石灰石粉对机制砂干混抹灰砂浆性能影响的试验研究

Experimental study on the effect of limestone powder on the properties of dry-mixed plastering mortar with machine-made sand

对石灰石粉对机制砂干混抹灰砂浆的性能影响进行了试验研究,并通过光学显微镜分析了水泥和石粉净浆的微观结构,解释了干混抹灰砂浆中水泥和石粉含量过多造成抹平困难的原因。结果表明:石粉作为矿物掺合料制备干混砂浆,石粉和粉煤灰双掺比单掺效果要好;从抹灰砂浆的施工角度考虑,每吨机制砂抹灰砂浆中总的粉料(小于0.075 mm)含量应≥230 kg,水泥和小于45μm的石粉颗粒总量应≤150 kg。

Experimental study on the effect of limestone powder on the properties of dry - mixed plastering mortar with machine - made sand was carried on. The microstructures of cement and limestone powder neat paste were observed by optical microscope,and the reason of floating difficulty created by too much cement and limestone powder content in mixed plastering mortar was explained.The results showed that when limestone powder was used for mineral admixture in preparing mixed mortar,the effect of double - doped limestone powder and fly - ash was better than that of single - doped limestone powder or fly - ash.From floating construct of plastering mortar perspective,the total content of the powder（including cement and limestone powder）with less than 0.075 mm in per ton mixed mortar should be equal or greater than 230 kg and the total content of cement and limestone powder with less than 45 μm should be equal or less than 150 kg.