Influence of Metakaolin and Curing Conditions on Service Life of Reinforced Concrete

Abstract

This investigation focuses on studying the effect of using metakaolin (MK) and/or different curing conditions on service life of reinforced concrete exposed to chloride-induced corrosion. Three main stages of service life are studied: corrosion initiation, propagation, and damage periods. The initiation and propagation periods were studied experimentally using small reinforced concrete samples and were also calculated using some available empirical models in the literature for comparison. The experimental variables were the use of MK (0–20%), cover thicknesses (20, 30, and 40 mm), and curing conditions (10 different curing temperatures and durations). The experimental results showed that curing conditions had a clear effect on the initiation and propagation periods but showed a nonsignificant effect (verified by statistical analysis) on the length of the damage period in all tested samples. The incorporation of MK significantly increased both the initiation and propagation periods with little increase in the damage period. The results also indicated that similar trends were found, irrespective of curing condition and cover thickness, from comparing both the initiation and propagation periods using the experimental data and theoretical models.