为了研究纤维增强复合材料(Fiber Reinforced Polymer,FRP)-超高性能混凝土(Ultra High Performance Concrete,U HPC)组合梁的受剪性能,对FRP-U HPC组合梁进行四点受弯试验.组合界面采用FRP剪力键(FRP Shear Key,FSK)与环氧树脂胶结混合处理的方式降低界面滑移的影响.对组合梁的破坏模式、荷载-位移响应、应变响应和滑移响应进行分析,研究了混凝土类型、FSK间距、混凝土板宽度和高度对组合梁受剪性能的影响.研究结果表明:FRP-U HPC组合梁的破坏模式是剪切破坏,FRP-普通混凝土组合梁的破坏模式是弯、剪协同破坏;组合梁存在剪力滞后效应,随着混凝土板宽度的增大,剪力滞后效应越明显;混凝土采用U HPC、减小FSK间距和提高混凝土板截面尺寸都可以有效提高组合梁的抗剪性能,并减小界面滑移.基于合理假定,提出了FRP-U H PC组合梁的抗剪承载力和考虑剪切变形的挠度计算方法,预测结果与试验结果吻合较好.
Shear Performance of FRP-UHPC Composite Beams with FRP Shear Key
To investigate the shear performance of fiber reinforced polymers (FRP)-ultra high performance concrete (UHPC) combined beams,four-point bending tests were conducted.The effects of interface slip were reduced by using the FRP shear key (FSK) and epoxy resin bonded hybrid connection.The failure mode,load-displacement response,strain response,and slipping response of the composite beams were analyzed to study the effect of concrete type,FSK spacing,and concrete width and height on the shear performance of the composite beams.The results indicate that the failure mode of the FRP-U HPC composite beam is shear failure,while the failure of the FRP-normal strength concrete composite beam is bending-shear failure. The composite beams exhibit shear lag effect,which become more apparent with increased concrete slab width. Using U HPC,reducing FSK spacing,and increasing concrete slab size can effectively improve the shear performance of the composite beams and reduce interface slipping.Based on reasonable assumptions,a calculation method for shear bearing capacity and a calculation method for deflection that consider shear deformation were proposed for the FRP-U HPC combined beam. The predicted results were in good agreement with the experimental results.
万方数据
维普
