高强CFRP筋/钢筋混凝土梁柱节点的抗震性能试验研究

Experimental study on seismic behavior of high strength CFRP bars/reinforced concrete beam column joints

为了增强梁柱节点的抗震性能,共设计了6组高强碳纤维增强复合筋(CFRP筋)/钢筋混凝土梁柱节点试件,研究了有无CFRP筋、轴压比、配箍率和混凝土强度对梁柱节点试件破坏形态和抗震性能的影响。结果表明,6组高强CFRP筋/钢筋混凝土梁柱节点试件的破坏形式都为梁端弯曲破坏,滞回曲线呈“弓形”和“梭形”,未添加CFRP筋的GJ1试件的滞回曲线饱满程度相对其他试件要低;CFRP筋有助于提升梁柱节点试件的承载力和屈服后刚度,节点配箍率和轴压比对节点试件的承载力影响较小,使用聚乙烯纤维砂浆(PE-ECC)和C30混凝土会降低节点试件的承载力;6组梁柱节点试件的位移延性系数都大于3,低轴压比、高节点配箍率、局部使用PE-ECC和使用低强度C30混凝土有助于提升节点试件的延性和耗能能力。

In order to enhance the seismic performance of beam column joints,six groups of high-strength carbon fiber reinforced composite bars(CFRP bars)/reinforced concrete beam column joints are designed,the effects of CFRP bars,axial compression ratio,stirrup ratio and concrete strength on the failure mode and seismic performance of beam column joints are studied.The results show that the failure forms of six groups of high-strength CFRP bars/reinforced concrete beam column joint specimens are beam end bending failure,the hysteretic curve is"bow"and"shuttle",and the fullness of the hysteretic curve of CJ specimen without CFRP bars is lower than that of other specimens;CFRP bars helps to improve the bearing capacity and post yield stiffness of beam column joint specimens.The stirrup ratio and axial compression ratio have litle ffect on the bearing capacity of joint specimens.The bearing capacity of joint specimens will be reduced by using polyethylene fiber mortar(PE-ECC)and C30 concrete;The displacement ductility coefficients of the six groups of beam column joint specimens are greater than 3.Low axial compression ratio,high stirrup ratio,local use of PE-ECC and low-strength C30 concrete are helpful to improve the ductility and energy dissipation capacity of the joint specimens.