基于SHPB试验的聚丙烯纤维增强混凝土动态力学性能研究

Dynamic Performances of Polypropylene Fiber Reinforced Concrete Based on SHPB Experiment

采用变截面大尺寸Hopk inson压杆,对直径100 mm的两种聚丙烯纤维混凝土和素混凝土试件进行了冲击压缩试验,得到了不同应变率下试件的动态压缩强度及应力应变全过程曲线。从能量耗散的角度讨论了聚丙烯纤维对混凝土的增韧作用,用弹簧一摩擦块复合模型对聚丙烯纤维对混凝土的增韧机理进行了探讨。结果表明,在冲击压缩的高应变率加载条件下,在冲击压缩的初始阶段,聚丙烯纤维的增韧作用并不明显,在卸载阶段,聚丙烯纤维混凝土韧性要明显好于素混凝土。试验为聚丙烯纤维混凝土在防护工程领域与军事领域的应用提供了参考。

Using the large size improved Hopkinson pressure bar with variable cross-sections,a shock compression test with three kinds strain rates was carried out for the 100 mm diameter plain concrete and polypropylene fiber reinforced concrete specimens.The dynamic compression strengths and the overall process curves for stress-strain of specimens under different strain rates were obtained.The experimental results indicated that under the shock compression with high strain rateloading condition,in the initial impac...