Properties of Warm Mix Asphalts with Reclaimed Asphalt Pavement

The environmental and economical advantages of using Reclaimed Asphalt Pavement (RAP) in asphalt mixes are well known by the road industry. However, their combined use with Warm Mix Asphalt (WMA) technologies still provokes certain doubts. There is currently a lot of discussion about the role of the aged binder present in the RAP and how it blends with a fresh binder. This matter becomes even more relevant when the production temperature of the mix is reduced, as is the case in warm mix asphalts. In this work, the mechanical properties of warm asphalt mixtures, containing 30 and 50 percent by mass of RAP were prepared at temperatures 40 degrees C lower than usual, are discussed. Mechanical tests such as dynamic modulus, fatigue and thermal stress restrained specimen tests were carried out with these samples. Rheological measurements of the binders used in these samples are also presented. Similar properties were observed between the WMA containing RAP and a reference hot mix asphalt. A study on the workability of mixtures RAP is also discussed. Workability was measured using two different methods, one based on the torque required to work an asphalt mix and another based on the use of a gyratory compactor.