Numerical evaluation of the behaviour of steel- and FRP-confined concrete columns using compression field modelling

New constitutive models for confined concrete were formulated and implemented into in-house nonlinear finite element programs at the University of Toronto. A program for analysis of axisymmetric solids was specifically developed for this work. The confinement models proposed follow a compression field modelling approach that combines nonlinear elasticity and plasticity-type modelling. In this paper, the formulations are corroborated by examining the behaviour of reinforced concrete columns confined with fibre reinforced polymers (FRP), steel, or a combination of both. The analytical responses agree well with the experimental results, showing the capabilities of the models to reasonably model pre- and post-peak behaviour, and strength enhancement.