Title: Monitoring Corrosion Risk in Concrete Structures-Review of 10 Years Experience and New Developments

Author(s): M. Raupach and P. Schie?l

Publication: Symposium Paper

Volume: 192

Issue:

Appears on pages(s): 19-34

Keywords: cathodic protection; concretes; corrosion; reinforced concretes; steels

DOI: 10.14359/5739

Date: 4/1/2000

Abstract:
Since 1990 the Anode-Ladder-System has been used world-wide to monitor the corrosion risk of new concrete structures. This sensor-system is an embedded macrocell system indicating the depth of the critical chloride content initiating corrosion of the reinforcement. Subsequently the time-to-corrosion of the reinforcement can be determined continuously, enabling the owners of buildings to initiate preventive protection measures before damage like cracks and spalling occur. However, this system can only be installed before placement of the concrete. Therefore a new sensor system has been developed to monitor the corrosion risk for the reinforcement also in existing or repaired structures. This new Expansion-Ring-System consists of 6 anode rings separated by sealing rings and a cathode bar, which are installed in small holes drilled into the concrete and connected by a special expansion mechanism. Actually it is in the stage of final testing in laboratories and pilot projects.