An investigation into impressed current cathodic protection systems in Australian wharves

Over the past forty years a significant number of corroding and at risk structures have been maintained using Impressed Current Cathodic Protection (ICCP). Recent studies have shown that steel within a concrete structure protected by ICCP can remain passive for a number of years after the system is discontinued. This indicates that a form of lasting or residual protection is afforded to the structure by the ICCP system. This study examines this phenomenon of residual protection by suspending the operation of an established ICCP system in a Victorian wharf and monitoring the activity of the steel for a period of 106 days.Residual protection was observed in seven of the test beams located in the splash zone.The results appear to support the hypothesis that residual protection is dependent on the local environment as well as the amount of charge injected over the life of the structure.