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体外预应力FRP-混凝土组合梁是在体外预应力钢-混凝土组合梁的基础上,分别采用GFRP型材替代型钢、GFRP筋替代钢筋、CFRP筋替代预应力钢筋而形成的一种新型组合梁。开展了体外预应力FRP-混凝土组合梁(分别采用工程中常用的2种抗剪连接方式,即双排FRP开孔板连接件与环氧粘结)在单调静力荷载下的受力性能试验研究。试验表明:2种组合梁的破坏均发生在FRP型材上翼缘与混凝土板的连接界面处,破坏时2种组合梁的混凝土板均未被压碎,CFRP筋的应变值远低于其极限应变;2种组合梁的荷载-跨中挠度曲线均大致为线性;采用环氧粘结的组合梁的最大跨中弯矩为136.5kN·m,对应的梁端截面处FRP型材与混凝土板之间的滑移为0.69mm,相比之下,采用开孔板连接的组合梁的最大跨中截面弯矩为109.7kN·m,此时梁端滑移值则为0.75mm,这是由于双排FRP开孔板连接件的抗剪承载力与抗剪刚度较低所致。试验测得的组合梁极限承载力与参照《钢结构设计规范》(GB50017-2003)的计算值吻合良好。
External prestressed FRP-concrete composite beams are a kind of new-type composite beams formed by replacing prestressed steel-concrete composite beams with GFRP profiles instead of steel bars, replacing GFRP bars with steel bars and replacing CFRP bars with prestressed steel bars. The test of mechanical properties of prestressed FRP-concrete composite beam (using two kinds of shear connection methods commonly used in engineering, namely, double-row FRP perforated plate connector and epoxy bonding) under monotonic static load the study. The test results show that the failure of the two kinds of composite beams occurs at the connection interface between the flange of FRP profile and the concrete slab, and the concrete slabs of the two kinds of composite beams are not crushed when they are damaged. The strain of CFRP tendons is far below the limit Strain. The load-span mid-span deflection curves of both composite beams are almost linear. The maximum inter-span bending moment of epoxy composite beam is 136.5 kN · m. The corresponding FRP profile and concrete slab In comparison, the maximum cross-section bending moment of the composite beam connected by perforated plates is 109.7kN · m, and the beam end slip value is 0.75mm at this time. This is because the double Row FRP perforated plate connectors shear strength and shear stiffness due to lower. The ultimate bearing capacity of the composite beam measured by the test is in good agreement with the calculated value of the “Code for Design of Steel Structures” (GB50017-2003).