Selecting an adequate procedure for the electrochemical chloride removal

Abstract

This paper concerns the proper selection of the electrochemical chloride removal (ECR) current and the ECR duration. Four constant ECR current densities, 100, 200, 400 and 800 mu A/cm(2), were applied to concretes for 1 to 6 weeks. The remaining chloride contents nearby the reinforcement were measured to understand how fast the ECR process can remove chloride ions out of concrete. The open circuit potential and corrosion rate measurements were performed to examine the corrosion status after ECR. In addition, the pH value nearby the reinforcement and the apparent electrical resistivity of concretes after ECR were measured. The results showed that the remaining chloride ions decreased, the open circuit potential became nobler, the corrosion rate decreased, the pH value increased and the apparent electrical resistivity increased as the ECR parameter, defined as the product of the ECR current density and the ECR duration, increased, The ECR parameter can provide a direction in designing the ECR process. (c) 2006 Elsevier Ltd. All rights reserved.