粉煤灰掺量对钢渣蓄热水泥砂浆耐热性能的影响

Influence of Fly Ash Content on Heat Resistance of Steel Slag Thermal Storage Cement Mortar

为探究粉煤灰对钢渣蓄热水泥砂浆耐热性的影响规律,对粉煤灰掺量为0~80%的砂浆热稳定性及高温力学性能进行研究。结果表明:一定掺量的粉煤灰能改善钢渣水泥砂浆的热稳定性,使砂浆线膨胀系数曲线趋于平稳;随着粉煤灰掺量增加,砂浆高温力学性能呈现出抗压强度损失率逐渐减小,抗折强度损失率先减小后增大的规律,粉煤灰掺量在30%内,抗折、抗压强度损失率皆随掺量的增加而降低;同时研究发现,砂浆线膨胀系数与其抗压强度呈线性关系,单位抗压强度热膨胀系数也随着粉煤灰掺量的增加而增大,这为蓄热砂浆线膨胀系数的预测调节提供了参考;综合分析,粉煤灰替代水泥制备钢渣蓄热水泥砂浆的最佳掺量为30%。

In order to explore the influence of fly ash on the heat resistance of steel slag thermal storage cement mortar,the thermal stability and high temperature mechanical properties of mortar with fly ash content of 0-80%were studied.The results showed that:a certain amount of fly ash can improve the thermal stability of steel slag cement mortar and stabilize the linear expansion coefficient curve of the mortar;As the amount of fly ash increased,the high temperature mechanical properties of the mortar showed that loss rate of compressive strength gradually decreased,and the flexural strength loss rate decreased first and then increased.When the content of fly ash is within 30%,the flexural strength and compressive strength loss rate would decrease with the increase of the content;At the same time,the study found that the linear expansion coefficient of mortar had a linear relationship with its compressive strength,and the thermal expansion coefficient of specific compressive strength also increased with the increase of fly ash content,which could provide a reference for the prediction and adjustment of thermal storage mortar linear expansion coefficient;Based on comprehensive analysis,the optimal content of fly ash to replace cement to prepare steel slag thermal storage cement mortar was 30%.