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纤维增强聚合物(Fiber Reinforced Polymer,FRP)管环向约束超高性能混凝土(Ultra-high Performance Concrete,UHPC)结构是一种性能优越的新型组合结构形式.对4个无约束对比试件,4种FRP种类、3个纤维布缠绕层数共计36个约束试件进行了轴心受压试验,分析了FRP种类和纤维布层数对约束UHPC试件轴压性能的影响规律.结果显示:FRP约束能够有效提高UHPC试件的强度和极限应变;膨胀比率在加载初期约等于未约束UHPC的泊松比,当FRP充分发挥作用后膨胀比率趋于定值,但大于普通混凝土;峰值应变受约束刚度和FRP管断裂应变的影响较大.将实测应力-应变曲线与目前有代表性的FRP约束混凝土本构模型进行了比较,提出了一种新的FRP管约束UHPC应力-应变关系模型,结果表明新模型能更精确地预测约束试件的极限状态和应力-应变关系.
Fiber Reinforced Polymer (FRP) The UHPC tubular structure is a new type of composite structure with superior performance. For 4 unconstrained comparison specimens, 4 The results of FRP type, the number of layers of three fiber cloths and the total number of 36 constrained specimens under axial compression were analyzed, and the influence of FRP type and number of fiber layers on the axial compression properties of UHPC specimens was analyzed. The restraint can effectively increase the strength and ultimate strain of UHPC specimens. The expansion ratio is approximately equal to the Poisson’s ratio of unconfined UHPC at the initial stage of loading. When the FRP fully exerts its effect, the expansion ratio tends to be fixed but larger than that of ordinary concrete. The peak strain is restrained Stiffness and FRF pipe fracture strain.Comparing the measured stress-strain curve with the existing representative constitutive model of FRP-constrained concrete, a new FRPC-constrained UHPC stress-strain model is proposed, and the results It shows that the new model can predict the ultimate state and the stress-strain relationship of the constrained specimens more accurately.