钢渣-矿渣-脱硫石膏复合胶凝材料的制备及水化机理

加速钢渣水化过程、胶凝活性激发对钢渣综合利用率的提高有重要意义。以矿渣和脱硫石膏为复合激发剂，基于交叉试验的设计方法，对复合胶凝材料的组成进行了优化，分析了复合胶凝材料的综合性能，采用X射线衍射(X-ray diffraction, XRD)、扫描电子显微镜(scanning electronic microscopy, SEM)、傅里叶变换红外光谱(Flourier transform-infrared spectroscopy, FT-IR)等测试方法表征了复合胶凝材料的组成及结构，并以此揭示复合胶凝材料协同优化的机理。复合胶凝材料配合比的交叉试验结果表明：钢渣30%、矿渣60%、脱硫石膏10%,水灰比为0.5,28 d抗压强度为40.4 MPa,其他各项性能指标满足GB/T1346—2011要求。通过多项测试手段可以判断出，矿渣在脱硫石膏的激发作用下不断水解，缩短了水化诱导前期和延长了诱导期，提升早期水化反应程度，释放大量热量，生成了generates ettringite (AFt)和C—S—H凝胶。而浆体的pH值上升，促进钢渣水化反应，加速了浆体由液相反应转为固相反应，证明了...

Preparation and hydration mechanism of composite cementitious materials containing steel slag, slag and desulfurization gypsum

It is of great significance to accelerate the hydration process of steel slag and stimulate the gelation activity to improve the comprehensive utilization rate of steel slag. Using slag and desulfurized gypsum as composite exciters, based on the design method of cross-experiment, the composition of composite cementitious materials was optimized, the comprehensive properties of composite cementitious materials were analyzed, and X-ray diffraction (XRD), scanning electronic microscopy (SEM), fourier transform-infrared spectroscopy (FT-IR), and other test methods were used to characterize. The composition and structure of composite cementitious materials were analyzed, and the mechanism of synergistic optimization of composite cementitious materials was revealed. The cross-experiment results of the mixing ratio of the composite cementitious material show that, steel slag 30%, slag 60%, desulfurization gypsum 10%, water-cement ratio is 0.5, 28 d compressive strength is 42.4 MPa, and other property indexes meet the requirements of GB/T1346-2011 Test methods for water requirement of normal consistency, setting time and soundness of the Portland cement. Through a number of testing methods, it can be judged that the slag is continuously hydrolyzed under the excitation of desulfurized gypsum, which shortens the early stage of hydration induction and prolongs the induction period, improves the degree of early hydration reaction, releases a lot of heat, and generates ettringite (AFt) and C-S-H gels. The increase of the pH value of the slurry promotes the hydration reaction of the steel slag and accelerates the conversion of the slurry from the liquid phase reaction to the solid phase reaction, which proves that there is a synergistic reaction between the raw materials.