Effects of Stainless-Steel Waste Metal Strips and Recycled Aggregate on the Structural Behavior of Reinforced Concrete Beam: Experimental Case Study

Abstract

This study investigates the structural performance of reinforced concrete (RC) beams incorporating recycled aggregates (RA) and stainless-steel fibers (SSF) derived from commercial metal waste. A total of nine RC beams (1.5 m × 0.15 m × 0.1 m) were cast using varying RA contents (0%, 25%, and 50%) sourced from hollow blocks, along with SSF dosages of 0%, 0.25%, and 0.5% by volume. Additionally, 27 cubes and 9 cylinders were prepared to evaluate compressive and tensile strengths for each mix design. The beams were tested under two-point loading using a 1500 kN frame. Experimental results demonstrated that the inclusion of SSF significantly enhanced the flexural behavior and tensile strength of the concrete matrix, while the use of RA led to a general reduction in mechanical behavior. However, the strength loss due to RA was partially offset by the presence of SSF. Compressive and tensile strength increased consistently with higher SSF content across all RA levels, with the most notable gains observed at 0.5% SSF. The increased density of the specimens was attributed to the high specific gravity of SSF (8000 kg/m³) compared to conventional concrete (2400 kg/m³). Overall, the incorporation of SSF improved the mechanical performance of RC beams and mitigated the adverse effects associated with recycled aggregates. All tests and evaluations were conducted by BS 8110-1:1997.