摘要
以脱硫石膏、铝土矿和普通硅酸盐水泥为原料制备自流平材料,研究了胶凝材料的表观性状、强度发展、结构与产物,以及胶凝机理。结果表明,脱硫石膏掺量20%~40%时,自流平材料表面性状良好,水化作用较快,凝结时间合理,具有密实的钙矾石胶凝结构;脱硫石膏掺量不足时,无法形成以钙矾石为主的胶凝结构,过量则导致胶凝体强度显著下降、凝结时间明显延长、后期强度几乎不发展。钙黄长石和硅酸钙可以指示28 d胶凝体的＂亏钙＂程度。因此,掺量不大于40%的脱硫石膏可与铝土矿、普通硅酸盐水泥制备混合基自流平材料,为资源化利用脱硫石膏提供了新途径。
In China, a large quantity of flue gas desulfurization （FGD） gypsum, which consists mostly of CaSO4 2H2O, has been produced and increased dramatically in the past decade. In the experiment, self-leveling screed material （SLSM） was investigated as a promising material for FGD gypsum utilization. The SLSM was prepared by blending bauxite and Portland cement with different dosages of FGD gypsum and water. The results show that the paste met the standard of gypsum-based SLSM for flowability, setting time, sweating and strength while the FGD gypsum in the paste was controlled within 20wt% -40wt%. The ettringite crystals contributed to the dense structure of SLSM. The less FGD gypsum in SLSM could lead to a failure to the cementitious structure, while too much of FGD gypsum gave a decrease in the strength, a delay of setting and an inhibition on later strength development. The SLSM prepared from FGD gypsum, bauxite and Portland cement is very likely of the promising alternatives in utilizing the FGD gypsum.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2014年第2期253-260,共8页
Bulletin of the Chinese Ceramic Society
基金
浙江省科技计划项目(2007C23055)
863计划课题(2009AA064002-3)
关键词
脱硫石膏
自流平砂浆
铝土矿
钙矾石
FGD gypsum
self-leveling screed material
bauxite
ettringite
