Effect of waste fibers on the mechanical properties of concrete

The main objective this study was to investigate the effect of waste steel fibers on the mechanical properties of concrete. The steel fibers obtained from waste tires were used, and physical and mechanical properties of these fibers were determined as a first step of the study. Fibers having different aspect ratios were used in concretes at various amounts. A concrete without any fibers was also cast. Compressive, flexural and splitting tensile strengths of the concretes were obtained. Fracture energies were also obtained using a closed-loop testing machine. Results showed that post-cracking strength and toughness of the concretes containing waste steel fibers were significantly increased. Flexural and splitting strength of the concretes were also improved. The experimental results showed that the waste steel fibers recovered from waste tires could be used for the production of steel fiber reinforced concretes. Utilization of waste steel fibers can help to protect environment by reducing the need for steel fiber production. Thus, the reuse of waste fibers in concrete contributes to a more sustainable fiber reinforced concrete production. Since the costs of the waste steel fibers are substantially lower than the commercial steel fibers, more economical steel fiber reinforced concretes can also be obtained.