摘要：针对大掺量粉煤灰、矿渣粉导致干混砂浆早期强度和后期强度较低的问题,研究脱硫石膏对该干混砂浆性能的影响;采用X射线衍射、扫描电镜及孔结构分析等手段进行微观机理讨论。结果表明,在大掺量粉煤灰矿粉干混砂浆中掺加占胶凝材料总质量6%～8%的脱硫石膏,对和易性无不良影响,并可显著提高浆体的抗压强度及拉伸粘结强度,收缩率降低10%以上,并改善抗碳化能力,使砂浆体积更稳定;脱硫石膏对粉煤灰及矿渣粉起到激发硫酸盐和碱性的双重作用,并在一定程度上促进水泥水化;胶凝材料的水化产物改善砂浆浆体内部结构,使砂浆浆体中的孔隙大大减少。

关键词：脱硫石膏；粉煤灰；矿渣粉；干混砂浆

Abstract：Aiming at the large volume of fly ash and slag powder in dry-mixed mortars making the early and later strength of pastes low,the effect of desulfurization gypsum on the properties of dry-mixed mortars was researched.XRD,SEM and pore structure analysis were used to discuss the mechanism.The results show that adding mass fraction 6% to 8% of desulfurization gypsum into the dry-mixed mortars with large volume of fly ash and slag powder large volume of fly ash and slag powder,no adverse effects on workability of the mortars,the compressive strength and tensile bond strength of pastes increase,the shrinkage reduces more than 10% and the anti-carbonation capacity improves.The desulfurization gypsum plays a dual role to stimulate the sulfate and alkaline of fly ash and slag powder and promote the hydration of cement.The hydration products of cementitious materials improve the internal structure of the mortar pastes and greatly reduce the pores in the pastes.

Keywords：desulfurization gypsum；fly ash；slag powder；dry-mixed mortar