Corrosion Behavior of Localized Region of Carbon Steel in Concrete and Simulated Concrete Solution by Four Point Probe Technology

Sheet resistance and corrosion depth of carbon steel were continuously monitored in simulated concrete solution and concrete with NaCl by a self-designed in-situ corrosion measurement system. The corrosion behavior in different regions was analyzed. The results show that corrosion of different regions on the surface of carbon steel in the solution was basically the same because of the direct and uniform function of chloride ion, meanwhile sheet resistance and corrosion depth followed binomial law in three stages of corrosion process. Nevertheless the corrosion of different regions in concrete was different. In some regions, the corrosion kinetics was the same as that in the solution, and in others sheet resistance and corrosion depth agreed with linear law in the first stage, then binomial law in the second and third stage. The kinetics of corrosion process would be acquired by sheet resistance method.