Compatibility and Rheological Study of ASR Asphalt Binder

When junk automobiles are shredded to recover the ferrous and nonferrous metals for recycling, a large quantity of nonmetallic residue, commonly called automotive shredder residue (ASR), is generated. Because ASR mostly contains plastic and rubber related materials, and the addition of plastic and scrap rubber from waste tires as a road material has been proven to be effective in solving existing pavement related problems, attempts were made to examine the feasibility of ASR as a road material additive. As a part of this effort, compatibility, rheological, and leaching properties of ASR modified asphalt were studied. The photomicrographs and Tg of ASR modified asphalt demonstrated some compatibility between ASR and asphalt. Dynamic mechanical analysis indicated that rutting and aging properties of asphalt should improve with the addition of ASR. The toxicity characteristics leaching procedure test indicated that leaching levels of various metals from ASR modified asphalt were well below the Environmental Protection Agency regulatory level.