Advances in Electrochemical Impedance Measurements in Reinforced Concrete

Abstract

EIS measurements in reinforced concrete have been carried out from the first studies of J. Dawson et al at the beginning of the eighties. Since their first papers already proposing an electrical equivalent circuit having in series two individual Randles ones, not very much advances have been achieved in the interpretation of the results. In the present paper a contribution to the understanding of the physical meaning of the EIS results obtained is presented. Three main frequency regions with processes having very different capacitive behaviour and therefore, time constant responses, are identified. Finally, it is pointed out the need to use specimens with well defined geometry in order to enable the correct frequency analysis and dielectric constant calculation to be made.