Predictive convection zone depth of chloride in concrete under chloride environment

Abstract

Based on the assumption that chloride concentration and water influential depth change linearly in convective zone, the chloride convection zone depth is used in Fick’s diffusion law to investigate the chloride diffusion characteristic of concrete at tidal zones. In this study, an artificial simulation environment and field tests were carried out to validate and calibrate the rationality of the chloride convection zone depth model. The distribution model of surface chloride concentration in concrete was determined by exploring the correlations among chloride concentration, elevation, time and linear distance from seaside. The results illustrated that the depth of chloride convection zone on the concrete surface varied and manifested in terms of a function of water influential depth. The relation between the surface chloride concentration and the linear distance from the seaside followed an S-curve function equation. The similarities and differences regarding the characteristic of chloride diffusion in concrete between experimental and in-situ test were discussed for surface chloride concentration, chloride convection zone depth and chloride diffusion coefficient.