Abstract:
Considerable amounts of Reclaimed Asphalt Pavement (RAP) are produced every year,
as the road network requires maintenance to ensure the safety and comfort of its users. RAP is a 100%
recyclable material and a useful fit to be re-introduced into another cycle without downgrading its
functionality. Despite the current knowledge about the benefits associated with RAP use, it is not yet
largely applied in several countries. This paper aims to validate, on the basis of both short- and long
term
mechanical behaviours, the application of a bituminous mixture with a high RAP incorporation
rate (75%) in road pavement wearing courses. A crude tall oil rejuvenator was used. Both short- and
long-term oven ageing procedures were employed to simulate the ageing that occurs during mixture
production and in-service life, respectively. The tests for validating the RAP mixture as an alternative
solution comprised stiffness, resistance to fatigue, permanent deformation, and determination of
the water sensitivity. Furthermore, the RAP bitumen mobilisation degree was evaluated and a
mixing protocol was established. In comparison with virgin bituminous mixtures, it was found that,
in general, the high RAP mixtures presented similar or better behaviour. The ageing process had
a hardening effect namely in terms of stiffness and resistance to permanent deformation, without
significant effects on the resistance to fatigue and water damage.
