粉煤灰对水泥水化浆体微结构的影响  

Influence of fly ash on microstructure of cement paste

作　　者：孙海燕[1] 何真[2] 龚爱民[1] 彭玉林[1] 

机构地区：[1]云南农业大学水利水电与建筑学院,云南昆明650201 [2]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《混凝土》2011年第12期79-82,共4页Concrete

基　　金：国家自然科学基金项目(50972109);云南省科技计划项目(2008ZC052M)

摘　　要：为探讨粉煤灰对水泥水化浆体微结构的影响，通过原子力显微镜以及能谱分析，对纳米尺度下基准及掺有粉煤灰水泥浆体中水化产物的形状、大小以及堆聚结构的形成机制进行了研究。试验结果显示，在基准水泥浆体中的水化产物大部分是粒级大约40～80mm的圆球形颗粒，而且试验还观察到在它们中还镶嵌着一些尺寸大于1μm的板状和薄片状水化产物。然而，圆形颗粒的尺寸随养护龄期的增长有逐渐减小的趋势，且圆球形颗粒有分散和团聚两种堆聚形式。在水化早期，水化浆体微结构呈较松散的堆聚结构；随着养护龄期增长，由于颗粒的重排列，形成更低尺度的颗粒呈紧密的堆聚结构。然而，粉煤灰的掺入会影响水化产物的形状和堆聚形式，研究结果表明，由于粉煤灰的掺入，降低了浆体Ca／Si，使水化浆体的微结构无论是早期还是后期，其堆聚结构均较基准水泥样松散，而且浆体中还观察到许多椭球状的水化产物，经分析认为这是致使浆体微结构呈疏松状态的主要原因。In order to research the influence of fly ash （FA） on microstructure of cement paste, the shape, size and packing structure of the hydration products in the plain and FA cement pastes were conducted by AFM and EDAX.The results show that there are many round particles about 40-80nm mostly,in which are enehased some tabular and flake hydration products more than 1μm in the plain samples.However, the size of the round particles has been tended to become small with the increasing days.Generally, for round particles, there were two types packing structure of decentralization and cluster,which was formed the loose packing structure at the early ages.But the packing structure became tight because of the rearranged particle with the increasing days.Moreover, fly ash would affect the shape and packing of hydration products.The results indicate that the particles in FA cement paste appear the elliptical shape and looser packing structure due to its low C/S ratio.

关 键 词：微结构 粉煤灰 水化浆体 水化硅酸钙 形貌 颗粒堆聚 钙硅比 

分 类 号：TU528.041[建筑科学—建筑技术科学]