Coupling effect of the connected pores and pore solution on chloride ion migration in cement-based materials. (23rd August 2021)

• Record Type: Journal Article
• Authors: Wang, Ruipan; He, Fuqiang; Chen, Changping; Dai, Lizong
• Is Part Of: Construction & building materials. Volume 297(2021)
• Publication Date: 2021-08-23
• Subjects: Coupling effect -- Connected pores -- Pore solution -- Chloride ion migration -- Cement-based materials; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2021.123773
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A method for determining connected pores in cement-based materials was developed. Contributions of pores, pore solution and their interaction to D m were evaluated. D m and σb of hardened cement pastes have similar cement-fly ash-slag ratio ranges. Abstract: 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 χ 1, pore solution factor χ 2, pore–pore solution factor χ 3 and coupling factor χ on the non-steady state chloride ion migration coefficient ( D m ) were evaluated. The results indicated that χ 1, χ 2, χ 3 and any single parameter did not have good correlations with D m, and χ had an excellent linear correlation with D m . This confirms that the coupling effect of the pores, the pore solution and their interaction control the chloride ion migration process. The contributions of χ 1, χ 2 and χ 3 to D m 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 χ 1 and χ 3, which can be obtained through a reduction in the connected porosity and the accompanying reduction in δ . 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.