碳纤维增强复合材料(CFRP)筋常以环氧树脂胶为传力介质应用于建筑工程中。通过分析CFRP筋-环氧树脂胶界面黏结应力的组成及其影响因素,采用拔出试验对两种直径的压纹CFRP筋与环氧树脂胶界面最大黏结应力τmax及临界黏结长度lcr(小于该长度时测得平均黏结应力可认为等于τmax)以及界面压应力对黏结性能的影响,界面的破坏模式,拔出力-滑移量关系曲线进行研究,并提出了压纹类CFRP筋-环氧树脂胶界面τmax的理论预测模型。结果表明:压纹CFRP筋-环氧树脂胶界面lcr值远小于CFRP筋-混凝土界面;CFRP筋直径的大小对界面的破坏模式和拔出力-滑移量的力学关系有较大影响;界面压应力大小对界面τmax值影响较大。
Carbon fiber reinforced plastic(CFRP) tendons have been widely used in the construction engineering combine with the load transmission medium of epoxy resin.The composition of the bond stress of CFRP tendon-epoxy resin interface and its influencing factors were analyzed,and the maximum bond stress of τmaxof interface corresponding to critical bond length(lcr) with spirally indented surface condition tendons of different diameters were tested through pullout test,the average bond stress of the interface could be considered as equal to τmaxif the bond length was no more than the critical bond length.The effect of interface compressive stress on bonding properties,the failure modes of the interface,and the pullout load-slip curves were also studied,a theoretical prediction model for ambossing CFRP tendon-epoxy resin intertface was also proposed.The results showed that the lcrof the CFRP tendonepoxy resin was far less than the CFRP tendon-concrete's.The diameter of tendon had greater effect on the failure mode and pullout load-slip curve,and the interface compressive stress had the greater effect on the value of τmax.