Temperature: A key parameter on soil content reduction simulation in recycled asphalt aggregate

Abstract Reclaimed asphalt pavement is obtained from road repair. The most convenient usage for this material is in the asphalt mix production, but sometimes it is utilized as roadbed material because of an unsuitable management or because it does not match the requirement related to the possible maximum soil content. For instance in Japan, USA and Europe 10.6 million tons (2005), 3.4 million tons (2017), 7.8 million tons (2014) were used as unbound layer or in landfill. Hence, it is necessary to improve the management of reclaimed asphalt pavement and its treatment by using screens in processing plants, in case it fails observing the mentioned requirement. The former is possible to be mitigated by better planning, the latter is more complicated because clogging of the screens can occur in case that soil contaminates the reclaimed asphalt pavement. To this end, a piece of screenless equipment was proposed. This study shows a simulation on soil content reduction in the mentioned material, using a numerical model obtained from the proposed piece of equipment's experimental results. The results show that soil and aggregate properties, and water content, could affect the soil content reduction in reclaimed asphalt pavement. Besides, it was found that temperature can have a double effect on the mentioned activity. Further, compared with hot mix asphalt, the hot mix asphalt with 30% of processed aggregate by the piece of screenless equipment could represents an emission reduction of 4.8kg/Ton.