Influence of High Temperature on Steel Fiber Reinforced Concrete

Abstract

This investigation includes an experimental study of the changes in compressive strength, splitting tensile strength, modulus of rupture and static modulus of elasticity after exposure to high temperature ranging between 250 to 750°C of plain and steel fiber reinforced concrete (SFRC) in comparison with ordinary temperature (25°C). Hooked and straight steel fibers with aspect ratio of 60 and two different percentages by volume (0.5% and 1%) were used. Each group of specimens was heated to a specified temperature and kept at that temperature for one hour before being gradually cooled to room temperature, and then they were tested. The results show an appreciable decrease in compressive strength, splitting tensile strength, modulus of rupture and elastic modulus after exposure to temperature higher than 350°C of both plain and SFRC. The inclusion of fibers very slightly affects the compressive strength of concrete at temperature below 350°C, while the loss in compressive strength for SFRC is lower relative to plain concrete after exposure to temperature higher than 350°C. The results also show that the loss in splitting tensile strength and modulus of rupture for SFRC is appreciably lower in comparison with that of plain concrete for all heating temperatures up to 750°C. The volume content of fiber slightly affects the compressive strength of concrete; also the type and volume .....