湿度对水化硅酸钙力学性能影响的分子动力学模拟

硅酸盐通报 ›› 2022, Vol. 41 ›› Issue (5): 1554-1561.

湿度对水化硅酸钙力学性能影响的分子动力学模拟

刘士达¹, 李宗利^1,2, 童涛涛¹, 李云波¹, 肖帅鹏¹

1.西北农林科技大学水利与建筑工程学院,杨凌 712100;
2.西北农林科技大学旱区农业水土工程教育部重点实验室,杨凌 712100

收稿日期:2022-01-04 修回日期:2022-02-23 出版日期:2022-05-15 发布日期:2022-06-01
通讯作者: 李宗利,博士,教授。E-mail:zongli02@163.com
作者简介:刘士达(1996—),男,硕士研究生。主要从事水泥基材料的分子动力学研究。E-mail:liushidaxx@163.com
基金资助:
国家自然科学基金(51379178);国家重点研发计划(2017YFC405101)

Molecular Dynamics Simulation on Effect of Humidity on Mechanical Properties of Calcium Silicate Hydrate

LIU Shida¹, LI Zongli^1,2, TONG Taotao¹, LI Yunbo¹, XIAO Shuaipeng¹

1. College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, China;
2. Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, China

Received:2022-01-04 Revised:2022-02-23 Online:2022-05-15 Published:2022-06-01

摘要/Abstract

摘要： 水化硅酸钙(C-S-H)是水泥水化产物中最重要的组成成分,是水泥基材料的主要胶凝相。C-S-H层间水对其纳米结构和力学性能会产生显著影响。利用分子动力学研究了不同湿度C-S-H在结构和力学性能方面的差异。通过原子径向分布函数和浓度分布、弹性常数以及应力应变关系分析了湿度对C-S-H结构和弹性性质以及拉伸、压缩、剪切力学性能和变形性能的影响。结果表明:湿度增加会导致C-S-H中Si、Ca原子近程范围内的O原子集聚增多,还会导致C-S-H层间距离增大,分层更加明显,同时会降低C-S-H的弹性性质;湿度的增加会降低C-S-H拉伸、压缩、剪切力学性能和变形性能;湿度对抗拉与抗剪强度影响较大,对抗压强度影响较小,对拉伸时的变形性能影响最大,对压缩时的变形性能影响最小。

关键词: 水化硅酸钙, 分子动力学, 湿度, 层间水, 力学性能, 受力状态

Abstract: Calcium silicate hydrate (C-S-H) is the most important component of cement hydration products, and is the main cementitious phase of cement-based materials. The interlayer water of C-S-H has a significant effect on its nanostructure and mechanical properties. The structure and mechanical properties of C-S-H with different humidity were studied by molecular dynamics method. The influence of humidity on the structure and elastic parameters of C-S-H as well as the mechanical and deformation properties under tension, compression and shear conditions were analyzed by radial distribution function and concentration distribution of atoms, elastic constants and stress-strain relationships. The results show that the increase of humidity leads more O atoms to accumulate around Si and Ca atoms in C-S-H, and makes the distance between layers larger and the stratification more obvious. At the same time, the increase of humidity also reduces the elastic properties of C-S-H. With the increase of humidity, the mechanical and deformation properties of C-S-H under different stress states reduce. The influence degrees on tensile strength and shear strength are greater than that on compressive strength. In terms of deformation properties, humidity has the greatest influence on deformation properties under tension and has the least influence on deformation properties under compression.

Key words: calcium silicate hydrate, molecular dynamics, humidity, interlayer water, mechanical property, stress state

中图分类号:

刘士达, 李宗利, 童涛涛, 李云波, 肖帅鹏. 湿度对水化硅酸钙力学性能影响的分子动力学模拟[J]. 硅酸盐通报, 2022, 41(5): 1554-1561.

LIU Shida, LI Zongli, TONG Taotao, LI Yunbo, XIAO Shuaipeng. Molecular Dynamics Simulation on Effect of Humidity on Mechanical Properties of Calcium Silicate Hydrate[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(5): 1554-1561.

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