This paper presents an
analytical study performed on concrete girders reinforced with FRP bars with the goal of
evaluating current ACI-440 design equations for bond development length. The
analytical model is based on finite element formulation of anchored bar
problems with inelastic constitutive laws for the corresponding materials. The
bond stress-slip behavior between FRP bars and concrete was calibrated from
experimental data obtained from a large database set of over 50 test specimens
available in the literature. A large number of analytical simulations were
conducted in order to investigate the effect of different
parameters on the
development length. These parameters include: bar type (GFRP, CFRP), bar
strength, bar modulus of elasticity, bar diameter, surface coatings, concrete
strength, and confinement. The analytical study concluded by proposing a new
equation for development length that accounts for the effect of these
parameters.