Autogenous Deformation and Internal Curing of Concrete Cover illustration by Johannes Lura Autogenous Deformation and Internal Curing of Concrete Proefschrift ter verkrijging van de graad van doctor aan de Technische Universiteit Delft, op gezag van de Rector Magnificus prof.dr.ir. J.T. Fokkema voorzitter van het College voor Promoties, in het openbaar te verdedigen op maandag 14 april 2003 om 16:00 uur door Pietro LURA Ingegnere civile (Università degli Studi di Brescia) geboren te Desenzano (Italïe) Dit proefschrift is goedgekeurd door de promotor: Prof.dr.ir. K. van Breugel Samenstelling Promotiecommissie Rector Magnificus voorzitter Prof.dr.ir. K. van Breugel Technische Universiteit Delft, promotor Prof.dr.ir. J. Walraven Technische Universiteit Delft em.Prof.Dr.-Ing.habil.Dr.-Ing.E.h. F.S. Rostásy Technische Universität Braunschweig, Deutschland Prof.dr. O.M. Jensen Aalborg Universitet, Danmark Prof.dr.ir. G. De Schutter Universiteit Gent, Belgïe Dr.ir. E.A.B. Koenders Technische Universiteit Delft Dr.ir. E. Schlangen Intron BV, Nederland Prof.dr.ir. J.M.J.M. Bijen Technische Universiteit Delft, reservelid Published and distributed by: DUP Science DUP Science is an imprint of Delft University Press P.O. Box 98 2600 MG Delft The Netherlands Telephone: +31 15 27 85 678 Telefax: +31 15 27 85 706 E-mail: [email protected] ISBN 90-407-2404-0 Keywords: high strength concrete, internal curing, autogenous shrinkage Copyright (cid:1) 2003 by Pietro Lura. All rights reserved. No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without written permission from the publisher: Delft University Press. Printed in the Netherlands …fatti non foste a viver come bruti, ma per seguir virtute e canoscenza. Dante Alighieri, La Divina Commedia, Inferno, Canto XXVI Chi troppo studia, matto diventa. Annunciata Malvezzi per Yvonne e Piera Table of contents List of symbols xi List of abbreviations xv PROLOGUE Chapter One: Introduction 3 1.1 Introduction 3 1.2 Scope of this thesis 3 1.3 Terminology: autogenous phenomena and internal curing 5 1.4 Objectives of this thesis 8 Chapter Two: From hydration to autogenous deformation 11 2.1 Introduction 11 2.2 Hydration and formation of microstructure 11 2.3 Driving forces of autogenous shrinkage 15 2.4 Macroscopic expansion 18 2.5 Blast furnace slag cement 21 2.6 Silica fume 25 2.7 Internal curing 25 2.8 Measurements of autogenous deformation 28 2.9 Conclusions 34 PART I: CEMENT PASTE Chapter Three: Paste measurements at room temperature 37 3.1 Introduction 37 3.2 Materials 37 3.3 Methods 38 3.4 Results and discussion 42 3.5 Conclusions 50 Chapter Four: Paste measurements at different temperatures 51 4.1 Introduction 51 4.2 Materials 52 4.3 Methods 52 4.4 Results and discussion 54 4.5 Conclusions 60 Chapter Five: Modeling of self-desiccation shrinkage 63 5.1 Introduction 63 vii Table of contents 5.2 Modeling of self-desiccation shrinkage 63 5.3 Self-desiccation shrinkage of a Portland cement paste 65 5.4 Self-desiccation shrinkage of a BFS cement paste 71 5.5 Conclusions 75 PART II: NORMAL WEIGHT CONCRETE Chapter Six: Measurements on NWC 79 6.1 Introduction 79 6.2 Materials 79 6.3 Methods 80 6.4 Results 82 6.5 Discussion 89 6.6 Conclusions 91 Chapter Seven: Modeling of shrinkage of NWC 93 7.1 Introduction 93 7.2 Materials 93 7.3 Calculation of concrete shrinkage 94 7.4 Results 96 7.5 Discussion 97 7.6 Conclusions 100 PART III: LIGHTWEIGHT AGGREGATE CONCRETE Chapter Eight: LWAC with Liapor aggregates 103 8.1 Introduction 103 8.2 Properties of LWA 104 8.3 Experiments on LWAC 108 8.4 Modeling of internal curing 119 8.5 Conclusions 124 Chapter Nine: Pumice aggregates and lightweight mortar 127 9.1 Introduction 127 9.2 Materials 127 9.3 Absorption-desorption isotherms of pumice aggregates 128 9.4 Low Temperature Calorimetry study of pumice aggregates 132 9.5 X-ray absorption test and chemical shrinkage 134 9.6 SEM observation of the interface between pumice and cement paste 141 9.7 Mortars with different pumice content 145 9.8 Conclusions 152 viii Table of contents EPILOGUE Chapter Ten: Conclusions and further research 155 10.1 Conclusions 155 10.3 Recommendations 156 10.4 Future research 156 References 159 Appendix A: Derivation of Raoult and Kelvin laws 171 Appendix B: Powers’ model 175 Appendix C: Amount of entrained water 177 Summary Samenvatting Acknowledgements Curriculum vitae ix