在硫酸盐环境中化酸盐侵蚀分子动力学模拟研究研究
Mengjie You1, Xiaosan Yin1,2, Yuzhou Sun2,3
1School of Architecture and Engineering, Zhongyuan University of Technology, Zhengzhou 451197, China.
Materials (Basel, Switzerland)
|December 17, 2024
概括
硫酸盐离子通过增加离子吸附和促进脱,加速化 (C-S-H凝) 侵蚀,从而导致石膏和石的形成. 较高的硫酸度加剧了C-S-H凝水解和离子扩散,加剧了材料降解.
科学领域:
- 材料科学 材料科学 材料科学
- 化学 化学 化学
- 地质化学 地质化学
背景情况:
- 化酸 (C-S-H凝) 是水泥材料中的一个关键成分.
- 硫酸盐攻击是混凝土和其他基于酸盐的材料的主要降解机制.
- 了解硫酸盐环境中C-S-H凝侵蚀的微机制对于材料的耐用性至关重要.
研究的目的:
- 在硫酸溶液中研究C-S-H凝侵蚀的微机制.
- 在分子水平上阐明硫酸盐离子和C-S-H凝之间的相互作用机制.
- 为了将离子运输和C-S-H凝结构变化与侵蚀进展相关联.
主要方法:
- 开发C-S-H凝/硫酸固体-液体分子动力学模型.
- 在不同度 (5%,8%,10%) 的硫酸中模拟离子运输.
- 扫描电子显微镜 (SEM) 用于分析侵蚀样本的微形态.
主要成果:
- 增加的Na2SO4度增加了C-S-H离子吸附能力.
- 硫酸盐离子促进C-S-H脱,形成石膏和石 (AFt).
- 硫酸盐的攻击加速了C-S-H水解,增加了Na+和Ca2+的扩散,加剧了侵蚀.
- Na+通过 Na-Os 键在 C-S-H 孔面上表现出强烈,稳定的吸附.
- 硫酸盐离子与水分子迁移得更快,从而加剧腐蚀.
结论:
- 硫酸盐离子的入和吸附是C-S-H凝侵蚀的关键驱动因素.
- 石膏和石的形成,加上加速的水解,显著降解了C-S-H结构.
- 分子动力学模拟为控制硫酸盐攻击C-S-H凝的复杂相互作用提供了宝贵的见解.
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