Abstract
When a concrete cylinder is confined laterally by a steel tube, or it is strongly reinforced with closely-spaced hoop reinforcement bars, the axial strength and ductility of concrete are improved considerably. In such structures, large confining pressures are passively induced by steel due to the lateral expansion of concrete.
The present paper proposes a constitutive model for describing the multiaxial deformational behaviour of concrete under passive confinement by using the work-hardening elasto-plasticity theory. The derivation of the proposed model is based on the use of experimental information obtained from tests in which concrete has been subjected to passive confinement. A computer program for finite-element (FE) analysis based on the use of the proposed model has been developed. The FE analysis successfully predicted the load-carrying capacities and deformational responses of concrete-filled composite columns subjected to eccentric loading.
