【摘要】 综合利用钢的延性和CFRP(carbon fiber reinforced polymer)的耐久性等性能，在闭合矩形钢带外缠绕浸渍环氧树脂胶的CFRP条带，形成CFRP-钢复合带箍替代常规钢箍用于混凝土梁。为了探索这种新型箍筋对混凝土梁受剪性能特别是延性的作用，对纯CFRP带箍梁、钢带箍梁、复合带箍梁等5根不同配箍的混凝土梁开展对比试验。研究结果表明：当配箍能力密度相当时，CFRP-钢复合带箍梁和纯钢带箍梁承载力接近，配箍效率系数分别为1.10和1.12，远高于纯CFRP带箍梁的0.76；在加载前期，复合带箍主要靠刚度大的钢带抑制裂缝开展，后期则由弹性的CFRP条带对钢带屈服后的变形起到约束作用，且其承担的剪力不断上升，使混凝土梁能够持续平稳承载，因此，复合带箍梁的延性明显高于钢带箍梁的延性，极限挠度增幅高达65.9%；复合带箍间距对混凝土梁受剪性能有明显影响，当复合带箍间距从160 mm减小为110 mm时，梁的受剪承载力和极限挠度分别增加了24.3%和69.8%。更多还原

【Abstract】 To comprehensively utilize the good ductility of steel and durability of carbon fiber reinforced polymer(CFRP), a novel type of stirrup combining CFRP and steel was developed as an alternative to conventional steel stirrups for concrete beams. The CFRP strip was impregnated with epoxy resin and wrapped around a closed-form rectangular steel tie to form hybrid stirrups of CFRP-steel strap. Experiments were carried out to understand the effect of hybrid strap stirrups on the shear performance and ductility of concrete beams. Five concrete beams with different stirrups were prepared, including CFRP strap, steel and hybrid strap stirrups beams. The results show that at the same level of stirrup capacity, the bearing capacity of CFRP-steel hybrid strap stirrups beam is similar to that of steel strap stirrups beam, and the stirrup efficiency is 1.10 and 1.12, respectively, which is much higher than that of CFRP strap stirrups beam(0.76). Under the cooperative working condition, the steel strap with high rigidity can restrain the crack development in the early stage, and the externally bonded CFRP strap can effectively restrain the large deformation of the steel strap in the later stage, the reason is that the concrete beam can bear the load stably, and therefore, the ductility of beam with hybrid strap stirrups is significantly better than that of beam with steel strap stirrups, which results in increment of ultimate deflection up to 65.9%. Besides, reducing the spacing of the hybrid strap stirrups can furtherly improve the shear performance and ductility of the beam. When the stirrup spacing deduces from 160 mm to 110 mm, the shear bearing capacity and ultimate deflection of the concrete beam increases by 24.3% and 69.8%, respectively.更多还原