Feasibility study of milled and crushed reclaimed asphalt pavement for application in unbound granular layers

The assessment of performance is vital to ensure confidence in recycled materials. This paper presents a technical and environmental feasibility study of using reclaimed asphalt pavement (RAP), processed by milling and crushing, in pavement unbound granular layers. An experimental programme was undertaken to address the geometrical, physical, mechanical and environmental properties. The crushed RAP showed the best performance whereas milled RAP has had to be mixed with a natural aggregate to improve its properties. The laboratory and lysimeter leaching tests indicated that RAP does not pose environmental risk. The overall results highlighted the viability of using both RAP types for the aforementioned purpose.