ABSTRACT
Abstract Two material parameters in equation of chloride diffusion are modeled, one is the chloride binding capacity and the other is the chloride diffusivity. The basic trends of the chloride binding capacity and the diffusivity are predicted by the present model successfully. With increasing w/c, both the diffusivity and the increment of free chloride increases. With the same w/c, longer curing time leads to more bound chloride and lower diffusivity. Since the diffusivity of aggregates are usually lower than that of cement paste matrix in concrete, with increasing volume fraction of aggregate, the effective diffusivity of concrete decreases. The present mathematical models are used in the nonlinear chloride diffusion equation which predicts profiles of the chloride penetration very well. Keywords: concrete, transport, diffusion, chloride, microstructure.
