Mechanics-based formulation for modeling of ultra high-performance fiber reinforced concrete material using bonded discrete elements

Abstract

Ultra High-Performance Fiber Reinforced Concrete (UHPFRC) possesses high strength and ductility relative to traditional concrete. As a relatively novel material, utilization of UHPFRC generally requires comprehensive studies on feasibility and applicability, where numerical modeling techniques become more convenient and cost-effective as compared to laboratory or field testing. In this study, a numerical model based on the bonded discrete element method is developed to simulate mechanical behaviors of UHPFRC materials. The formulation consists of three major components, which correspond to physical counterparts of fine aggregates, the cementitious matrix, and embedded steel fibers. A mechanics-based derivation is presented that facilitates calibration of the associated constitutive parameters. As validation of the numerical modeling and demonstration of the calibration procedure, results from laboratory experiments conducted on UHPFRC specimens are reproduced via simulation. In addition, parametric studies targeting the effect of particle size and packing are carried out to assess framework robustness.