中文摘要：

自密实超高性能钢纤维混凝土具有高强、高韧、高流动性和高耐久性的优势,但其抗拉强度仍远低于抗压强度。通过静力加载试验,研究超高性能纤维混凝土梁的抗弯性能,以及配置550 MPa受拉纵筋时超高性能钢纤维混凝土无腹筋梁,在剪跨比分别为2.5、3时的受剪性能。试验梁的钢纤维体积率为2%,其中超细钢纤维和端弯钢纤维以3∶1比例混合,基体混凝土强度大于C100的强度,梁试件采取自密实成型和常温标准养护方法。试验结果表明：与无钢纤维混凝土梁相比,混合钢纤维超高性能混凝土梁的极限荷载和延性得到明显改善。无腹筋梁的初裂荷载提高了25%～180%、裂缝宽度0.2 mm时的荷载提高了73%～183%、极限荷载提高了68%～317%、延性提高了3.2倍～4.4倍。

英文摘要：

Self-compacting ultra-high performance steel fiber reinforced concrete has the advantages in high strength, high toughness, high fluidity and durability. However, its tensile strength is still far below the compressive strength. In this experiment, superfine fiber and end-bend fiber with steel fiber volume ratio of 2% are mixed at a proportion of 3：1 in the concrete with a matrix strength higher than C100, to be applied into the ultrahigh performance fiber concrete beam of 550 MPa tensile reinforcement. Six beams with shear span ratio of 2. 5 and 3 are studied in this experiment through the method of static loading tests. The results show that at compare with beams without fiber, the imitial crack load of ultra-high performance reinforced concrete beams with steel bar and hybrid steel fiber is increased by 25% - 180% ,the load of 0. 2 mm crack width is increased 73% - 18% ,the ultimate load is increased by 68% 317%, the ductility is increased by 3.2 -4.4 times.