Relationship between conductivity of concrete and corrosion of reinforcing bars

An attempt is made to explain the roleplayed by the conductivity of concrete in the corrosion of reinforcing bars. Tests carried out on bimetallic couples embedded in concrete support the hypothesis of direct proportionality between concrete conductivity and corrosion rate. Severalfactors rule out the hypothesis of ohmic control. On the contrary, it is suggested that the process of corrosion is governed by the fraction of the metallic surface wetted by the interstitial liquid present in the concrete.