Foreword_1998_Lea-s-Chemistry-of-Cement-and-Concrete

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Foreword 
Leas Chemistry of Cement and Concrete has existed, literally, as a standard work for my 
life time, with the first edition jointly authored by Frederick Lea and Cecil Desch 
appearing in 1935. Much has changed since the third edition was published in 1970. 
The cement industry itself has changed on the world stage, and there have been major 
improvements in the manufacturing process and quality control leading to a more 
uniform product. With the significant growth of the ready mixed and precast concrete 
industries over the past 40 years, customer demand has also changed (e.g. higher early 
strength for precasting). Finally in this Hst of changes in a changing world, the attitude 
of the ultimate customers for cement and concrete - the owners of structures - has been 
conditioned by the growing concern about durability. The somewhat disappointing 
durability performance of a proportion of the vast numbers of concrete structures built 
since the 1960s - interspersed by major concerns such as alkali-silica reaction (ASR) 
and the still persistent corrosion issue (due mainly to chlorides, in their various forms) -
has provoked a much greater interest in the properties of cement and concrete on the part 
of a wider cross-section of the construction industry, and, indeed, by the public at large. 
This continuing saga, no doubt fuelled by fresh concerns over environmental and 
sustainability issues, will maintain that interest in the future, and will demonstrate the 
need for a further edition of this book in the years to come! 
Another significant development influencing the content of this book is that 
construction (and with it cement and concrete) has gone truly international. The 
supporting generation of information and the ability to share that knowledge and 
experience has led to an information explosion, which is often difficult for the user to 
absorb, comprehend and apply. There is a genuine need among all professionals in the 
construction industry for a series of safe-havens, where all existing knowledge can be 
brought together on a particular topic and distilled by experts for easy reference and 
use. Such is the case for any authoritative reference and it is the case for the continued 
existence of Lea's Chemistry of Cement and Concrete - an acknowledged and respected 
standard work. The obvious next question is, has this quality and need been met by the 
team charged with replacing Lea himself and producing this fourth edition? 
To answer that question, it is first necessary to reflect on how the book will be used, and 
by whom. This has always been an authoritative reference work, painstakingly compiled 
with an eye for detail. As such, it has been referred to by specialists such as cement 
chemists, and dipped into by other professionals in the construction industry in quest of 
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detailed information on specific topics. Both uses will continue. However, the non-
specialist use is likely to increase, for the reasons mentioned earlier, and there is a need 
for this edition to reflect that by taking account of the concerns and trends over the 
intervening 27 years. 
The international flavour of construction (and the scale of the problem) is confirmed 
by the fact that the editor has brought together 17 other recognised and respected 
international experts to produce this volume. Under these circumstances, the job of 
editor is no sinecure. In maintaining the currency, calibre, continuity and content of 
the work (while ensuring a proper update, and looking ahead) there is the monumental 
task of integrating the output of so many individuals into a coherent and comprehensive 
whole. Peter Hewlett has achieved that successfully, while contributing himself as a co-
author of Chapter 15. I have little doubt that Frederick Lea himself would have 
approved. 
So, what about the book itself? How has it changed to face the modern world? The first 
clear impression is that it is bigger - around 1050 pages compared with the 740 of the 
third edition. A casual overview also tells us that there are fewer chapters - 16 compared 
with 21. In part, this perhaps reflects the expertise and interests of the individual 
contributors. More significantly, it represents restructuring into a more logical layout 
for current needs. Nothing is lost in doing this (the scope is largely unaffected) and, 
indeed, certain aspects have been strengthened. Moreover, some subjects have blossomed 
and are deserving of a chapter on their own; admixtures are one example and production 
of low-energy cement is another. 
A further clear impression from a general overview is the comprehensive list of 
references that appear a the end of each chapter (several over 200 in number and, in one 
case, over 500). This reflects the information explosion mentioned earher, has the merit of 
bringing all relevant information together, and is helpful to the reader should he or she 
wish to pursue interests in even greater depth. While the scope of Lea's book has always 
been more than just the chemistry of cement, there will inevitably be topics where further 
exploration is necessary for the in-depth study of related or interlocking subjects, and this 
new style makes that easier and represents a significant enhancement in this edition. 
An awareness of the changes introduced by the new team comes first with Chapter 2 on 
the classification of cements. While, to a large extent. Lea's book transcends changes in 
standards, cement has become an international comniodity and recognition of the 
requirements of standards is now more important. In particular, the development of a 
European Standard for cement is significant. For that reason, this chapter has been 
substantially rewritten, updated and expanded, with the emphasis on European and 
American standards. A classification is given both in terms of composition and of 
performance-related properties; this latter development is especially important in 
response to the greater interest in the characteristics of the wide range of cements now 
available with regard to durability. This same chapter comprehensively covers the 
manufacturing process (a separate chapter in earlier editions), where again there has been 
significant change. 
The above brief description of Chapter 2 typifies those that follow - rewritten, updated 
and expanded are all key words, with a stronger emphasis on performance and on a wider 
range of engineering properties. Some chapters have substantially the same title, but with 
recast and updated content. Chapter 13 on calcium aluminate cements is a case in point; 
the original coverage is still there, in updated form, but with the addition of a broad and 
realistic perspective on usage following the failures in the UK in the early 1970s. Chapter 
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16 on aggregates is a mini-reference book in its own right, containing, among other 
things, an up-to-date review of alkah-aggregate reaction. 
In my opinion, there has always been a need for this book - the safe-haven referred to 
earher. That need has not fundamentally changed, and therefore it was essential to retain 
the character, coherence and calibre of Lea's original work, but to put it in a modern 
setting. In doing so, the attitudes of a modern readership had to be recognised; interest 
in the subject is wider, and, without doubt, the new style and approach permits easier 
understanding and access to the intelligent non-expert. That is as it should be for the next 
millennium. 
The production of this fourth edition could not have been an easy task - modernising a 
standard respected work while avoiding sacrificing the principles and approach of the 
original author. Without doubt, the new team has been successful in meeting its brief of 
providing an authoritative reference, in the tradition begun by Frederick Lea more than 
60 years ago. 
Professor George Somerville November 1997 
Director of Engineering 
British Cement Association