短切玄武岩纤维对磷酸镁水泥砂浆性能的影响

采用固定水胶比和固定流动度两种方案进行对比试验,研究了不同掺量的玄武岩纤维对复合磷酸镁水泥(MPC)砂浆流动度和力学性能的影响,并采用扫描电子显微镜(SEM)观察了微观形貌。结果表明:在固定水胶比的情况下,随着玄武岩纤维掺量的增加,MPC砂浆的流动度降低,但力学性能有所提高,且掺量为3.5 kg/m^(3)时,力学性能最优,超过此掺量则增幅下降;在固定流动度而水胶比随纤维掺量增加而增大的情况下,MPC砂浆的力学性能整体呈下降趋势;SEM结果表明,在一定掺量范围内,玄武岩纤维在MPC砂浆中分散均匀,掺量过多则会产生纤维团聚现象;MPC砂浆与玄武岩纤维之间有一定的黏接力和摩擦力,但二者的黏结性或相容性不足;MPC砂浆的水化过程不会对玄武岩纤维造成损伤。

Effect of Chopped Basalt Fiber on the Properties of Magnesium Phosphate Cement Mortar

The comparative tests were carried out with two schemes of fixed water-binder ratio and fixed fluidity,and the effect of different content of basalt fiber on the fluidity and mechanical properties of composite magnesium phosphate cement(MPC)mortar was studied,and the scanning electron microscope(SEM)was used to observe its microscopic appearance.The results show that under the condition of fixed water-binder ratio,the fluidity of MPC mortar decreases but its mechanical properties improve with the increase of basalt fiber content,and the mechanical properties are optimal when the content is 3.5 kg/m³,but the increase decreases when the content exceeds 3.5 kg/m³.When the fluidity is fixed and the water-binder ratio increases with the increase of fiber content,the overall mechanical properties of MPC mortar tend to decline.The SEM results show that within a certain content range,basalt fiber is evenly dispersed in MPC mortar,while over-mixing will produce fiber cluster phenomenon.MPC mortar and basalt fiber have certain adhesion and friction force,but the adhesion or compatibility is insufficient.The hydration process of MPC mortar will not cause damage to basalt fiber.