Evaluation of asphalt pavement maintenance using recycled asphalt pavement with asphalt binders

Road maintenance projects require innovative, economical, and environmental solutions. This study evaluated recycled asphalt pavement (RAP) as a greener aggregate alternative to natural aggregate for the maintenance of asphalt concrete in flexible pavements. The mechanistic performance of warm mix and cold mix asphalt concretes using recycled asphalt pavement (RAP) was furthermore investigated in this study. The bitumen binders used were asphalt cement AC60/70 for warm mix asphalt concrete and asphalt emulsion CMS-2 h for cold mix asphalt concrete. Laboratory tests undertaken include Marshall stability and flow, indirect tensile strength, indirect resilient modulus, indirect tensile fatigue, and permanent deformation were performed to ascertain the true performance of RAP-AC60/70 and RAP-CMS-2 h mixtures as maintenance asphalt concretes. The laboratory test results of RAP-AC60/70 and RAP-CMS-2 h mixtures were compared with those of a conventional warm mix asphalt concrete using limestone and asphalt cement AC60/70. The results indicated that the overall performance of both RAP-AC60/70 and RAP-CMS-2 h mixtures was comparable to the Limestone-AC60/70 mixtures. The total material cost of RAP-60/70 and RAP-CMS-2 h mixtures was approximately 60% lower than Limestone-AC60/70 mixture. However, the RAP-CMS-2 h mixture had more advantages than RAP-60/70 in terms of maintenance operation and carbon footprint emission. The usage of RAP with both CMS-2 h for repairing pavement deterioration was found to provide a more cost-effective and greener solution.