Effects of aggregate and interface characteristics on chloride diffusion in concrete based on 3D random aggregate model

Abstract The chloride diffusion in concrete with different aggregate volume ratios (AVR) and interfacial transition zone (ITZ) were studied in this paper. According to the finite element method, the 3D concrete model with aggregates and ITZ is modeled, and the chloride diffusion characteristics were numerically simulated and compared with the experimental results. Furthermore, the reasons for the better chloride resistance of nanocomposite concrete are studied. The results show that the established model can well reflect the material properties of concrete and has a good application effect on chloride diffusion. The increase of AVR inhibited the chloride diffusion and there is significant influence on the simulation results when use different AVR to back calculation. However, it is little influence on the simulation results when change the ITZ condition of back calculation. The better chloride diffusion resistance of nanocomposite concrete is mainly due to the improved anti-diffusion properties of the ITZ.