Advanced Bituminous Mix Designs Incorporating Natural Fibers for Enhanced Performance and Sustainability

Abstract

comprehensive study comparing the performance of Bituminous Concrete (BC) and Stone Matrix Asphalt (SMA) mixes, both with and without the addition of natural sisal fibers. The research investigates the effects of varying binder contents (from 4% to 7%) and fiber contents (from 0.3% to 0.5%) on the mechanical properties of the mixes. Using 60/70 penetration grade bitumen as the binder, the work aims to explore how sisal fibers influence the stability, durability, and tensile strength of the mixes. A series of experiments, including Marshall stability, static indirect tensile strength (ITS), static creep tests, and drain down tests, were conducted to evaluate these properties. The study finds that the inclusion of fibers generally enhances stability and reduces deformation in both BC and SMA mixes. Specifically, adding 0.3% sisal fiber to SMA significantly improves its performance, reducing binder drain down and improving tensile strength, making it more suitable for flexible pavements. The research concludes that sisal fibers are effective in improving mix properties, and SMA with fiber offers superior performance over BC. The study also suggests that sisal fiber is a cost-effective, environmentally friendly stabilizing additive, as it reduces industrial waste while offering practical engineering benefits. The work highlights potential areas for future research, including the investigation of other natural and synthetic fibers, fatigue properties, and resistance to rutting​​.