硅酸盐学报2017，Vol.45Issue(8)：1101-1112,12.DOI:10.14062/j.issn.0454-5648.2017.08.08
钙对碱激发胶凝材料的促凝增强作用
Setting Acceleration and Strength Enhancement Derived from Calcium Species for Alkali-activated Cementitious Materials
摘要
Abstract
The setting time and strength of alkali-activated cementitious materials (AAM) with different calcium species were investigated.The results show calcium species except calcium carbonate have a significant acceleration effect on setting and hardening.Calcium chloride is the most dominant accelerator among calcium species (i.e.,calcium chloride,calcium hydroxide,calcium oxide and calcium carbonate).Besides calcium carbonate,the other three calcium species enhance the strength,but the excessiveness cause a decrease in the strength due to the rapid hardening.The different calcium sources exhibit different mechanisums of shortening the setting time and enhacing the strength.Calcium chloride,as a readily soluble salt,provides the precipitaion of heterogeneous uncleation centers and the formation of calcium silicate hydration gels with a low Ca/Si ratio.The combined effects above lead to a shorter setting time of pastes with 1.0％ calcium chloride (i.e.,＜10 min).However,the improved effect of calcium chloride on strength is only valid at early stage.Calcium hydroxide,as a sparingly soluble compound,also causes the formation of gels that shortens the setting time and enhances the strength,but its effectiveness becomes poor because there is no coupling effect of nucleation centers.Calcium oxide can react in solution to form calcium hydroxide that provides the nucleation templates to accelerate geopolymerization,but the duration of this reaction is longer,so that the rapid hardening just occurs in pastes with a high volume of 5％.Calcium carbonate,as an insoluble salt,does not provide any acceleration effect.关键词
钙/碱激发胶凝材料/促凝/增强Key words
calcium/alkali-activated cementitious materials/setting acceleration/strength enhancement分类
化学化工引用本文复制引用
叶家元,张文生,史迪..钙对碱激发胶凝材料的促凝增强作用[J].硅酸盐学报,2017,45(8):1101-1112,12.基金项目
国家自然科学基金项目(51572252) （51572252）
国家“863”计划课题(2015AA034701)资助. （2015AA034701）
