Verifying the Reliability of Impressed Current Method to Simulate Natural Corrosion in Reinforced Concrete

Abstract

In order to accelerate the corrosion of steel reinforcement in the reinforced concrete structures for laboratory research, the impressed current method has been used widely regardless of the appropriacy of this method on the various aims of the studies relating to the deterioration of the reinforced concrete structures. The aim of this study is to characterize the influence of the impressed current method on the steel-concrete interface in the reinforced concrete to verify the reliability of this method on simulating the natural corrosion. The mill-scale of the steel reinforcement and the steel-concrete interfacial region were investigated using SEM-EDS. The results indicate that impressed current can induce the non-uniform and localized corrosion on the steel reinforcement. The corrosion products formed were likely to the natural corrosion induced by chloride environments. However, the oxidization of OH^- at anode can inhibit the precipitation of corrosion products at steel-concrete interfacial region and then slowing down the formation of crack in concrete. This positively leads to an overestimation of load capacity of corroded structure and raises doubt on utilizing this technique to simulate the corrosion behavior.