LAUSR

Abstract Based on the transport model of moisture, this paper establishes a prediction model of chloride transport in unsaturated concrete. For the moisture transport model, different water diffusion coefficients are assigned to the drying and wetting processes respectively. Based on considering the interaction between the transport of moisture and chloride ions in concrete and multi-factors influence on chloride diffusion coefficient, the constitutive equation of chloride diffusion-convection in unsaturated concrete is built. Two groups of tests of concrete specimens under drying and wetting cycles with different time ratios of drying-wetting are carried out and verify the rationality of the prediction model. Furthermore, a two-dimensional concrete model based on finite element method is developed to investigate the chloride transport in unsaturated concrete on meso-level. The simulation results show that the random distribution of aggregates could have a significant influence on the chloride transport. Also, the randomness and inhomogeneity of chloride concentration distribution are well reflected in the meso-scale concrete model under the action of drying and wetting cycles.