Design Mixture of RAP-HMA Pavements: A Review

Abstract

Abstract Roads are the national assets of a country. Once they are non-functional, they can be recycled to serve the next design life. Flexible pavements are the predominant type of pavement all over the world. The distressed flexible pavement material can be termed as Reclaimed Asphalt Pavement (RAP) material. The most common percent of RAP in the recycling process is 20% only. For higher incorporation of RAP material, there is uncertainty in the performance of RAP-HMA mixture. Design Mixture of RAP incorporated HMA technology depends on criteria’s like the viscosity of aged RAP extracted binder, dosages of recycling agents, overheating of RAP material and method of intrusion of RAP material in plant production units etc. The fields cum laboratory studies have found rutting, fatigue and moisture susceptibility as major concerns in this technology. The uses of rejuvenators have been found to improve the fatigue resistance of asphalt mixture but its over-dosages may impact rutting resistance. Hence, a balanced mixture design method which involves performance evaluation of recycled mixture is required. This paper discusses the mixture design of RAP-HMA pavement.