Potential step voltammetry: An approach to corrosion rate measurement of reinforcements in concrete

Abstract

This paper presents a Potentiostatic Step Voltammetry approach to corrosion rate measurement of reinforcements in concrete. We have termed this approach PSV-TE since it is based on the Tafel extrapolation method, but with the added advantage that long and slow potentiodynamic scans are no longer required to obtain the Tafel slopes. In this way, the irreversible polarization of rebars is prevented, so PSV-TE is considered to be a non-destructive method. The Tafel slopes are obtained by fitting the current-time response of the system to a theoretical model which we have outlined and validated previously. In this way, the concrete's electrical resistance and double layer capacity are also obtained. In this study, the optimal PSV-TE design has been established and validated on a range of reinforced concrete specimens. Results show minimal deviation between PSV-TE and reference methods. Therefore, PSV-TE is part of the corrosion monitoring system we have patented.