Investigating the chloride ion resistance of cracked concrete through Reverse-seepage and Saturation based Action Anti-corrosion Tech (RS-AAT): Experimental and numerical analysis

Abstract

This study investigates the chloride ions transport in cracked concrete with the impact of RS-AAT (Reverse-seepage and Saturation based Action Anti-corrosion Tech) in the environment of wet-dry cycling and soaking conditions. With the effect of reverse water pressure, the chloride ions accumulation surrounding the crack on the concrete surface and the chloride ions penetration within the concrete along the cracks are demonstrated by the indoor experiments. A two-dimensional convective diffusion model of chloride ions in cracked concrete is established to simulate the correlation between crack size and the change of reverse water pressure. Four types of cracks with widths of 0 mm, 0.2 mm, 0.4 mm and 1 mm, and a depth of 20 mm were selected. Three types of water pressures with values of 0.2 MPa, 0.3 MPa and 0.4 MPa were used for the technique. The experimental results show that the anti-convection effect induced by the reverse water pressure can inhibit the accumulation of chloride ions around the cracks and effectively limit the intrusion of chloride ions into the concrete protection layer. With the increase of reverse water pressure, the inhibition effect of seepage flow on chloride ions is more obvious. The experimental findings provide valuable references for investigating marine concrete durability and resistance to chloride ion erosion.