Properties of hybrid basalt-polypropylene fiber reinforced mortar at different temperatures

Fiber-reinforced cement-based materials have attracted wide attention in the past decades. However, the properties of cementitious materials and fibers will deteriorate under fire conditions, the addition of hybrid fibers may improve the fire resistance of fiber-reinforced cement-based materials. In the current study, experiments were performed to evaluate the effects of temperature on the performance of hybrid basalt-polypropylene fiber reinforced mortar. The unit weight, compressive strength, flexural strength and microstructure of the specimens at different temperatures were investigated. The fiber reinforcement and failure mechanism of hybrid fiber mortar at different temperatures were studied. The experimental results show that the compressive properties of mortar specimens increased first and then decreased sharply with the increasing of temperature, but the change trend of flexural strength was quite different. For hybrid fiber reinforced mortar with 0.2% of basalt fiber and 0.1% polypropylene fiber at 200℃, the compressive strength and flexural strength increase by 18.53% and 21.73% compared with the reference mixture.