Mechanical Behavior of Ultra-High Performance Concrete Reinforced with Hybrid Different Shapes of Steel Fiber

Abstract

The impact of different shape fibers on the cracking restriction and bearing capacities, and mechanical behaviors of ultra-high performance hybrid-fibers reinforced concrete were experimentally investigated. The compressive strength, flexural strength, fracture energy, and bend ductility of the Ultra-high performance hybrid-fiber reinforced concrete were investigated with cube specimens and beam specimens. The results shown that, when the fiber volume ratio was 2%, compressive strength and flexural strength of long ultra-fine steel fiber reinforced concrete was the highest. Compared with plain concrete, it is increased by 31.4% and 75.7% respectively. The length of fiber has positive effect on flexural strength and ductility. The largest fracture energy and bending toughness index was obtained with hybrid-fibers, where the volume ratio of long ultra-fine fiber was 1.5%, and the ratio of long end-hooked fiber was 0.5%. The hybrid-fibers here have generated positive intermixing effect.