大尺寸高轴压比钢筋混凝土短柱剪切-粘结破坏试验研究

Experimental study on shear-bond failure of large-scale reinforced concrete short columns with high axial compression ratio

剪切-粘结破坏是钢筋混凝土柱的一种重要的震害形式,为研究大尺寸钢筋混凝土短柱在高轴压比下的剪切-粘结破坏性能,采用40 000kN的大型加载设备对2个横截面为700×700的钢筋混凝土短柱进行了低周反复加载试验,研究试件的破坏过程、滞回特性、承载能力和耗能能力等抗震性能,并进行了影响因素分析。结果表明:试件发生剪切-粘结破坏,耗能能力较低;试件J-0.4,J-0.6的峰值荷载基本相同;为了避免短柱发生剪切-粘结破坏,依据试验结果认为《混凝土结构设计规范》(GB 50010—2010)规定的每侧纵筋配筋率不大于1.2%的设定值偏高。

Shear-bond failure of reinforced concrete columns is a common form of the earthquake damage.In order to study the behavior of shear-bond failure of large-scale reinforced concrete short columns with high axial compression ratio,two 700×700 reinforced concrete short columns were test under low cycle reversed loading by using 40 000 kN loading system.The seismic behaviors including the failure characteristic,hysteretic behavior,shear capacity and energy dissipation were studied,and the influence factors were analyzed.The results show that the short columns occur shear-bond failure,energy dissipation capacity of the specimen is poor,and the shear bearing capacity of specimen J-0.4 is approximately equal to the specimen J-0.6.In order to avoid shear-bond failure of short columns,according to the test results,it shows that the longitudinal reinforcement ratio of each side is not greater than 1.2%in Code for design of concrete structures(GB 50010—2010)is a little bit higher.