粉煤灰对混合石膏基砂浆性能的影响

Influence of Fly Ash on the Properties of Mixed Gypsum-Based Mortar

将粉煤灰等质量取代重钙,研究粉煤灰对混合石膏基砂浆体系力学性能以及耐水性能的影响,进而采用X射线衍射分析(XRD)和扫描电镜分析(SEM)等现代测试方法对其水化性能进行追踪测定。结果表明,粉煤灰取代率在15%~20%之间时,砂浆中钙矾石(AFt)含量明显增多,其填充于水化相的空隙中,促使砂浆微观结构更加致密,砂浆强度增大、耐水性提高,砂浆软化系数达到了0.50。建议粉煤灰取代率为15%~20%,此时制备出的混合石膏基找平砂浆经济性高、性能优良。

The influence of fly ash on the mechanical properties and water resistance of gypsum based mortar was studied by replacing heavy calcium with fly ash.The hydration properties of gypsum based mortar were determined by XRD and SEM.The results show that when the replacement rate of fly ash is between 15%and 20%,the content of ettringite(AFT)in mortar increases obviously,which fills in the voids of hydration phase,makes the microstructure of mortar more compact,the strength and water resistance of mortar increase,and the softening coefficient of mortar reaches 0.50.It is suggested that the replacement rate of fly ash should be 15%~20%.At this time,the prepared mixed gypsum based leveling mortar has high economy and excellent performance.