New solution for prediction of chloride ingress in reinforced concrete flexural members

Control and monitoring of chloride-induced reinforcement corrosion is of practical significance if premature failure of reinforced concrete structures is to be prevented. Of all predictive models available, it appears that Fick's second law has been the most widely used in practice to determine the. chloride:ingress in, concrete. Although research findings have suggested that existing solutions to Fick's second law are inapplicable for the prediction of chloride ingress in reinforced concrete of practical use due to various assumptions employed in deriving the solution, few solutions have been developed that are unconstrained from these assumptions. This paper attempts to develop a new solution to Fick's second law for the prediction of chloride ingress in reinforced concrete flexural members. In this paper the fundamental mechanism of diffusion of chloride ions in concrete is studied and an analytical solution is derived and verified by experimental data. The chloride ingress in concrete under different cracking conditions is also examined and compared with that predicted by the I derived solution. A merit of the developed solution is that the basic,design parameter of crack width is included in the prediction of chloride ingress in concrete. In addition, the derivation of the solution does not resort to unproven assumptions.