Advancing sustainable roller-compacted concrete using innovative pre-treatments: Enhancing aggregate-matrix bonding and mechanical performance

Reclaimed Asphalt Pavement (RAP) offers a sustainable alternative for pavement production; however, its use in roller-compacted concrete (RCC) is typically limited to 15–50% replacement due to weak bonding between aged asphalt and the cement matrix. This study introduces, for the first time, five innovative RAP pre-treatment techniques, including mixer grinding, Los Angeles grinding, acid treatment, emulsifier treatment (Sulfonic Acid and Texapon), and cement stabilization (with or without heat). The techniques were designed to enable 100% RAP replacement, maximizing sustainability without compromising mechanical performance. Experimental results demonstrated the superior effectiveness of these approaches compared to conventional methods. Los Angeles grinding achieved the highest compressive strength, with a 53% improvement compared to the mix without pre-treatment, significantly improving surface roughness and interfacial bonding. Meanwhile, mixer grinding offered a practical 23% gain. Heat-assisted cement stabilization further increased strength by 37%, while a cement-only coating provided 19% improvement, highlighting both scalability and cost-efficiency. Acid treatment and Texapon emulsifier produced modest 4% and 6% gains, respectively. Silica fume slurry increased strength by 4%, demonstrating the importance of proper application methods. These findings indicate that combined mechanical, chemical, and mineral pre-treatments can produce high-strength, durable 100% RAP-RCC, providing a sustainable, cost-effective, and scalable strategy that surpasses the limits of conventional partial replacement. • Full replacement of RAP in RCC is achieved through innovative pre-treatments. • Five mechanical, chemical, and mineral RAP treatments are systematically assessed. • A 53% strength increase is obtained using Los Angeles grinding pre-treatment. • Heat-assisted cement stabilization provides a 37% improvement in strength. • Durable and scalable 100% RAP-RCC is developed for sustainable pavement use.