新型结构胶加固桥梁的性能研究

Study on the Performance of New Structural Adhesive for Strengthening Bridges

通过室内试验研究了新型纤维增强结构胶加固前后交通荷载对钢筋混凝土桥梁性能的影响。8根横梁被测试为失效。其中7根梁用一种代表实际桥梁所用材料的预制单向碳纤维层压板加固。试验变量包括环氧固化期间施加荷载循环的强度和频率、环氧层厚度和FRP带厚度。所有加固试件在最大弯矩区均发生FRP脱粘破坏。对于安装期间和安装后应用的所有交通荷载方案,未观察到加固效果降低。采用ACI 440.2R-02设计建议,对失效时的FRP应变和FRP引起的强度增加进行了非保守预测。

In this paper,the influence of the traffic load on the performance of reinforced concrete bridges before and after the reinforcement of the new fiber-reinforced structural adhesive is studied through indoor experiments.Eight beams were tested to failure.Seven of the beams were strengthened with a prefabricated unidirectional carbon fiber laminate that represents the material used in the actual bridge.Test variables included the intensity and fre⁃quency of load cycles applied during the epoxy-curing period,the thickness of the epoxy layer,and the thickness of the FRP strip.All the reinforced specimens have FRP debonding failure in the maximum bending moment zone.For all of the traffic load regimens applied during and after installation,no reduction in the effectiveness of the strength⁃ening was observed.Use of ACI 440.2R-02 design recommendations,non-conservative predictions of FRP strain and FRP-induced strength increase at failure are made.