作　　者： (张海东）; (韦江雄）; (赵志广）; (余其俊）; (李方贤）;

机构地区： 华南理工大学材料科学与工程学院,广州510640 广东省建筑材料低碳技术工程技术研究中心,广州510640

出　　处： 《材料导报》 2017年第14期122-126,137,共6页

摘　　要： 选取石灰与无定形二氧化硅为原料,利用水热合成法在不同热工条件下制备了水化硅酸钙晶种,研究水化硅酸钙晶种对硅酸盐蒸压制品强度的影响。通过化学分析法探讨了不同蒸压时间下水化硅酸钙晶种对粉煤灰反应程度的影响;利用X射线衍射(XRD)、电子扫描电镜(SEM-EDS)和压汞法(MIP)分析了晶种对不同蒸压时间下CaO-SiO_2-H_2O体系水化产物种类及形貌的影响。研究结果表明:采用钙硅物质的量比为1.0、水热合成温度低于150℃时制备的水化硅酸钙晶种提高CaO-SiO_2-H_2O蒸压体系强度最明显,水化硅酸钙晶种的掺入促进了粉煤灰中SiO_2快速溶出以及水石榴石的分解,提高了水化产物含量;水化硅酸钙晶种的加入可以细化孔结构,使孔结构分布均匀,增加50nm以下的无害孔及少害孔数量,减少大于200nm的多害孔数量。 The effect of calcium silicate hydrate seed on the CaO-SiO2-H2O hydrothermal reaction was studied.Calcium silicate hydrate seed were prepared by hydrothermal synthesis with lime and nano silica under different thermal conditions.Chemical analysis method was used for the determination of reactive degree of fly ash.The effect of calcium silicate hydrate seed on types and morphology of hydration products was characterized by X-ray diffraction（XRD）and scanning electron microscopy（SEM-EDS）.The distribution of pore size was investigated by mercury intrusion porosimetry（MIP）.The results indicated that the compression strength of CaO-SiO2-H2O autoclaved system increased most obviously when mixed with calcium silicate hydrate and synthesized under the 150 ℃ with calcium silica ratio of 1.0.Calcium silicate hydrate seed promoted dissolution of SiO2 PPP from fly ash and decomposition of hydrogarnet,and accelerated the generation of hydration products（mainly C-S-H（B）and tobermorite）.Meamwhile,the pore structure was refined and the distribution of the pore size was more uniform with the addition of calcium silicate hydrate.The addition of calcium silicate hydrate caused the number of pores below 50 nm increase and the number of pores above 200 nm decrease,compared with the reference sample.

关 键 词： 水化硅酸钙 晶种 蒸压硅酸盐制品 粉煤灰 水化程度