The coupling effect between bacteria and steel fibers has also been investigated to further enhance the mechanical and physical properties of concrete. The incorporation of steel fibers (1.0 % and 1.5 % volume fraction) in bacterial concrete (1.0 % bacterial content) resulted in long-term compressive strength increases at 180 days by 45 % and 55 %, respectively, compared to 15 % and 27 % for concrete without bacteria. SEM analysis further revealed that the addition of steel fibers in mixes with bacteria improved the crack bridging capability and acted as a scaffold supporting the deposition of bacterial calcite, leading to a superior self-healing concrete through a synergistic effect. This combination leverages the mechanical benefits of steel fibers and the biological healing properties of bacteria, potentially extending the concrete's lifespan and reducing the need for frequent repairs , , .