钢管高强再生混凝土柱轴压性能试验研究

为研究钢管高强再生混凝土柱与钢管高强普通混凝土柱轴心受压性能的差异，进行了圆形和方形两种截面形状、高强普通和再生两种混凝土、方钢管内配置与不配置钢筋两种构造的5个钢管混凝土足尺试件轴压性能对比试验。通过试验，分析了混凝土种类、截面形状和配置钢筋对试件承载力、耗能及延性的影响。试验结果表明：钢管再生混凝土柱的损伤发展过程和破坏形态与钢管普通混凝土柱相似；在截面积、含钢率、材料强度相同的条件下，圆形截面试件较方形截面试件具有更高的承载能力和较好的变形能力；混凝土种类对方形截面试件轴心受力性能影响不大；方钢管内配置钢筋可加强对核心混凝土的约束作用，提高试件的承载力和变形性能。根据国内外相关规程对试件的轴压承载力进行了计算，引入尺寸效应影响系数，提出了方钢管混凝土柱承载力计算式，计算结果与试验结果符合较好。

Experimental research on highstrength recycled concrete-filled steel tube columns subjected to axial compression

To study the difference of axial compressive performance of highstrength recycled concrete-filled steel tube(CFST) columns and highstrength normal CFST columns, five specimens were designed to test under axial loading, and the different section shape, concrete type and internal structure were regarded as major variable parameters. Through the experiment, the influence of concrete type, section shape and steel reinforcement cage on the load-bearing capacity, energy dissipation and ductility of the specimens were analyzed. The test results indicate that the damage development and failure mode of recycled concrete-filled steel tube columns are similar to those of normal CFST columns. With the same cross-sectional area, steel ratio and material strength, circular section specimens have higher load-bearing capacity and better deformability than square section specimens. Concrete types have little influence on axial compressive mechanical properties of square section specimens. The steel reinforcement cage inside the square section specimen strengthens the confinement to core concrete, therefore the bearing capacity and deformability are improved significantly. According to the relevant regulations at home and abroad, the ultimate bearing capacity of the specimens were calculated and analyzed. Considering size effect, the bearing capacity calculation formula is proposed for square concrete-filled steel tube columns, and the calculation results agree well with the test results.