Mechanical Properties of Ultra High Performance Fibre Reinforced Concrete and Its Response to Impact Loading

This manuscript presents the findings of an experimental study aiming to develop an Ultra High Performance Fibre Reinforced Concrete (UHPFRC) best suitable for impact loading. The mechanical properties of this material and the failure mechanisms under impact loading were investigated. The UHPFRC developed in this research program is a cement–based material with increased percentage of microsilica and a combination of two types of steel fibres: 6 mm long with 0.16 mm diameter and 13 mm long with 0.16 mm diameter. It includes local calcarenite sand with grains 125–500 μm in size. Four composition mixtures were produced, three UHPFRC and one Ultra High Performance Concrete (UHPC), without steel fibres. The influence of the amount and type of steel fibres was examined. Slabs with dimensions: 200 × 200 mm and thickness of 15, 30, 50 and 70 mm were produced and were subjected to projectile impact (real shotgun used). The penetration depth and material volume loss were measured.