The 4th Asian Concrete Federation Symposium on Emerging Technologies for Structural Longevity (ACF2023- ETSL)

75 / 2022-04-13 11:17:34

A novel method for assessing C-S-H chloride adsorption in cement pastes

Bound chloride,Cement paste,C-S-H,Friedel’s salt

The binding of chloride can retard the penetration process and is of important significance for the durability of concrete structures. The previous researches calculated the content of C-S-H absorbed chloride mainly through chemical synthesized C-S-H and thermodynamic modeling, rather than in real cement pastes. This study proposed a feasible method for assessing C-S-H adsorbed chloride in real cement pastes by utilizing the order of decomposition of Friedel’s salt, Kuzel’s salt and C-S-H gel during carbonation and the significant content difference between them. All the parameters used for analysis were obtained experimentally, and thus have high reliability. The content of bound chloride adsorbed on C-S-H and combined in Friedel’s salt was determined with this novel method in pastes under two different exposure conditions.