【摘要】 为研究不同混杂纤维超高性能混凝土(Ultra High Performance Concrete,UHPC)的拉伸性能，本文将钢纤维与四种非金属纤维进行了混杂，通过7组试件的单轴拉伸试验，研究了各组试件的受力过程、破坏形态和应力-应变曲线，分析了混杂纤维UHPC试件的抗拉强度、峰值应变、轴拉韧性比和断裂能等。结果表明：单掺钢纤维与混杂纤维UHPC试件拉伸应力-应变曲线均表现出应变软化；纤维总体积掺率相同时，混杂纤维UHPC试件的抗拉强度和峰值应变均优于单掺钢纤维，玻璃纤维与钢纤维混杂后提升效果最显著；混杂纤维可充分发挥阻裂增韧作用，提高UHPC的拉伸韧性，混掺粗聚丙烯纤维对提升轴拉韧性最为显著，混掺玻璃纤维对提升断裂能最为明显，钢纤维2.00%混掺0.50%玻璃纤维UHPC试件的断裂能比单掺钢纤维提高了27.21%。最后，本文还对混杂纤维改善UHPC拉伸性能的作用机理进行了分析。更多还原

【Abstract】 In order to investigate the influence of hybrid fibers on the tensile properties of Ultra High Performance Concrete(UHPC), steel fiber is mixed with four types of nonmetallic fibers, respectively. Through the tensile test of seven groups of specimen, the loading process, failure mode and stress-strain curves of each group are studied. And the tensile strength, peak strain, tensile toughness ratio, and fracture energy were analyzed. The results show that the stress-strain curves of UHPC specimens only with steel fiber or with hybrid fibers exhibit strain softening characteristics. The tensile strength and peak strain of hybrid fiber UHPC specimens are higher than that of steel fiber specimens at the same volume ratio, in which, steel fiber combined with glass fiber has the most significant effect. Hybrid fibers can give full play to their crack resistance and toughness enhanced effects, improving the tensile toughness of UHPC. Steel fiber combined with polypropylene fiber has more significant effect on improving the tensile toughness ratio. Steel fiber combined with glass fiber has more significant effect on improving the fracture energy. The fracture energy of UHPC specimens containing 2.00% steel fiber combined with 0.50% glass fiber is 27.21% higher than steel fiber only. In addition, the influence mechanism of hybrid fibers on the tensile properties of UHPC was analyzed.更多还原