Investigation of bond strength of FRP-to-concrete interface

The study of bonding strength of FRP-to-concrete interface is a fundamental issue in analysis of fiber reinforce polymer (FRP) externally strengthened reinforced concrete structures. In this paper, a modified shear retention model for cracked concrete element is introduced and the meso-scale finite element method is used to analyze the bonding strength of the interface. A new semi-theoretical and semi-experiential constitutive model for FRP-to-concrete interface is developed to model the mechanical behavior of FRP-to-concrete interface based on meso-scale finite element outcomes and direct pullout test results. The proposed constitutive model is demonstrated to be accurate and effective and possess excellent computational stability by comparing with the experimental results and results from other literatures.