CTRM加固震损短肢剪力墙连梁抗弯性能研究

Research on the Flexural Behavior of Seismic Damaged Short-Limb Shear Wall Coupling Beams Reinforced with CTRM

制作了2个缩尺比例为1:3的“T”字型带连梁短肢剪力墙试验模型,先对两模型施加低周往复荷载,使连梁在端部发生不同程度的预损,即在节点处连梁产生不同程度的弯曲破坏,在不卸除墙体轴力的情况下,用碳纤维网增强的高性能复合砂浆(CTRM)对梁根部破坏部位进行抗弯加固,再施加低周往复荷载,探究加固后短肢剪力墙连梁的抗弯承载力、抗裂性、刚度、延性及耗能能力。试验研究结果表明:采用CTRM加固震损短肢剪力墙连梁是一种有效的加固方法,与原结构相比,加固层使震损的梁端或墙梁节点处抗震性能得到了恢复甚至提升,且震损程度越轻,提升越明显。最后对加固前后的试验模型进行了有限元分析,有限元分析结果与试验结果较符合,说明所建模型较为可靠。

Two test models of T-typed short-limb shear wall coupling beam in a scale ratio of 1:3 have been designed and fabricated.Firstly,low cycle reciprocating load is applied to the two models so as to make the coupling beams suffer different degrees of pre-damage at the end,i.e.,the coupling beams experience different degrees of bending failure at the joints.Under the condition of not removing the axial force of the wall body,high performance composite mortar(CTRM)reinforced by carbon fiber mesh is used to strengthen the bending resistance of the damaged part of the beam root,with the low cycle reciprocating load applied to explore the flexural bearing capacity,crack resistance,stiffness,ductility and energy dissipation capacity of the reinforced short-leg shear wall coupling beam after reinforcement.The experimental results show that CTRM is a very effective method to strengthen the coupling beam of short-limb shear wall coupling beams;compared with the original structure,the seismic performance of the damaged beam ends or wall-beam joints can be well restored or even improved by the reinforcement layer;the lighter the earthquake damage is,the more obvious its improvement will be.A further finite element analysis has been carried out of the test model before and after reinforcement,with its results in good agreement with the test results,indicating that the finite element analysis model is characterized with a good reliability.