Modeling of Effective Diffusion Coefficient of Substances in Concrete Considering with Spatial Properties of Composition Materials

Abstract

This research was conducted to develop a model to estimate the effective diffusion coefficient of substances in concrete considering with spatial properties of each composition material. In this model, concrete was assumed to be composed of cement paste, interfacial transition zone and aggregate. Proposed model could appropriately evaluate the effective diffusion coefficient of chloride ion in concrete in previous research. The influence of spatial properties of each composition material on the dispersion of effective diffusion coefficient of chloride ion in concrete was investigated. The influence of cement particle arrangement on the dispersion was larger than that of aggregate arrangement, and that influence became remarkable as W/C became low. Moreover, in the calculation of the effective diffusion coefficient of concrete, when the change in pore volume was considered without considering microstructure development in detail, an annronriate value may be obtained with a reasonable accuracy.