钢管自密实混凝土轴压受力机理试验研究

通过钢管混凝土短柱轴压试验,研究不同混凝土强度等级、钢管中部是否开小孔或不同高度的横槽以及不同加载方式对钢管自密实混凝土极限承载力、荷载—变形曲线和荷载—横向变形系数曲线的影响,探究钢管自密实混凝土的轴压受力机理。试验结果表明:当钢管与混凝土轴压同时受荷时,采用不同尺寸的应变片或中部某标距范围内的位移计测试可准确记录钢管的轴向变形;随着混凝土强度等级的提高,钢管自密实混凝土极限承载力不断增大,而剩余承载力基本不变;钢管与混凝土是否同时受荷对极限承载力和剩余承载力影响不大;钢管开小孔,钢管自密实混凝土轴向压缩变形性能减弱,钢管轴向承压能力减弱,而极限承载力和剩余承载力基本不变;钢管开槽,其受力机理发生变化,变形性能减弱,极限承载力降低,钢管更多地参与横向受拉工作。

Experimental Study on the Behavior of Self-Compacting Concrete Filled Circular Steel Tubular Stub Columns

This paper presents an experimental study on the behavior of self-compacting concrete filled circular steel tubular(SCCFST) stub columns concentrically loaded in compression to failure.Test methods on the axial deformation of specimens were compared.Specimens were tested to investigate the effect of compressive strength of concrete,small hole notched,full perimeter direction hole notched with different vertical dimension at steel tube and different loading conditions on the ultimate capacity and the load-deformation behavior of the columns.The behavior of these stub columns for confinement was discussed.Experimental results show that the strain gauges with different dimensions could record the strain of steel tube and electronic displacement transducers with certain gauge length could record the axial displacement of steel tube accurately when the top and base surfaces of specimen was level and the load was applied evenly across the cross-section and simultaneously to the steel and concrete core.For higher compressive cube strength of concrete provided a significant increase in load capacity,but nearly maintained constant in residual capacity after failure.Once the steel tube was notched,deformation ability would be reduced.Sometimes the ultimate capacity also be reduced and the steel tube acts as more transverse confinement than axial compression.