中文摘要：

对钢骨-方钢管自密实高强混凝土短柱的轴压力学性能进行了试验研究和理论分析。通过13根短柱试件的轴压试验，研究了混凝土的强度、方钢管的宽厚比和型钢的用量等因素对该组合柱受力性能的影响。试验结果表明，方钢管、混凝土和钢骨的协同工作使该组合柱具有很高的承载力和很好的延性，其中方钢管的宽厚比是影响核心混凝土强度提高的主要因素，而混凝土的强度、方钢管的宽厚比和型钢的用量等因素对构件延性的提高均具有显著影响。在试验研究的基础上提出了核心约束混凝土的应力-应变模型，并利用该模型对钢骨-方钢管自密实高强混凝土轴心受压短柱的荷载-轴向变形关系曲线进行了计算，计算得到的极限承载力和峰值荷载后的变形规律均与试验结果吻合良好。该模型还可用于抗震结构中组合柱弯矩-曲率关系曲线的分析。

英文摘要：

The mechanical behavior of a new type of composite column, composed of square steel tube filled with steel-reinforced self-compacting high-strength concrete and subjected to axial compressive load, is investigated through experimental study and theoretical analysis. Thirteen specimens of short columns were tested under axial compression. Effects of the concrete strength, the width-to-thickness ratio of the tube, and the steel ratio of the skeleton p,, on the behavior of the composite column are discussed. The results show that the composite columns are of high strength and ductility due to the concerted actions of the steel tube, the concrete and the steel skeleton. The width-to-thickness ratio of the tube has the most significant effect on the increase of the strength of the core concrete, while the concrete strength, the width-to-thickness ratio of the tube, and the steel ratio of the skeleton ρ, have significant effects on the increase of the ductility of the columns. Based on the experimental results, a stress-strain model for confined core