Coupling effect of the connected pores and pore solution on chloride ion migration in cement-based materials

In this study, a new method for determining the connected pore porosity, tortuosity and constrictivity was developed based on AC impedance tests. The effects of the pore factor x1, pore solution factor x2, pore-pore solution factor x3 and coupling factor x on the non-steady state chloride ion migration coef-ficient (Dm) were evaluated. The results indicated that x1, x2, x3 and any single parameter did not have good correlations with Dm, and x had an excellent linear correlation with Dm. This confirms that the coupling effect of the pores, the pore solution and their interaction control the chloride ion migration pro -cess. The contributions of x1, x2 and x3 to Dm accounted for 54.44%, 13.05%, and 31.27%, respectively. Therefore, the migration of chloride ions can be controlled to a large extent by reducing x1 and x3, which can be obtained through a reduction in the connected porosity and the accompanying reduction in S. This means that the connected pores play a decisive role in controlling the migration of chloride ions in cement-based materials, whose conductivity can be used for quickly determining the extreme value of the chlorine-related durability. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A new method based on AC impedance tests was developed to determine connected pore porosity, tortuosity, and constrictivity in this study. The effects of different factors on the chloride ion migration coefficient were evaluated, with a focus on the importance of reducing connected porosity for controlling chloride ion migration.