Soil corrosivity determination by electrochemical methods

Measurements of soil specific corrosivity were performed on bare steel in clay and sand (15-35% moisture content). Rp was obtained either from potentiokinetic linear polarization method and impedance technique. The values of the former method were corrected of IR deduced from the ac technique. A method to evaluate Rp from impedance technique is proposed which generally gives results close to dc method. The results indicate that corrosion process is largely conditionated by the moisture content in the clay and very scarcely in the sand. Impedance data allow some interpretation of rate corrosion determining process.