Experimental study of cathodic protection for reinforced concrete submerged in saline water

Cathodic protection (CP) has been approved in practice to be an effective technique to protect steel reinforcement in concrete from corrosion under severe environmental conditions. Using constant current for CP is the most popular approach in practice, particularly for the structures exposed to atmospheric conditions. However, for submerged structures, the situation of the reinforcement is quite different, if the constant current approach is efficient to provide adequate protection is still not very clear. To have a deep understanding for the question, an experimental investigation has been conducted for reinforced concrete specimens protected by impressed electrical current of both constant current density and constant potentiostatically controlled potential, respectively. Reinforced concrete specimens had varied chloride contents and submerged into salty solutions that have the same amount of chloride added in the concrete mixture have been examined. The performance of protection has been evaluated and discussed. Corrosion potentials and concrete resistivity were also measured and compared with those of chloride content/corrosion rate