PERFORMANCE OF HIGH STRENGTH STEEL FIBRE REINFORCED CONCRETE SUBJECTED TO FLEXURE AND IMPACT LOADINGS

In this research, the flexural and impact resistance of steel fibre reinforced concrete (SFRC) under static and impact loadings was experimentally investigated. High-strength reinforced concrete steel fibre containing 1% by volume fibre content with a constant w/c 0.39. Hooked steel end fibers were used with a circular cross section of 1 mm in diameter and an aspect ratio of 30. Flexural behaviour of SFRC was carried out on a beam specimen of size 1200 x 100 x 200 mm subjected to two-point bending test as per ASTM C78 standard specification. Impact resistance was performed on a thin SFRC slab specimen of size 600 x 600 x 50 mm subjected to low velocity drop weight impact test as per the prescribed ACI 944-89. For comparison purpose, the conventional RCC specimens were also cast and tested. The test results found that the flexural strength and toughness of SFRC specimen remarkably increased by 35% and 50% respectively compared to RCC specimen. The addition of steel fibers to concrete increases the stiffness and ductility characteristics. The first crack and ultimate energy absorption potential of SFRC slab specimens were increased by 173.5 and 3.72 times, respectively, compared with RCC slab specimens. From the test results concluded that the flexural and impact resistance was significantly improved with addition of steel fibres in concrete.