Analytical solutions of moisture‐chloride ion coupled transport in unsaturated concrete

Abstract

Studies of chloride-induced corrosion in reinforced concrete structures are performed based on the reliable predictions of chloride and moisture distributions in concrete. This paper adopted the Laplace Transformation and the inverse Laplace Transformation to obtain the analytical solutions of the moisture-chloride two-way coupled transport processes. Additionally, the model has involved with realistic material parameters to predict the internal distributions of relative humidity and free chloride ions in concrete samples. To illustrate the accuracy of the present model, the calculations were compared with the available experimental results, and good agreements were obtained. It indicates that the present analytical model can successfully characterize the two-way coupling effects between chloride transport and moisture diffusion in concrete; and the model can provide the distribution profiles of both chloride and relative humidity in concrete, which are useful for predicting the service life of reinforced concrete structures.

A review on chloride transport model and research method in concrete

“…Concrete is a porous medium, which is composed of solid mortar, aggregate, pores and cracks containing liquid phase water and gas phase air. Among them, pores and microfractures provide migration channels for chloride ions [6]. In order to deeply explain the transmission mechanism of chloride ions in concrete, as early as the 19th century, COLLEPARDI et al [7] proposed the diffusion model of chloride ions in concrete, namely Fick's second law.…”