表层嵌贴碳纤维板混凝土试件疲劳性能研究

An experimental investigation on the fatigue performance of NSM CFRP strip-concrete interface

为分析表层嵌贴碳纤维板加固钢筋混凝土结构的界面疲劳性能,设计制作了5个表层嵌贴碳纤维板−混凝土试件,采用单剪拔出的方法,研究不同荷载幅值和黏结长度参数对试件界面应变分布、界面滞回性能和界面疲劳耗散能的影响规律。研究结果表明:达到设计疲劳次数的试件,界面剥离过程仅有快速传力阶段和界面稳定传力阶段。而未达到设计疲劳次数的试件有完整的快速传力阶段、界面稳定传力阶段和失稳传力阶段。距加载端14 cm处的板条界面疲劳滞回性能呈现出与静力试验滑移−黏结应力曲线相似性质。同一测点相同疲劳加载次数时,试验荷载幅值由32%增加至40%的过程中,界面损伤程度增大,界面耗散能最大值增大;黏结长度由200 mm增加至280 mm的过程中,界面损伤程度越小,界面耗散能最大值越大。

To research the fatigue performance of the NSM CFRP-concrete interface,5 NSM CFRP-concrete specimens were designed.The simple shear pull-out test was conducted to analyze the influence of the load amplitude and bond length on the interface strain distribution,interface hysteresis performance,and interface dissipation energy.The results show that the interface debonding progress of the specimens,which reached to the designing fatigue cycle,is characterized by the high-speed load transmission period and the stable load transmission period.However,for other specimens,the interface debonding possesses the complete high-speed load transmission period,the stable load transmission period and the unstable load transmission period.The fatigue hysteresis performance,at the position 14 comfrom the load end,shows the similar situation of the slip-stress compared with the static experiment.For the measuring point with the same fatigue loading times,the interfacial damage level and the maximum value of the interfacial dissipation energy increase,when the load amplitude increases from 32%to 40%.the interfacial damage level decreases,the maximum value of the interfacial dissipation energy increases,when the bond length of the specimens increases from 200 mm to 280 mm.