Corrosion Performance of Steel in Self-compacting Concrete Exposed to Chloride Environment

Abstract

The objective of this paper is to investigate the durability performance of self-compacting concrete (SCC) in terms of corrosion performance of steel reinforcement. The corrosion performance was evaluated by half-cell potential measurement, which provides information about the probability of occurrence of steel reinforcement corrosion and determining the corrosion current density by linear polarization resistance (LPR) measurement, which indicates the corrosion rate of steel reinforcement. Keeping this in view, in the present work prismatic reinforced concrete specimens with a centrally embedded steel bar were made from SCC mixes. Ordinary Portland cement (OPC) was used as a binder, and two w/c ratios of 0.40 and 0.43 were used for the preparation of concrete mixes. The fresh properties of SCC were evaluated by conducting slump flow, T50cm time, V-funnel flow time, L-box, and sieve segregation tests, and the compressive strength was determined for the hardened property. The prismatic reinforced concrete specimens were exposed to sodium chloride solutions for 180 days with alternate wetting–drying cycles. The fresh concrete test results revealed satisfactory filling ability, passing ability, and segregation resistance at both the water–cement (w/c) ratios. From results of corrosion parameters, it is observed that higher concentration of chloride ions increased the corrosion current density at longer exposure period. Further, higher corrosion current density was observed at w/c ratio of 0.43 as compared to that at w/c ratio of 0.40 at the longer exposure period.