圆钢管约束型钢再生混凝土短柱抗震性能

Seismic performance of circular steel tube confined steel reinforced recycled concrete short columns

针对圆钢管约束型钢再生混凝土短柱的抗震性能进行研究,在验证了分析模型合理性的前提下,考虑了圆钢管径厚比、再生粗骨料取代率和轴压比等设计参数对试件力学性能的影响规律,获取了试件滞回曲线、骨架曲线、延性系数、等效黏滞阻尼系数等抗震性能指标和试件的峰值承载力,并与已有试验进行了对比分析。结果表明:在再生混凝土取代率、轴压比、含钢率等参数基本相同时,圆钢管约束型钢再生混凝土短柱比型钢再生混凝土柱和圆钢管型钢再生混凝土柱表现出更好的变形和耗能能力;再生粗骨料取代率对滞回曲线等抗震性能指标影响不大,可基本满足工程抗震要求,并可广泛应用于工程的承重结构中;在取代率和轴压比相同时,随着径厚比的增大,试件弹性阶段初始刚度、峰值承载力和耗能能力逐渐下降,但延性会有一定幅度的提升,延性变形能力可提高30%~40%;在取代率和径厚比相同时,随着轴压比的增大,试件的峰值承载力和耗能能力变化不大,延性越来越差。

The seismic performance of circular steel tube confined steel reinforced recycled concrete short columns was studied.On the premise of verifying the rationality of the analysis model,the influence of design parameters such as diameter-thickness ratio of circular steel tube,replacement rate of recycled coarse aggregate and axial compression ratio on the mechanical properties of the specimens was considered.The seismic performance indexes such as hysteresis curve,skeleton curve,ductility coefficient,equivalent viscous damping coefficient and the peak bearing capacity of the specimens were obtained and compared with the existing tests.The results show that when the parameters such as the replacement ratio of recycled concrete,axial compression ratio and steel ratio are basically the same,the circular steel tube confined steel recycled concrete short column shows better deformation and energy dissipation capacity than the steel recycled concrete column and the circular steel tube steel recycled concrete column.The replacement rate of recycled coarse aggregate has little effect on the seismic performance index such as hysteresis curve,which can basically meet the seismic requirements of the project and can be widely used in the bearing structure of the project.When the replacement rate and axial compression ratio are the same,with the increase of diameter-thickness ratio,the initial stiffness,peak bearing capacity and energy dissipation capacity of the elastic stage of the specimen gradually decrease,but the ductility will be improved to a certain extent,and the ductility deformation capacity can be increased by 30%-40%.When the replacement rate and the diameterthickness ratio are the same,with the increase of the axial compression ratio,the peak bearing capacity and energy dissipation capacity of the specimens do not change much,and the ductility is getting worse and worse.