Li Jing, Yu Qijun, Huang Haoliang, Yin Suhong
School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Materials (Basel). 2019 Apr 18;12(8):1268. doi: 10.3390/ma12081268.
The effects of Ca/Si ratio, aluminum and magnesium on the carbonation behavior of calcium silicate hydrate (C-S-H) were investigated by using X-ray powder diffraction (XRD), nuclear magnetic resonance (NMR) and thermogravimetric analyzer (TGA). The results showed that the Ca/Si ratio, Al/Si ratio and Mg/Si ratio had a significant influence on the structure, carbonation products and carbonation resistance of C-(M)-(A)-S-H. The mean chain length of silicate chains in C-S-H increased as the Ca/Si ratio decreased. Aluminum uptake in C-S-H increased the content of bridging silicate tetrahedron (Q). A cross-linked structure (Q) appeared when magnesium uptake in C-S-H. The carbonation product of C-S-H was vaterite if the Ca/Si ratio was lower than 0.87. The carbonation products of C-S-H were vaterite and calcite if the Ca/Si ratio was higher than 1.02. C-M-S-H had more polymerized units, stronger bond strength and better carbonation resistance than C-S-H.
采用X射线粉末衍射（XRD）、核磁共振（NMR）和热重分析仪（TGA）研究了钙硅比、铝和镁对硅酸钙水合物（C-S-H）碳化行为的影响。结果表明，Ca/Si比、Al/Si比和Mg/Si比对C-(M)-(A)-S-H的结构、碳化产物和抗碳化性能有显著影响。随着Ca/Si比降低，C-S-H中硅酸盐链的平均链长增加。C-S-H中铝的掺入增加了桥连硅酸盐四面体（Q）的含量。当C-S-H中掺入镁时，出现了交联结构（Q）。若Ca/Si比低于0.87，C-S-H的碳化产物为球霰石。若Ca/Si比高于1.02，C-S-H的碳化产物为球霰石和方解石。与C-S-H相比，C-M-S-H具有更多的聚合单元、更强的键合强度和更好的抗碳化性能。
