Application of rejuvenators and virgin bitumen to restore physical and rheological properties of RAP binder

Abstract

Both chemical and rheological aspects of aged bitumen in reclaimed asphalt pavement (RAP) material play an important role in the final performance of bituminous mixtures containing recycled asphalt material. This must be especially considered in the case of pavements containing high RAP content. The use of rejuvenators and/or virgin bitumen in recycled mixtures helps improving the properties of aged bitumen. This research study investigates RAP oxidised bitumen and its possible rejuvenation with virgin bitumen and addition of various additives as rejuvenator agents. Tests were conducted to analyse the chemical, rheological and physical behaviours of several binder mixes before and after laboratory ageing processes. Long-term ageing of rejuvenated binder mixes was also investigated to assess the effectiveness of rejuvenation over time. The results showed that the addition of virgin bitumen and rejuvenators could improve the performance of oxidised bitumen and increase its resistance to further ageing.

Keywords:

• oxidised bitumen
• rheological behaviour
• ageing index
• RAP
• rejuvenator