Research on the Corrosion Behavior and Cathodic Protection of Defected-Epoxy-coated Reinforcement Exposed to Chloride Environment

Abstract

The application of epoxy coated rebar (ECR) is an effective method to improve the durability of reinforcement in chloride environment. However, the coating defects caused in construction will significantly decrease its corrosion resistance to chloride. Herein, the corrosion behaviors of different defects rate in ECR under chloride attack in South China are investigated. The results indicate that the corrosion of ECR is due to the coating defects, the corrosion potentials of defected-ECR are shifted to negative, and the corrosion current density is significantly increased with increasing the defect rate. The corrosion resistance of defected-ECR is improved by applying the anode-mortar cathodic protection system, both the exposure test and engineering application all show that the durability of defected-ECR is increased with the high polarization potential (≥200mV) and negative protection potential (＜-800 mV).