基于有限断裂力学的FRP-混凝土界面粘结强度研究

Bond Strength Analysis of FRP-concrete Interface Based on Finite Fracture Mechanics

为了提供一种精准、高效预测外贴式纤维增强聚合物材料(FRP)粘贴于混凝表面强度的数学模型,本文设计了8个单剪试件,利用精密玻璃珠控制胶层厚度,同时采用真空辅助成型技术(VARI)制作FRP板条并外贴于混凝土试块表面。研究混凝土强度和胶层厚度2种变量参数对FRP-混凝土粘结界面强度的影响,依据试验结果分析了界面破坏能和峰值剪切应力与胶层厚度及混凝土强度之间的联系。采用有限断裂力学获取界面裂纹扩展失稳时的脱粘荷载,将理论值与试验结果对比表明FFM模型有良好的精度。

To explore a precise and efficient mathematical model for predicting the bond strength of externally bonded fiber reinforced polymer（FRP） material to concrete,8 single shear specimens of concrete to FRP were designed in this study by use of precision glass beads to control the adhesive thickness, while adopting vacuum assistant resin infusion process（VARI） to fabricate FRP slab affixed to the concrete surface. Two kinds of impact variable parameters on the interfacial strength of FRP-concrete bond were considered and one was concrete strength and the other was adhesive thickness. According to the experimental results,this paper analyzed the relationship between fracture energy and peak shear stress and the concrete strength and thickness of adhesive layer. The finite fracture mechanics was applied to obtain the debonding load when the interface crack was unstable. The comparison between the theoretical and experimental results showed that the FFM model has good accuracy.