Increasing the content of reclaimed asphalt in asphalt mixture by using rejuvenators

Recycling pavements is beneficial on various levels, since using reclaimed asphalt (RA) has a positive effect on the economy and environmental protection at the same time. Removed old asphalt pavement is no longer considered as a waste material, which has to be landfilled, but a useful material for further applications. Leading to a reduction of the need for virgin materials and preserve the planet. At the start, RA was used for construction of embankments and unbound granular layers, later cold recycling became another effective solution. After years of experiments, the rate of RA has increased to reach even the 100 %. But typical RA content in hot asphalt mixtures is between 25 % to 40 %. The presence of RA in the asphalt mixture has a negative effect on the mixture properties. Two alternatives were used in order to soften the aged bitumen – use of softer binder or special additives, i.e., rejuvenators.

This study evaluated the possibility of increasing the RA content (30 % and 50 %) in asphalt mixture by adding mainly bio-based alternative rejuvenators. Mechanical performance was evaluated by means of laboratory investigations for typical characteristics dedicated to durability, stiffness and cracking potential.