The use of rejuvenators as an effective way to restore aged binder properties

Abstract

The amount of Reclaimed Asphalt recycling using rejuvenating agents has increased recently due to environmental and economic constraints. Rejuvenating agents are now regularly used to restore the aged binder properties similarly to those of a virgin binder. The current European specifications for asphalt paving bitumen use only empirical testing. Such procedure is appearing not sufficient to address the effect of rejuvenating agents. More advanced rheological analysis using DSR and BBR equipment appears promising. Parameters such as viscous to elastic transition (VET) from DSR or the difference between the creep stiffness and m-value critical temperature (ΔTCR) from BBR provide apparent indication of a binder’s flexibility and ability to relax stresses in cases of rejuvenation. This paper investigates the effect of three various rejuvenators on aged binder behaviour and shows that the rejuvenation process has a large impact on the material properties. Particularly rheological measurements demonstrated that as the aging process progresses the variance in rejuvenated binder behaviour increases especially in terms of performance at intermediate (VET) and low temperatures (ΔTCR)