薄壁方形钢管再生块体混合短柱轴压破坏研究

Study of Axial Compression Destroy of Thin-Walled Square Steel Stub Columns Filled with Recycled Demolished Concrete Lump

进行了薄壁方形钢管再生块体混合短柱的轴压试验,观察了其破坏形态与变形特征,测得了荷载与应变(或变形)关系曲线.分析了薄壁方形钢管再生块体混合短柱荷载与应变(或变形)关系曲线,探讨了再生块体与新拌混凝土组合层核心混凝土强度对试件受力性能和破坏形态的影响,提出了该种结构构件的理论破坏模型.结果表明:薄壁方形钢管再生块体混合短柱试件主要破坏形态为腰鼓形压皱破坏;在弹性阶段,钢管中截面和角部的应变增长均匀且二者纵向应变增长相对一致;在破坏阶段,不带肋试件呈现软化现象,带肋试件呈现加劲特性.组合层处的核心混凝土强度对试件的力学性能和破坏形态有较大影响.

To reveal axial compressive deformation and failure mode of thin-walled square steel stub columns filled with recycled demolished concrete lump, the tests were taken under axial loading with the result that the failure mode and overall deformation characters were observed and curves of load and strain （or deformation） were obtained. Through the curves of load and strain（or deformation）, and by analysis of the mechanical performance and failure mode influenced by the strength of core concrete in combination layer between recycled demolished concrete lump and green concrete, the theoretical failure model of this structure component was proposed. Test results show that waist drum shape crumple failure is the main failure mode. In the elastic state, each strain growth is uniform in middle section and corner of steel stub, and both of the longitudinal strain growth is also uniform. In destruction stage, no ribbed stiffener specimens take on the ruck building, and ribbed stiffener specimens take on stiffening character. The strength of core concrete in combination layer has greater influence on the mechanical performance and failure mode,