Effect of Black PET Fiber as Additive on the Mechanical Properties of Stone Mastic Asphalt (SMA) Mixtures

Abstract

Stone Mastic Asphalt (SMA) is a type of gap-graded hot mix asphalt which consists of a coarse aggregates’ skeleton and high binder content. This type of mixture has been used in many countries due to its toughness, stability and rut resistance mixture that relies on stone-to-stone contact for its strength and a rich mortar binder for its durability. On the other hand, there are some distresses that occur in SMA road pavement, which leads to a significant decrease in the life of the asphalt pavement. Therefore, the asphalt mixture needs to be modified by additive, such as fiber, to improve its mechanical properties and delay the deterioration. In this study, the influence of black PET fiber as an additive in the SMA mixture was focused. Six sets of asphalt mixtures were prepared using different proportions of black PET fiber content (0.2%, 0.4%, 0.6%, 0.8%, and 1.0% by the total mixture weight). Volumetric properties, Resilient Modulus, and Indirect Tensile Strength performance were investigated. The result showed that the optimum binder content for SMA mixture was 6.22%. It is also indicated that the use of black PET fiber as additive improved the Resilient Modulus and Indirect Tensile Strength performance. In conclusion, the use of Black PET fiber in SMA mixture indicates a positive potential to be applied in flexible pavement construction.