Developments in cathodic protection applied to reinforced concrete

Impressed current cathodic protection (CP) has been shown to provide an eff ective means of restraining corrosion associated with the presence of chlor ide ions in reinforced concrete structures. Advances in extended anode syst ems and monitoring methods, together with improved understanding of how to minimize the risks of adverse side effects, have led to widespread acceptan ce of the approach for treating such problems. Interesting developments in recent years have included the use of very low current density CP for preve nting the initiation of corrosion in new structures (cathodic prevention) a nd intermittent or temporary forms of CP for restoring the passivating char acter of contaminated cover concrete. Progress is also being made in the ap plication of sacrificial anode CP, particularly as a means of enhancing the performance of patch repairs, which as yet have not been considered a dura ble method of restoring chloride-contaminated reinforced concrete.