The depletion of natural resources necessitates a significant shift in our approach, particularly in valuing waste products to decrease landfill usage and raw material dependence. The urgency to find alternatives that reduce natural resource exploitation, energy consumption, and carbon emissions is clear. While much research has focused on substituting coarse aggregates with construction waste, there is a lack of studies on replacing fine aggregates with waste materials. This study explores using precast concrete waste (PCW) as a fine aggregate replacement in asphalt mixes for flexible pavements. PCW was tested in various proportions (0%, 25%, and 50%) to assess its physical and mechanical properties and its viability as a substitute for fine aggregates. The experimental procedures included aggregate gradation, Marshall testing, indirect tensile strength tests, resilience modulus tests, and dynamic creep tests. The findings show that a 25% inclusion of PCW yielded optimal results, with tensile strength ratio (TSR), dynamic creep modulus (DCM), and slope at steady state (SSS) values of 0.90, 79.81 MPa, and 0.251, respectively. Consequently, the study concludes that PCW can replace up to 25% of fine aggregates in asphalt mixes for flexible pavements effectively.