Evaluation of bond stress-slip models for FRP reinforcing bars in concrete

In this paper several currently available bond stress-slip models for steel and FRP reinforcing bars in concrete are firstly reviewed, and both merits and demerits of these models are discussed. The models which are promising to be used for describing the bond-slip behaviour of FRP reinforcing bars in numerical analysis are evaluated through finite element analysis of FRP-reinforced concrete beams with bond-slip effect taken into account. A newly developed composite beam element with bond-slip is employed for finite element analysis of a GFRP-reinforced concrete beam and a CFRP-reinforced concrete beam with the selected bond stress-slip models built in the finite element model. The suitability and capability of the bond stress-slip models informed from the finite element analyses are summarised and concluded. Finally, parametric study is carried out on the most appropriate bond stress-slip model to investigate the effect of different surface conditions of reinforcing bars on the structural behaviour.