When doped volume ratio of fiber (volume fraction) was 2. 0%, through cubic compressive tests and beam flexural tests, hybrid-fibers between end-hooked and superfine tape steel fibers with different ratios of length to diameter and different parameters were used to study their effects on compressive strength, flexural strength, ductility of the ultra-high performance concrete (UHPC). The results show that the end-hooked and superfine fibers have their own dominative effects on mechanical properties of the bearing capacity and ductility behavior. With the increase doped volume ratios of superfine fibers, the mechanical properties of compressive strength, flexural strength and bend ductility of the UHPC increase. With the increase doped volume ratios of end-hooked fibers, the beam has a better performance on ductility. Hybrid-fibers between end-hooked and superfine fibers can enhance performance in all aspects of mechanical properties of concrete. Taking all factors of mechanical property index and economical efficiency into consideration, it is the best mixture proportion when doped volume ratios of end-hooked and superfine fibers are 0. 5%, 1. 5%.%采用工程上常用的2种不同长径比、不同强度的端弯型钢纤维和超细型钢纤维,通过立方体抗压试验和小梁抗弯试验,研究纤维体积率(体积分数)为2.0％时,端弯纤维和超细纤维混合比例对超高性能混凝土抗压强度、抗弯强度、延性的影响.结果表明:端弯纤维和超细纤维分别主导了超高性能混凝土强度和延性性能;随着超细纤维体积率增加,超高性能混凝土抗压强度、抗弯强度和弯曲韧性提高;随着端弯纤维体积率提高,小梁的延性增强;2种纤维混合,可以均衡地改善基体混凝土的相应性能;综合考虑各力学性能指标和经济性,端弯纤维与超细纤维体积率分别为0.5％和1.5％时为最佳配比.
展开▼
