Characteristics of Steel Fibre Reinforced High Strength Concrete Beams: Efficiency in Size Reduction for Flexure

Abstract

Mechanical properties of concretes substituted with steel fibres and its relative merits on the size reduction of concrete specimens had been investigated in this study. Reinforcing efficiency of steel fibres on the flexural bending characteristics of thick and slender concrete sections had been experimentally verified. High strength concretes were produced using two different types of steel fibre anchorage profile consisting of single hooked and double hooked ends. The effects of steel fibres distribution in random and aligned direction were tested in various fibre concrete mixes substituted with 0.5% and 1.0% V_f of steel fibres. Fracture characteristics of various concrete specimens were tested using notched beam tests subjected to third point loading arrangement.  Test results indicated a positive synergy of fibre profile and alignment which provided an effective bonding and increased fracture strength of fibre concretes. Fibre concretes incorporating double hooked end steel fibres showed higher fracture toughness (12.42 N-m) and fracture energy (955 (N/m) than single hooked steel fibre concretes. Better fibre-matrix bonding and alignment of steel fibres along beam axis have contributed for enhanced fracture resistance of fibre concretes as well as size reduction efficiency of fibre concrete sections.