聚对苯二甲酸乙二醇酯纤维布约束中空夹层钢管混凝土柱轴压性能试验研究

Experimental study on axial loading behavior of hollow concrete-filled double skin steel tubular wrapped with PET

进行了聚对苯二甲酸乙二醇酯纤维(PET)和碳纤维(CFRP)布约束中空夹层管混凝土柱的轴心受压试验研究。主要试验参数包括外包材料种类(PET、CFRP)、外钢管厚度、内钢管直径以及外钢管是否开孔等。试验结果表明:外包PET柱较对应外包CFRP柱的极限荷载平均提高了14.71%,极限位移平均提高了104.73%,表明PET在对中空夹层钢筋混凝土轴压承载力及延性的贡献上较CFRP更为明显。在试验的基础上分析了PET和CFRP对构件轴压承载能力及延性的提升效果,可得出外包PET或CFRP均能显著提高结构的轴向承载力和延性的结论,其中PET效果更好。最后结合现有的双层薄壁钢管混凝土柱及FRP外包混凝土柱的承载力计算模型,提出了CFRP/PET环包中空夹层钢管混凝土构件的轴压承载力计算模型,并通过与试验结果的对比验证了模型的准确性。

The experimental studies were carried out on the axial loading performance of PET( polyethylene terephthalate) and CFRP( carbon fiber reinforced polymer) confined double-skin concrete-filled steel tubular( CFST)columns. The main test parameters were warping materials( PET or CFRP),thickness of outer steel plate,diameter of inner steel plate and whether or not the outer steel plate had holes. Compared with CFRP,PET wrapped columns' average enhancement ratio of ultimate load was 14. 71%,and that of ultimate displacement was 104. 73% which means that the contribution of PET on axial load bearing capacity and ductility of CFST are more obvious than CFRP's. On the basis of experiment,the enhancement effect on axial load bearing capacity and ductility of CFRP or PET were analyzed,and it's concluded that wrapping CFRP or PET both can enhance structural axial load bearing capacity and ductility significantly,and PET makes it better. Based on the combination of current design models for CFST columns and FRP warped concrete columns,a new design model for predicting the strength of PET or CFRP warped CFST columns was proposed and accuracy of the design model is verified by the test results.