Application and Performance of RAP in Highway Construction: A Literature Review

Abstract

Reclaimed Asphalt Pavement (RAP) is degraded asphalt that has been removed from damaged flexible pavement. The second-largest road network in the world, with a length of more than 63.72 lakh km, is found in India, according to the MoRTH's annual report for 2021–2022. Large quantities of RAP are produced each year during highway maintenance and construction. When the flexible pavements are removed for reconstruction or resurfacing, they are dumped in landfills, posing serious environmental concerns. Recycling overcomes the exploitation of natural resources, reduces the unwanted increase of road elevation due to periodical overlays, and disposal of RAP generated from pavement construction. An overview of the application of RAP is provided in this publication, to understand its importance and performance in highway construction when mixed with different materials viz. rejuvenators, nanomaterials, WMA additives, reinforcement with polymer or bamboo, fly ash – lime, etc. The use of recycled asphalt pavement is progressively expanding in India for road building, which meets the overall goal of sustainable development by lowering the consumption of natural resources, the emission of hazardous gases, the cost and energy of disposal, and landfill utilization.