盐激发对大掺量固废胶凝材料及其制备混凝土性能的影响

Effect of salt excitation on the properties of high volume solid waste cementitious materials and concrete preparation

为了大规模消纳钢铁冶炼渣,实现其高附加值利用,激发钢渣潜在活性,在m(钢渣)∶m(矿渣)∶m(水泥)=36∶54∶10时,研究了Na_(2)SO_(4)和Na_(2)SiO_(3)两类常用激发剂单掺及复掺对钢渣-矿渣复合胶凝材料性能的影响。结果表明,Na_(2)SiO_(3)和Na_(2)SO_(4)复掺的激发效果要优于单掺,最佳复合激发剂掺量为3%Na_(2)SiO_(3)+1%Na_(2)SO_(4)。复掺激发剂时,钢渣-矿渣复合胶凝体系除了出现新相黝帘石外,其它水化产物种类基本相同,均为AFt、CH和无定形的C-(A)-S-H凝胶,其中SO_(4)^(2-)能够加速钢渣和矿渣玻璃体结构的解聚,而SiO_(3)^(2-)水解形成H_(3)SiO_(4)^(-)和OH^(-),同样可以提高体系的碱度,促进水化反应的进程。

In order to absorb the steel smelting slag on a large scale,improve the cementitious activity of the steel raising slag and realize its high added value utilization,when the cementitious material is steel slag∶mineral slag∶cement=36∶54∶10,the effects of single and compound mixing of two common activators Na_(2)SO_(4) and Na_(2)SiO_(3) on the properties of steel slag-mineral slag composite cementitious material were studied.The results show that the excitation effect of the mixture of Na_(2)SiO_(3) and Na_(2)SO_(4) is better than that of the single mixture,and the optimal mixture of 3%Na_(2)SiO_(3)+1%Na_(2)SO_(4).Except for the inclusion of Na_(2)SiO_(3) and Na_(2)SO_(4) as activator,the hydration products of steel slag-slag composite gelling system were basically the same,which were AFt,CH and amorphous C-(A)-S-H gels.SO_(4)^(2-)can accelerate the depolymerization of steel slag and mineral slag glass structure,while SiO_(3)^(2-)hydrolyzes to form H_(3)SiO_(4)^(-)and OH^(-),which can also improve the alkalinity of the system and promote the process of hydration.