A low frequency impedance study of steel/concrete interface

To understand concrete reinforcement behaviour from the corrosion point of view it is necessary to have a thorough knowledge of the parameters characterizing the reinforcement passivity state. These parameters, varying with the cement type, the w c ratio, the moisture content, etc., can be determined by the a.c. impedance method. In order to improve the knowledge of these parameters, tests were performed over extended time periods on steel/concrete electrodes for some commercial cements. Results of a.c. impedance measurements carried out both during the concrete setting and in the following period are presented and discussed. © 1990.