Engineering Properties of Waste Plastic and Nanomaterials Modified Asphalt Mixtures

Abstract

Stone Mastic Asphalt (SMA) has shown an extraordinary contribution in pavement engineering research and industry. Due to the climate changes and load conditions differences, using specific additives in SMA is essential. Therefore, it is vital to utilize a modern mixture with a high capacity to survive the high traffic loads. The current study aims to use the combination of waste HDPE and Nano-silica (NS)and waste polymer as a newly developed hybrid additive in SMA modification, which could improve the rutting and stiffness performance. By using the dry mix process, waste high density polyethylene (HDPE) and NS were blended with the C320 bitumen binder to produce the SMA mixtures. The Nano silica was added to the C320 binder (2%,4%, and 6% by weight of the binder). The engineering properties were assessed through the Marshall stability, Marshall flow, Marshall Quotient, wheel tracking test, and 4 points bending fatigue tests. The results indicated that the addition of 4% -6% nano-silica improve the rutting and stiffness performance of the modified SMA mixtures in comparison with the non-modified mixtures. Results revealed that mixtures modified with the hybrid additive of 4 HDPE- 6%NS have exceptional performance, in terms of better stiffness, rutting resistance and longer fatigue life.