Standards for monitoring the performance of cathodic protection systems on reinforced concrete structures actually recognized are based on the measurement of the polarized potential of the reinforcement (polarization/depolarization, E Log I tests). A new methodology to measure this performance has been developed based on the passivation of the rebar rather than on the level of potential polarization. This new technique is based on the Electrochemical Impedance Spectroscopy concept with a modulated confinement of the applied current. The results are not quantitative, but properly define the passivity of the rebar under protection and its resistance to corrosion.

The new technique has been evaluated in the laboratory as well as in the field with successful results. Laboratory and field evaluations included sacrificial and impressed current systems.

Results obtained with this technique were compared to results achieved by standard polarization methods and were found to be in agreement. The new technique is faster than standard methods and do not require interruption of the cathodic protection current.

Subject
Protection practices, Galvanic anodes, Anodic protection, Cathodic protection, Rebar, Zinc anodes, Piles, Corrosion protection, Impressed current, Jackets, Bridges, Concrete, Reinforcement
Keywords:
Anode, cathode, concrete, cathodic protection, confinement, electrochemical impedance spectroscopy, passivation verification
© 2004 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).
2004
Association for Materials Protection and Performance (AMPP)
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