无碱液体速凝剂与水泥的适应性及水化促凝机理分析  

Compatibility and Hydration-accelerating Mechanism Analysis of Alkali-free Liquid Accelerating Agent

作　　者：张力冉[1] 王栋民[1] 张述雄[1] 刘辉[1] 李娟[1] 逄建军 

机构地区：[1]中国矿业大学(北京),北京100083

出　　处：《硅酸盐通报》2014年第6期1365-1371,共7页Bulletin of the Chinese Ceramic Society

基　　金：中国矿业大学(北京)博士研究生拔尖创新人才培育基金项目(00-800015Z637)

摘　　要：通过微、宏观测试分析,研究了无碱液体速凝剂与水泥基材料的适应性及其水化促凝机理。结果表明:自制无碱液体速凝剂对实验中的三种水泥初凝时间均小于3 min 31 s,终凝时间均小于7 min 35 s表现出良好的适应性,与聚羧酸超塑化剂或萘系超塑化剂复掺时,降低水灰比至0.32时,水泥凝结时间均可达到JC477-2005要求;通过XRD、TG/DTA与SEM分析微观结构得出,速凝剂对1～28 d的水化产物的类型基本没有影响。在掺入速凝剂的水泥-速凝剂-水体系中,速凝剂的主要成分硫酸铝与CH生成微细针柱状AFt,其主要是通过液相反应-沉淀过程形成。结晶水化产物的生长、发展,在水泥颗粒间交叉连续生成网络型结构,而加速凝结;水泥水化早期生成的CH被速凝剂消耗,且形成钙矾石加速了硅酸二钙(C_2S)、硅酸三钙(C_3S)的水化进程,使水泥快速凝结硬化。A so-called macro and micro testing method was employed to study the compatibility between alkali-free liquid accelerating agent and cement-based composites, and to analyze its hydration-coagulation mechanism. The results shown that the compatibility between alkali-free liquid accelerating agent and three kinds of cement-based compositesis stayed in an excellent state, in this station, their initial setting time are less than 3 min 31 s, final setting time are less than 7 min 35 s. and when the accelerating agent was doped with superplasticizer, reducing the water cement ratio to 0.32 could make the cement＇ s congealing time meet the requirements of JC477-2005; XRD, TG/DTA and SEM analysis of microstructure demonstrated that the accelerating agent had barely effect on the types of 1-28 d hydration products. In the system of cement-accelerating agent-solution, the main components of the accelerating agent were aluminum sulfate and it could generate slight needle cylindrical Aft together with CH, while the Aft was mainly formed through the liquid phase reaction and precipitation process. The crystalline hydration products grew and developed across the cement particles and the continuous network structure, accelerating condensation, formed; While CH generated during the cement＇ s early hydration wasconsumed by accelerating agent, the formation of ettringite accelerated C2S, C3S hydration, resulting in the condensation sclerosis of cement.

关 键 词：无碱液体速凝剂 微观结构 水化 促凝机理 

分 类 号：TU528[建筑科学—建筑技术科学]