Utilization of waste fibers in stone matrix asphalt mixtures

摘要

Waste fibers produced from manufacturing processes such as scrap tire processing and automotive carpet manufacturing are sometimes used in other applications, but commonly are disposed of in landfills. If these fibers could be beneficially utilized in any application, it would reduce the load on the nation's landfills. Also, since these are waste materials, the cost of using these fibers compared to fibers manufactured for a specific application could be considerably less. The major objective of this research was to determine the feasibility of utilizing waste tire and carpet fibers in stone matrix asphalt (SMA). Many states utilize such rut resistant SMA mixtures on heavily traveled highways. Fibers are included in SMA mixtures as a stabilizing additive to prevent excessive draindown caused by relatively high contents of polymer modified asphalt binder. The common types of fiber used in SMA include cellulose and mineral fibers. This study compared the performance of SMA mixtures containing waste tire and carpet fibers with mixes made with commonly used cellulose and other polyester fibers produced specifically for use in hot mix asphalt (HMA). No significant difference in permanent deformation or moisture susceptibility was found in mixtures containing waste fibers compared to cellulose or polyester. Also, the tire, carpet, and polyester fibers significantly improved the toughness of the mixtures compared to the cellulose fibers. (C) 2004 Elsevier B.V. All rights reserved.