Effects of Rubber on Asphalt Mixes Author(s): Gowda, G.V.; Elliott, Robert and Hall, Kevin, University of Arkansas Origin: Arkansas Date: January, 1997 Categories: Performance Key Words: Asphalt-Rubber mixes, crumb rubber modifier Summary: This project was conducted to develop an understanding of the behavior of asphalt concrete mixes that incorporate ground scrap tire rubber. The project focused primarily on the behavior and performance of a mix that was to be placed as an overlay on a portion of Interstate 40 near Russellville, AR. That mix incorporated a finely ground rubber as a portion of the aggregate. This process of adding rubber is referred to as a “dry” process in contrast with processes in which the rubber is blended “wet” with the asphalt cement. The study found that the “dry” process as used on the I-40 project was not beneficial to the mix and in fact appeared to be detrimental. Limited testing was performed as an evaluation of the wet process. This testing showed that the “wet” process addition of rubber can be beneficial. However, the results are not sufficient to determine whether or not the benefit justifies the additional costs.