Electrochemical evaluation of corrosion inhibitors for repairing of highway transportation infrastructures

Abstract

Among the methods to tackle corrosion of steel reinforcement in highway transportation infrastructure, using corrosion inhibitors has been identified as the most easily and economically applied technique. This study used Electrochemical Impedance Spectroscopy (EIS) to evaluate four corrosion inhibitors in simulated pore solution (SPS) and saturated calcium hydroxide solution (CHS). Three promising inhibitors were identified. It was also found that the electrochemical laboratory test was practical to evaluate corrosion inhibitors quickly and effectively in simulated concrete solutions. A simulated field concrete repair method was devised in order to verify the developed electrochemical laboratory test result. Sixty-three concrete short beam specimens were used. The embedded steel rebars were exposed to chloride environment and electrochemically monitored in accordance with the ASTM G109 procedure. After active corrosion of the upper rebars was detected, the chloride- contaminated concrete was removed. The three aforementioned promising inhibitors were applied to corroded rebars, and new concrete was cast. These rebars were electrochemically monitored to evaluate the effectiveness of corrosion inhibitors for corrosion control. It was found that there was a good correlation between these two test results, and the most effective inhibitor was finally identified.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.