Potential and current distribution across different layers of reinforcement in reinforced concrete cathodic protection system- A numerical study

Abstract Cathodic Protection (CP) is being applied extensively to protect reinforced concrete structures exposed to aggressive environment from corrosion. However, protection provided by cathodic protection is dependent on several parameters such as concrete resistivity, applied current density and the geometrical arrangement of anode and cathode. For the first time, the distribution of potential and protection current along different layers of reinforcement in concrete is numerically investigated. A parametric study was done to analyse the effect of applied current density and concrete resistivity on protection achieved by different layers of reinforcement. The results show, concrete with anode applied at one surface is only able to protect top two reinforcement layers with current density of 40 mA/m2, compared to anode at two adjacent concrete surfaces which protect all four layers of reinforcement with minimum 10 mA/m2 of current density. 80–90% of protection current reached the top layer of steel near the anode. Bottom layers of reinforcement received very minimal current and thus shows negligible protection. A drastic drop in protection was observed on moving down the reinforcement layers. Moreover, protection provided is highly depended on concrete resistivity.