Performance evaluation of gap graded Asphalt Rubber mixtures

In this research, an extensive laboratory test program was conducted in order to investigate the mechanical performance (stiffness, fatigue, permanent deformation and thermal cracking) of a gap graded Asphalt Rubber Asphalt Concrete (ARAC) establishing an important database of ARAC engineering performance. Additional tests were performed on Asphalt Rubber binder and ARAC mix in order to verify whether the new Mechanistic Empirical Pavement Design Guide (MEPDG) can be used effectively for AR materials. Results were compared with those of reference materials tested in laboratory or found in literature.

Research highlights
► Fatigue and rutting behaviour of ARAC clearly outperform traditional asphalt concretes.
► The ARAC mixture showed excellent thermal cracking resistance.
► Some refinements of MEPDG are needed to better predict the AR performance.