Many underwater tunnel structures have been experiencing water leakages worldwide. Tunnel structures experiencing water leakages are not only old, but also new in some case. The concrete tunnels structures located underwater are generally protected by waterproof membranes as the first defense to prevent water leakages and rebar corrosion. However, once water leakage occurs, the corrosion mechanism is quite different from other concrete structures which are exposed to marine or de-icing salt environments.

When rebars corrode in concrete, the accumulating corrosion products develop expansive force and crack the concrete. When the concrete cracks grow, the concrete spalls and falls to the roadway. For the based slab, concrete spalls create potholes on the driveway. Therefore, it is important to clearly understand the corrosion condition of the rebars in the tunnel caused by salt water leakage. This paper discusses the mechanism of rebar corrosion of underwater reinforced concrete tunnel once water leakage occurs.

Subject
Water, Salts, Rebar, Walls, Leaks, Concrete surfaces, Corrosion cracking, Slabs, Roofs, Tunnels, Chlorides, Corrosion potential, Concrete
Keywords:
Rebar corrosion, reinforced concrete tunnel, waterproof membranes, corrosion survey, cathodic protection, corrosion potential, chloride profile
© 2013 Association for Materials Protection and Performance (AMPP). 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 AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2013
Association for Materials Protection and Performance (AMPP)
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