不同纤维替代自密实混凝土梁中抗剪箍筋的试验研究

摘要： 通过对一系列有箍筋和无箍筋自密实混凝土简支梁在两点对称集中荷载作用下的受剪试验分析，本文研究了纤维类型、纤维掺量以及配箍率等变化参数对混凝土梁斜截面受力性能的影响，并分析了用钢纤维和混杂纤维部分替代抗剪箍筋的可能性。试验梁加载时采用位移控制。结果表明，适量的钢纤维和混杂纤维能够部分替代混凝土梁中的箍筋。当箍筋和混杂纤维共同作用时可显著提高自密实混凝土梁的极限剪力、荷载峰值后的剩余承载能力以及韧性。混杂纤维能够改变按构造要求配置箍筋的混凝土梁的破坏形态，使梁从脆性的剪切破坏转为延性的弯曲破坏。

Using Hybrid Fiber as Replacement of Stirrups for Enhancing the Shear Behavior of Self-compacting Concrete Beams

Abstract: An experimental investigation on the shear behavior of hybrid fiber reinforced self-compacting concrete (FRSCC) beams was carried out. A series of simply supported beams with and without stirrups was tested under symmetrically placed two-point concentrated loading. FRSCC beams were designed to study the influence of: a) various fiber types; b) different fiber contents; c) different stirrup ratios on the shear performance of RC beams, and to analyze the possibility of using different fibers to replace the shear stirrups. The experimental results show that the amount of shear stirrups can be reduced by steel/hybrid fibers, the combination of hybrid fibers and stirrups can enhance the residual load-carrying capacity and ultimate shear load as well as the toughness of RC beams. Furthermore, the results indicate that the addition of hybrid fibers in adequate content can change the brittle mode of shear collapse into a ductile flexural mechanism.