Behavior and Modeling of Hybrid CFRP/Steel Reinforced Concrete Beams with Cathodic Protection in a Marine Environment

Abstract

Impressed current cathodic protection (ICCP) has been proven to be an effective technique to inhibit steel corrosion. Based on the principle of ICCP, a hybrid carbon fiber–reinforced polymer (CFRP)/steel reinforced concrete (RC) structural system with cathodic protection has been proposed considering the dual function of CFRP, namely, the anode material of ICCP and reinforcement of concrete structures at the same time. For this system, the larger structural deflection and brittle failure caused by the low elastic modulus and linear elastic behavior of the CFRP bar can be avoided, and ICCP is activated only when the steel bar is at risk for corrosion. In this paper, the flexural performance of the proposed structural system with different reinforcement configurations was investigated. First, an accelerated precorrosion test was conducted for the steel bar with a theoretical corrosion ratio of 8%. Then, wet–dry cycle corrosion was performed by companies with ICCP treatment for 150 and 180 days. Finally, four-point bending tests were carried out, followed by a comparison of the experimental bending capacities and predicted values. The results showed that for the proposed structural system, the further corrosion of steel bars was inhibited significantly with a protection current density of 10 mA/m2, leading to the maintenance of satisfactory structural performance without a marked deterioration of the CFRP anode performance or the CFRP-concrete bond behavior. The reinforcement configuration with CFRP bars in the lower row and steel bars in the upper row was the most effective to maintain a satisfying bending capacity and inhibit steel corrosion for the proposed structural system in a corrosive environment.