表层嵌入混合FRP筋的连续梁弯曲性能与影响因素
Flexural properties and influence factors of continuous RC beam strengthened with near-surface mounted mixing FRP tendons

通过4根表层内嵌入不同FRP筋加固连续梁试件的静载试验,研究了试验梁的弯曲性能,借助通用有限元分析软件分析了影响试验梁承载力的混凝土强度、初始荷载、FRP筋弹性模量与配纤率等因素。分析结果表明:FRP筋与混凝土之间未发生剥离破坏,加固效果显著; 与未加固梁相比,加固梁屈服荷载与极限荷载提高幅度分别可达31%、56%; 随着混凝土强度、FRP筋弹性模量与含纤率的提高,加固梁屈服荷载与极限荷载提高幅度分别可达38%、17%; 随着初始荷载的增大,加固梁屈服荷载与极限荷载降低幅度分别可达6%和24%; 试验梁屈服荷载模拟值与试验值的平均比值为0.969,极限荷载模拟值与试验值的平均比值为0.962,钢筋屈服时跨中挠度模拟值与试验值的平均比值为1.104,梁破坏时跨中挠度模拟值与试验值的平均比值为1.024,荷载-挠度模拟曲线与试验曲线走势基本一致,这说明有限元分析结果与试验结果吻合较好,有限元法可以较好模拟试验梁的力学性能。
The flexural properties of four continuous reinforced concrete(RC)beams strengthened with near-surface mounted(NSM)mixing fiber reinforced polymer(FRP)tendons were studied by static test. The influence factors of bearing capacities of test beams were analyzed by finite element analysis(FEA)software, such as strength of concrete, initial load, elastic modulus and content of FRP tendons. Analysis result indicates that the reinforcement effect without debond between FRP tendons and concrete is significant. Compared with unstrengthened RC beam, the yield load and ultimate load of strengthened RC beam can increase by 31% and 56% respectively. When concrete strength, elastic modulus and content of FRP tendons increase, the yield load and ultimate load can increase by 38% and 17% respectively. When initial load increases, the yield load and ultimate load can decrease by 6% and 24% respectively. For test RC beams, the mean ratio of simulation and test values for the yield load is 0.969, 0.962 for the ultimate load, 1.104 for the midspan yield deflection, 1.024 for the midspan destructive deflection, and the trends of simulation load-deflection curves are basically consistent with test curves, so FEA result is in good agreement with test result, and FEA can accurately simulate the mechanical properties of test beam. 4 tabs, 18 figs, 22 refs