Improving Recycled Asphalt Mix Performance Through Rejuvenation

Abstract

Developing technologies that provide sustainable solutions for future pavement construction is vital given the ever-increasing demand on the supply of bitumen and good-quality pavement construction materials. Recycled asphalt pavement (RAP) is a technology that presents many advantages in cost and environmental savings. This study investigated the performance of RAP mixes containing rejuvenation additives to determine the effects of those additives on the deformation (rutting) resistance, cracking resistance, and fatigue performance of RAP mixes. Laboratory testing was conducted on 11 RAP mixes that were manufactured with RAP proportions of 15% and 30%, as well as with the addition of different types of rejuvenating agents. Results produced useful performance indicators for the use of rejuvenation additives in RAP. The mixes that had rejuvenation additives preserved the high deformation resistance of RAP mixes, particularly at the higher RAP proportion of 30% when compared with a mix with no RAP, and concurrently the addition of rejuvenators counteracted against overstiffening effects of RAP. The addition of RAP, especially 30% RAP proportion, had poorer fatigue performance than when only 15% RAP was used, but with the use of rejuvenation agents, the fatigue performance of the high RAP mixes improved significantly. Use of a maltene fraction for RAP rejuvenation had marginally better fatigue performance than a chemical rejuvenation agent. The research results provide a valuable understanding of the behavior of RAP mixes and, in particular, the positive performance results that can be gained by using rejuvenation additives.

Mechanical performance of sustainable asphalt mixtures manufactured with copper slag and high percentages of reclaimed asphalt pavement

“…Researchers have studied the incorporation of different types of materials and design methodologies to avoid an excessive increase in the stiffness modulus, which is a characteristic of mixtures with high RAP content that can affect long-term performance, turning them into a brittle material susceptible to the appearance and propagation of cracks. The use of rejuvenating additives (oils and waxes) [24,25], polymer modified binders [26,27] or lower grade PG (stiffness compensation) [10], the use of warm mixtures (reduction of short-term aging of RAP) [28,29] and the use of stabilizing additives (slag, fibers, and minerals) [30][31][32][33][34][35] are some of them. On the one hand, these techniques make it possible to counteract the aging of RAP by controlling its viscoelasticity and, on the other hand, to stabilize the behavior of RAP mixtures against the phenomena of loss of adhesiveness due to moisture conditions, fatigue damage, and permanent deformation, the main causes of deterioration of this type of mixtures [36].…”

Renovation the Physical Characteristics of Aged Bitumen Using Vacuum Residue

“…In reality, the fatigue output of this rejuvenated RAP mixture was similar to the 15% RAP-only mix, showing that the use of rejuvenating agents will enable higher RAP quantities to be used without compromising the RAP. [10] Research conducted by Zaumanis et al[ has evaluated effectiveness for Rejuvenating additives in the processing of 40-100 percent RAP mixtures. variety of softening additives, including waste derived oils, plant oils, base oils from refineries (both non-traditional and traditional) and engineered oils have been used.…”