Recycling waste plastics in roads: A life-cycle assessment study using primary data

The present study investigates - from an environmental perspective - the processes that lead to the conversion of waste plastics into recycled plastic pellets to be used either as an additive (wet method) or as a replacement of natural aggregate (dry method) in the production of asphalt mixes. Data from recycling facilities in Victoria, Australia, were collected and used as the basis for a comparative life cycle assessment (LCA) study. Analyses were conducted by considering several replacement ratios of virgin material by its recycled counterpart in the so-called wet and dry method. A case study considering the production of recycled-plastic asphalt to be applied in the construction of a typical surface layer of a road in Victoria was evaluated. In general, the results show that recycling plastics as a polymer for bitumen modification and as a synthetic aggregate replacement in asphalt mixes has the potential to be environmentally advantageous compared to their virgin counterpart (i.e. virgin polymers and natural quarry aggregates).