Reclaimed asphalt recycling agents: Looking into the blueprint of their mechanisms of action

•Investigating the effects of oxidative aging on the mechanical and physico-chemical properties of bitumen.•Reversal of the effects of the aging phenomenon on aged bitumen using Recycling Agents.•Differentiation of rejuvenation effect from softening effect of a Recycling Agent.•Evaluating the effectiveness and applicability of the techniques used in this study for the investigation of bitumen aging and its potential recycling/reuse.•The study combines Rheology, Microscopy and Calorimetry techniques.