Understanding the Effects of Plastic Fines as a Bitumen Modifier on the Performance Properties of Hot Mix Asphalt

Abstract

The mechanical properties of most asphalt binders may not be sufficient to withstand the increased load requirements experienced by flexible pavement in practice, especially in regions notorious for severe climatic conditions. This necessitated the need to often enhance the properties of asphalt binder so that it can counteract most pavement distresses, such as rutting and moisture susceptibility. In this study, economical industrial waste plastic dust (IWPD) from high-density polyethylene (HDPE) origin was used to modify base bitumen with a penetration grade of 60/70, and its effect on the moisture susceptibility and rutting potential of hot-mix asphalt (HMA) was investigated thereafter. The IWPD was added at varying percentages (3%, 6%, and 9%) to the base bitumen by weight of the optimum bitumen content. Afterward, Marshall stability and indirect tensile strength ratio were performed on HMA samples produced with the IWPD-modified bitumen blends to evaluate, respectively, its rutting and moisture susceptibility. Based on the results obtained from the analysis, it was found that the modified blends of bitumen enhance the properties of the conventional bitumen. More importantly, the modified blend of bitumen with 6% IWPD content gave optimal results in terms of the increment of rutting resistance and improvement of moisture susceptibility of HMA.

Keywords

• flexible pavement
• industrial waste plastic dust
• hot-mix asphalt
• moisture susceptibility
• rutting
• tensile strength ratio