Study on Dynamic Impact Mechanical Properties of UHPC with High-Content and Directional Reinforced Steel Fiber

Ultra-high-performance concrete (UHPC) is a kind of building material with ultra-high strength, toughness, and durability. However, under the conditions ordinary molding technology, most fibers cannot play bridging role in direction force. In this study, UHPC specimens different steel fiber contents (0%, 2%, 4%, 6% by volume) directional reinforced were prepared. Based on split-Hopkinson pressure bar (SHPB), influence distributed dynamic impact mechanical properties specimen systematically investigated. The stress–strain curves, stress peaks, increase factor (DIF), ductile energy absorption at strain rates obtained. results showed that oriented significantly increases property UHPC. peak strain, stress, DIF 2% 35.78%, 8.8%, 12.6% higher than prepared normal respectively. Moreover, content, absorption, multiple-impact compression resistance greatly improved. When content was 6%, compressive strength ratio, capacity 3.09, 1.45, 4.1 times reference group,