A fluid–solid-chemical coupled fractal model for simulating concrete damage and reinforcement corrosion.

[Display omitted] • A fluid–solid-chemical coupled fractal model is developed. • The fractal dimension of tortuosity decreases rapidly with corrosion. • The corrosion of low porosity concrete reinforced by chloride ions can improve the transport of chloride ions. • The change of concrete porosity has nonlinear effect on steel corrosion and concrete pore structure evolution. Chloride ion invasion into reinforced concrete is a common disease. In this study, we combine the diffusion of free chloride ions, the corrosive expansion of iron, and the destruction of concrete. Considering the fractal characteristics of concrete pore structure, a fractal diffusivity model is established. A fluid–solid-chemical coupling model was established considering the non-uniform corrosion of iron. The correctness of the model is verified by comparison with experimental data. The corrosion thickness and pore structure evolution of concrete under different chloride ion concentration invasion and different porosity were simulated. The results show that: (1) the fractal dimension of tortuosity decreases gradually and then sharply at the initial stage of corrosion; (2) compared with concrete with high porosity, concrete with low porosity invaded by chloride ions has a more significant improvement in its own transport; (3) concrete porosity has nonlinear effect on steel corrosion and concrete pore structure evolution. [ABSTRACT FROM AUTHOR]