摘要：This experimental studyinvestigated the effects of hybrid steel fiber of different size (0.2 and 0.5 mm)diameter andshape (smooth and corrugated steel fiber) on the compression and flexural performance of ultra-high performance concrete (UHPC).The compressive strength of UHPC with water-cementitious ratio of 0.23 exceeded 150 MPa after oven curing. The flexural stress- strain graph of UHPC shows a linear-elastic behaviour up to failure, which is unique from that of conventional concrete. The failure pattern, load – deflection relationship, stress–strain relationshipand toughness under UHPC mixture with no fiber and five UHPC mixtures with hybrid steel fiber content of 2% by volume of UHPC, were examined. This examination provides a detailed report of experimentaltest results for the compressive and flexural behaviour of Ultra High Performance Concrete, with increased strength and modulus of toughness. An UHPC mixture with 1.5% of 0.2 diameter and 0.5% of 0.5 diameter fiber showed the best compressive and flexural behavior, whereas those with 2% of 0.5 diameter fiber exposed the worst properties. Based on the attained peak stress, strain at peak stress, and modulus of elasticity, compression and flexural toughness index. UHPC showed high performance under compression and flexural loading. High peak load carrying capacity shows well toughness index and reinforcing properties of the hybrid steel fiber. UHPC has very high mechanical performance.
关键词：Ultra High Performance Concrete (UHPC); Hybrid steel fiber; Compressive strength; Flexural strength; Load – Deflection Relationship; Stress-strain relationship modulus of elasticity; Modulus of toughness; Ductility of UHPC
