Numerical simulation of bond-slip interface and tension stiffening in GFRP RC tensile elements

In this work, a methodology to implement bond-slip behaviour between concrete and reinforcement into a FEM model is presented. The inverse analysis is used to characterise the bond mechanisms active in a pull-out test. The obtained constitutive behaviours are thereafter implemented into a FE program by using connector elements and surface-to-surface contacts, and GFRP RC tensile elements are modelled. Numerical results are compared to experimental ones available in the literature, showing good accuracy in terms of load-deformation, crack width and crack spacing, as well as strains and bond stress and slip distributions along the reinforcing bar.