RELATION BETWEEN RESISTIVITY AND CORROSION RATE OF REINFORCEMENTS IN CARBONATED MORTAR MADE WITH SEVERAL CEMENT TYPES

In this present paper results of corrosion rate and simultaneous electrical resistance values of rebars in mortar fabricated with six different types of cements are given and the relation between those values is presented. The specimens were carbonated in order to promote active corrosion of the rebars. They were held in chambers with different relative humidities. The results of this study indicate a strong relationship between the corrosion rate measured on the rebars (by means of Polarization Resistance method) and the electrical resistance of the concrete, which suggests a method of estimating the rebar corrosion rate from the simple measurement of the electrical resistance when rebars are depassivated. The relation between i//c//o//r//r and R//o//h//m obtained is quite similar in all the cases and suggests that the concrete electrical resistivity may act as a 'controlling' factor of the corrosion rate.