Experimental and finite element analysis of push-out shear test for adhesive joints between pultruded GFRP and concrete

Abstract Adhesively bonded joints have expanded widely in recent years as more and more advanced glass fibre reinforced materials are being utilized in the civil engineering applications. Hybrid pultruded GFRP concrete bonded beams have been proposed as an economical structural solution for building and footbridge applications due to their favourable properties. Evaluation of shear strength for the adhesive joint is considered as the most important parameter for the design of these hybrid beams. However, the absence of standard method for testing GFRP/concrete bonded joints makes the application of this technology in construction work far from being achieved. There is then a need to make more effort to improve design procedure and to understand the behaviour of this assembly. In this context, the present paper aims to characterize the shear test “Push out” in order to provide more information about the influence of the different geometrical parameters on the shear strength of the adhesive joint. For this purpose, experimental and numerical investigations were carried out to investigate the effect of various parameters on the failure load and the failure mode of the specimens such as surfaces treatment, shape of GFRP profile, adherents’ dimensions (width and thickness), adhesive thickness, bonded length and free height. The numerical investigations were performed by three-dimensional (3D) nonlinear Finite Element (FE) model. The constitutive relationship of the pultruded GFRP is modelled by means of a linear orthotropic law, while the concrete behaviour is defined by means of an elastic plastic damage model with a non-local formulation. In order to reduce computing time, interface elements with zero thickness were used to model the adhesive joint with a linear constitutive law. Using this model, stress distributions along the interface were investigated and the effects of different geometrical parameters were discussed.