冲击荷载下3种典型纤维混凝土的动态力学性能研究

Dynamic mechanical properties of three typical fiber reinforced concretes under impact load

为研究玻璃纤维、钢纤维、聚丙烯纤维对纤维增强混凝土动态力学性能的影响,采用Hopkinson压杆,对不同纤维类型、纤维质量掺量和打击气压下50 mm×25 mm的混凝土试件进行动态压缩试验,对比其与普通混凝土在冲击荷载作用下动态力学性能的区别,得到各类纤维混凝土试件在不同打击气压下的动态压缩强度及应力-应变全过程曲线。结果表明,掺入适量纤维可提高混凝土的抗冲击性能,对混凝土的强度、塑性、能量耗散情况均有一定程度的改善,其中效果最好的是掺1.5%钢纤维的纤维混凝土,各项性能均明显优于普通混凝土。

In order to study the effects of glass fiber,steel fiber and polypropylene fiber on the dynamic mechanical properties of fiber reinforced concrete,Hopkinson pressure rod was used to carry out dynamic compression experiments on fiber reinfored con-crete specimens of 50 mm×25 mm under different fiber types,mass dosages and loading air pressures,and compared the differences between their dynamic mechanical properties and ordinary concrete under impact loading,and the whole process curves of dynamic compressive strength and stress-strain of various fiber reinfored concrete specimens under different percussive air pressures were obtained.The results show that the impact resistance of concrete can be improved by adding an appropriate amount of fiber,and the strength,plasticity and energy dissipation of concrete are improved to a certain extent,among which the best effect is fiber reinfored concrete mixed with 1.5%steel fiber,and the performance in all aspects is significantly higher than that of plain concrete.