A critical review of agro-based fibre applications in asphalt concrete mixtures

The increasing demand for sustainable construction materials has led to the exploration of alternative materials in asphalt concrete mixtures. One promising approach is the incorporation of agro-based fibres, which are derived from agricultural by-products such as coconut husk, rice straw, jute, and sisal. These fibres are biodegradable, economical, and capable of improving asphalt performance. This critical review examines their influence on mechanical properties, durability, and environmental sustainability of asphalt mixtures. The review highlights various studies that evaluate the impact of fibre content on parameters such as stiffness, fatigue resistance, rutting, and moisture susceptibility. Furthermore, challenges related to fibre treatment, uniform dispersion, and compatibility with bituminous binders are emphasized. Finally, the paper outlines future research needs to optimise fibre modification techniques and support large-scale application. Overall, agro-based fibres show strong potential as sustainable modifiers for durable and eco-friendly asphalt pavements.