玄武岩纤维-箍筋复合约束混凝土柱的轴压试验研究

PERFORMANCE OF CONCRETE CONFINED WITH STEEL SPIRALS AND BFRP UNDER AXIAL COMPRESSION

通过21根圆形截面玄武岩纤维(BFRP)-箍筋复合约束混凝土柱的轴压试验,研究玄武岩纤维层数、箍筋的间距对约束混凝土柱的轴压性能影响。试验结果表明,玄武岩纤维-箍筋复合约束混凝土的轴压性能明显优于单一材料(玄武岩纤维或箍筋)约束的混凝土,随着玄武岩纤维层数的增加以及箍筋间距的减小,玄武岩纤维-箍筋复合约束混凝土试件的承载能力和变形能力有效提高。玄武岩纤维-箍筋复合混凝土试件的应力-应变曲线可分为弹性阶段、过渡阶段、强化阶段及残余阶段4个阶段。基于本文及相关文献的试验研究结果,提出纤维-箍筋复合混凝土圆柱的承载能力计算模型,对比表明该模型与试件结果吻合较好。

A total of 21 specimens was tested under axial compression to investigate the performance of the concrete columns externally confined with the fiber-reinforced polymer（ FRP） and internally confined with steel spirals.The main experimental parameters of the experiment were the number of FRP layers and the spacing of the steel spirals. The test results show that performance of the FRP-steel-confined concrete columns is superior to that with only one confining material（ FRP or steel）. With the increase in the number of BFRP layers or the confinement ratio of steel spirals,the bearing capacity and deformation ability of the specimens increase accordingly. Longitudinal stressstrain curves of FRP-steel-confined concrete specimens consist of four stages of elastic stage,transition stage,hardening stage and residual stage. Based on the test results in this study and previous literature,the bearing capacity calculation model was proposed. The comparisons show that the predicted results are in good agreement with the experimental values.