不同分散介质中新拌水泥浆体的微结构与流动性  

Microstructure and Flowability of Fresh Cement Paste in Different Dispersions Media

作　　者：张艳荣[1] 孔祥明[2] 高亮[1] 严熵 

机构地区：[1]北京交通大学土木建筑工程学院,轨道工程北京市重点实验室,北京100044 [2]清华大学土木工程系,北京100084

出　　处：《硅酸盐学报》2016年第8期1104-1109,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金联合基金项目(U1301241,U1234211);中国博士后科学基金面上项目(2015M580042)

摘　　要：采用乙醇、水以及乙醇-水混合液作为分散介质,研究了不同分散介质中新拌水泥浆悬浮分散体系的微结构与流动性的变化规律,以揭示新拌空白水泥浆体微观结构与宏观性能的本质关联。通过调节分散介质中水与乙醇的比例(水/乙醇),测试了新拌水泥浆体的zeta电位、粒径分布以及流动度;采用Morphologi G3光学显微镜分析了水泥颗粒在不同分散体系中的显微结构形态。结果表明:在乙醇分散介质中,水泥颗粒表面带有大量本征正电荷,新拌浆体中絮凝结构尺寸最小,颗粒分散程度最大,浆体流动度最大。随着分散介质中水/乙醇比的增加,水泥颗粒表面电位先降低至负值后升高为正值;当电位的绝对值降至最低时,絮凝结构尺寸达到最大,水泥颗粒分散程度最小,浆体流动性降至最低。分散介质的变化显著改变了水泥颗粒的表面电荷性质,进而导致新拌水泥浆体的粒径分布、显微结构乃至宏观流动性均发生相应的变化。The microstructure and flowability of fresh cement pastes in different dispersion media like ethanol, deionized water and ethanol-water solution were investigated to reveal the correlation between microstructure of blank fresh cement pastes and their macroscopic properties. The zeta potential, particle size distribution and spread diameter of fresh cement pastes with different water to ethanol ratios were determined. The morphology and organization of cement particles in different dispersion media were analyzed via a model Morphologi G3 instrument. The results indicate that in the case of being dispersed in ethanol, cement particles have numerous intrinsic charges for dispersion and the size of aggregates in cement paste is the smallest, consequently leading to the better flowablity of fresh cement paste. The zeta potential on particles in pastes firstly becomes a negative value and then increases to a positive value when the water to ethanol ratio increases. It is indicated that the charge characteristic of cement particle surface is closely related to the dispersive media, which can lead to the changes of the particle size distribution, microstructure and rheological properties of fresh cement paste.

关 键 词：不同分散介质 ZETA电位 粒径分布 显微结构 流动性 

分 类 号：TU528.2[建筑科学—建筑技术科学]