大分子缓凝剂对建筑石膏水化进程的影响及缓凝机理  

INFLUENCE OF MACROMOLECULE-TYPE RETARDERS ON THE HYDRATION PROCESS OF BUILDING GYPSUM AND ITS RETARDING MECHANISM

作　　者：彭家惠[1] 张建新[1] 陈明凤[1] 吴莉[1] 瞿金东[1] 

机构地区：[1]重庆大学建筑材料系,重庆400045

出　　处：《硅酸盐学报》2008年第7期896-900,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金资助项目(50572126)

摘　　要：研究了大分子缓凝剂(骨胶)对建筑石膏水化进程、液相离子浓度与过饱和度及二水石膏晶体形貌的影响,结合X光电子能谱分析技术对其缓凝机理进行了分析。结果表明:骨胶能抑制建筑石膏早期水化,使其水化放热减缓,早期水化率降低,凝结时间延长;骨胶对二水石膏晶体形貌影响较小,但使二水石膏晶体尺度明显增大;骨胶与二水石膏晶核表面钙元素作用,在其表面形成化学吸附层,降低晶核表面能,抑制二水石膏晶核生长,使建筑石膏水化进程变缓。The effect of macromolecule-type retarder bone glue on the hydration process, ion concentration in liquid phase and supersaturation degree, and crystal morphology of dehydrate of building gypsum was investigated. Furthermore, by using the X-ray photoelectron spectroscopy technique, its retarding mechanism was also studied. The results indicate that the addition of bone glue retards the early hydration of building gypsum, which leads to a delay in the hydration heat evolution. It can also decrease the hydration ratio at in the early stage and the prolong induction period of building gypsum. Bone glue has a minor effect on the crystal morphology of dehydrate and a lower negative effect on the strength of hardened gypsum paste than low molecule-type retarder. But it causes the large crystal sizes. Bone glue interacts with the Ca element on the crystal nuclei surface of dehydrates and forms a chemical adsorption layer, decreasing its surface energy, inhibiting its growth, and consequently slowing down the hydration process.

关 键 词：石膏 缓凝剂 水化进程 晶体形貌 缓凝机理 

分 类 号：TU526[建筑科学—建筑技术科学] TQ177.3[化学工程—硅酸盐工业]