Warm recycling of flexible pavements: Effectiveness of Warm Mix Asphalt additives on modified bitumen and mixture performance

Results indicate that lower production temperatures allowed a significant decrease in stiffness, effectively balancing the inclusion of RAP material without penalizing mixture performance. Compactability, volumetric and fracture properties indicate the possibility to produce suitable recycled warm mixtures when the appropriate WMA additive is selected. The chemical additive appeared able to provide overall improved performance, whereas the organic additive made the mixture brittle and susceptible to permanent cracking.