端部锚固对温度作用下CFRP-混凝土界面黏结行为影响

为了明确端部锚固措施对碳纤维复合材料(CFRP)-混凝土界面黏结行为的影响,采用解析理论手段建立了温度作用下端锚CFRP-混凝土界面剥离全过程理论模型.结合常温界面黏结理论,引入双线性黏结-滑移本构,推导了界面滑移、界面剪应力以及CFRP正应力分布表达式,给出了界面荷载-滑移响应及界面剥离承载力模型,通过与试验和数值结...

Effect of end anchorage on bond behavior of CFRP-to-concrete interface subjected to temperature variation

To reveal the effect of additional end anchorage on the bond behavior of carbon fiber reinforced polymer (CFRP)-to-concrete interface, the debonding process model of CFRP-to-concrete bonded interface subjected to temperature variation was established by means of analytical theory. Based on the interfacial bonding theory and bi-linear bond-slip constitutive, a series of analytical models were deduced, including the distributions of interfacial slip, interfacial shear stress, and CFRP axial stress. The calculation models of load-slip curve and interfacial debonding load were also given. By comparing the experimental and numerical results, the correctness of the analytical models was verified, and parametric analysis was then carried out. Results show that compared with external bonded interface, the end anchorage increased the interfacial debonding load and effectively decreased the interfacial slip and shear stress caused by temperature variation. Besides, CFRP axial stress increased when subjected to the same temperature variation, which enhanced the strength utilization of the CFRP material. For CFRP-to-concrete bonded interface with end anchorage, the bearing capacity of the interface increased with increasing temperature before the temperature reached the glass transition temperature of adhesives. The decreasing temperature led to the premature interfacial debonding at the load end of the bonded interface, which reduced the interfacial bearing capacity. Further, when the thickness or modulus of the CFRP material increased, the effect of temperature variation on the bond behavior was more significant.