Effectiveness of Simultaneous Application of Patch Repair and Cathodic Protection on RC Structures Damaged by Chloride-Induced Deterioration - 3-Year Evaluation

It is known that macro-cell corrosion occurs at the interface between the base material and the repair material in the repair method using the patch repair. This paper focuses on a repair method that combines the patch repair method with the impressed current cathodic protection method applied to the base concrete to prevent such re-deterioration. The method was applied to RC beam specimens severely deteriorated by chloride damage in a marine environment, and monitoring was conducted over three years. The corrosion protection state of the rebar was evaluated using electrochemical methods, including potential monitoring and polarization measurements. The results showed that while the rebar in the base concrete was sufficiently polarized by the impressed current anode, the rebar in the patch repaired with polymer cement mortar exhibited low polarization. This is attributed to the high electrical resistivity of the polymer cement mortar. On the other hand, it was confirmed that the polymer cement mortar provided sufficient corrosion protection even without polarization due to its high electrical resistivity. Additionally, it was confirmed that the rebar at the interface of the repair patch was adequately protected by the cathodic protection method.