Corrosion behavior of steel submitted to chloride and sulphate ions in simulated concrete pore solution

Electrochemical measurements of open circuit potential, linear polarization and electrochemical impedance spectroscopy (EIS) were utilized to investigate the corrosion behavior and chloride threshold value (CTV) of reinforcing steels submitted to chloride and sulphate attack in simulated concrete pore solution in this study. Determination of corrosion initiation was made by combining half-cell potential (Ecorr) with corrosion current density (Icorr) as well as EIS curves. Results showed that electrochemical measurements were effective in detecting corrosion behavior of steels. CTV of steels was 0.5-0.6 mol/L in simulated concrete pore solution contaminated by chloride ions while threshold value of steels submitted to sulphate ions was 0.2-0.3 mol/L. The concomitant presence of chloride and sulphate ions led to higher corrosion current density which indicated sulphate ions accelerated the corrosion of reinforcing steels in simulated concrete pore solution.