Effect of Electrochemical Treatment in Inhibiting Corrosion of Steel in Concrete

Abstract

This study concerns the effectiveness of electrochemical treatment in enhancing the resistance of steel to corrosion in concrete. The current density for electrochemical treatment ranges from 250, 500, and 750 mA/m(2) (0.161, 0.323, and 0.484 mA/in.(2)) for 1 week to 125, 250, and 500 mA/m(2) (0.081, 0.161, and 0.323 mA/in.(2)) for 2 weeks. The steel-mortar interface was also examined using backscattered electron (BSE) images after treatment. As a result, an increase in the current density of the specimens resulted in an increase of the chloride threshold level, ranging from 0.82 to 2.72% by weight of cement, whereas the untreated specimens produced a lower threshold level, ranging from 0.35 to 1.52%. Thus, the time to corrosion was increased from 167 to 571 days. It was seen in the BSE image analysis that electrochemical treatment at a high current density resulted in the formation of cracks and large voids in the vicinity of the steel and a delay in cement hydration.