为澄清无水硫铝酸钙的水化反应机理,利用化学试剂CaCO3、Al2 O3、CaSO4合成纯度达90%以上的无水硫铝酸钙( C4 A3?) 单矿物,研究其在水灰比为0.3、05、0.7条件下的水化反应,包括不同水化时间的水化产物及变化规律,用X射线衍射仪、综合热分析仪和扫描电子显微镜对水化产物进行分析.结果表明:水化产物为含不同摩尔结晶水的2种单硫型水化硫铝酸钙C4 A?H12( AFm-12) 和C4 A?H1 4( AFm-14)以及无定形状态的铝凝胶( AH3 ) ,整个水化过程未生成钙矾石(AFt);随着水化时间的延长,C4A?H12(AFm-12)会逐渐转化为C4A?H14(AFm-14);水化反应主要集中发生在3~12 h,后期C4 A?H1 4 晶体不断长大.
Calcium sulphoaluminate ( C4 A3?) with high purity (>90%) was synthesized from CaCO3 , Al2 O3 and CaSO4, and the hydration of C4A3?, including hydration products and their evolution at different hydration time, was investigated at different water/solid ratios ( mw/ms=0.3, 0.5, 0.7) , aiming to clarify the hydration mechanism. The hydration products were examined by means of X-ray diffraction, differential scanning calorimetry-thermogravimetry and scanning electron microscope. There are two kinds of calcium monosulphoaluminate, namely, C4A?H14 and C4A?H12, and amorphous aluminium gel (AH3), while there is no ettringite ( AFt) in the hydration products. C4A?H12 gradually converts to C4A?H14 as the extension of hydration duration. The hydration reaction mainly occurs between 3 and 12 hours after mixed with water. The crystals of C4A?H14 grow larger in later period.
参考文献
| [1] | 韩建国;阎培渝.锂化合物对硫铝酸盐水泥水化历程的影响[J].硅酸盐学报,2010(4):608-614. |
| [2] | Winnefeld, F.;Barlag, S..Calorimetric and thermogravimetric study on the influence of calcium sulfate on the hydration of ye'elimite[J].Journal of thermal analysis and calorimetry,20103(3):949-957. |
| [3] | MARTIN DOVAE;MARTIN PALOU;VLADIMIR KOVAR.HEAT EVOLUTION AND MECHANISM OF HYDRATION IN CaO-Al_2O_3-SO_3 SYSTEM[J].ceramics,20052(2):104-108. |
| [4] | M.J. Sanchez-Herrero;A. Fernandez-Jimenez;A. Palomo.C4A3S hydration in different alkaline media[J].Cement and Concrete Research,2013:41-49. |
| [5] | H. EL-DIDAMONY;T. M. EL-SOKKARI;KH. A. KHALIL;MOHAMED HEIKAL;I. A. AHMED.HYDRATION MECHANISMS OF CALCIUM SULPHOALUMINATE C_4A_3S, C_4AS PHASE AND ACTIVE BELITE β-C_2S[J].Cearmics: Silikaty,20124(4):389-395. |
| [6] | Jong-Taek Song;J. Francis Young.Direct Synthesis and Hydration of Calcium Aluminosulfate (Ca_4Al_6O_(16)S)[J].Journal of the American Ceramic Society,20023(3):535-539. |
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