Fiber-reinforced asphalt-concrete – A review

Asphalt concrete (AC), a mixture of bitumen and aggregates, is a sensitive material compared to other configurations used in civil engineering. Therefore scientists and engineers are constantly trying to improve the performance of asphalt pavements. Modification of the asphalt binder is one approach taken to improve pavement performance. Nowadays, there are different materials that have been employed to reinforce asphalt concrete. Furthermore, fibers and polymers are two important examples used for this purpose. However, it has been claimed that among various modifiers for asphalt, fibers have gotten much attention for their improving effects. Different researchers reported the results of the addition of a large variety of fibers to asphalt concrete as fiber-reinforced asphalt-concrete (FRAC). Basically, fiber reinforcement is considered as a coin with two sides. One side includes the randomly direct inclusion of fibers into the matrix, i.e. asphalt concrete and/or Portland Cement Concrete slabs. Another side comprises oriented fibrous materials, e.g. Geo-synthetics family. It is emphasized that the former concept is not as well-known as the second. As a result, this paper is going to focus on the first side of the coin and to investigate FRAC materials modified by random fiber inclusion. Also, the effect of different fibers, mixing procedures and executive problems on asphalt concrete will be inspected. In this way, different literature reviews illustrated that the use of fibers in AC material has been involved with three dissimilar targets: mechanical improvement, preparation of electrically conductive mixtures, and creation of a new market to manage the waste fibers.