Influences of Electric Potential and Electrolyte on Electrochemical Chloride Removal in Reinforced Concrete

Abstract

The first purpose of this paper was to find appropriate parameters for the electrochemical chloride removal method; that is, type of electrolyte solution, electric potential and charging duration. The second was to determine the efficiency of the chloride removal at remote areas from the position of installation. The 30×30×10 cm3 and 70×70×7.5 cm3 concrete specimens were prepared for the first and second purposes respectively. The chloride removal process was performed by applying electric potential between the reinforcement bars embedded in concrete and an external electrode installed on the concrete surface submersed in external electrolyte. With 28 days charging, this method could remove up to 76% of chloride by using the Ca(OH)2 solution as electrolyte with 15 V DC electric potential. The efficiency of chloride removal decreased as the distance from the position of installation increased. This was consistent with the equation of Nernst Planck which described the movement of chloride ions mobility through the concrete by electric current. As a result, there was a good tendency for using electrochemical chloride removal method to remove chloride ions from reinforced concrete.