Experimental and numerical investigation on the effect of cracks on chloride diffusion and steel corrosion in concrete

Various environmental factors limit the durability of reinforced concrete. Chloride ion is the main factor causing rebar corrosion in concrete. It attacks the rebar surface with its strong diffusion ability, destroying the passive film and accelerating structural damage. Cracks in the structure also provide natural channels for chloride ion diffusion, increasing the rebar corrosion rate and reducing the structure service life. In this study, the influences of water-cement ratio, age, and crack width, depth, and spacing on chloride diffusion and steel corrosion were explored using the silver nitrate colourimetric method, X-ray diffraction, COMSOL finite element simulation, polarisation curve method, and electrochemical impedance spectroscopy. The rationality of the finite element simulation of the influence of cracks on chloride diffusion was verified, and the influence of chloride on reinforcement corrosion was analysed. This study provides a theoretical basis for optimising the modelling of chloride diffusion in concrete with cracks and improving the understanding of the damage evolution mechanism of cracks.