Analysis of time-dependent chloride diffusion in surface-treated concrete based on a rapid numerical approach

Reinforcement corrosion induced by chloride penetration is a major threat to reinforced concrete structures in marine environments. The use of surface treatments to improve the durability of reinforced concrete structures has drawn increasing attention in recent decades due to their cost-effectiveness and convenience in construction. However, current knowledge of a practical, durable design to protect surface-treated concrete structures from chloride-induced steel corrosion remains insufficient. On this account, a rapid numerical approach was developed in this study to analyse the chloride diffusion in bilayer materials. In this approach, the time-dependency was considered for the chloride diffusion coefficients of both the surface-treated layer and the underlying concrete substrate and for the surface chloride content. The validity of this approach was verified with the finite element method and the computation time was only one hundred-thousandth that of the latter. This proposed approach makes it feasible in practice to estimate the probability of corrosion initiation in surface-treated concrete structures via Monte Carlo simulation.