摘要
为了实现Si-Mn矿渣的高效利用,通过气流分级机将Si-Mn矿粉分为D_(50)=6.9μm、17.9μm和56.4μm三个不同的粒度区间。采用等温量热仪(TAM air)、X射线衍射(XRD)仪、全自动压汞仪(MIP)、扫描电子显微镜-能谱(SEM-EDS)分析测试技术,研究了Si-Mn矿粉粒度对复合胶凝体系水化行为和微观结构的影响,并对其胶砂强度进行了评价。结果表明:各粒度区间的Si-Mn矿粉均能促进游离石灰、铝酸盐相和C_(3)S等矿物的早期水化(30 min)放热速率;水化后期,Ca(OH)_(2)和熟料衍射峰强度随着Si-Mn矿粉粒度减小而显著降低;掺入细粒度的Si-Mn矿粉可增加硬化复合胶凝材料浆体凝胶孔数量,有效降低最可几孔径和总孔隙率;SEM-EDS结果进一步证实了硬化浆体孔结构的优化是由于细粒度Si-Mn矿粉表面生成了大量低钙硅比的C-S(Al,Mg)-H水化产物。值得注意的是:D_(50)=6.9μm和17.9μm的Si-Mn矿粉掺量高达30%时,复合胶凝材料的胶砂强度超过了GB 175标准中42.5等级水泥的技术指标。因此这些粒度区间的Si-Mn矿粉可以被建议作为绿色水泥的生产和高性能混凝土配制中的矿物掺合料。
To achieve the high efficient utilization of Si-Mn slag, a Si-Mn slag powder was classified into three fractions by an air classifier, with D_(50) =6.9 μm, 17.9 μm, 56.4 μm, respectively. The effect of size fraction of Si-Mn slag on hydraulic activity and physical property in composite cementitious system were investigated by isothermal calorimeter(TAM air), X-ray diffraction (XRD), mercury intrusion porosimeter(MIP), scanning electron micorscope and energy dispersive X-ray spectrometer(SEM-EDS). The test results indicated that the early hydration reaction(30 min) of free lime, aluminate and C_(3)S phase were promoted by all size fractions of Si-Mn slag from nucleation induction. The intensity peaks of Ca(OH)_(2) and clinker decreased dramatically with the decrease of particle size in the late hydration. The blended cement paste with finer Si-Mn slag resulted in a decrease in the most probable pore size and total porosity than that of the one with coarser Si-Mn slag. The SEM-EDS results further demonstrated that the hardened blended cement paste containing fine Si-Mn slag powder produced a denser microstructure because more C-S (Al, Mg)-H gels hydration products with low calcium were produced. It was noted that the strength could surpass the technical index of 42.5 grade cement in GB 175 standard when the content of Si-Mn slag powder with D_(50) =6.9 μm and 17.9 μm was reached up to 30%. Thus, these fractions were strongly recommended to serve as mineral admixtures in blended cement production or concrete making.
作者
周祥
赵华堂
李亮
杜浪
周双福
邵瞾
张晓敏
ZHOU Xiang;ZHAO Huatang;LI Liang;DU Lang;ZHOU Shuangfu;SHAO Zhao;ZHANG Xiaomin(Chengdu Institute of Products Quality Inspection Co.,Ltd.,Chengdu 610100,China;National Center for Building Material Quality Supervision and Inspection(Sichuan),Chengdu 610100,China;Sichuan Institute of Product Quality Supervision and Inspection,Chengdu 610100,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第S01期279-283,共5页
Materials Reports
关键词
Si-Mn矿粉
粒度
水化机理
微观结构
力学性能
Si-Mn slag
particle size
hydraulic mechanism
microstructure
mechanical property
