Predicting the chloride penetration of mineral admixture concrete exposure at salt lake site

Abstract

A model for predicting chloride penetration in concrete under long-term exposure in a salt lake environment was developed. The empirical model was based on 0.5-, 0.75-, 1-, 2-year investigation of concrete in a salt lake site. Regression analysis of the data was carried out by applying Fick's second law of diffusion to generate an empirical formula for chloride concentration in concrete. The model used mineral admixture content, distance from the concrete surface, and exposure time. The results show that: (1) With the increase of mineral admixture content the chloride diffusion of concrete decrease. (2) The model can predict chloride concentration at any depth of cement and admixture concretes in a salt lake environment at any exposure period longer than 2 years. (3) Admixture strongly affected chloride diffusion in concrete; higher admixture replacement clearly produced better chloride resistance in concrete under a salt lake environment.