Experiment on flexural behavior of steel-GFRP-concrete composite beams

Abstract

為研究鋼與GFRP-混凝土空心組合板通過不同連接方式形成組合梁的受彎性能, 對3根組合梁試件進行了靜載試驗研究。 3個試件中鋼梁與GFRP-混凝土組合板間的連接方式分別為環氧樹脂膠結及栓釘連接。 通過比較不同連接方式下組合梁截面應變、跨中撓度、界面相對滑移的變化規律, 驗證了環氧樹脂膠層及抗剪栓釘分別作為組合梁界面連接件的可行性。 基于不同連接方式下組合梁的破壞模式, 給出了栓釘連接方式下組合梁抗彎承載力的簡化計算方法。 研究結果表明:環氧樹脂膠結組合梁的破壞模式為剪彎段GFRP板沿縱向剪切破壞, 栓釘連接組合梁的破壞模式為典型的彎曲破壞; 栓釘連接件較環氧樹脂膠層表現出更高的界面剪切剛度; 栓釘連接組合梁的抗彎承載力約為環氧樹脂膠結組合梁承載力的2倍。 In order to investigate the flexural behaviors of beams composed of steel girders and GFRP-concrete composite hollow slabs, three composite beams formed with different connection methods were tested under static load. The connection methods between the steel girders and the GFRP-concrete composite slabs were based on epoxy resin adhesive and shear studs for 3 specimens, respectively. The feasibilities of the aforementioned connection methods for interfacial connectors of the composite beams were verified by the comparison of change laws of sectional strain, mid-span deflections and interfacial slips of different specimens. Based on the failure modes for the tested specimens with different connection methods, a simplified calculation method was proposed to analyze the flexural capacity of the composite beams connected by shear studs. The results show that the composite beam connected by epoxy resin adhesive fails in shear fracture of GFRP plate along the length of the beam. While the composite beams connected by shear studs fail with the typical bending failure mode. The shear stud connectors exhibit higher interfacial shear stiffness than epoxy resin adhesive layer. The ultimate load-carrying capacity of the beam connected by shear studs is about twice of that of the beam connected by epoxy resin adhesive.