A novel method to measure the actual corrosion resistance/rate of steel reinforcement during impressed-current accelerated corrosion test

Abstract

Impressed-current accelerated corrosion (ICAC) technique has been widely employed in laboratories to fabricate corroded steels within a relatively short timeframe. In this technique, however, the disparity between theoretical and actual mass losses, characterized as current efficiency, is difficult to measure quantitatively and nondestructively. In this study, a two-circuit setup along with a particular calculation method for the measurement of current efficiency, without interrupting ICAC current and destructing steel samples, was proposed and investigated. The test results showed that the proposed setup was able to measure electrochemical responses effectively, and the calculation method could offer a satisfactory measurement of current efficiency for bare steel bars. This method not only traces the changes of current efficiency as a function of time but also explains the current efficiency exceeding 100% for the first time. It is also found that further development is needed for proposed calculation method to apply to steel bars in cement, due to the chemical complexity of cement pore solution. This will be investigated in future studies.