Durability of Conductive Polymer for Cathodic Protection of Rebars in Concrete Piling

摘要

Four electrically conductive, EPDM-based synthetic rubber materials have been evaluated as candidate materials for anodes in cathodic protection of reinforcing steel in concrete. The materials were tested by impressing anodic current densities in accelerated laboratory tests using a sodium chloride solution. The effects of current density, exposure time and organic contamination on polarization, apparent resistivity, mechanical strength, ductility and physical dimensions were evaluated. In the absence of organic contaminants, the tests showed that the materials with the lowest EPDM content experienced the fastest degradation. A limited test sequence showed that periodic, direct contact with lubricating oil and diesel fuel caused severe swelling and degradation of the electric properties of all four materials. Diesel fuel was the most damaging. Detailed tests should be conducted to ensure adequate resistance to residual amounts of organic contaminants such as those encountered in actual service.