UNDERWATER CONCRETING AND REPAIR Edited by

Andrew McLeish Head of Structural Appraisal, W S Atkins Structural Engineering, Epsom, Surrey, UK Editorial Advisor Tony C Liu, US Army Corps of Engineers, Washington DC 20314, USA

Halsted Press An imprint of John Wiley & Sons, Inc. New York

Toronto

© 1994 Andrew McLeish First published in Great Britain 1994 Library of Congress Cataloging-in-Publication Data Available upon request ISBN O 470 23403 2 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronically or mechanically, including photocopying, recording or any information storage or retrieval system, without either prior permission in writing from the publisher or a licence permitting restricted copying. Printed and bound in Great Britain.

Preface

The construction of a wide range of structures including bridge piers, harbours, sea and river defences over many decades, and more recently the development of offshore oil fields, has required placement of concrete underwater. This process can be successfully carried out and sound, good quality concrete produced if sufficient attention is paid to the concrete mix itself and the methods of construction employed. This book is intended for the practising engineer, who whilst being experienced in the techniques and approaches for construction above water needs practical advice and guidance on underwater concreting. The contents of the book are arranged in a progressive order starting with considerations that must be given to the design of the concrete mix to minimise the effects of contact with water, and to take into account the practicalities of placing and compacting the concrete. The methods that can be employed to prepare the construction site, types of form work available and methods of placement are then described and their relative merits and potential problems discussed. As much underwater concrete is of considerable age and is exposed to severe conditions, techniques for inspecting underwater to identify defects, and the methods of repair that can be employed are important issues that are described. Finally, the durability of concrete in an underwater environment is discussed and the potential areas of concern highlighted. A McLeish January 1994

List of Contributors

R S Mangat Head of Research, School of Construction, Sheffield Hallam University, City Campus, Pond Street, Sheffield, UK.

A McLeish Head of Structural Appraisal, W S Atkins Structural Engineering, Woodcote Grove, Ashley Road, Epsom, Surrey, UK.

FRendell Anglia Water Services Ltd, Compass House, Chivers Way, Histon, Cambridge, UK.

P J Scatchard Samos Ltd, 3 West Drive, Brighton, UK.

BWStaynes Consultant Engineer, 6 Shenstone, Lindfield, West Sussex, UK. Editorial Advisor

TCLiu US Army Corps of Engineers, Washington DC 20314, USA