The effect of repairs on the corrosion of reinforcing bars in concrete was studied on concrete slabs that contained a rectangular recess or "pothole" to facilitate the development of corrosion macrocells. The slabs were exposed to 4 wet-dry cycles with each cycle consisting of 4 days of ponding with a 3 1/2 % salt solution followed by 10 days drying in laboratory air. This resulted in salt penetration over the entire concrete surface, but preferential corrosion of the exposed steel in the "pothole." During the third day of wet exposure, the corrosion behavior of the slabs was monitored with half-cell potential measurements. After completion of the wet-dry cycles, the slabs were repaired with three repair materials having different properties and ease of placement. Following the repairs, the salt exposure and corrosion monitoring continued. During the initial salt exposures, half-cell potentials on the exposed bar were more negative than on the rest of the reinforcement. No such trend could be identified after the slabs were repaired. For the one slab that has been opened to date, destructive examination revealed a small amount of rust adjacent to the repaired area and a significant amount of rust on the supporting chairs for the reinforcement mat.

Subject
Concrete repair, Materials, Salts, Rebar, Slabs, Polymers, Repair, Cement, Chlorides, Half cell potential, Half cells, Concrete, Reinforcement
© 1990 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).
1990
Association for Materials Protection and Performance (AMPP)
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