Simulation of reinforced HPFRCC deformation capacity under flexure-and shear-dominated stress states

High-Performance Fiber-Reinforced Cementitious Composites (HPFRCCs) have a high material toughness that allow them to sustain compressive strains without spalling beyond that of normal concrete. Recent experimental findings have shown that unlike ordinary reinforced concrete elements that often fail in flexure due to concrete crushing, reinforced HPFRCCs can undergo high inelastic deformations resulting in tensile reinforcement fracture before crushing of the cementitious material. Experimental results to date have shown that reinforcement ratio strongly influences member deformation capacity due to rebar fracture. Specifically, by increasing reinforcement ratio in HPFRCCs, the reinforcement strains decrease for a given level of deformation, providing high deformation capacity in members that are more heavily reinforced. In this paper, the deformation capacity of reinforced HPFRCC structural elements subjected to various stress states has been investigated through numerical simulation. Of particular interest is the influence of flexure and shear stress states on member deformation capacity. Computational simulations are conducted on members with two different shear span-to-depth ratios and three different reinforcement ratios. For the same reinforcement ratio, simulation results show that there is a 5 to 20% reduction in the deformation capacity of shear dominated beams compared to flexure dominated beams. The observed dominant crack patterns are used to investigate reinforcement strain distribution and rebar fracture in different beams. The simulation results show similar damage pattern and strain localization phenomenon that has been observed in recent experimental studies.