Influence of Roofing Shingles on Asphalt Concrete Mixture Properties

Abstract

It is estimated that the production of new roofing shingles generates approximately 1,000,000 tons of waste annually in the U.S., and about 36,000 tons of this waste is in the Twin Cities Metro Area of Minnesota. With another 8.5 million tons of waste materials which are similar to those used in asphalt concrete, it seems viable that their use in hot-mix would be an attractive alternative to disposing of them in landfills. This report presents the results of an effort to evaluate the use of roofing waste generated by manufacturers and from reconstruction projects. It was shown that up to 5%, by weight of mixture, manufacturing waste roofing shingles could be used in asphalt concrete with a minimum impact on the properties of the mixture. At a level of 7.5%, a noticeable softening of the mixture occurs, and this might be detrimental to pavement performance. The use of shingles from roof reconstruction projects resulted in the embrittlement of the mixture which may be undesirable for low temperature cracking of pavements. The manufactured shingle waste seems to work well in stone mastic asphalt mixtures.