煅烧凹凸棒石粘土对干粉砂浆性能的影响

Influence of calcined attapulgite clay on properties of dry-mixed mortar

为了改善干粉砂浆性能,掺入占水泥质量20%的煅烧凹凸棒石粘土,研究其对干粉砂浆各项性能的影响.试验结果表明:在所研究的3种凹土中,以Z型煅烧凹土对砂浆稠度、保水性、抗压强度、粘结强度、收缩和抗渗性的改善效果最好;掺入450℃以下煅烧凹凸棒石粘土对砂浆强度、收缩和粘结强度没有显著改善;掺入高于450℃煅烧的凹凸棒石粘土,砂浆的抗压强度、粘结强度、收缩和抗渗性均有显著改善;掺入Z型凹土的砂浆28d抗压强度较空白砂浆提高了102.1%、粘结强度提高了39.7%、抗渗性能提高了25%.

The influence of three types of calcined attapulgite clay on the dry-mixed mortars was investigate. The results show that among them, type Z calcined attapulgite clay is the most effective one in improving the fluidity, water retentivity, compressive strength, bond strength, dry shrinkages and impermeability of mortars. It is found that attapulgite clay calcined below 450℃ has only limited effect on the compressive strength, dry shrinkage and impermeability of mortars, while that calcined at above 450℃ results in a significant improvement in these properties. In particular, after calcining at 850℃ for two hours, the mortar dry-mixed with the type Z attapulgite clay shows the best performance.