Reuse of plastic waste in asphalt mixtures with residual porous aggregates

The reuse of plastic and poor-quality residual aggregates in the manufacture of bituminous mixtures for paving could contribute to reclaim significant quantities in the pavement construction industry since certain polymers can enhance the mixture properties. This study investigates the potential use of waste from recycled polyethylene terephthalate (PET) in asphalt mixtures with extemely-vesiculated residual aggregates, which are also rejected in quarry production. In this research, the physical, compaction, and mechanical properties of asphalt mixtures with these marginal aggregates, different binder consistencies and PET contents replacing part of the aggregate are studied. The results indicate that limited proportions of waste PET (up to 1%) are compatible with extremely porous aggregates and can improve certain mixture engineering properties, such as the resistance to water action and to rutting. These mixtures meet specifications for base courses and even for pavement surfaces under limited heavy-truck traffic, while contributing to the sustainability of asphalt pavements by reducing the extractive demand of natural resources and replacing them with waste materials.