • 23.4.1.1 Mortars

            • 23.4.1.2 Self-compacting concrete

          • 23.4.2 Drying shrinkage

            • 23.4.2.1 Mortar

            • 23.4.2.2 Self-compacting concrete

          • 23.4.3 Combination of an SRA and of an expansion agent to decrease to total shrinkage

          • 23.4.4 Effect of SRAs on air entrainment

          • 23.4.5 Resistance to freezing and thawing

        • 23.5 Field applications

        • 23.6 Conclusion

        • References

      • 24 - Corrosion inhibition

        • 24.1 Introduction

        • 24.2 The effect of chloride ions on reinforcing steel bars

        • 24.3 Increasing the protection of steel reinforcement against corrosion

          • 24.3.1 The use of low w/c or w/b concrete to decrease the risk of corrosion

          • 24.3.2 Cathodic protection

          • 24.3.3 Corrosion inhibitors

            • 24.3.3.1 Calcium nitrite

        • 24.4 Mitigating steel corrosion

          • 24.4.1 Epoxy-coated reinforcing bars

          • 24.4.2 Stainless steel reinforcing bars

          • 24.4.3 Galvanized reinforcing steel

        • 24.5 Eliminating steel corrosion

        • 24.6 Conclusion

        • References

    • Four - Admixtures used to water cure concrete

      • 25 - Curing compounds

        • 25.1 Introduction

        • 25.2 Curing concrete according to its w/c

        • 25.3 Specifying the curing of a concrete with a w/c greater than the critical value of 0.42

        • 25.4 Specifying the curing of concretes having a w/c lower than the critical value of 0.42

          • 25.4.1 External curing

          • 25.4.2 Internal curing

          • 25.4.3 Curing concrete columns

        • 25.5 Enforcing adequate curing practices in the field

        • 25.6 Conclusion

        • References

  • Four - Special concretes

    • 26 - Self-consolidating concrete

      • 26.1 Introduction

      • 26.2 SCC formulation

      • 26.3 Quality control

      • 26.4 Fresh properties

        • 26.4.1 Plastic shrinkage

        • 26.4.2 Pumping

      • 26.5 Hardened properties

      • 26.6 Case studies

        • 26.6.1 Senboku LNG Terminal II in Osaka, Japan

        • 26.6.2 Construction of the reaction walls of the structural laboratory at the Université de Sherbrooke

      • 26.7 Selling SCC to contractors

      • 26.8 Conclusion

      • References

    • 27 - Ultra high strength concrete

      • 27.1 Introduction

      • 27.2 Ultra high strength concrete concept

        • 27.2.1 Increasing the homogeneity of UHSC

        • 27.2.2 Increasing the packing density

        • 27.2.3 Improving the microstructure by thermal treatment

        • 27.2.4 Improving the ductility of UHSC

        • 27.2.5 Improving the packing density of different powders

        • 27.2.6 Reinforcing the cement paste matrix with hard inclusions

      • 27.3 How to make a UHSC

        • 27.3.1 Why such cement characteristics?

        • 27.3.2 Selection of the superplasticizer

      • 27.4 Construction of the Sherbrooke pedestrian bikeway

        • 27.4.1 Design

        • 27.4.2 Construction

          • 27.4.2.1 Phase I: fabrication of the confined post-tensioned diagonals

          • 27.4.2.2 Phase II: construction of the deck and the lower beam

          • 27.4.2.3 Phase III: curing

          • 27.4.2.4 Phase IV: transportation to the site

          • 27.4.2.5 Phase V: assembling the prefabricated elements

          • 27.4.2.6 Phase VI: post-tensioning

      • 27.5 Testing the structural behaviour of the structure

      • 27.6 Long-term behaviour

      • 27.7 Some recent applications of UHSC

        • 27.7.1 The extension of Haneda Airport in Tokyo

        • 27.7.2 The MUCEM in Marseille

        • 27.7.3 Louis Vuitton Foundation building in Paris

      • 27.8 Conclusion

      • References

  • Five - The future of admixtures

    • 28 - Conclusions and outlook on the future of concrete admixtures

      • 28.1 Chemical admixtures are to concrete, what spices are to cooking

      • 28.2 Of good and bad concrete

      • 28.3 Environmental challenges

      • 28.4 The science of chemical admixtures

      • References

  • 1: Useful formulae and some applications

    • A1.1 The ‘hidden’ water in concrete

    • A1.2 Saturated surface dry state for aggregates

    • A1.3 Moisture content and water content

    • A1.4 Specific gravity

    • A1.5 Supplementary cementitious material content

      • A1.5.1 Case 1

      • A1.5.2 Case 2

    • A1.6 Superplasticizer dosage

      • A1.6.1 Specific gravity of the superplasticizer

      • A1.6.2 Solids content

      • A1.6.3 Mass of water contained in a certain volume of superplasticizer

      • A1.6.4 Other useful formulae

      • A1.6.5 Mass of solid particles and volume needed

      • A1.6.6 Volume of solid particles contained in Vliq

    • A1.7 Sample calculation

      • A1.7.1 Example 1: Expressing a dosage in L/m3 as a percentage of solids content

      • A1.7.2 Example 2: Moving from a dosage expressed as a percentage of solids to a dosage expressed in L/m3

    • A1.8 The absolute volume method

      • A1.8.1 Introduction

      • A1.8.2 Trial batches

        • A1.8.2.1 First trial batch

        • A1.8.2.2 Second trial batch

        • A1.8.2.3 Third trial batch

      • A1.8.3 Simplified method to calculate the composition of 1m3 of concrete with a given w/c or w/b ratio

        • A1.8.3.1 Sample calculation

    • References

  • 2: Experimental statistical design

    • A2.1 Introduction

    • A2.2 Terminology

      • A2.2.1 Notions of factor, level of a factor and response

      • A2.2.2 Dimensionless coded values

      • A2.2.3 Experimental domain

        • A2.2.3.1 Definition

        • A2.2.3.2 Selection of the experimental domain

      • A2.2.4 Application 1

    • A2.3 Mathematical treatment of a statistical design

      • A2.3.1 Expression of a response as a function of the factors and their interaction

      • A2.3.2 Interaction

      • A2.3.3 Validation of the model

      • A2.3.4 Case of a first-order interaction

      • A2.3.5 Criterion of optimality

      • A2.3.6 Application 2

        • A2.3.6.1 Influence of the w/c and water dosage on the SP dosage of an HPC

        • A2.3.6.2 Results and discussion

        • A2.3.6.3 Exploitation of the model

    • A2.4 Conclusion

    • References

  • 3: Statistical evaluation of concrete quality∗

    • A3.1 Introduction

    • A3.2 Normal frequency curve

      • A3.2.1 Variability of concrete properties

      • A3.2.2 Mathematical expression of the normal frequency curve

      • A3.2.3 Some properties of the normal frequency curve

      • A3.2.4 Areas under the normal frequency curve

      • A3.2.5 Coefficient of variation

    • A3.3 Controlling the quality of concrete production

      • A3.3.1 Histogram

      • A3.3.2 Within-test variation

      • A3.3.3 Sample calculation

      • A3.3.4 Discussion of results

    • A3.4 Specifying concrete compressive strength

    • A3.5 Limitations of a statistical analysis

      • A3.5.1 The case of a good but unlucky concrete producer

      • A3.5.2 The case of a bad but lucky concrete producer

      • A3.5.3 The risk to the producer and the risk to the consumer

    • A3.6 Conclusion

    • References

  • Index

    • A

    • B

    • C

    • D

    • E

    • F

    • G

    • H

    • I

    • J

    • K

    • L

    • M

    • N

    • O

    • P

    • Q

    • R

    • S

    • T

    • U

    • V

    • W

    • X

    • Y

    • Z

  • Back Cover

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