Aggregates in Concrete by Mark Alexander and Sidney Mindess

Aggregates in Concrete Contents

• Introduction
• Natural aggregate sources and production
• Properties and characterization of aggregates
• Aggregates in plastic concrete
• Aggregates in hardened concrete: physical and mechanical properties
• Aggregates in hardened concrete: durability and transport properties
• Special aggregates and special concretes
• Standards for aggregates

Preface to Aggregates in Concrete PDF

Cementitious materials are certainly the oldest manufactured
materials of construction, their use going back at least 9000 years.

Today,
portland cement concrete is the most widely used construction material
worldwide, its production far outstripping that of asphalt, timber, steel or
other building materials.

Indeed, it is second only to water as the most widely
used material of any type. Since concrete aggregates typically make up about 70
percent of the mass of concrete, they are clearly a vitally important
ingredient for two main reasons:

1. Their properties must affect to a considerable degree the
   properties of the concrete; and
2. The vast quantities of aggregates used in
   concrete production has a significant environmental impact.

In spite of their importance, however, aggregates tend very
much to play ‘second fiddle’ to the other principal ingredient of modern
concrete, namely portland cement.

Most concrete research over the past decades
has focused on the binder phase (i.e. the portland cement and the supplementary
cementitious materials and chemical admixtures that are commonly combined with
it).

This is, perhaps, understandable, since it is largely through the
intelligent manipulation (or ‘engineering’) of the binder that we can now
‘tailor-make’ concretes with such a wide range of properties, such as ultrahigh
strength concretes or self-compacting concretes.

However, it must be remembered
that even these very high-performance concretes would not be possible without an
intelligent selection of their aggregates as well.

What aggregate research
there is has tended to focus either on aggregates which are chemically reactive
with portland cement, such as those involved in alkali-aggregate reactions, or
on aggregates for special concretes (low density concretes, concretes for
radiation shielding, etc.).

These aggregates, while important, make up only a small fraction of modern concrete production.

Indeed, it is still commonly
assumed that aggregates are essentially an inert component of concrete, used
primarily as an economical filler, and to give the concrete some volume
stability. At least part of this book’s purpose is to show this belief’s falsity.

The aim of this book is to describe and explain the role of the aggregate
phase in concrete.

That is, it is not intended to be merely a bald description
of the origins of various rock types and their chemical and physical properties
(although some of that material will of necessity be included). Rather it is
intended to show the relevance of these materials and their properties to the behavior of concrete.

While much of the material presented will, perforce, be
of an empirical nature, the underlying science will be dealt with whenever
possible.

The intent is to present a unified view of the role of concrete
aggregates in the light of this science, rather than simply as a series of more
or less unrelated facts. The book comprises eight chapters.

After a general
introduction, Chapter 2 describes the origin, classification, and production
methods for naturally occurring aggregates, while Chapter 3 discusses the
physical, mechanical, and chemical properties of these aggregates as they
relate to the properties of concrete.

The role of aggregates in fresh concrete
is covered in Chapter 4, with particular emphasis on particle packing and
concrete rheology.

Chapter 5 deals with how aggregates affect hardened concrete’s physical and

mechanical properties. Chapter 6 is concerned primarily
with the effects of aggregates on the transport of substances in concrete and on
concrete deterioration and durability.

Special aggregates (such as lightweight
aggregates, synthetic aggregates, etc.) and the more stringent requirements of
aggregates for special concretes are discussed in Chapter 7. Finally, The description of standards for aggregates is given in Chapter 8.

Various
standards (ASTM, BS, CSA, and SANS) are referred to throughout the text. The
relevant standards are gathered in lists in the Appendices and therefore are
not referenced on each occasion when they appear.

Canadian (CSA) Standards are
only quoted where they differ from ASTM standards, or where no comparable ASTM
standard exists. This book is not written specifically as a textbook; however,
we hope it will be useful to students and practicing engineers.

It includes an extensive and up-to-date reference list, and numerous graphs and
tables. We wish to thank the following people who assisted in different ways:

Gill Owens of the Cement and Concrete Institute (C&CI), who sourced variously
photographs and diagrammatic material, as did Prof.

Yunus Ballim; the
wonderfully helpful librarians at the C&CI – Hanlie Turner, Ansie Martinek,
and Grace Legoale – who dug out much material that was obscure and not so
obscure; Lynette Alexander who typed the manuscript so diligently; students at
the University of Cape Town,

In particular Tom Gardner and Mafanelo Sibuyi, who
helped to withdraw many of the diagrams; several people who provided usefully
criticism and input on various sections, notably Prof. Geoff Blight,

Dr. Ian
Sims, and Dr. Bertie Oberholster for assistance with the section on the alkali-aggregate reaction in Chapter 6,

Dr. Clive Stowe for critical review of
the section on aggregate origins, petrography, and chemical properties, and Dr
Graham Grieve for critical reading of Chapter 8;

Dr. V.R. Kulkarni of the
Associated Cement Companies Limited of India, also Editor of the Indian
Concrete Journal, for providing data on cement and aggregate production in
India;

Mrs. Elly Yelverton for assisting hugely with getting the necessary
permissions for use of copyright material; others who provided photographically or
diagrammatic material – Profs J. Newman and T. Bremner, Dr. E. Garboczi, Dr. H.
Frimmel,

Mr. D. Labuschagne, Mr. P. Evans, Mr. N. Hassen, Mr. H. Hale, Mr. J. Cokart
or Mr. C. Casalena. Without doubt,

this book would not have been written were it
not for the keen interest and enquiring mind of Dr. Derek Davis, previous
Director of the Portland Cement Institute (now the Cement and Concrete Institute),

who initiated several studies on the effects of aggregates in concrete, and
inspired much of the work done by Dr. Alexander.

Download Aggregates in Concrete (Modern concrete technology series 13) PDF 

Author(s): Alexander, Mark Mindess, Sidney

Publisher: Taylor & Francis, Year: 2005

ISBN: 0415258391,9780415258395

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