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.
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.
作者
杨军
张高展
丁庆军
赵明宇
YANG Jun;ZHANG Gaozhan;DING Qingjun;ZHAO Mingyu(Advanced Building Materials Key Laboratory of Anhui Province,Anhui Jianzhu Univerity,Hefei 230022,China;School of Materials and Chemical Engineering,Anhui Jianzhu University,Hefei 230601,China;School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China;School of Materials Science and Engineering,Shenyang Jianzhu University,Shenyang 110168,China)
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2022年第6期565-571,584,共8页
Journal of Building Materials
基金
国家自然科学基金资助项目(52008002,51878003,U21A20149,51908378)。
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
Al substitution
calcium aluminosilicate hydrate(C-A-S-H)
molecular dynamics
mechanical property
cross-linking structure
