An experimental study on correlation between concrete resistivity and reinforcement corrosion rate

The purpose of this paper was to explore the possibility of establishing an empirical correlation between concrete resistivity and reinforcement corrosion rate utilizing the experimental data generated by measuring corrosion current density of reinforced concrete specimens subjected to chloride-induced corrosion at different levels of concrete resistivity.

To generate concrete resistivity vs corrosion current density data in a wide range, ten reinforced concrete specimens were prepared and allowed to corrode under severe chloride exposure. After significantly corroding the specimens, they were removed from the chloride exposure and were subjected to different moisture levels for achieving variation in the resistivity of concrete so that reasonably good number of resistivity vs corrosion rate data can be obtained. Resistivity and corrosion current density tests were conducted for all the ten specimens and their values were measured in wide ranges of 0.8-65 kΩ·cm and 0.08-11 μA/cm2, respectively.

Data generated through this study were utilized to obtain an empirical relationship between concrete resistivity and corrosion current density. The trend of results obtained using the empirical correlation model developed in the present study was in close agreement with that obtained using a theoretical model reported in literature.

The empirical correlation between concrete resistivity and reinforcement corrosion rate obtained under this work can be used for evaluation of reinforcement corrosion utilizing the resistivity values measured non-destructively.