Enhanced Performance of Hot Mix Asphalt Using a Polyethylene–Palm Kernel Shell Ash Composite Modifier

Abstract

The highway network plays a crucial role in promoting social and economic development within the nation, making its longevity essential. Improving the durability of Asphalt Concrete (AC) pavements can lead to reduced maintenance and repair efforts, enhanced ride quality, and minimized environmental impact. However, rising costs and difficulties in sourcing materials for construction, along with the negative environmental effects of industrial and agricultural by-products, highlight the need for research into better methods for enhancing the properties of asphalt concrete. One approach involves incorporating these by-products into the asphalt concrete mix design. Many studies have shown that adding mineral fillers to hot mix asphalt concrete can significantly improve its characteristics. Therefore, this study aims to investigate the effects of Palm Kernel Shell Ash (PKSA) and melted polyethylene on the mix design properties of asphalt concrete. The Marshall mix design methodology was used to accomplish this, allowing for the fabrication of representative samples. The Marshall Apparatus was utilized to determine stability and flow, while compressive strength and the retained strength index of both unsoaked and soaked samples were calculated using established models. The results indicated that the mechanical properties—such as stability, density, flow, air voids, compressive strength, and swelling index—of the modified hot mix asphalt concrete were superior to those of the unmodified version, thanks to the addition of PKSA and melted polyethylene. The optimal ratio for achieving maximum stability, flow, density, swelling index, and Voids in Total Mix (VTM) was found to be 19% by weight of binder and 9% PKSA by weight of aggregates. In conclusion, the combination of PKSA and polyethylene serves as an effective modifier and should be included in the production of asphalt concrete.