钢管钢纤维高强混凝土短柱轴压力学性能试验研究

Experimental research on axial compressive mechanical behavior of steel fiber reinforced high strength concrete filled steel tube short columns

为探讨钢管钢纤维高强混凝土短柱的轴压力学性能,对8根钢管钢纤维高强混凝土短柱和4根钢管高强混凝土短柱进行了轴压试验,主要考察了钢纤维掺量、含钢率、钢材强度对其力学性能的影响。结果表明:含钢率与钢材强度较高时,掺钢纤维对钢管高强混凝土力学性能几乎没有影响;含钢率与钢材强度较低时,随钢纤维掺量增加,试件由剪切型破坏演变为腰鼓型破坏;试件表面局部破坏逐渐减弱,峰值点后承载力趋势下降减缓,塑性变形能力与延性性能明显提升;掺钢纤维对钢管钢纤维高强混凝土承载力贡献不明显,其轴压承载力可按普通钢管混凝土轴压承载力计算方法进行计算。

In order to investigate the axial compressive mechanical behavior of steel fiber reinforced high strength concrete filled steel tube(SFRHCFST)short column,8 SFRHCFST short column specimens and 4 high strength concrete filled steel tube short column specimens were experimentally studied under axial compression load.The content of steel fiber,steel ratio and steel strength were all considered as experimental parameters.When the steel ratio and the teel strength are high,the addition of steel fiber has little effect on the mechanical behavior of SFRHCFST short columns;when the steel ratio and the steel strength are low,as the steel fiber content increases,the specimen evolves from shear failure to a waist-drum failure.The local damage on the surface of the specimen gradually weakened,the bearing capacity trend decreased after the peak point,and the plastic deformation ability and ductility performance were significantly improved.It has also been found that the addition of steel fibers has slight contribution to axial bearing capacity of SFRHCFST short columns,thus the axial bearing capacity calculation method of ordinary concrete filled steel tube is applied to SFRHCFST.