Springer Science and Business Media LLC

The present paper focuses on the behavior of Stone Mastic Asphalt (SMA) mixes incorporating rejuvenated Reclaimed Asphalt Pavement (RAP) materials. The RAP materials were tested for its physical properties and later were rejuvenated using various rejuvenators such as waste cooking oil, waste engine oil and shredded plastics. The rejuvenated RAP materials were incorporated in the SMA mixes at various replacement levels i.e. 0%, 30%, 50% and 70% (by weight). Various binder properties such as viscosity, rheological properties and chemical composition were evaluated for the aged and rejuvenated material. The rejuvenators were incorporated at different dosage levels i.e. 2%, 4% and 6% (by weight of binder). The optimal rejuvenation dosage for each type of rejuvenator was identified and mix design for the SMA was optimized for evaluating its physical and mechanical properties. Based on the results, the optimum rejuvenator dosage was identified at 6% for waste cooking oil and waste engine oil, while 2% for shredded plastics. It was observed that the addition of rejuvenators improved the performance of RAP based SMA mixes.

The study investigates the significance of fractionation as a process for the use of higher percentage of Reclaimed Asphalt Pavement (RAP) material in the design of bituminous mixtures. The fractionation is a process in which the RAP material is separated into two or more fractions to ensure consistency in the RAP gradation. In this study, the sieve analysis was carried out on the milled RAP material collected from five different locations to find the variation in the gradation. As the variation in the gradation was observed to be similar in nature for the milled RAP material obtained from all the five different locations, the detailed study was carried out on the RAP material from one particular location. The results showed that a 3-level fractionation had a significantly low variation in the RAP gradation even with the addition of 60% RAP material. A detailed study was carried out on the bituminous mixtures with three fractionation levels (un-fractionation, 2-level fractionation, and 3-level fractionation) and with three RAP percentages (40, 50 and 60). The ANOVA analysis showed that when compared to a 2-level and an un-fractionated RAP, a 3-level fractionated RAP substantially minimizes the variability in air voids, voids in mineral aggregate, Marshall stability, indirect tensile strength ratio, and Cantabro loss for the RAP added bituminous mixtures.