Changes of pore structure and chloride content in cement pastes after pore solution expression

Published on Feb 1, 2020in Cement & Concrete Composites7.586
路 DOI :10.1016/J.CEMCONCOMP.2019.103465
Xiang Hu11
Estimated H-index: 11
(Hunan University),
Caijun Shi73
Estimated H-index: 73
(Hunan University)
+ 2 AuthorsGeert De Schutter39
Estimated H-index: 39
(UGent: Ghent University)
Sources
Abstract
Abstract Pore solution expression is a widely accepted approach to extract pore solution of cement-based materials by appllying high pressure. In this study, the variations of pore solution distribution and chloride content in cement pastes before and after pore solution expression were examined. The results showed that the value of chloride concentration index Nc were mostly higher than 1.0 for cement pastes immersed in NaCl solution, and decreased with the chloride concentration of soaking solution and water-to-binder (w/b) ratio. During the pore solution expression, the pores larger than 40 nm were totally removed and the porosity of smaller pore was decreased. Based on a proposed physical model on structure of cement paste, the value of Nc was calculated according to the variations of pore structure and chloride content during pore solution expression. The calculated results showed similar trend as the experimental results obtained by pore solution expression method.
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