Effect of recycled tyre steel fiber on flexural toughness, residual strength, and chloride permeability of high-performance concrete (HPC)

Owing to a high tensile strength and fatigue toughness, recycled tyre steel fiber (RSF) can be used as a potential fiber reinforcement to advance the ductility of high-performance concrete (HPC). In the present study, compressive strength, splitting-tensile strength, load-deflection behavior, flexural strength, flexural toughness, residual strength, and chloride-migration coefficient of HPC made with different doses of RSF was investigated. The performance of RSF was compared with manufactured steel fiber (MSF) at the same fiber volume. The results showed that in splitting-tensile test results, RSF was 54% to 75% effective as compared to MSF, while flexural-tensile results showed that RSF was 61% to 77% effective compared to MSF at the same fiber volume. Chloride permeability of both MSF and RSF-reinforced concrete was almost similar. The increase in electrical conductivity due to presence of metallic fibers caused a rise in the chloride permeability, however, the corrosion-potential risk of RSF-reinforced HPC was 'low'.