FRP-钢夹层复合管混凝土桥墩轴压承载力试验

为改善现有钢管混凝土不耐腐蚀以及FRP约束钢管混凝土施工复杂的缺点,提出一种新型组合构件:FRP-钢夹层复合管混凝土.为探究其受力性能,进行了FRP-钢夹层复合管混凝土柱式桥墩轴压试验研究,并与FRP约束钢管混凝土以及钢管混凝土进行对比,分析3种结构形式的受力性能和破坏模式.试验结果表明:钢管混凝土短柱因含钢率较低而发生剪切破坏,而FRP-钢夹层复合管混凝土短柱与FRP约束钢管混凝土短柱由于外部FRP的附加约束作用均产生腰鼓型破坏; FRP约束钢管混凝土短柱树脂基体被挤压破碎,而FRP-钢夹层复合管混凝土短柱由于夹层的存在未发生树脂基体的挤压破碎;与FRP约束钢管混凝土短柱相比,由于夹层灌浆料的作用,FRP-钢夹层复合管混凝土短柱承载力提高35.3%,极限变形提高22.5%.此外,在现有钢管混凝土和FRP约束混凝土承载力计算公式基础上得到了FRP-钢夹层复合管混凝土短柱的承载力计算公式,计算结果与试验值吻合良好.

FRP-interlayer-steel tube concrete column piers under axial compression

To improve the corrosion resistance of concrete-filled steel tubular column (CFST) and construction inconvenience of FRP-steel tube concrete column (FSCC), a novel composite member is proposed, namely, FRP-interlayer-steel tube concrete column (FIST). In this paper, axial compression tests on FIST, FSCC and CFST were conducted to investigate the failure modes and the loading process. The experimental results indicated that the failure mode of FIST and FSCC was waist drum failure owing to the confinement of FRP, which is different from the shear failure mode of CFST resulting from low steel ratio. Compared with FSCC, whose resin matrix was crushed, FIST avoided this due to the existence of the interlayer. The bearing capacity and ultimate deformation of FIST increased by 35.3% and 22.5% respectively, higher than that of FSCC also owing to the interlayer. The design equation of the bearing capacity of FIST was proposed from the equations of the bearing capacity of CFST and FSCC. Calculations and test results showed good agreement.