Assessing the electrical resistivity of concrete structures for corrosion durability studies.

The use of concrete resistivity measurements, in conjunction with potential mapping was investigated with a view to improving the assessment of corrosion durability of reinforced concrete structures. The influence of the specimen geometry, of steel reinforcing bars and of surface skins upon the apparent resistivity measurement using the 4 point Wenner method were studied in the laboratory. Reinforced concrete specimens conditioned to promote corrosion and exposed to a marine environment for 2 years were monitored using half-cell potential and resistivity methods. The results were compared with direct corrosion rates obtained from perturbative a.c. studies. The initial results indicate that measurement of concrete resistivity can be used effectively alongside potential mapping to assess the severity of corrosion problems. (A)