Bond behavior between near-surface mounted fiber reinforced polymer strips and concrete using nonlinear finite element: a parametric study

A nonlinear finite element (NLFE) model is proposed to predict the bond behavior between concrete and near-surface mounted (NSM) fiber-reinforced polymer (FRP). The model is validated, based on the results from an experimental program carried out by the present authors, before being employed to generate a wide range of data considering key parameters, such as grooves spacing (50–200 mm), and embedment length (50–300 mm), and fiber type (basalt and carbon) of the NSM FRP strips as well as concrete's strength (25–55 MPa). The impact of steel reinforcement is also evaluated. The findings demonstrate a significant impact of NSM FRP strips' type, embedment length, and grooves' spacing on bond behavior. The higher-strength grade for concrete imparted noticeable improvements in bond characteristics, whereas the presence of steel reinforcement seems to enhance the pull-out force slightly by as much as 15% yet reduce bond ductility. The NLFE cracking patterns are used to help understand the influence of different parameters on bond failure mode between the NSM FRP strips and concrete.