Asphalt Mixes Produced with Asphalt Shingle Sand

摘要

The use of RAS particles obtained from grinding/shredding of asphalt shingles is currently limited to between 3 and 5 percent. The addition of the sand only portion of RAS can reach more than 10 percent or even 15 percent while providing rheological characteristics different enough from those of conventional HMA. The technique is to sieve the shredded RAS particles to separate the fibres/bitumen clusters from the sand component. Only the shingle sand is recycled to the mix to facilitate obtaining a completely homogeneous mixture. The formulation of HMA containing a high RAS sand content is based on characterizing the mechanical properties of the HMA. HMA modified with high RAS sand content have a total bitumen content of about 8 percent. This paper discusses the characterization of the mechanical properties of HMA modified with RAS sand and the advantages of this technique. It was determined that rutting, thermal cracking and asphalt module were close to values normally obtained for the same formulation without recycling. On the other hand, there is a significant difference in fatigue resistance which is increased compared to conventional HMA.