Enhancing HMA properties with polypropylene-based face mask integration: A qualitative comparison of wet mixing and dry mixing techniques

Abstract

<span lang="EN-US">In the wake of the emergence and widespread dissemination of the COVID-19 coronavirus, scientifically identified as SARSCoV-2, the utilization of medical equipment, specifically tri-layered polypropylene (PP)-based face masks, has experienced significant proliferation. The extensive adoption of single-use polymer-based face masks has raised notable environmental concerns, given their extended degradation period of up to 480 years and their substantial threat to ecosystems, particularly aquatic organisms, due to pervasive littering practices. Hence, this study is dedicated to assessing the influence of incorporating polypropylene (PP)-based face masks into asphalt formulations. The incorporation of PP-based face masks into asphalt was executed at three distinct weight percentages, employing both dry and wet mixing techniques. Comprehensive performance evaluations were carried out utilizing the Marshall test, indirect tensile fatigue test, and Hamburg wheel tracking rutting experiments and the best value for each. Remarkably, augmenting the PP content yielded improvements in both fatigue life and rutting resistance of the asphalt mixtures, and the maximum improvement was recorded at 0.3% replacement. Notably, asphalt specimens prepared using dry mixing techniques outperformed their wet mixing counterparts, demonstrating superior cohesion attributes.</span>