Effect of Basalt and Steel Fibers on the Microstructure and Strength of Concrete with Desert Sand

There is a growing trend toward employing sustainable materials to address the drawbacks of traditional construction materials. This experimental study explores the utilization of basalt and steel fibers, both independently and in combination, alongside fly ash and desert sand. The findings reveal that the introduction of further basalt fibers led to a reduction in concrete workability, density, and compressive strength. The optimal compressive strength for concrete made from desert sand was achieved in the mixed concrete incorporating 1% steel fibers, measuring at 50.6 MPa. Meanwhile, the highest flexural and tensile strengths were observed in a concrete mixture of 0.3% basalt fiber and 1% steel fiber, measuring 7.35 MPa and 4.6 MPa. Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and X-ray Diffraction tests were conducted to examine the concrete microstructure. The results demonstrate that including a low content of hybrid steel and basalt fibers significantly improved the concrete microstructure. This study recommends conducting further studies to investigate the durability of concrete mixtures containing desert sand and basalt fibers and enhance sustainability in the construction industry.