Title: Fatigue Resistance of Steel Fiber-Reinforced Concrete Deep Beams

Author(s): Benard Isojeh, Maria El-Zeghayar, and Frank J. Vecchio

Publication: Structural Journal

Volume: 114

Issue: 5

Appears on pages(s): 1215-1226

Keywords: deep beam; fatigue; steel fiber; strain evolution; strength; wind turbine foundations

DOI: 10.14359/51700792

Date: 9/1/2017

Abstract:
An investigation of the fatigue resistance of small-scale steel fiber-reinforced concrete deep beams with steel fiber-volume ratios of 0, 0.75, and 1.5% is reported. The behavior of steel fibers in enhancing the fatigue life of deep beams and reducing the congestion of reinforcement in concrete is studied, and the possibility of obtaining optimized structural sections that are cost-effective using steel fiber-reinforced concrete is verified. Evolutions and inclinations of average principal strains and bond strength between concrete and steel reinforcing bars within the shear spans were also observed. The use of steel fibers, especially with a volume ratio of 1.5%, was observed to reduce the progressive strain values in concrete and steel reinforcing bars, hence resulting in enhanced fatigue life. No significant evolution profile was observed for the inclination of the principal directions, while the use of adequate anchorage preserved the bond strength between concrete and steel reinforcement. In all specimens, fracture of the longitudinal reinforcing bars occurred at failure, and fiber pullout was more prevalent than fiber breakage.