The stability of bound chlorides in cement paste with sulfate attack
The stability of bound chlorides in cement paste with sulfate attack
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硫酸盐侵蚀下水泥浆体中结合氯的稳定性
DOI：
10.1016/j.cemconres.2014.11.010
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发表时间：
2015-02-01
影响因子：
11.4
通讯作者：
Mo, Li-wei
中科院分区：
文献类型：
--
作者：
Geng, Jian;Easterbrook, Dave;Mo, Li-wei
本文介绍了在氯离子污染的水泥浆体与不FA/矿渣受到Na 2SO 4和MgSO 4侵蚀时，结合氯离子的稳定性进行了实验研究。结果表明，当暴露于Na_2SO_4或MgSO_4溶液中时，在氯污染的膏体中释放出结合的氯。这主要归因于Friedel盐（FS）的分解，其中FS中结合的Cl-被SO 42-取代。然而，有较少的释放的氯化物中发现暴露于硫酸镁溶液比暴露于硫酸钠溶液中的糊剂。这部分是由于孔溶液中的低pH值，部分是由于水镁石对MgSO 4引起的离子传输的阻断作用。在混凝土中掺加粉煤灰/矿渣可以促进FS的分解，从而促进结合态氯化物的释放。然而，它也能抵抗Na 2SO 4的渗透，从而减少Na 2SO 4的侵蚀。(C)2014爱思唯尔有限公司版权所有。
This paper presents an experimental investigation on the stability of bound chlorides in chloride-contaminated cement pastes with and without FA/GGBS when subjected to Na2SO4 and MgSO4 attack. It is shown that bound chlorides were released in the chloride-contaminated pastes when exposed to Na2SO4 or MgSO4 solution. This is mainly attributed to the decomposition of Friedel's salt (FS), where Cl- bound in FS is replaced by SO42-. However there were fewer released chlorides found in the pastes exposed to MgSO4 solution than in those exposed to Na2SO4 solution. This is partly due to the low pH in the pore solution and partly due to the blocking effect of brucite on ionic transport caused by MgSO4. The inclusion of FA/GGBS in concrete can increase the decomposition of FS and thus the release of bound chlorides. However, it also resists the penetration of Na2SO4 and thus reduces the attack of Na2SO4. (C) 2014 Elsevier Ltd. All rights reserved.