Model of chloride penetration into cracked concrete subject to drying–wetting cycles

Abstract

Drying and wetting cycles condition is always identified as the most unfavorable environment condition for reinforce concrete structure subjected to chloride-induced deterioration processes. When a crack occurs, it accelerates the ingress of chloride ions and affects durability. In order to clarify the mechanism of deterioration subjected cyclic drying–wetting condition, an innovative model describing the transport of chloride ions in cracked concrete is elaborated, meanwhile the results of experimental investigation are also reported. The transporting mechanism of chloride ions in porous medium is supposed still valid for cracked concrete. The advection part is simulated by moisture transport in rough cracks, modeled as a flux based on Poiseuille law considering crack width, crack surface roughness, tortuosity and capillary pores at crack surface. In addition, the drag coefficient is first applied to calculate the influence of roughness on crack in present work. Finally, a simplified and modified Fick’s second law is proposed here to estimate the chloride ions profiles in cracked concrete.