Assessment of permanent deformation on asphalt mixtures incorporating Forta-Fi fibre as additive material

Abstract

Abstract An increasing number of load applications has caused permanent deformation that leading to longitudinal depressions in the wheel paths and small upheavals at the sides and subsequently effects the ride quality for road users. To address this issue, modifying asphalt mixtures using Forta-Fi fibre was introduced. This paper focuses to assess the permanent deformation and resistance to rutting of the asphalt mixtures containing Forta-Fi fibre. In this study, the influence of Forta-Fi fibre on asphalt mixtures was investigated by incorporating four different percentages of the fiber (0%, 0.3%, 0.5%, and 0.7%). The asphalt mixtures were prepared using a conventional bitumen 60/70 penetration grade as the base binder. Compacted specimens were subjected to dynamic creep testing with deviator stress levels of 207 kPa and 500 kPa, performed over 3600 cycles at a 60°C. The findings demonstrate that the inclusion of 0.3% Forta-Fi fiber in asphalt mixtures tested under deviator stress loads of 207 kPa and 500 kPa increased the creep stiffness by 26.1% and 43.1%, while the permanent deformation decreased by 18.4% and 43.8% compared to specimens without the Forta-Fi fibre. Additionally, the rutting values showed a reduction of 12.2% and 24.3% in the respective stress conditions. In contrast, an excessive percentage of Forta-Fi fibre was added, the creep stiffness exhibit reduce as increases permanent deformation and potential to rutting. This outcome is attributed to the impact of fibre components on the elastic behavior of the mixtures. In conclusion, the inclusion of 0.3% Forta-Fi fibre in the specimens resulted in improved resistance to rutting and overall better performance compared to conventional mixtures.