Service life prediction of RC structures based on correlation between electrochemical and gravimetric reinforcement corrosion rates

This paper outlines a comprehensive experimental investigation to establish relationships between electrochemically and gravimetrically measured reinforcement corrosion rates generated through a comprehensive experimental program. The investigation is based on testing a total number of 486 reinforced concrete (RC) specimens prepared using coarse aggregates obtained from two distinctly different sources of aggregate and considering three levels of five design variables (namely: cementitious material contents, water to cementitious materials ratios, fine to total aggregate ratios, concrete-cover thicknesses, and exposure to chloride-solutions). The correlation between corrosion rates measured using electrochemical method to that using gravimetric method is established and used to convert electrochemically measured corrosion rate into equivalent but more accurate gravimetric corrosion rate that would be valuable for service life prediction of RC members RC structures in corrosive environments. The experimental program and sample numerical results obtained are outlined and summarized. Then a methodology for predicting remaining service life of corroding RC members is illustrated through a numerical example.