Use of plastic wastes from greenhouse in asphalt mixes manufactured by dry process

This work assesses the applicability of low density polyethylene (LDPE), recycled from greenhouses used in agriculture, as a modifier of asphalt mixes manufactured by a dry process. To that end, a comprehensive laboratory study was conducted to design different asphalt mixes, formulated with recycled plastic, according to the European standards. Additionally, recycled plastic (LDPER) has been modified by compatibilizing agents (bitumen and oil), as a way to facilitate plastic incorporation into the mix. Results showed unmodified and modified plastics lead to bituminous binders with enhanced viscous and viscoelastic properties at medium-high in-service temperatures compared to a reference sample (PMB45/80-65). Plastic (and modified plastic) addition to AC asphalt mixes has enhanced mix behaviour associated to water sensitivity and rutting resistance. For high modulus asphalts MAM, the incorporation of plastics considerably improves the water sensitivity and fatigue resistance. Finally, BBTM mixes with added LDPE met technical requirements requested by Spanish regulations. However, compared to a mix manufactured with a PMB 45/80-65, plastic addition led to a poorer mix performance in term of particle loss and, above all, fatigue resistance.