International Evaluation of the Performance of Warm Mix Asphalts with High Reclaimed Asphalt Content

The Task Group 2 of the RILEM Technical Committee 264-RAP on non-cold recycling identified the need to gather some insights about possible durability issues associated with the combination of Warm Mix Asphalt (WMA) and of Reclaimed Asphalt (RA) in order to prioritize the characterization or research needs for relevant damage types. For this purpose, an international inter-laboratory testing program was launched in 5 different laboratories. This was developed on the basis of the challenges which a road material designer commonly faces: reduce the temperature, add RA, but preserve the same properties. Each laboratory characterized, according to its internal protocol, two variations of the same type of mixture (similar grading curve, binder content, etc.): a Hot Mix Asphalt (HMA) without RA taken as reference and a WMA with 40% RA. The performances of all the WMA with 40% RA are then compared in order to see if common trends emerge from the different characterization methods and reveal property issues specific to WMA + RA combinations.