高温后纤维矿渣微粉混凝土的劈拉性能

Splitting properties of fiber reinforced ground granulated blast furnace slag concrete after high temperature

通过劈拉试验,探讨温度、矿渣掺量、钢纤维掺量、聚丙烯纤维掺量等对高温后混凝土劈拉强度及变形的影响。结果表明:随受热温度的升高,纤维矿渣微粉混凝土劈拉性能不断劣化;掺入矿渣微粉、聚丙烯纤维和钢纤维均对高温后混凝土劈拉强度起到了增强作用;随混凝土基体强度的增强,高温后纤维矿渣微粉混凝土劈拉强度逐渐提高,但劈拉强度的损失也有所增大。最后,提出了考虑温度、矿渣微粉掺量和钢纤维掺量影响的纤维矿渣微粉混凝土高温后劈拉强度计算公式。

Based on the splitting experiments, the influences of temperature, ground granulated blast furnace slag （GGBFS） content, steel fiber dosage,polypropylene （PP） fiber dosage and concrete strength grade on residual splitting strength and deformation behavior are systematically ex- amined.The results show that the higher the temperature is, the more serious the deterioration of the microstructure and splitting properties is; the inclusion of GGBFS, steel fiber and polypropylene fiber all effectively improves the residual splitting strength of concrete; the residual splitting tensile strength is enhanced with the increasing of matrix strength of concrete, but at the same time the loss of splitting tensile strength after high temperature increases.Equations are proposed to predict the residual splitting tensile strength of concrete incorporating with GGBFS and steel fiber after being heated to high temperatures.