The study presented herein has been carried out in order to investigate the chloride diffusivity of recycled aggregate concrete (RAC). Meanwhile, the effect of the binder type, involving cement replacement materials such as, fly ash, slag and silica fume on the chloride diffusivity has also been investigated. For this purpose, RAC and concrete containing the different type of binders with w/b ratios of 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60 were used. As a result, the chloride diffusion coefficient of RAC is higher than that of natural concrete and the partial replacement of cement with fly ash, slag and silica fume is effective in decrease in the chloride diffusion coefficient, measured by a rapid chloride conductivity test.

The simulation analysis is an important part of theoretical study on concrete materials. It is a kind of quantitative analysis method of making full use of the computer technology and it has the advantages of high efficiency, safety, fewer limits of environmental conditions, easy change of the time and size etc. Quickly generation of a three-dimensional aggregate structure is a very important prerequisite for the computer simulation analysis of concrete. In this paper, in order to meet the demand of analysis and simulation, based on the technology of Unity3D，the program of three-dimensional aggregate is written, designed to use a large number of existing tools to quickly generate a concrete aggregate model as simple as possible.