【摘要】 将水泥石在不同温度进行低温煅烧,得到不同的脱水相物质,通过热重–差示扫描热分析、X射线衍射、红外光谱及29Si核磁共振等对水泥石在400,650℃及900℃的脱水相结构特征及其再水化性能、再水化产物的结构特征进行研究。结果表明:在400℃,由水化硅酸钙(C–S–H)凝胶脱水生成了无定形相,在650℃生成了不完全结晶的β-硅酸二钙(C2S),而900℃脱水相中存在结晶程度高的β-C2S。在再水化过程中,400℃和650℃脱水相水化生成了C–S–H凝胶,并且650℃脱水相的水化活性和水化产物聚合程度更高;900℃脱水相的水化活性极低,水化前后矿物结构特征几乎没有发生变化。更多还原

【Abstract】 Hardened cement paste was calcined at different low temperatures, and various dehydrated phases were acquired. Ther-mogravimetric–differential scanning calorimeter (TG–DSC), X-ray diffraction, infrared and 29Si nuclear magnetic resonance were used to investigate the structural characteristics, rehydration ability and rehydrating products structure of dehydrated phases prepared at 400, 650 ℃ and 900 ℃. The results show that, at 400 ℃, amorphous phase was generated in the dehydrating process of calcium silicate hydrate (C–S–H) gel. At 650 ℃, incompletely crystallized β-dicalcium silicate (C2S) was produced, and at 900 ℃, well-crystallized β-C2S was acquired. In the rehydration process, the dehydrated phases prepared at 400 ℃ and 650 ℃ reacted with water and produced C–S–H gel; the hydration activity of the latter, and the polymerization level of its hydration product were higher. However, the dehydrated phase prepared at 900 ℃ showes little rehydration ability; there is almost no change in the structural charac-teristic before and after the hydration process.更多还原