石膏-矿渣-石灰复合胶凝体系早期水化作用机理

Early Hydration Mechanism of Gypsum-Slag-Lime Composite Cementitious System

以石膏、矿渣、生石灰为主要原料制备矿山充填复合胶凝材料,采用X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、X射线能谱仪(EDS)、傅立叶变换红外光谱仪(FT-IR)、同步热分析仪(DSC-TG)等微观分析手段探究复合胶凝材料水化产物的作用机理。研究表明:通过极差分析和方差分析获得复合胶凝材料最佳工艺参数为生石灰添加量20%、石膏添加量1.0%、胶砂质量比1∶6、料浆浓度72%。复合胶凝体系的水化产物以钙矾石(AFt)和C-S-H凝胶为主,在生石灰和石膏的协同激发作用下,矿渣中玻璃体网络结构逐渐解聚,伴随水化反应的进行,钙矾石和C-S-H凝胶的生成量不断增加,交错黏结填充于浆体孔隙中,将骨料紧密联结成整体,提高了浆体结构密实性,是充填体早期强度的主要来源。

Gypsum,slag and lime were used as the main raw materials to prepare mine-filled composite cementitious materials.X-ray diffraction(XRD),field emission scanning electron microscope(SEM),energy dispersive X-ray spectrometer(EDS),Fourier transform infrared spectrometer(FT-IR),synchronous thermal analyzer(DSC-TG)and other analytical methods were used to explore the hydration product mechanism of composite cementitious materials.The results show that the optimal process parameters of composite cementitious materials obtained by range analysis and variance analysis are 20%quicklime addition,1.0%gypsum addition,mortar mass ratio 1∶6,and slurry concentration 72%.Compound gel system of hydration products to ettringite(AFt)and C-S-H gel is given priority to,under the effect of lime and gypsum collaborative inspire,slag vitreous network structure gradually depolymerization,along with the hydration reaction of ettringite and C-S-H gel generation increases,staggered bond fill in slurry pore,the aggregate bond tightly into a whole,improve the density of the slurry structure,is the main source of the early strength of filling body.