部分包覆钢-轻骨料混凝土组合长柱轴压性能研究

An Investigation on the Axial Compressive Behavior of Partially Encased Composite Steel and Lightweight Aggregate Concrete Long Columns

部分包覆钢-轻骨料混凝土组合长柱的自重较部分包覆钢-普通混凝土组合长柱的自重可减少15%以上,在装配式建筑中的应用前景广阔。为研究其轴压性能,建立了有限元分析模型,并在现有试验验证有限元模型可靠的基础上,对比分析了轻骨料混凝土与普通混凝土的材料属性及构件力学性能的差异。结果表明,采用相同强度的普通混凝土组合长柱的承载力预测轻骨料混凝土组合长柱的承载力是偏于危险的。之后,研究了轴压作用下该构件的全过程受力机理和破坏模式,探讨了材料强度、长细比、含钢率等参数对构件轴压性能的影响规律,验证了现有规程对计算该类组合长柱轴压承载力的适用性。研究成果可为部分包覆钢-轻骨料混凝土组合构件的理论研究和设计提供参考。

The self-weight of partially encased composite steel and lightweight aggregate concrete(PELC)columns is 15%lower than that of partially encased composite(PEC) columns,so PELC columns have a wide application in prefabricated buildings. To investigate the axial compressive behavior of PELC columns,finite element analysis models are built. For the verification of the finite element model by using the existing test data,the material properties of lightweight aggregate concrete and regular concrete,and the mechanical properties of PELC and PEC are compared. The results show that it is not safe to predict the bearing capacity of PELC columns with that of the PEC columns whose concrete strength is same. Then the stress and failure modes are analyzed.Also,this paper discussed the influence of strength of materials,slenderness ratio and steel ratio on the axial bearing capacity and deformation ability of PELC columns. In addition,the applicability of the existing procedures for calculating the axial compression capacity of long columns is verified. The research results can provide a reference for the theoretical research and design of PELC members.