HMA sustainability: Producing a recycled permeable mix that performs as well as the original porous mix

Porous European mixes are designed to have an air void content usually greater than 20% when compacted. At the end of their lifecycle many issues arise and these include variability of reclaimed asphalt pavement (RAP) material, and uncertainties on the potential for high percentage recycling. The objectives and scopes of this study focused on obtaining permeable pavements by recycling high percentages of RAP, under realistic assumptions about RAP variability. Two-and three-layer solutions were investigated. High percentages of RAP were used in the recycling process and traditional and advanced tests on both RAP and recycled mixes were carried out. RAP variability was examined and a method for facing its consequences was proposed. Mechanical performance was adequate. Recycling PEMs could be a proper way to achieve environmental sustainability in pavement construction as functional performance results are very promising and encouraging. Practical applications and perspectives in rehabilitation, maintenance, and research are outlined.