Role of interatomic bonding in the mechanical anisotropy and interlayer cohesion of CSH crystals

被引：70

作者：

Dharmawardhana, C. C. ^{[1
]}

Misra, A. ^{[2
]}

Aryal, S. ^{[1
]}

Rulis, P. ^{[1
]}

Ching, W. Y. ^{[1
]}

机构：

[1] Univ Missouri, Dept Phys & Astron, Kansas City, MO 64110 USA

[2] Univ Kansas, Dept Civil Environm & Architectural Engn, Lawrence, KS 66045 USA

来源：

CEMENT AND CONCRETE RESEARCH | 2013年 / 52卷

基金：

美国国家科学基金会;

关键词：

Calcium-silicate-hydrates; C/S ratio; Hydrogen bonding; Mechanical properties; Bond order (BO); C-S-H; CALCIUM-SILICATE-HYDRATE; ELASTIC-CONSTANTS; CEMENT; TOBERMORITE; 1ST-PRINCIPLES; NANOSTRUCTURE; ANGSTROM; DENSITY; ENERGY;

D O I：

10.1016/j.cemconres.2013.05.009

中图分类号：

TU [建筑科学];

学科分类号：

0813 ;

摘要：

Atomic scale properties of calcium silicate hydrate (CSH), the main binding phase of hardened Portland cement, are not well understood. Over a century of intense research has identified almost 50 different crystalline CSH minerals which are mainly categorized by their Ca/Si ratio. The electronic structure and interatomic bonding in four major CSH crystalline phases with structures close to those found in hardened cement are investigated via ab initio methods. Our result reveals the critical role of hydrogen bonding and importance of specifying precise locations for water molecules. Quantitative analysis of contributions from different bond types to the overall cohesion shows that while the Si-O covalent bonds dominate, the hydrogen bonding and Ca-O bonding are also very significant. Calculated results reveal the correlation between bond topology and interlayer cohesion. The overall bond order density (BOO) is found to be a more critical measure than the Ca/Si ratio in classifying different CSH crystals. (C) 2013 Elsevier Ltd. All rights reserved.

引用

页码：123 / 130

页数：8

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