矿渣掺量和水胶比对水泥浆体溶蚀特性的影响

Influences of Slag Content and Water-Binder Ratio on Leaching Behavior of Cement Paste

为了在较短时间内获得矿渣微粉和水胶比对溶蚀过程中水泥基材料抗溶蚀性能的影响,用6 mol/L NH4Cl溶液,对矿渣-水泥复合浆体薄片试件进行加速钙溶蚀实验,并利用饱水干燥称重法、X射线衍射分析和扫描电子显微镜等方法,分析了加速钙溶蚀过程中矿渣掺量、水胶比对矿渣-水泥复合胶凝材料硬化浆体的孔隙率、物相组成、微结构形貌和Ca/Si比等的影响。结果表明:同未掺矿渣的水泥浆体相比,掺有适量矿渣的复合水泥浆体在溶蚀过程中的微结构劣化速度慢、抗溶蚀性能好;水胶比为0.35时,矿渣掺量为40%的复合水泥浆体的孔隙率、钙硅比和微结构形貌变化较小,抗溶蚀能力最佳,而水胶比为0.55时,掺50%矿渣的复合水泥浆体具有较好的抗溶蚀性能。

In order to analyze the influences of blast furnace slag and water-binder ratio on the leaching behavior of cement-based materials in the process of calcium leaching, the accelerate leaching experiments of the slag-cement paste slice specimens in 6 mol/L NH4Cl solution were carried out. The porosity, phase composition, microstructure morphology and Ca-Si ratio of hardened slag-cement pastes in the process of calcium leaching at different slag contents and water-binder ratios were investigated by the saturation-drying weighing method, X-ray diffraction and scanning electron microscopy. The results show that compared to cement past, the slag-cement paste with the moderate slag has a slow deteriorated process of microstructures and a good calcium leaching resistance. The optimum slag contents in the slag-cement pastes are 40% and 50% corresponding to the lower （0.35） and higher water-binder ratio （0.55）, respectively, and the porosity, Ca-Si ratio and microstructures of the hardened slag-cement pastes have slow changes in the process of accelerating leaching, indicating that the optimum slag content could provide the optimum leaching resistance of slag-cement pastes.