8 Pages

Prediction method of concrete deterioration by electrochemical inspection

K. Toda & T. Nishido K. Uji

ABSTRACT: The electrochemical methods, e.g. half-cell potential and polarization resistance, are popular ones for the evaluation of the corrosion of reinforcing bar in concrete. But its accuracy and limitation are not verified; furthermore, the results of electrochemical measurement and actual corrosion situation are different on the whole. In this study, the accuracy of their results is discussed with the results of electrical acceleration test in which the chloride ion was transported into concrete. From the test results, there are good agreements between the judgment of electrochemical methods and the actual corrosion situation under the corrosive environment. But in the case of durable concrete, which have low water cement ratio and large cover thickness, the non-destructive test results does not correspond with the destructive test results. If the concentration of chloride ion at the reinforcing bar is over 2.0 kg/m3, the passive films will be destroyed. And if the concentration of chloride ion is over 4.0 kg/m3, the corrosion of their reinforcing bars may initiate in this accelerating method.