Polyester Fiber Reinforcement Effects on Cement-Stabilized Reclaimed Asphalt Pavement Base: Mechanical and Durability Characterization

This study explored the utilization of reclaimed asphalt pavement (RAP) material in cement-treated base (CTB) layers and investigated the synergistic effects of incorporating fibers. The research aimed to develop a sustainable and cost-effective solution for material scarcity by leveraging on-site processing using the RAP-CTB mix design. The focus was on enhancing the mechanical performance, durability, and structural reliability of CTB mixtures. Laboratory experiments were conducted in accordance with the standard specifications to evaluate the influence of RAP content and fiber reinforcement on CTB properties. The study systematically determined the optimal mix design based on the unconfined compressive strength (UCS) of 7-day-cured samples. In addition, the compressive performance was assessed at 3, 7, and 28 days to determine strength development trends with curing age of all the prepared mixes. Additionally, flexural strength tests were conducted to investigate the mixture’s ability to withstand bending stresses. Durability was assessed using wetting–drying and freezing–thawing cycles to simulate harsh environmental conditions. The findings indicate that a mixture containing 70% RAP, 4% cement, and 1% fiber exhibited superior strength and durability, meeting the required specifications. The fibers contributed as a secondary reinforcement in the matrix and significantly improved resistance to cracking and moisture-related distress, making it a promising construction material for CTB layers. In conclusion, this study demonstrated the feasibility of using RAP and fibers in sustainable pavement construction, offering both environmental and economic benefits.