While CSI curb the corrosion process by installing zinc anodes, another method, Impressed Current Cathodic protection (ICCP) is used to prevent corrosion occurring in the first place. ICCP forces a direct current from an external power supply to flow from an anode through the concrete to the reinforcing steel. A current of sufficient magnitude and direction is necessary to overcome the natural flow of electrons resulting from the corrosion process.
The direct current is supplied from an external source, most often an AC/DC (transformer) rectifier.
Standard – ASTM Standard STP 1137: Corrosion Forms and Control For Infrastructure