论文部分内容阅读
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。
Self-compacting super high-performance steel fiber reinforced concrete has the advantages of high strength, high toughness, high fluidity and high durability, but its tensile strength is still far below the compressive strength. Through the static loading test, the flexural behavior of ultra-high performance CFRP beams and the non-web beams with ultra-high-performance steel fiber reinforced concrete with 550 MPa tensioned tendons were studied. When the shear span ratios were 2.5 and 3, respectively, performance. The steel fiber volume fraction of the test beam is 2%. The superfine steel fibers and the end-bent steel fibers are mixed in a 3: 1 ratio. The strength of the concrete matrix is greater than that of C100. The beam specimens are self-compacting and room-temperature standard curing methods. The experimental results show that the ultimate load and ductility of the hybrid steel fiber ultra-high performance concrete beam are obviously improved compared with the steel fiber reinforced concrete beam. The load of initial crack without web reinforcement increased by 25% ~ 180%, the load with crack width of 0.2 mm increased by 73% ~ 183%, the ultimate load increased by 68% ~ 317% and the ductility increased by 3.2 ~ 4.4 times.