Date of Publication :17th January 2018

Abstract: Corrosion of steel embedded in reinforced concrete (RC) structures is a major problem resulting in reducing the service life and durability of RC structures and causing early failure of the structure. Corrosion also costs significantly for inspection and maintenance of deteriorating RC structures. Hence, for preventing premature failure of RC structures, assessment of reinforcement corrosion is of significant importance. Practically, based on visual observation or using qualitative electrochemical techniques like half-cell potential measurement, the level of corrosion can be evaluated. Since for existing structures, it difficult to calculate the rate of corrosion using quantitative electrochemical techniques like Tafel extrapolation technique, linear polarization technique etc. as the instruments require direct contact with corroding steel rebar. Such measurements require damaging the small area of the structure and besides this, the potential/current scans applied to reinforcing steel during measurements may accelerate the corrosion process. Hence it is essential to corroborate relation between qualitative and quantitative techniques used for measurement of corrosion. The present paper aims to establish the relation between two electrochemical techniques namely, half-cell potential and Tafel extrapolation technique. For experimental work, RC slabs reinforced with four steel bars were cast and subjected to accelerated corrosion. The electrochemical measurements were recorded every day till the completion of tests to establish the relation between Half-cell potential and corrosion current density values obtained from Tafel plots.

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