缓凝剂对建筑石膏水化过程和硬化体微结构的影响  

作　　者：吴莉[1] 彭家惠[1] 万体智[1] 张建新[1] 

机构地区：[1]重庆大学建材系,重庆市400045

出　　处：《新型建筑材料》2003年第7期1-3,共3页New Building Materials

基　　金：国家自然科学基金资助项目(50078055)

摘　　要：测定柠檬酸、聚合磷酸钠、骨胶3类缓凝剂对石膏性能的影响,通过不同水化时间的水化率和水化温度测定,研究了缓凝剂对建筑石膏水化过程的影响,采用SEM形貌分析和压汞法孔结构分析研究缓凝剂对石膏硬化体微结构的影响。结果表明,这3种缓凝剂均延缓了石膏的水化进程,使凝结时间延长,强度降低,低掺量时柠檬酸缓凝作用最显著;缓凝剂改变了二水石膏晶体生长习性,使晶体由针状转变为短柱状,晶体尺寸明显增加;缓凝剂使硬化体孔径分布粗化,孔结构劣化。The effect of citric acid,sodium polyphosphate,bone glue on the performance of gypsum was deter-mined.By testing hydration rate and hydration temperature at different times,the effect of the retarders on the hydration process of calcined gypsum was studied,and by analyzing morphology and pore structure,the effect of the retarders on the microstructure of gypsum was also studied.Results show that the three retarders have all delayed the hydration pro-cess,extended the setting time and reduced the strength,in which the retarding effect of citric acid is most distinct.The retarders have changed the growth habit of the dihydrate gypsum crystal,and changed the crystal from needle-shaped in-to short columnar,as well as notably increased its dimensions.The retarders make the pore diameter distribution of hard-ened gypsum thickening and the pore structure deteriorating.

关 键 词：建筑石膏 缓凝剂 水化进程 微结构 

分 类 号：TQ177.32[化学工程—硅酸盐工业]