Cyclic constitutive model for high-strength concrete confined by ultra-high-strength and normal-strength transverse reinforcements

In this paper, a cyclic constitutive model is developed for high-strength concrete (HSC) confined by ultra-high-strength and normal-strength transverse reinforcements (UHSTR and NSTR), with the intention of providing efficient modeling for the member and structural behaviour of HSC in seismic regions. The model for HSC subjected to monotonic and cyclic loading, comprises four components; an envelope curve (for monotonic and cyclic loading), an unloading curve, a reloading curve, and a tensile unloading curve. It explicitly accounts for the effects of concrete compressive strength, Volumetric ratio of transverse reinforcement, yield strength of ties, tie spacing, and tie pattern. Comparisons with test results showed that the proposed model provides a good fit to a wide range of experimental results.