羟乙基甲基纤维素对水泥水化产物Ca(OH)_2形貌特征的影响

利用场发射扫描电子显微镜(ESEM)研究了羟乙基甲基纤维素(HEMC)对水泥水化产物Ca(OH)_2形貌特征的影响以及HEMC的成膜特性.结果表明:羟乙基甲基纤维素会对水泥水化产物Ca(OH)_2的形貌特征和生长取向性产生显著影响,并导致气孔中生成较多的Ca(OH)_2,使得水泥浆体及其气孔中Ca(OH)_2晶体的生长呈现出多向性,其形貌特征多呈X形状或花瓣状,这种影响在水化早期尤为显著;羟乙基甲基纤维素能在水泥浆体中形成细小的线状聚合物膜,也有少量的连续聚合物膜,并搭接在Ca(OH)_2晶体表面及其层隙之间,起到了一定的桥接作用,改善了Ca(OH)_2晶体之间的界面特性.

Effect of Hydroxyethyl Methyl Cellulose on the Morphology Characteristics of Ca(OH)2 in Portland Cement Paste

The effect of hydroxyethyl methyl cellulose(HEMC) on the morphology of calcium hydroxide(Ca(OH)2) and the formation of polymer films in cement paste at different curing ages were studied by using environmental scanning electron microscopy(ESEM). The results show that HEMC dramatically affects the morphology and the oriented growth of Ca(OH)2 in cement paste. HEMC also increases the enrichment of Ca(OH)2 in pores, thus enhances the multidirectional growth of Ca(OH)2 which exhibit X shape or petal like morphologies both in cement paste and in pores, especially at earlier hydration time. Tiny linear polymer films of HEMC are formed in cement paste, bridging the Ca(OH)2 plates and even covering on them, and accordingly to improve the interfacial characteristics of Ca(OH)2 plates.