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 Pavements (RAP) is a technology that presents many benefits in terms of both cost and environmental savings. This study investigated the performance of RAP mixes containing rejuvenation additives in order 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 using RAP proportions of 15% and 30%, as well as with the addition of different types of rejuvenating agents. The 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 to a mix with no RAP, and concurrently the addition of rejuvenators counteracted against over-stiffening effects of RAP. The addition of RAP, especially 30% RAP proportion, had poorer fatigue performance than when only 15% RAP, but with the use of rejuvenation agents, the fatigue performance of the high RAP mixes was improved significantly. The use of a maltene fraction for RAP rejuvenation had marginally better fatigue performance than a chemical rejuvenation agent. The research results provided a valuable understanding of the behaviour of RAP mixes, and in particular the positive performance results that can be gained by using rejuvenation additives.