配置500MPa钢筋套筒灌浆连接预制混凝土柱抗震性能试验研究

Experimental research on seismic performance of precast concrete columns with 500 MPa reinforcements splicing by grout-filled coupling sleeves

试验中设计了6个钢筋套筒灌浆连接预制混凝土柱和2个现浇混凝土柱,对其进行低周反复加载试验,其中配置的纵筋和箍筋均为500 MPa钢筋,研究了预制柱的破坏形态、滞回曲线、骨架曲线、位移延性、耗能能力以及承载力,分析了轴压比、配箍形式和灌浆料强度对其抗震性能的影响。研究结果表明:预制柱的位移延性、耗能能力和承载力均与现浇柱相近;预制柱套筒区形成刚域,套筒顶部破坏最为严重;轴压比较小的预制柱,其柱根部灌浆层结合面发生破坏,且滞回曲线会出现捏拢;轴压比较大的预制柱在保护层剥落后,出现核心区混凝土压碎破坏;预制柱的位移延性系数的均值仅为2.20,但极限位移角的均值可达1/31。

Low frequency cyclic loading tests were conducted on six concrete columns with reinforcements splicing by grout-filled coupling sleeves and two cast-in-situ concrete columns,in which the nominal yield strength of longitudinal reinforcements and stirrups were both 500 MPa. Failure patterns,hysteretic curves,skeleton curves,displacement ductility,energy dissipation capacity and bearing capacity were analyzed. The influences of axial compression ratio,arrangement of stirrups and strength of grouting material on the seismic behavior were also investigated. The research results show that the displacement ductility,energy dissipation capacity and bearing capacity of the precast concrete columns are similar to those of cast-in-situ concrete columns. Meanwhile,sleeves of precast concrete columns have formed the rigid zone,top of which is seriously damaged. The interface of precast concrete columns with low axial compression ratio is also destroyed,which results in the obvious pinching of hysteretic loops. For the precast concrete columns with high axial compression ratio,the core concrete will also be crushed after the spalling of the concrete cover. The average value of displacement ductility coefficient for precast concrete columns is merely 2. 20,but that of ultimate displacement drift ratio is up to 1 /31.