Recycling Agricultural Plastic Mulch Waste into a Modifier in Asphalt Paving Materials

Abstract Polyethylene plastic mulch (PE mulch) has been increasingly used by specialty crop growers to improve crop yield and quality. However, most PE mulch after use ends up in landfills, causing plastic pollution. The challenge of recycling agricultural PE mulch waste is due to its high contaminant content. To address this challenge and promote the recycling of PE mulch, this study explored the processing of PE mulch waste and used it as a modifier in asphalt paving materials. The results of performance tests showed that the addition of PE mulch stiffened asphalt binders, which benefited rutting resistance, but slightly compromised cracking resistance. Recycled PE mulch had a lower effectiveness to modify asphalt binders than virgin PE mulch because of its lower effective plastic content. The dry mixing method is recommended to incorporate PE mulch waste into mixtures, as it has a lower adverse effect on cracking resistance than the wet mixing method.