矿渣预处理与碱碳酸盐-矿渣胶凝材料的性能

碱激发碳酸盐矿胶凝材料是在常温下直接制备得到的一种低环境负荷型胶凝材料，其与高炉矿渣复合后可以获得更好的早强、高强和抗渗性能。但是，与高炉矿渣的复合会引起胶凝材料的工作性能如凝胶时间和流动性能等的急剧变差，且难以采用传统的缓凝技术如碱矿渣水泥的缓凝技术等加以解决。研究发现，当对矿渣采用低浓度的硅酸钠溶液进行一定时间的预处理后可以较好地解决上述问题。研究结果表明：矿渣的预处理能够使该胶凝材料的凝胶时间得到较大幅度的延长和流动性能得到较为显著的改善，但会使材料强度有所降低；凝胶时间延长和流动性能改善的幅度随着材料中矿渣质量掺量的提高和硅酸钠浓度的增大而减小。

Effect of the Pretreatment of Ground Granulated Blast-furnace Slag on the Performance of Alkali-activated Carbonatite-slag Cementitious Material

Alkali-activated carbonatite cementitious material(AACCM) prepared at room temperature is a new kind of cementitious material with low environmental load.When ground granulated blast-furnace slag(GGBFS) is added to AACCM,high strength both at early and late ages and good impermeabiliy are achieved.But with the addition of GGBFS,the workability of the cementitious material,such as gel time and flowability,is greatly decreased.This problem can't be solved by the traditional retarding method,such as the retarding methods suitable to cement or alkali-activated slag cement.It was found that the problem could be well solved by pretreating the GGBFS to be added to AACCM with sodium silicate solution of low concentration for a certain time under room temperature.The results show that after the pretreatment both the gel time and flowability of AACCM with GGBFS addition can be significantly improved,but the strength of the materials at early ages is somewhat decreased in comparison to control samples.The extended gel time and flowability with the pretreating method are varied with GGBFS addition and the concentration of alkali-activator.