One of the problems that concrete structures may face is fire exposure, which can cause several issues for concrete structures, deterioration, reduction in serviceability, and potentially demolition. In this study, self-compacting concrete was used and reinforced with steel fiber as a volume fraction Vf by 0.75, 1.25, and 1.75% for both hook and micro steel fiber. The fresh and mechanical properties of all the tested mixes were examined. It was observed that the addition of fibers reduced the fresh properties and increased the mechanical properties for both types of fibers, especially for hook steel fiber. To study the effect of fire exposure on the properties of concrete, the samples were subjected to direct burning at temperatures reaching 300, 400, and 500°C for one hour of exposure, followed by gradual cooling to ambient temperature. It was noted that the mechanical properties significantly decreased with increasing burning temperatures, and the presence of fibers mitigated the deterioration that concrete is subjected to during burning. This enhancement was directly proportional to the augmentation of fiber volume fraction for both types, except for 1.75% hook steel fiber at 400 and 500°C, where there was a decrease in the improvement rates. Moreover, as for 1.75% micro steel fibers, this behavior was observed at 500°C only.

self-compacting concrete, hook steel fiber, micro steel fiber, percentage volume fraction, fire flame, and mechanical properties