在酸水合物矩阵上解开水的分子结行为
Siyuan Zhang1, Songyue Chai1, Dongshuai Hou1
1Department of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China. wangpan@qut.edu.cn.
Physical chemistry chemical physics : PCCP
|January 23, 2024
概括
酸水合物 (CSH) 矩阵通过影响水影响混凝土的耐用性. 较高的Ca/Si比率会造成表面缺陷,削弱CSH相互作用,促进孔内冰的形成.
科学领域:
- 材料科学 材料科学 材料科学
- 化学 化学 化学
- 土木工程 土木工程是指土木工程.
背景情况:
- 混凝土的耐用性受到基材料的水化产品的显著影响,主要是酸水合物 (CSH).
- 了解CSH结构中的水的行为,特别是在结条件下,对于预测混凝土性能和寿命至关重要.
- 现有研究强调了CSH在确定混凝土对冷-解周期的抗性方面的重要性.
研究的目的:
- 通过分子动力学模拟,研究各种酸水合物 (CSH) 矩阵中的水的结行为.
- 探索不同与 (Ca/Si) 比率在冷过程中对水分子和CSH表面之间的相互作用的影响.
- 阐明控制未结冰水膜形成的分子机制及其与CSH结构性质的关系.
主要方法:
- 用分子动力学 (MD) 模拟来建模被限制在CSH矩阵中的纯水溶液的结过程.
- 模拟了四个不同的CSH矩阵,具有不同的Ca/Si比率,以分析成分的影响.
- 分析的重点是和离子相互作用,结晶核化,链行为和表面缺陷形成.
主要成果:
- CSH矩阵加强了与冰晶附近的水分子的相互作用,形成了一个未结的水膜,抑制了结晶.
- 增加的Ca/Si比率导致链断裂,在CSH矩阵上形成表面槽.
- 这些表面缺陷削弱了与水的键,促进了结晶,从而在较高的Ca/Si比率下产生更薄的未水膜.
结论:
- /Si比率极大地影响CSH中的水的结行为,影响未结的水膜的形成和厚度.
- 表面缺陷,例如链裂变造成的沟,在水分子捕获和随后的结中起着关键作用.
- 这种分子层面的理解提供了对水泥材料的抗解能力和整体可靠性的洞察.
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