硅酸钙水化过程的X射线衍射分析

X-Ray Diffraction Analysis of Calcium Silicate Hydration

对水化反应不同时间的硅酸钙水化产物进行了X射线衍射(XRD)研究,并与未水化的无水硅酸钙进行了对比.结果表明:硅酸钙水化过程中,其无定型相对应的弥散峰相对强度逐渐降低,同时水化硅酸钙(C-S-H)衍射峰相对强度逐渐上升.此外,还观察到氢氧化钙(CH)晶相对应的衍射峰相对强度呈先增后减变化,证实了在硅酸钙水化反应早期,溶液中CH浓度逐渐增大形成过饱和溶液,进而生成CH晶相并增多.随着水化反应的进行,溶液中CH浓度降低,从而导致CH晶相溶解进而减少.

The hydration product of calcium silicate that hydrated different period of time was studied by X-ray diffraction （XRD）, as well as unhydrated anhydrous calcium silicate for comparison. The results reveal that the relative intensity of the dispersed peak corresponding to amorphous phase of calcium silicate decreased gradually, and the relative intensity of diffraction peak of calcium silicate hydrate（C-S-H） rose up as well. Besides, we also observed that the relative intensity of diffraction peaks corresponding to calcium hydroxide（CH） crystals firstly increased and then went down, which indicates that the concentration of CH in the solution increased and supersaturated gradually in the early stage of the hydration, hence the crystal phase of CH formed and grew. As the hydration continued, the concentration of CH decreased. Therefore, the CH crystals redissolved and got fewer. This work could be as reference to the research of complex cement hydration system.