An assessment of constitutive models for concrete columns confined with fibre composite sheets

Fibre reinforced composite materials are becoming more frequently used in civil engineering structures. One of the most practical applications of these new materials concerns the strengthening of reinforced concrete columns by means of confinement with fibre composite sheets. In the literature, various theoretical models have been proposed to describe the behaviour of confined concrete columns. These models can be grouped into three families: empirical, nonlinear elastic, and elastoplastic. The last two classes are considered in this paper. Comparisons of numerical predictions with experiments show that the nonlinear elastic approach is not very suitable for fibre composite confinement. The elastoplastic formulation gives predictions that agree quite well with experimentally determined axial load–deformation curves.