Recycled steel fibers (RSF) could be introduced as a replacement for engineered steel fiber (ESF) in the production of fiber- reinforced concrete (FRC) to derive economic benefits while maintaining mechanical properties. First, three scenarios, namely: (1) adding 0.5% RSF to plain concrete, (2) replacing 0.5% ESF with 0.5% RSF, and (3) hybrid utilization of both RSF and ESF each at 0.25% dosage, are experimentally examined in terms of workability, compressive strength (CS), split- ting tensile strength (TS), impact resistance (IR), ultrasonic pulse velocity (UPV), and water absorption (WA). Moreover, to investigate the desirability of RSF as shear reinforcement, reinforced concrete (RC) beams without stirrups are experimen- tally analyzed. Finally, environmental (including global warming, acidification, and fossil fuel depletion potentials) and cost analyses are performed on each concrete mix. The results established that RSF not only fulfills the strength requirements of FRC – slightly higher CS, identical TS behavior, and moderately lower IR values compared to the mix containing ESF – but also satisfies the economic and environmental criteria. Adding 0.5% RSF to plain concrete increased its CS by 36.6%, multiple its cost about 1.5 times, and slightly incremented the environmental indices. However, replacing 0.5% ESF of by 0.5% RSF slightly improved CS by about 6.4%, reduced the cost of mix to a half, and significantly decreased the environmental indices. Additionally, 0.5% RSF incorporation achieve a great success in bridging cracks in loaded RC beams without stirrups and make an outstanding contribution to load-bearing capacity. Compared to RC beam with 0.5% ESF, the load-bearing capacity of beam enhanced about 8%, and ductility index improved more than 1.5 times by 0.5% RSF inclusion.

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