Pavement Sustainability: Permeable Wearing Courses by Recycling Porous European Mixes

The main objective of this research is the formalization of strategies and technical procedures for recycling PEMs (Porous European Mixes) back to permeable wearing courses. A number of issues were studied: mitigating the drawback of clogging and its related consequences (decay of acoustic and permeability performance over the time); preserving traditional (bearing properties, skid resistance) and premium (quietness, permeability) performance; recycling high percentages of cold milled RAP-from-PEM (where RAP stands for reclaimed asphalt pavement); investigating on collateral effects in terms of sustainability. In order to investigate on the abovementioned issues an experimental plan was designed. Mixes with high RAP contents were produced and tested. Design and construction features, including mix design and mixing procedures, were addressed. Even if other experiments are needed, mechanical and environmental properties are promising. Furthermore, the tests carried out are encouraging about the possibility of achieving a satisfactory level of surface performance. Practical applications for rehabilitation interventions are outlined.