中文摘要：

钢纤维通常加工成端部扁平（简称＂端平＂）或端部弯起（简称＂端弯＂）形状以增强纤维与混凝土的粘结锚固,不同纤维形状对超高性能纤维混凝土力学性能影响差异有待试验验证。对纤维体积率分别为1%、2%、2.5%和3%,端平或端弯两种钢纤维制成的超高性能纤维混凝土的性能差异进行了试验研究。试验结果表明：纤维体积率为2%时,端平纤维超高性能混凝土的工作和力学性能最佳;体积率在2%～2.5%时,端平钢纤维混凝土的抗弯强度和断裂能都优于端弯纤维混凝土;由于端弯纤维的端部锚固效果好,端弯纤维混凝土梁在超过峰值荷载后的延性好于端平纤维梁。

英文摘要：

The steel fibers used in fiber reinforced concrete were shaped with flattened end or hooked end to strengthen the anchoring effect between the concrete matrix and fibers.However,the mechanical difference of ultra-high performance fiber reinforced concrete（UHPFRC） with these two deformed fibers remains to be confirmed experimentally.In this paper,the end-flattened and end-hooked fibers were used in producing UHPFRC with the fiber volume ratio of 1%,2%,2.5% and 3% to investigate the different fiber reinforcing effect.The results showed that with the fiber volume ratio of 2%,the UHPFRC with end-flattened achieved the best workability and mechanical performance;with the fiber volume ratio of 2%~2.5%,the flexural strength and fracture energy of UHPFRC with end-flattened fibers exceeded that of end-hooked fibers;due to the better anchoring effect,UHPFRC beams with end-hooked fibers behaved more ductile than that with end-flattened fibers after the peak load.