高铝粉煤灰制备混凝土膨胀剂  

The Application of High-Alumina Fly-ash on Expanding Admixture of Concrete

作　　者：唐明[1] 黄知广[1] 

机构地区：[1]沈阳建筑大学材料科学与工程学院,辽宁沈阳110168

出　　处：《沈阳建筑大学学报（自然科学版）》2008年第2期256-260,共5页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金资助项目(50378057)

摘　　要：目的利用高铝粉煤灰制备一种能够满足工程要求的新型混凝土膨胀剂，合理利用工程废弃物，减少建筑成本．方法利用测量限制膨胀率的方法观察高铝粉煤灰与硬石膏混合后对水泥砂浆试件的补偿收缩效果．采用不同的硬石膏、粉煤灰以及其他膨胀剂的质量配比，分析高铝粉煤灰与其他膨胀剂混合使用时产生的膨胀效果、膨胀速率、稳定时间以及叠加效应．结果高铝粉煤灰的膨胀反应依赖于石膏的存在，当其和硬石膏混合后能够产生较为明显的膨胀效果．随着石膏掺量的增加，限制膨胀率呈增大的趋势．早期和后期膨胀率的增长都较为明显．石膏与粉煤灰的质量比为0．6～1时，膨胀稳定得最快，而且限制膨胀率也能保持在一个很高的水平．高铝粉煤灰部分替代CSA后，限制膨胀率依然可以满足国家标准的技术要求，膨胀速度较快，稳定期较早，替代率可以达到50％．高铝粉煤灰与CSA混合使用时，还可以产生有利于膨胀的叠加效应、结论采用合适的石膏、粉煤灰质量比可以配制出限制膨胀率超过0．04％的膨胀荆，且膨胀量能在10d左右达到稳定，替代部分CSA膨胀剂后限制膨胀率最高能超过0．05％．The purpose of the study is to develop a new expanding admixture with high-alumina fly-ash. The effect of shrinkage-compensation of high-alumina fly-ash on mortar has been studied. Different compounding of high-alumina fly-ash, anhydrite, and CSA can affect the degree and speed of mortars＇ restrained expan- sion. Along with the increasing of anhydrite fly-ash ratio the restrained expansion became more obvious, no matter in the early age or in the latter. The best mass ratio of anhydrite and fly-ash for the restrained expansion is 0.6-- 1. With this ratio range, the mixture can substitute CSA partly, and the restrained expansion remain accord to the state＇ s standards. A synergistic effect on the restrained expansion has been observed when the high-alumina fly-ash, anhydrite and CSA were used together. In order to clarify this phenomenon, the hydration of cement pastes containing these kinds of admixture was followed through restrained expansion measurements and mass loss measurements.

关 键 词：混凝土膨胀剂 高铝粉煤灰 石膏 限制膨胀率 

分 类 号：TU528[建筑科学—建筑技术科学]