摘要
水分子和离子在纳米孔道中的传输是混凝土材料的耐久性的重要影响因素。利用分子动力学方法可以模拟水分子和离子在非饱和及饱和状态下的毛细传输过程,进而探究纳米孔道中水分和离子的传输规律以及与C-S-H界面之间的相互作用特性。非饱和状态下,水分子和离子的传输主要受到毛细作用的驱使,以半月板形界面沿3.4 nm的水化硅酸钙孔道向上侵入;饱和状态下的水分子的传输主要是上下部水分子互相扩散而形成的交互传输过程,使得水分子沿孔道的扩散速度减慢。且饱和状态下,孔道界面处水化层更为紧密稳定,易形成离子簇,直接阻碍了后续水分子和离子的进入。因此,非饱和状态下水分子携带离子在纳米孔道中的传输速度远快于饱和状态。
The movement of water molecules and ions in the nanometer pores is an important factor affecting the durability of concrete material.Molecular dynamics was utilized to study the capillary transport of water molecules and ions in unsaturated and saturated state,and then to explore the transport law of water and ions in the nanopore and the interaction characteristics with the C-S-H interface.In the unsaturated state,the transport of water molecules and ions is mainly driven by capillary action,and it invades along the 3.4 nm hydration calcium silicate channel at the meniscus-shaped interface;in the saturated state,the transport of water molecules is mainly due to the interactive transmission process formed by the diffusion of water molecules in the upper and lower parts,which slows down the diffusion of water molecules along the channel.And in the saturated state,the hydration shell at the interface is more tight and stable,which leads to the formation of ion clusters,directly hinders the subsequent entry of water molecules and ions.As a result,in the unsaturated state,the transport of water molecules in the nanometer pores is much faster than the saturated state.
作者
贾玉婷
赵铁军
侯东帅
李海斌
李涛
杨铁军
JIA Yu-ting;ZHAO Tie-jun;HOU Dong-shuai;LI Hai-bin;LI Tao;YANG Tie-jun(School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China)
出处
《硅酸盐通报》
CAS
北大核心
2019年第3期615-621,共7页
Bulletin of the Chinese Ceramic Society
基金
国家重点基础研究发展计划(973项目)(2015CB655100)
国家自然科学基金(51420105015
51508292
51678317)
关键词
水化硅酸钙
分子动力学
非饱和及饱和状态
传输
calcium silicate hydrate
molecular dynamics
unsaturated and saturated state
transport
