PC结构混凝土柱抗震性能试验研究

Experimental Study on Seismic Performance of Precast Concrete Column

针对PC框架结构节点区施工复杂、震后柱叠合面处混凝土易开裂的问题,提出了一种梁柱节点预制的PC结构,该结构将薄弱区由节点转移到框架柱的中部。为了研究此类PC柱的抗震性能,设计并完成了一个足尺PC柱与现浇混凝土对比柱的拟静力试验,得到了2个试件的破坏形态、滞回曲线、骨架曲线、位移延性、耗能能力以及极限承载力。结果表明,PC柱和现浇柱均为弯曲破坏;PC柱极限承载力比现浇柱高6.1%;刚度退化规律大致相同,PC柱的初始刚度和极限刚度分别为现浇柱的1.30倍和0.93倍;PC柱的延性系数为现浇柱的1.47倍;2个试件耗能能力基本相同。综上可知,此类PC柱和现浇注的抗震性能相近,且施工方便、节能环保,是一种值得推广的装配式结构连接形式。

In view of the complicated construction of the joint region of the precast concrete structures(PC structures)and the serious cracks of the post-earthquake combined interface of the columns,a new precast concrete beam-column joint is developed,which transfers the weak region from the joint region to the middle of the column.To study the seismic performance of the structure,two full-scale columns were prepared and tested under cyclic lateral load.One column was cast-in-situ and served as a control specimen,the other was precast.Based on the failure modes,the hysteretic curves,the envelop curves,the ductility coefficient,the energy dissipation capacity and the ultimate bearing capacity of the two specimens were discussed in detail.The results show that the failure mode of the two specimens is bending failure.The ultimate bearing capacity of PC column is 6.1%higher than that of cast-in-situ column.The stiffness degradation is roughly in the same law.The initial stiffness and the ultimate stiffness of PC column are 1.30 and 0.93 times that of cast-in-situ column,respectively.The ductility coefficient of PC column is 1.47 times that of cast-in-situ column.The two specimens have the same energy dissipation capacity.In summary,PC column and cast-in-situ column have the similar seismic performance,and the construction is convenient,energy saving and environmental protection.The assembled structure connection form is worth to be promoted.