Experimental Investigation of the Fracture Properties for Crumb Rubber Modified (CRM) Asphalt Mixtures

Abstract

Cracks that develop daily and seasonally due to the environmental or mechanical effects caused by axle loads, propagate over time and become an important type of distress in asphalt layers. This type of distress can significantly increase the maintenance and rehabilitation costs of pavements. The use of rubber powder or fine granules in certain proportions to the bitumen content can extend the life of the pavements and reduce the environmental problems caused by waste tire disposal. In this study, the fracture behavior of normal and rubber-modified asphalt mixtures was investigated in accordance with AASHTO TP105 by adding waste tire granules at the ratio of 20% by weight of bitumen to hot mix asphalt. It has been determined that when the waste tire powders are added to the hot mix asphalt by replacing 20% of the bitumen weight, coatings with 37% more elastic ability could be made on sustainable pavements. Waste tire powder-mixes performed 118% higher in maximum load and 97% higher in fracture toughness compared to control-mixes. It has been shown that low temperature performance could be improved when waste tire powder-added bitumen processed by dry method is mixed to hot mix asphalt up to 20%.