The use of fibres in asphalt mixtures: A state of the art review

The various acknowledged benefits given by the use of fibre for construction materials made this component essential for specific applications, including asphalt pavements. Fibres in asphalt mixtures usually play two important roles: acting as an asphalt stabilizer to decrease the drain-down effect; and as a reinforcing additive to enhance the mechanical performance of asphalt mixtures. To better understand their use, this paper aims to review the various uses of different types of fibres in asphalt pavements. The main variables that influence the effectiveness of fibres and the reinforcing mechanism of using fibres are discussed. Furthermore, a state-of-the-art of the combined use of fibres and other additives, such as crumb rubber, polymer modifiers, and nano-size modifiers, is presented. Results from relevant studies confirmed the effectiveness of using fibres in asphalt pavements and the significance of optimizing the mixing method, size and dosage of fibres to achieve more suitable performance. Additionally, the latest research findings and experimental applications are discussed, with a specific focus on waste and recycled materials. Exploring feasible recycled alternatives to natural and traditional fibres, optimizing the use of fibres from wastes, and combining the use of fibres with other sustainable technologies, could maximize the environmental benefits of using fibres in asphalt pavements.