半干法脱硫灰应用于抹灰砂浆力学性能及耐久性研究

Research on mechanical properties and durability of plastering mortar prepared with semi-dry sintering desulfurization ash

研究了半干法烧结脱硫灰对抹灰砂浆基本力学性能、抗冻融性、干燥收缩性能的影响,并采用SEM分析了掺加半干法烧结脱硫灰抹灰砂浆的微观结构。研究结果表明,半干法烧结脱硫灰反应活性较粉煤灰低,脱硫灰取代率大于60%时,抹灰砂浆的抗压强度、拉伸粘结强度明显降低,干燥收缩值增大,不利于砂浆的耐久性。少量取代粉煤灰在抹灰砂浆中应用具备一定的可行性,力学性能和耐久性能良好,符合GB/T 25181—2019《预拌砂浆》的要求。

In this paper,the influence of semi-dry sintering desulfurization ash on the basic mechanical properties,freeze-thaw resistance and drying shrinkage of plastering mortar was studied,and the influence of semi-dry sintering desulfurization ash on the microstructure of plastering mortar was analyzed by scanning electron microscope(SEM).The results show that the reactivity of semi-dry sintering desulfurization ash is lower than that of fly ash.When the desulfurization ash replacement rate is greater than 60%,the compressive strength and tensile bond strength of the plastering mortar decrease obviously,and the drying shrinkage value increases,which is not conducive to the durability of the mortar.It is feasible to replace fly ash with a small amount of desulfurization ash in preparing plastering mortar,with good mechanical properties and durability,which can meet the performance index requirements of GB/T 25181—2019"Ready-Mixed Mortar".