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采用单搭接头剪切试验比较FRP-混凝土界面使用不同树脂黏结剂在不同浸水时长下的剪切黏结强度、破坏模式、剪切断裂能、黏结滑移曲线等黏结特性。最大6个月的20℃浸水试验表明,采用多乙烯多胺混合硬化树脂的界面黏结强度降低了11%～14%,采用多胺硬化树脂的界面黏结强度降低了2%～10%,黏结层断裂能和局部最大剪应力也有所降低。浸水后的界面破坏模式由浸水前的混凝土黏聚层转移为界面黏着层,这表明浸水条件下界面黏着力降低。同时,树脂黏结材料的材料试验结果表明,树脂本身的抗拉强度在浸水6个月后有所提升,而剪切黏结强度只有微小降低。局部黏结滑移关系的计算结果表明浸水后最大局部剪切应力有所降低,同时界面的平均剪切断裂能降低26%。
The shear bond strength, failure mode, shear fracture energy and bond slip curve of FRP-concrete interface with different resin binders at different immersion time were compared by single-ended shear test. The maximum immersion test at 20 ℃ for 6 months showed that the interfacial adhesion strength of multi-ethylene polyamine mixed hardened resin decreased by 11% -14%, the interfacial bonding strength of polyamine-hardened resin decreased by 2% -10%, the adhesive layer Fracture energy and local maximum shear stress also decreased. The interface failure mode after immersion is transferred from the pre-soaked concrete cohesive layer to the interfacial adhesive layer, which indicates that the interfacial adhesion decreases under soaking conditions. At the same time, the test results of the material of the resin bonding material show that the tensile strength of the resin itself is improved after 6 months immersion, and the shear bond strength is only slightly reduced. The calculation results of the local bond-slip relationship show that the maximum local shear stress decreases after soaking, and the mean shear fracture energy at the interface decreases by 26%.