Chemical and rheological analysis of modified bitumens blended with "artificial reclaimed bitumen"

Bitumen characteristics are fundamental for the development of good performance in asphalt mixtures, particularly when the mix includes Reclaimed Asphalt (RA) as aged bitumen can strongly affect the properties of the final bituminous phase. In this study three modified bitumens with different contents (1.8%, 2.8% and 3.8%) of SBS polymer were selected. Blends of these bitumens with various percentages of an artificial reclaimed bitumen (itself polymer modified), long-term aged in laboratory, were analyzed. A chemical characterization together with classical and innovative rheological tests were performed. The chemical investigation conducted using FTIR analysis showed that different percentages of artificial reclaimed bitumen included in the blends influence the final SBS amount. Rheological tests demonstrated that the addition of the artificial reclaimed bitumen does not penalize the final bituminous blend characteristics thereby indicating that the maximum amount of Reclaimed Asphalt incorporable in a mixture (according to the highest percentage of artificial reclaimed bitumen investigated) does not appear to be limited by the rheological characteristics of the final bituminous phase.