This study investigates the structural performance of Ultra-High-Performance Reinforced Concrete (UHPRC) rectangular columns under axial, uniaxial, and biaxial loading, with a focus on enhancing strength, ductility, and durability for modern construction. Eighteen columns were fabricated using three concrete grades (M60, M70, M80) and three reinforcement ratios (1.34%, 2.09%, 3.01%), and tested in a 2000 kN capacity loading frame. The effects of material strength, reinforcement content, and load type on load-carrying capacity and failure behavior were systematically assessed. Finite Element (FE) models, comprising 2D plane stress and 3D simulations, were developed and calibrated against experimental results, enabling accurate prediction of peak load, crack propagation, and post-cracking response. Experimental outcomes revealed that higher-grade UHPRC and greater reinforcement ratios substantially improved peak load capacity, post-peak ductility, and energy absorption across all loading conditions. Failure modes displayed gradual post-cracking behavior, highlighting enhanced structural resilience. An analytical load–moment interaction model was formulated and validated with close agreement to experimental and FE findings. The results confirm UHPRC’s potential for high-performance structural applications, providing valuable insights for designing strong, ductile, and durable rectangular columns in advanced engineering practice. Keywords: Ultra-High-Performance Reinforced Concrete, rectangular columns, finite element modeling, axial loading, uniaxial bending, biaxial bending.
Patil et al. (Wed,) studied this question.