在钢筋混凝土(RC)柱中配置核心型钢以提高超高轴压比柱的抗震性能。进行9个核心型钢混凝土(CSRC)柱试件的低周反复加载试验,主要试验参数包括核心型钢配钢率、轴压比和核心型钢截面形式。通过试验数据检验各参数对试件强度、刚度、延性、滞回特性、耗能能力和轴向变形性能等的影响。基于试验结果和平截面假定,研究并提出CSRC柱轴压比限值的简化计算方法。研究结果表明,设置核心型钢可有效提高RC柱的变形能力和滞同耗能能力,提高RC柱的轴压比限值。随核心型钢配钢率的增大,试件强度和刚度衰减速度减缓,耗能能力增加。核心型钢可有效提高重载RC柱弹塑性阶段竖向承载能力的稳定性。计算分析结果表明,根据轴向变形协调计算的CSRC柱轴压比限值与试验吻合较好,可供工程实践参考。提出了考虑核心型钢配钢率的CSRC柱轴压比限值的建议取值。
The seismic behavior of reinforced concrete (RC) columns with high axial load can be improved with core steel set in the central section of the columns. Nine core steel reinforced concrete (CSRC) columns were tested under cyclic loading with core steel ratio, axial compression ratio and section formation of core steel as the main parameters. The effects of these parameters on the strength, stiffness, ductility, hysteretic behavior, energy dissipation capacity and axial deformation behaivor of CSRC columns were investigated using the test results. A simplified method of calculation for the limit value of axial compression ratio of CSRC columns was proposed based on plane section assumption and the test results. It is indicated that the deformation capacity and energy dissipation capacity of RC columns were effectively enhanced and the limit value of axial compression ratio of RC columns was increased when core steel was used. Strength and stiffness deteriorations were reduced and the hysteretic energy dissipation capacity was increased when the steel ratio of specimens was increased. The axial stability of RC columns during plastic deformation phases was remarkably enhanced due to the core steel. The simplified calculation method for the limit value of CSRC column axial compression ratio agreed well with the test results. Limit values of CSRC column axial compression ratio considering core steel ratio were proposed .