Reliability of chloride diffusion coefficients calculated from rapid chloride migration experiments Available to Purchase

Chloride-induced corrosion of steel reinforcement in concrete is one of the most critical durability issues in reinforced concrete structures. Chloride diffusion in concrete involves complex processes, and the diffusion coefficient obtained from a specific test may not necessarily represent the actual mechanisms at play. In this study, the reliability of the rapid chloride migration test (RCMT) for determining the chloride diffusion coefficient was evaluated, focusing on the influence of test duration and applied voltage. Experimental analyses of chloride penetration depths and concentration profiles under varying conditions revealed that both factors significantly affect the calculated migration coefficients, raising concerns about the consistency of the RCMT method. Notably, the chloride concentration profiles exhibited a gradual decline with depth, deviating from the sharp fronts predicted by the Nernst–Planck equation. These findings advance the understanding of chloride transport mechanisms in concrete and underscore the need to reconsider the assumptions underlying the RCMT methodology.