Abstract: The convection effect of moisture predominantly controls the transport of chloride ions within the unsaturated concrete.To examine the durability of unsaturated concrete structures,C40 concrete specimens with varying water-binder ratios were designed.A non-Darcy moisture seepage model was developed based on the Izbash equation to describe the nonlinear relationship between specific discharge and hydraulic gradient.Via Boltzmann transformation,an analytical solution for chloride ion transport was derived.The acceptability of the proposed chloride ion transport model was validated by comparing with laboratory experimental data and COMSOL numerical simulation results.The results indicate that both the apparent chloride ion diffusion coefficient and permeability coefficient of concrete decrease gradually over time and stabilize finally.Both parameters are positively correlated with the water-binder ratio.The established mathematical model can be used to accurately simulate the transport process of chloride ions within the unsaturated concrete.The chloride ion migration rate and migration start-up time for the non-Darcy seepage model are significantly lower than those for the traditional Darcy model.The research provides theoretical support for optimizing corrosion prevention techniques in coastal engineering projects.