配置组合封闭箍筋叠合框架梁端抗震性能试验

Experimental Study on Seismic Performance of Composite Concrete Frame BeamEnds With TwoPiece Closed Stirrups

摘要:

通过6个试件的低周反复加载试验，研究了配置HRB500纵筋和组合封闭箍筋的叠合混凝土框架梁端的破坏形态、滞回曲线、骨架曲线、延性等抗震性能以及极限承载能力.结果表明：叠合试件的叠合面和根部结合面出现开裂和滑移，其滞回曲线捏拢，耗能、极限承载力和位移延性系数均小于整浇试件；叠合试件的位移延性系数为3.6～4.5；叠合试件与整浇试件的极限承载力之比平均为0.90，但与按规范GB 50010—2010得到的计算值之比平均为1.31；达到极限承载力前，各试件的高强纵筋和斜拉破坏试件的箍筋均能受拉屈服；配箍形式和根部结合面类型对叠合试件的抗震性能和极限承载力影响不大.

Abstract:

Six concrete frame beamends were tested under low frequency cyclic loading. The seismic behaviors of the specimens with HRB500 highyieldstrength longitudinal rebars and twopiece closed stirrups were analyzed including failure mechanism, hysteretic behavior, skeleton curves, drift ductility and bearing capacity. The results show that the beamend interface and the horizontal interface of composite beam crack and slip，which results in the pinching of hysteretic loops. At the meantime, the energy dissipation capacity and the bearing capacity of the composite beams are smaller than the castinsitu one. Moreover, the displacement ductility factor of specimens is from 3.6 to 4.5. The bearing capacity of composite beams is similar to the castinsitu one, the average ratio of two is 0.90. However, the ratio of composite beams’ ultimate bearing capacity is 1.31 times of that calculated by the code GB 50010—2010. The specimens’ longitudinal rebars yield before the peak load, and the stirrups of the specimens which are subjected to the diagonaltension failure also yield. The effect of stirrup arrangement and beamend interface type on displacement ductility and bearing capacity is not obvious.