Conventional flexible pavements are released to different types of failure in the initial phases of their service life due to high traffic density, high speeds, heavy loads, and harsh climates. To eliminate pavement damage and failure early, the present search investigates the impact of adding glass, steel, and basalt fibers in the asphalt mixtures. Also, the study evaluates these materials characteristics compared to the mixtures without fibers. The Marshall test and tensile strength ratio test (TSR) were utilized to evaluate the asphalt mixture's performance. A set of specimens were produced by incorporating glass fiber (GF), steel fiber (SF), and basalt fiber (BF) at (0.10%, 0.15%, 0.20%), (0.25%, 0.35%, 0.45%), and (0.15%, 0.35%, 0.50%), respectively. When using these fibers, the findings showed an improvement in Marshall stability, flow, volumetric properties, and TSR value. The highest improvement in Marshall stability and TSR value was obtained at 0.10% of GF by 14% and 11.5%, at 0.25% of SF by 16% and 10%, and at 0.15% BF by 8% and 14.1%, respectively, compared to the control mixture. Therefore, fibers can be used as a convenient modifier for asphalt mixtures to improve the performance of flexible pavement with an optimal addition of 0.1% GF, 0.25% SF, and 0.15% BF to the total mass of the mix.
