Non-steady state chloride diffusion in concrete with different crack densities

Abstract

With an increasing concern about long-term durability, chloride transport and service-life prediction of cracked concrete are now a hot area in concrete research. However, only few researches up to now investigated the effect of crack density on chloride transport in cracked concrete. Nevertheless, in real concrete structures, multiple cracks instead of a single crack are most commonly observed. The present study investigates non-steady state chloride diffusion in concrete samples with different crack densities prepared by a non-destructive notch method. The relationship between diffusion coefficient and crack density is discussed. Water and acid soluble chloride contents increase significantly with increasing crack density up to a certain value. A linear function is found for the relationship between diffusion coefficient determined by acid soluble chloride and crack density. A piecewise function including linear and exponential function is proposed to describe the relationship between diffusion coefficient determined by water soluble chloride and the crack density.