Al^3＋掺杂对硅酸三钙结构及水化活性的影响

Effect of Al^(3+) on the Structure and Hydration Reactivity of Tricalcium Silicate

利用X射线衍射仪、差示扫描量热-热重分析仪、红外光谱及微量热分析等,研究了Al3+掺杂对硅酸三钙C_3S结构及活性的影响。结果表明:Al^(3+)在C_3S中固溶同时取代Ca和Si,并伴随少量Ca空位的形成保持电荷平衡。当Al_2O_3掺量高于0.5%(质量百分数,下同)时,Al取代Si比例增加。Al_2O_3掺量≤0.5%时仅使C_3S晶胞参数改变,当掺量达1%时,可稳定T3晶型,符合离子稳定C_3S多晶态规律。Al3+在C_3S中固溶形成大量非本征缺陷,显著提高C_3S早期水化反应活性。

The effect of Al^3＋doping on the crystal structure and hydration reactivity of tricalcium silicate（ C_3S） was studied by X-ray powder diffraction,differential scanning calorimetry,Fourier transform infrared spectroscopy and isothermal calorimetry. It shows that Al^3＋can replace Ca as well as Si with the formation of a small amount of calcium vacancies to maintain charge balance. A greater proportion of Al will replace Si at the higher concentration of Al_2O_3 0. 5%. Changes in the crystal structure could mainly be monitored by changes in the lattice parameters when incorporation of Al_2O_3 at the lower concentration（ Al_2O_3≤ 0. 5%）. However,T_3 type C_3S can be stabilized at the higher concentration of1% Al_2O_3,which follows the law for the stabilization of C_3S polymorphisms. The initial hydration reactivity of C_3S is greatly improved due to the fact that a lot of extrinsic defects are formed resulting from the incorporation of Al_2O_3.