Behaviour of Ultra High Performance Fibre Reinforced Concrete Subjected to Pure Shear

Recent years have shown Ultra High-Performance Fibre-Reinforced Concrete (UHPFRC) to be applicable to practical design problems, including 100-metre length bridges being built without conventional shear reinforcement. Although UHPFRC is promising, its shear response is an area that requires more research. An experimental program consisting of five large-scale UHPFRC panel elements was completed to better understand the behaviour of UHPFRC under pure shear. The panels had varying amounts of conventional reinforcement and a constant 2% volume fraction of steel fibres. The panels cracked at lower stresses than their companion prisms. However, the panels demonstrated a strain-hardening response with a linear post-cracking stiffness and reached a peak shear stress of 8-10 MPa. At peak shear stress, fibres began to pull out along a single crack where strains localized, causing gradual degradation in strength. Finite element predictions captured the strength of the panels well but identified areas in which modelling could be improved.M.A.S