The use of natural fibers in stone mastic asphalt mixtures: a review of the literature

All over the world, highway traffic is increasing rapidly, as is the population and the road network. The country’s maximum and minimum temperatures also vary greatly. Moreover, the pavements are subjected to various types of damage. Pavement binders and mixtures are a constant area of research and development for scientists and engineers. Adding fibers to bituminous mixes may improve the properties of fatigue and strength of the material. Natural fibers may be used to improve asphalt mixtures performance due to their inherent compatibility with asphalt cement and excellent mechanical properties. Also, the high stone content and relatively high asphalt content in SMA mixture led to the occurrence of drain-down of the asphalt mastic from the mixture, and this problem requires the use of stabilizing additives such as cellulose fibers, mineral fibers, or polymers to mitigate this problem and ensure long-term performance. The most public sort of stabilizing additives is cellulose fiber. Overall, natural fibers in stone mastic asphalt mixes are discussed in this paper. An additional focus is on how asphalt concrete will be affected by natural fibers, mixing techniques, and managerial decisions. According to the review, the stabilizing and strengthening impact of natural fibers on the performance of asphalt mixes have been extensively researched. Natural fibers can significantly increase the rut and flow resistance of asphalt mixtures. Adding natural fibers to pavement can increase structural resistance to pavement distress.