Constitutive relation for steel fibre concrete under biaxial compression

Abstract

This paper presents an analytical model for predicting the response of steel fibre concrete under biaxial compression up to failure. The model treats the steel fibre concrete as an orthotropic material for which the constitutive relation based on a total stress-strain formulation is derived. In the derivation, the biaxial compressive strength of steel fibre concrete is first evaluated by treating it analogous to a plain concrete under triaxial compression, with a confining pressure due to the fibres in the third direction. By defining equivalent uniaxial stress-strain relations and establishing the secant moduli in the principal directions, the stress-strain relation for steel fibre concrete under biaxial loading is obtained by a stepwise procedure. The stress-strain relations so derived are found to compare well with available experimental data. © 1994.