Solutions to improve the recycling rate and quality of plant produced hot mix asphalt

Abstract

The highways network is fundamental for the development of any country, since the transportation of people and goods is essential for current lifestyle, and roads can ensure the necessary access to any part of the territory. Thus, it is necessary to apply maintenance or rehabilitation techniques to keep their quality in an acceptable level. When these policies are not correctly used, reconstruction may be necessary, and in that case pavement recycling is one the most sustainable solutions, where the use of higher amounts reclaimed asphalt (RA) is becoming more common. However, the aged bitumen comprised in the RA material implies extra care in handling, namely regarding the use of lower production temperatures (or selective heating of RA and new aggregates) and this may involve the use of new bitumens with higher degree of penetration or the use of rejuvenating additives. This work aims to show the results of a laboratory study carried out to select the best rejuvenator to produce a mixture incorporating 50% of RA, prior to mass production in the plant, in order to obtain a recycled mixture with a quality equivalent to that of a conventional mixture.