Assessment of nonlinear bond laws for near-surface-mounted systems in concrete elements

摘要

This paper presents a numerical plane Finite Element (FE) Model for use in simulatingthe behaviour of different types of Near Surface Mounted (NSM) Fibre ReinforcedPlastic (FRP) strengthening systems for concrete elements. Based on a nonlinear bondlaw for simulating the behaviour of the FRP reinforcement-adhesive-concrete interface,the model employs an interface element between the NSM FRP reinforcement and the concrete. The results of two different experimental programs, both dealing with 'bondtests' but with distinct set-ups, are briefly summarised and analysed. The main objectiveof this research is to assess the values of the parameters that define the nonlinear bondlaws for each type of FRP reinforcement tested. This assessment was accomplished byinverse analysis, fitting numerically the pullout load–displacement curves that wereexperimentally recorded. The effect of bond length on different types of NSM FRPreinforcement is assessed. Finally, the bond behaviour in the transverse plane isexamined too.