Monitoring system for the penetration of chlorides, carbonation and the corrosion risk for the reinforcement

Abstract To monitor the corrosion risk for the reinforcement in concrete structures exposed to aggressive environment due to chlorides penetrating into the concrete or due to carbonation of the concrete a special monitoring system has been developed. It consists of several pieces of different metals (anodes and cathodes) which are embedded in the actual concrete at defined positions. The time-to-corrosion for the reinforcement can be estimated by measuring the electrical current flow between the anodes and cathodes. Additional measurements indicate also the corrosion rates to be expected after the reinforcement will have been depassivated. The theoretical background and the practical experience from installations on site are presented and discussed.