| 摘要: |
| 通过试验结合分子动力学，模拟研究了Al掺杂影响水化硅铝酸钙（C-A-S-H）的机理.结果表明：Al掺杂对于C-A-S-H凝胶中硅铝氧链链长的影响可等效为同摩尔量Si的影响，但会使C-A-S-H凝胶层间距增加的幅度更大；提高养护温度促进了C-A-S-H凝胶中硅氧四面体的聚合，当养护温度达到80 ℃时，C-A-S-H凝胶的层间距减小，相邻主层上硅铝氧链之间形成了交联结构，部分转变为交联C-A-S-H凝胶，其力学性能大幅度增加；Al掺杂桥接了断裂的硅氧链且形成了硅铝氧长链，提升了C-A-S-H凝胶沿y轴方向的力学性能，对其沿x轴和z轴方向力学性能的影响较小. |
| 关键词: 铝掺杂 水化硅铝酸钙 分子动力学 力学性能 交联结构 |
| DOI：10.3969/j.issn.1007-9629.2022.06.003 |
| 分类号:TU528.01 |
| 基金项目:国家自然科学基金资助项目（52008002，51878003，U21A20149，51908378） |
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| Molecular Structure and Mechanical Properties of Aluminum Substituted C-S-H |
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YANG Jun1,2, ZHANG Gaozhan1,2, DING Qingjun3, ZHAO Mingyu4
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1.Advanced Building Materials Key Laboratory of Anhui Province， Anhui Jianzhu Univerity， Hefei 230022， China;2.School of Materials and Chemical Engineering， Anhui Jianzhu University， Hefei 230601， China;3.School of Materials Science and Engineering， Wuhan University of Technology， Wuhan 430070， China;4.School of Materials Science and Engineering， Shenyang Jianzhu University， Shenyang 110168， China
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| Abstract: |
| The influence mechanism of Al substitution on the nanostructure and properties of the calcium aluminosilicate hydrate（C-A-S-H） gel was investigated through the combination of experiment and molecular dynamics simulation. The results show that influence of Al on the molecular chain length of the aluminosilicate chain substitution of C-A-S-H gel structure can be considered to be due to the same molar amount of Si， but Al substitution leads to a larger increase in the basal spacing of C-A-S-H gel. Elevated curing temperature promotes the polymerization of the aluminate/silicate tetrahedra in the C-A-S-H gel， resulting in increasing mean chain length of C-A-S-H gel. When the curing temperature reaches up to 80 ℃， the spacing between the C-A-S-H gel primary layers abruptly reduces. Cross-linked structure are formed between the aluminosilicate chains on the adjacent main layer， which indicates parts of C-A-S-H gel are cross-linked. The mechanical properties of cross-linked C-A-S-H gel induced by the aluminum are greatly increased. Substituted Al bridges the broken silicon-oxygen chain. The formation of the long aluminosilicate chain improves the mechanical properties of C-A-S-H gel along the y-axis， but shows negligible effect on its mechanical properties along the x- and z-directions. |
| Key words: Al substitution calcium aluminosilicate hydrate（C-A-S-H） molecular dynamics mechanical property cross-linking structure |
