利用矿渣和粉煤灰制备地聚物胶凝材料的正交试验研究

Orthogonal experiment research on geopolymer synthesis by utilizing slag and fly ash as raw material

为了研究矿渣和粉煤灰在地聚物制备中的应用,将不同配比的矿渣和粉煤灰混合作为硅铝原料,经机械粉磨和激发剂激活后制备地聚物胶凝材料。正交试验研究了矿渣和粉煤灰的配比、水灰比和水玻璃模数3个因素对地聚物抗压强度的影响,并采用XRD、SEM对地聚物的微观结构进行分析。结果表明:当矿渣和粉煤灰配比为1∶1、水灰比为0.4、水玻璃模数为1.2时,所制得地聚物28 d龄期的抗压强度最高,达到68.45 MPa。XRD和SEM分析表明:随着试样养护龄期的增长,生成更多的硅铝酸盐凝胶体,并且原料中部分晶相逐渐转化为非晶相,凝胶产物将未反应完的原料颗粒黏结在一起,使试样结构更趋致密,从而有利于抗压强度的提高。

To research the utilization of slag and fly ash in the geopolymers,geopolymers were synthesized from slag and fly ash,which were activated by mechanical grinding and activators.The effects of the ratio of slag and fly ash,water cement ratio and the modulus of water glass on the compressive strength of geopolymers were investigated by orthogonal experiment.The microstructure of the samples was characterized by X-ray diffraction(XRD)and scanning electron microscope(SEM).The results show that the highest 28-day compressive strength of geopolymer samples is 68.45MPa when the ratio of slag and fly ash is 1∶1,the water cement ratio is 0.4 and the modulus of water glass is 1.2.XRD and SEM analysis of samples prepared under the optimum experimental conditions indicated that the more amorphous aluminosilicate was generated,and the partial crystals gradually transformed into amorphous gelatinous substances with increasing curing age.The incompletely reacted slag and fly ash are closely cemented by the gelatinous substances to form compact internal structure in samples,which promotes the compressive strength of samples.