Incorporating Recycled Textile Fibers into Stone Mastic Asphalt

The increasing environmental impact of industrial waste, particularly from the textile sector, has driven efforts to integrate alternative materials into road construction. This study explores the feasibility of incorporating recycled cotton textile fibers into Stone Mastic Asphalt (SMA) mixtures to enhance their mechanical performance and sustainability. The bituminous mixture SMA 11 surf 35/50 was designed with 0.3% textile fibers, a dosage optimized to prevent binder drainage while maintaining adequate structural properties. Laboratory tests were conducted to evaluate bulk and maximum density, air void content, water sensitivity, and resistance to permanent deformation. The results demonstrated that the inclusion of 0.3% textile fibers significantly reduced binder drainage, improved moisture resistance with an ITSR of 96.30%, and enhanced stability under traffic loads. Although the WTSAIR value of 0.12 mm/1000 cycles did not fully comply with PG-3 requirements for T2 traffic, slight adjustments in binder content or composition could optimize performance. Beyond technical benefits, this study highlights the environmental and economic advantages of repurposing locally generated textile waste, reducing landfill accumulation, and fostering synergies between industries. Future research should focus on optimizing bitumen content, conducting fatigue and aging tests, and validating field performance under real traffic and environmental conditions to ensure long-term durability and compliance with road specifications.