Precast concrete materials, manufacture, properties and usage - Chapter 0 pot

PRECAST CONCRETEMaterials, Manufacture, Properties and Usage... PRECAST CONCRETE Materials, Manufacture, Properties and Usage M.LEVITT ARCS, BSc, DIC, PhD Head—Materials Science Departme

PRECAST CONCRETE

Materials, Manufacture, Properties and Usage

PRECAST CONCRETE Materials, Manufacture, Properties and Usage

M.LEVITT

ARCS, BSc, DIC, PhD

Head—Materials Science Department, John Laing Research and Development Limited, Borehamwood, Hertfordshire, UK

APPLIED SCIENCE PUBLISHERS

LONDON and NEW JERSEY

This edition published in the Taylor & Francis e-Library, 2004.

APPLIED SCIENCE PUBLISHERS LTD Ripple Road, Barking, Essex, England APPLIED SCIENCE PUBLISHERS, INC Englewood, New Jersey 07631, USA

British Library Cataloguing in Publication Data

Levitt, M.

Precast concrete.

1 Precast concrete

I Title

691 ′·3 TA683·7 ISBN 0-203-49057-6 Master e-book ISBN

ISBN 0-203-79881-3 (Adobe eReader Format) ISBN 0-85334-994-0 (Print Edition)

WITH 40 TABLES AND 109 ILLUSTRATIONS

© APPLIED SCIENCE PUBLISHERS LTD 1982

All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publishers, Applied Science Publishers Ltd, Ripple Road,

Barking, Essex, England

The author wishes to express his appreciation to John Laing Research and Development and The British Precast Concrete Federation Limited for their permission to publish this book In particular the encouragement of Laing should be mentioned, with particular reference

to assistance given by Cyril Hobbs, the Laing Group’s Scientific Adviser,

as well as the Precast Concrete Federation’s declassification of a great deal of the originally restricted research data

Gratitude is also expressed to the following precast concrete manufacturers who not only supplied illustrations, but many of whom also took upon themselves the task of checking the technical accuracy of many parts of the original manuscript

Bardon Hill Quarries Limited Beton Machinery Sales Limited Dean Jesmond & Co

ECC Quarries Limited Forticrete Limited Richard Lees Limited Marshalls of Halifax Redland Tiles Limited Rocla Pipes Limited Thermalite Limited

This book is intended to meet the need for a general treatise on precast concrete, as the last relevant book on this subject was published in 1961 Since then there have been several publications dealing with particular parts of the subject which serve as useful back-up reading, but the precast concrete industry is complex and needs to be discussed in both general and particular terms over a large number of subject areas

The book is aimed not only at people who have considerable experience but also at those new to the subject Both of these groups of people will wish to extend their knowledge, either in their existing fields

or new ones Although high degrees of knowledge of mathematics, physics, chemistry and engineering are not required of the reader, it is assumed that he or she will have had two or three years of what may be loosely and internationally described as further education Specifiers, manufacturers, contractors and teachers will all find something of use Engineering design and detailing are not covered in this book but details of materials, properties, manufacture and usage are discussed in

as full a way as possible Most of the data, although based upon UK experience, are equally applicable in other countries Care has been taken

to ensure that no matter what process, environment or materials are under consideration the reader will be able to abstract the data required

to facilitate production and use of as good a quality product as possible The common factors in precast concrete products are aggregates, hydraulic cement and water, coupled with a technique for moulding these into a required shape Although certain rules and guidelines can be laid down, technology can only be used part of the way, as ‘know-how’ and

a large degree of ‘alchemy’ play important roles One of the purposes of this book is to outline how far one can take the technology and when one needs to develop one’s own experience All that is asked of the reader is the same number of degrees of flexibility as there are variables relating to

the properties of the final product A rigid philosophy will not bear fruit, therefore, great care should be exercised to take a number in its context and not treat it as sacrosanct

The reader should also bear in mind that imparting good practice information rarely breaches secrecy and will always result in a better image for the industry as a whole Bad performance, whether due to design, materials and/or workmanship, is news that travels fast and even the innocent suffer in the aftermath Since precast concrete is often one of the choices open to the specifier no one can be excused for promoting the alternatives through their own errors Pride in the product is the aim and this is easy to achieve Should any of the basic rules or guidelines be ignored one will find that there is only one rule and that is that the percentage number of rejects is inversely proportional to the control one has

BIBLIOGRAPHY

H.G.CHILDE, Concrete Products and Cast Stone, Concrete Publications,

London, Ninth Edition, 1961.

Architectural Precast Concrete, Prestressed Concrete Institute, Chicago, 1973.

J.G.RICHARDSON, Formwork Construction and Practice, Cement and

Concrete Association, London, 1977.

Acknowledgements

Introduction

1 Moulds and Materials

2 Admixtures

3 Pigments

4 Fly Ash

5 Production—General Considerations

6 Production—Specific Processes

7 Accelerated Curing

8 Properties and Performance

9 Quality Assurance

10 Repairs