ABSTRACT
Ever since its first real trial in the mid 1970s, impressed current cathodic protection (ICCP) has developed as a practical corrosion control technique for reinforcement steel in concrete.
The earliest documented installations for above-ground structures were carried out in California, USA. These involved placing anode materials in saw-cut slots in roadway bridge decks. The original anode materials were conductive carbon loaded asphalt overlays. Later they advanced to resins and other polymers cast into the slots around platinized niobium-coated copper-cored wires (primary anodes). DC to power the system was supplied from transformer rectifier units. Restrictions on the output current density achievable and the impracticality of applying these original anode materials on anything but a horizontal, easily accessible, deck surface encouraged developers to look for alternative materials and application techniques. A great deal of research, effort and funding has since been directed at improving the durability and ease of application of ICCP anodes for reinforcement concrete and the success of these developments, in both commercial and technical terms, can now be seen world-wide.
