Developments in Cathodic Protection Applied to Reinforced Concrete

Abstract

Impressed current cathodic protection (CP) has been shown to provide an effective means of restraining corrosion associated with the presence of chloride ions in reinforced concrete structures. Advances in extended anode systems and monitoring methods, together with improved understanding of how to minimize the risks of adverse side effects, have led to widespread acceptance of the approach for treating such problems. Interesting developments in recent years have included the use of very low current density CP for preventing the initiation of corrosion in new structures (cathodic prevention) and intermittent or temporary forms of CP for restoring the passivating character of contaminated cover concrete. Progress is also being made in the application of sacrificial anode CP, particularly as a means of enhancing the performance of patch repairs, which as yet have not been considered a durable method of restoring chloride-contaminated reinforced concrete.