A New Approach for Automatic Control and Monitoring of Cathodically Protected Reinforced Concrete Structures

Abstract In this paper the aspects of monitoring and control of cathodic protection systems for reinforced concrete are reviewed and discussed; emphasis is devoted to prestressed and post-tensioned structures, where the risk of hydrogen embrittlement of steel rebar actually exists. A new approach for monitoring criteria is illustrated, that is essentially based on the monitoring the anode potential, typically of titanium mesh type, instead of the cathode potential, as usually done. This monitoring technique allows a reliable and safe control of the protection conditions on the steel rebar, avoiding any risk of over-protection. An automatic device is illustrated, which consists of a control unit, able to log anode potential readings, and after a proper elaboration, to regulate the feeding conditions. Examples of the described monitoring criteria, taken from service experience on real structures, are shown.