Behavior of Steel Fiber Reinforced Concrete Deep Beams at Elevated Temperature

This paper presents an experimental investigation on the behavior of steel fiber reinforced concrete deep beams at elevated temperature. Twelve reinforced concrete deep beams were cast and tested. The beams were tested under a four-point loading scheme after being subjected to elevated temperatures of 25 (room temperature), 200 °C, and 400 °C. Three volumetric steel fiber ratios of 0, 0.2 and 0.4% and two ratios of shear span to effective depth of 0.4 and 0.8, were used. Results show that ultimate loads of deep beams are increased when heated at 200°C by 69.39%, 28.75% and 4.24%, and decreased when heated at 400°C by 2.04%, 25%, and 42.37% for steel fiber ratios of 0, 0.2%, and 0.4%, respectively. Steel fibers perform better in unheated beams. Incorporating 0.2 and 0.4% of steel fibers increases ultimate loads by 63.27% and 140.82% for unheated beams, 24.1% and 48.19% for beams heated at 200°C, and 25% and 41.67% for beams heated at 400°C, respectively. Also, the shear span to effective depth ratio still dominates the strength of deep beams at elevated temperature as at ambient temperature.