Electrochemical Technique to Evaluate Carbonation Behavior of Reinforced Concrete

The present work postulates the use of electrochemical techniques to evaluate the condition of rebar and concrete subjected to accelerated carbonation front. Potentiodynamic polarization was carried out to find the anodic corrosion current density (icorr), and EIS was used as a non-destructive technique (NDT) to determine the carbonation front progression in concrete. The experimental results reveal that the high-frequency arc of impedance spectra increases with increase in exposure duration. The effect of cement type on the progress of carbonation front is also evaluated. The results show that densification caused due to CaCO3 formation inside the concrete decreased the ingress of carbonation front in OPC concrete. The carbonation depth was further predicted by fitting equivalent circuit on the obtained impedance spectra. Variation in the measured and predicted carbonation depth was found to be below 10% for most of the exposure durations, indicating effectiveness of EIS data to evaluate the carbonation depth of concrete.