Self-Compacting Concrete

334 Pages·2008·3.62 MB·English

by  De Schutter

Self-Compacting Concrete
Geert De Schutter, Peter J. M. Bartos,
Peter Domone and John Gibbs
Whittles Publishing
Published by
Whittles Publishing,
Dunbeath,
Caithness KW6 6EY,
Scotland, UK
www.whittlespublishing.com
Distributed in North America by
CRC Press LLC,
Taylor and Francis Group,
6000 Broken Sound Parkway NW, Suite 300,
Boca Raton, FL 33487, USA
© 2008 G. De Schutter, P. J. M. Bartos, P. Domone and J. Gibbs
ISBN 978-1904445-30-2
USA ISBN 978-1-4200-6833-7
All rights reserved.
No part of this publication may be reproduced,
stored in a retrieval system, or transmitted,
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without prior permission of the publishers.
The publisher and authors have used their best efforts in preparing this book, but assume no responsibility for any
injury and/or damage to persons or property from the use or implementation of any methods, instructions, ideas or
materials contained within this book. All operations should be undertaken in accordance with existing legislation and
recognized trade practice. Whilst the information and advice in this book is believed to be true and accurate at the time
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Typeset by Compuscript Ltd., Shannon, Ireland.
Printed by Athenaeum Press Ltd.
Preface
Self-compacting concrete (SCC) is an important and significant advance within
concrete technology which is having a major impact on concrete practice. Originally
developed in Japan with the first significant applications in the early 1990s, it has
rapidly been adopted worldwide in construction. SCC is a ‘new’ material requiring
new placing techniques, and is providing novel insights and innovative developments
to ‘classical’ concrete technology. Starting from this basis, we explain how and why
the new concept of SCC requires a re-evaluation of traditional material models. This
process of rethinking relates SCC technology to classical concrete technology.
This book provides essential information for readers who do not yet have an
adequate knowledge of SCC and experience of its applications. However, it is also
aimed at experienced readers who can benefit from some fundamental background to
rheology, hydration and microstructure, which strongly influence the engineering
properties and durability of SCC. Information on the selection of the constituent
materials, key characteristics, test methods, mix proportioning, construction
processes, engineering properties, production and conformity checking of SCC will
all be of use. Practical guidance is also given as to how to select and specify SCC and
the key properties required for some typical applications are explained extensively.
Throughout the book it is assumed that the reader has some experience of
traditional vibrated concrete (TVC) and has a basic knowledge and understanding of
classical concrete technology. Many of the chapters can easily be understood without
a very detailed knowledge of cementitious materials, and are therefore accessible to
all readers, from practitioners who are involved in daily casting operations on-site to
doctoral students desiring an introduction into modern, state-of-the-art concrete
technology. For other chapters, for example those dealing with hydration,
microstructural aspects and durability, a more advanced knowledge is required,
However, the advanced parts of the book are presented such that they may be
bypassed without impairing the reader’s understanding and the basic principles of
SCC.
It is clear from worldwide experience that there is no such thing as an ideal SCC
mix. However, this book will be helpful to those who wish to make an SCC
appropriate for their specific application with their local materials. The readers who
are new to the field will find sufficient information to get acquainted with the subject
and to start developing mixes. Those readers who already have experience of using
SCC will find additional information on both practical and fundamental issues
relevant to SCC.
Unlike many SCC ‘guidelines’, Self-Compacting Concrete not only shows how
fresh and hardened SCC behaves, it also explains why it does so, whenever such
information is available. This combination of practical guidance and a review of
underlying principles and explanations makes this book suitable for a wide readership
of practitioners, students, architects, engineers, contractors, public authorities and
xiii
PREFACE
researchers. It is intended to enhance the reader’s theoretical and practical knowledge
of concrete technology and facilitate the further development and application of SCC
worldwide, and the realisation of its many advantages within modern construction
technology.
Geert De Schutter
Peter Bartos
Peter Domone
John Gibbs
Acknowledgments
During the preparation of the book several of our colleagues have been of great
assistance. We would particularly like to thank:
Dr. Ir. Anne-Mieke Poppe and Dr. Ir. Veerle Boel who made significant
contributions to the subject of hydration and the microstructure of concrete discussed
in Chapter 8. The additional contributions by Dr. Ir. Katrien Audenaert, Dr. Guang
Ye and Ir. Gert Baert are also gratefully acknowledged.
Dr. Ir. Veerle Boel and Dr. Ir. Katrien Audenaert have also provided valuable
assistance and contributions during the writing of Chapter 10.
Finally we would all like to acknowledge the contributions of our colleagues on
the RILEM technical committees and in the two EU-funded programmes on SCC
from whom we have learnt so much, and who have therefore indirectly contributed to
this book.
Geert de Schutter
Peter J.M. Bartos
Peter Domone
John Gibbs
xiv
Contents
Chapter 1 Introduction and glossary of common terms........................................1
1.1 Introduction.................................................................................................1
1.2 Glossary of common terms related to self-compacting concrete................3
Chapter 2 Self-compacting concrete........................................................................8
2.1 The need for self-compaction......................................................................8
2.2 Definition of self-compacting concrete.....................................................15
2.3 A brief history of self-compacting concrete..............................................16
References.................................................................................................20
Chapter 3 Constituent materials............................................................................22
3.1 Coarse aggregates......................................................................................22
3.1.1 Type..............................................................................................22
3.1.2 Maximum size..............................................................................22
3.1.3 Fine aggregate..............................................................................22
3.1.4 Overall aggregate grading............................................................23
3.2 Cements and additions...............................................................................24
3.3 Admixtures................................................................................................25
3.3.1 Superplasticisers...........................................................................25
3.3.2 Viscosity modifying admixtures..................................................26
3.3.3 Other admixtures..........................................................................27
3.4 Fibres.........................................................................................................27
References.................................................................................................28
Chapter 4 Properties of fresh self-compacting concrete mixes...........................32
4.1 Introduction to rheology............................................................................32
4.1.1 Newtonian flow............................................................................34
4.1.2 Non-Newtonian flow....................................................................35
4.1.3 Rheology and consistence (workability) of fresh concrete.........37
4.1.4 Concrete rheometers.....................................................................38
4.2 Key characteristics of fresh self-compacting concrete..............................41
4.2.1 Filling ability................................................................................44
4.2.2 Passing ability..............................................................................44
4.2.3 Segregation resistance..................................................................44
4.2.4 Interactions and additional properties..........................................46
4.2.5 Flow-rate......................................................................................47
4.2.6 Other characteristics.....................................................................47
References.................................................................................................48
Chapter 5 Tests for key properties of fresh self-compacting concrete.............50
5.1 Introduction...............................................................................................50
v
CONTENTS
5.2 Sampling....................................................................................................51
5.3 Test methods..............................................................................................52
5.3.1 Slump-flow...................................................................................52
5.3.2 Flow-rate, determined during the slump-flow test......................57
5.3.3 Orimet..........................................................................................58
5.3.4 V-funnel.......................................................................................61
5.3.5 J-ring............................................................................................64
5.3.6 L-box............................................................................................69
5.3.7 Sieve segregation test...................................................................74
5.3.8 Settlement column........................................................................77
5.3.9 Penetration test for segregation....................................................80
5.3.10 Other tests....................................................................................82
5.4 Review of performance of tests for properties of fresh self-compacting
concrete......................................................................................................84
5.4.1 Basic performance parameters.....................................................84
5.4.2 Variations in test results...............................................................85
5.4.3 Basic rheology and tests for key properties of fresh self-
compacting concrete.....................................................................86
5.5 Review of applications of tests for fresh self-compacting concrete.........87
5.5.1 Tests for filling ability.................................................................87
5.5.2 Tests for passing ability...............................................................89
5.5.3 Tests for segregation resistance...................................................90
5.5.4 Tests for flow-rate........................................................................91
5.6 Conclusions...............................................................................................93
References.................................................................................................94
Chapter 6 Mix design..............................................................................................96
6.1 Introduction...............................................................................................96
6.2 Concrete requirements...............................................................................96
6.3 General considerations for mix proportioning..........................................99
6.4 Mix design procedures............................................................................101
6.4.1 General method..........................................................................103
6.4.2 Modifications and developments of the general method...........105
6.4.3 CBI method................................................................................105
6.4.4 Extensions of the CBI method...................................................109
6.4.5 Analysis of mixes.......................................................................112
6.4.6 Other approaches........................................................................113
6.5 UCL method of mix design.....................................................................115
6.5.1 Equipment..................................................................................116
6.5.2 Procedure....................................................................................116
6.6 Conclusions.............................................................................................121
References...............................................................................................122
Chapter 7 Construction process...........................................................................125
7.1 Batching and mixing................................................................................125
7.1.1 Requirements for the production plant......................................125
vi
CONTENTS
7.1.2 Control of materials...................................................................125
7.1.3 Mixers........................................................................................125
7.1.4 Quality control of the production process................................128
7.2 Transport..................................................................................................129
7.3 Placing.....................................................................................................130
7.3.1 Pumping.....................................................................................130
7.3.2 Skip and crane and other methods.............................................133
7.4 Formwork................................................................................................134
7.4.1 General requirements.................................................................134
7.4.2 Formwork pressure....................................................................135
7.5 Curing......................................................................................................136
7.6 Finishing..................................................................................................137
7.6.1 Features and properties of surfaces............................................137
7.6.2 Factors affecting surface finish in concrete...............................139
7.6.3 Factors affecting surface finish in self-compacting concrete....140
7.6.4 Special case of large slabs and pavements................................144
7.7 Conclusions.............................................................................................144
References...............................................................................................145
Chapter 8 Hydration and microstructure...........................................................146
8.1 Introduction.............................................................................................146
8.2 Development of the microstructure of concrete......................................146
8.2.1 Hydration process of Portland cement.......................................146
8.2.2 Microstructure and pore structure of hardened cement
paste............................................................................................150
8.2.3 Microstructure and pore structure of concrete...........................153
8.3 Calculation of the porosity......................................................................154
8.3.1 Powers’ model............................................................................154
8.3.2 Phase distribution in hydrating cement paste............................155
8.3.3 Capillary pores and gel pores in hydrated cement paste...........156
8.3.4 Porosity in concrete....................................................................157
8.3.5 Interfacial transition zone...........................................................157
8.4 Hydration of self-compacting concrete...................................................158
8.4.1 General aspects...........................................................................158
8.4.2 Limestone powder......................................................................158
8.4.3 Fly ash........................................................................................166
8.4.4 Blast furnace slag.......................................................................169
8.5 Microstructure of self-compacting concrete............................................170
8.5.1 General aspects...........................................................................170
8.5.2 Self-compacting concrete without an addition..........................173
8.5.3 Powder-type self-compacting concrete......................................173
8.6 Conclusions.............................................................................................186
References...............................................................................................186
Chapter 9 Engineering properties........................................................................192
9.1 Introduction.............................................................................................192
vii
CONTENTS
9.2 Compressive strength and modulus of elasticity.....................................193
9.2.1 In situ compressive strength, near-surface strength and
surface hardness.........................................................................195
9.2.2 Effect of curing conditions on compressive strength................197
9.2.3 Modulus of elasticity and toughness..........................................197
9.3 Tensile and shear strength.......................................................................198
9.4 Creep........................................................................................................199
9.5 Shrinkage.................................................................................................200
9.6 Bond with reinforcement.........................................................................201
9.6.1 Ordinary steel reinforcement.....................................................201
9.6.2 Prestressing steel........................................................................202
9.7 Conclusions.............................................................................................202
References...............................................................................................203
Chapter 10 Durability...........................................................................................206
10.1 Introduction.............................................................................................206
10.2 Transport properties.................................................................................206
10.2.1 Gas transport..............................................................................206
10.2.2 Liquid transport..........................................................................213
10.2.3 Ion transport...............................................................................217
10.3 Deterioration processes............................................................................218
10.3.1 Carbonation................................................................................219
10.3.2 Chloride penetration...................................................................221
10.3.3 Freeze–thaw...............................................................................224
10.3.4 Alkali–aggregate reactions.........................................................226
10.3.5 External chemical attack............................................................227
10.3.6 Fire resistance............................................................................233
10.4 Conclusions.............................................................................................235
References...............................................................................................236
Chapter 11 Standards and specifications...........................................................243
11.1 Introduction.............................................................................................243
11.2 Specification of self-compacting concrete..............................................243
11.3 International advisory documents for self-compacting concrete............245
11.3.1 European guidelines...................................................................245
11.3.2 Other national guidelines...........................................................249
11.4 Advisory documents available from concrete and admixture
suppliers...................................................................................................252
11.5 Standards for test methods......................................................................253
11.5.1 European EN standards..............................................................253
11.5.2 EN 13670, the execution standard.............................................254
11.5.3 International standards...............................................................254
References...............................................................................................254
Chapter 12 Benefits of using self-compacting concrete....................................256
12.1 Working conditions.................................................................................256
viii
CONTENTS
12.1.1 Noise..........................................................................................256
12.1.2 Vibration....................................................................................258
12.1.3 Physical strain............................................................................259
12.2 Environmental benefits............................................................................260
12.2.1 Noise..........................................................................................260
12.2.2 Recycled and waste materials....................................................260
12.3 Quality and economy...............................................................................260
12.3.1 Quality........................................................................................260
12.3.2 Direct costs.................................................................................260
12.3.3 Indirect costs..............................................................................263
12.4 Design and management..........................................................................264
References...............................................................................................267
Chapter 13 Practical applications.......................................................................269
13.1 Industrial structures.................................................................................269
13.1.1 Gas tanks in Texas, USA...........................................................269
13.1.2 Industrial hall in Veurne, Belgium............................................271
13.2 Public buildings and housing..................................................................273
13.2.1 Residential buildings in Brazil...................................................273
13.2.2 Trump Tower, Chicago, IL, USA..............................................275
13.2.3 World Financial Centre, Shanghai, China.................................278
13.2.4 Villa Gistel, Belgium.................................................................280
13.3 Bridges.....................................................................................................281
13.4 Other examples........................................................................................282
13.4.1 Multifunction sports complex for SK Slavia Praha
football club a.s. in the Czech Republic....................................282
13.4.2 Citytunnel, Malmö, Sweden.......................................................284
References...............................................................................................285
Subject Index..........................................................................................................287
Author Index..........................................................................................................295
ix
Chapter 1
Introduction and glossary of
common terms
1.1 Introduction
Concrete is without any doubt a fascinating building material. In one way, it is very
simple: anyone can mix water, cement and aggregates, cast it in moulds of almost any
shape and finally obtain an artificial stone with some strength. In another way, it is an
extremely difficult material: no one completely understands its complex behaviour
both when fresh and when hardened. This ambiguity makes concrete both the most
used building material in the world and a material which creates many problems when
not properly designed or placed.
One of the key issues for traditional concrete is that external energy has to be
provided to compact it. This can be obtained on site from vibrating pokers and in
concrete factories from vibrating tables or alternative methods. Concrete practice has
shown that for on-site casting, vibration is not always carried out as it should be. This
is quite understandable – no one really likes to handle a vibrating tool for a whole day
– but it is surely harmful to the quality of the final structure. The quality of
nonvibrated traditional concrete is far lower than its intrinsic quality when properly
compacted. The loss in strength may be acceptable in some cases, but the decrease in
durability can often be much more significant, leading to accelerated degradation
processes such as reinforcement corrosion, frost damage, sulfate attack etc.
SCC is not new. Highly specialised, expensive and difficult to control mixes for
underwater placement were successfully produced a very long time ago. However, it
was not until the late 1980s that advances in admixtures allowed us to increase the
fluidity of the fresh mix sufficiently to make it self-compacting but still cohesive
enough to avoid the hitherto inevitable segregation. In simple terms, this concrete fills
the formwork like a viscous liquid and does not need any external compaction energy
(see Figure 1.1). There is some debate about whether the ‘modern’ SCC is a new
material or just a new placing technique; it can be shown to be both. The requirement
for self-compaction demands a composition which is significantly different from the
composition of traditional vibrated concrete (TVC), as will be explained in Chapter
6. Differences in composition inevitably lead to changes in hydration, microstructure,
and the behaviour of the cementitious material in service.
Even if SCC is considered to be a new material, it remains a cementitious material.
Consequently, the basic concrete technology is still largely valid. This book assumes
that most readers will have a basic knowledge of concrete technology. There is
therefore a focus on the differences between TVC and SCC, in both the fresh state and
when hardened. The knowledge needed for SCC could be seen as providing an
extension to the ‘classical’ concrete technology. Basic principles are still valid, but
1