An analytical solution for chloride diffusion in concrete with considering binding effect

Abstract

This paper presents a novel analytical solution for the chloride diffusion problem in concrete when chloride binding is taken into account. The analytical solution is obtained by splitting bound chlorides into chemically-bound and physically-bound chlorides. The former is treated as moving particles that are trapped in randomly distributed immobile holes. The latter is modelled using a linear binding isotherm. Under this assumption the original problem of diffusion with binding can be transformed to the problem of diffusion with a moving boundary for which an analytical solution can be developed. The present solution is validated using existing experimental data.