Scrap tire recycling mandates are written into both the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 and the Resource Conservation Recovery Act. South Carolina Department of Transportation (SC DOT) has been conducting several research projects utilizing crumb rubber in asphalt mixtures since 1991. This research project was divided into two sections: laboratory phase and field phase. In the laboratory phase the use of crumb rubber utilizing the "wet" method was investigated. A total of 360 laboratory-prepared Marshall specimens were made and tested. The materials used to prepare the specimens were typical of those used for Type 1A surface mixtures used by SC DOT. The experimental design consisted of using three aggregate sources, three antistrip additives, and four rubber percentages (i.e., 0%, 12%, 15%, and 18% by weight of asphalt cement). The indirect tensile strengths, tensile strength ratio, visual strip rating, percent air voids, and bulk specific gravities were determined and statistically analyzed. The results indicated that, in general, as the rubber percentage increased, the strength decreased. However, the specimens containing antistrip additives had a higher increase in strength compared to that of the virgin materials. In addition, the optimum asphalt content generally increased as the rubber percentage increased. In the field phase, several field test sections of asphalt mixtures containing crumb rubber were constructed and monitored for several months. In addition, one project which was constructed approximately 3 years ago with the "dry" process (i.e., PlusRide) was monitored. The specifications for some of these field test sections were prepared. Every three to six months, field cores were obtained from these field test sections and tested for several properties (e.g., BSG, dry and wet ITS, TSR, etc.). In addition, the skid resistance of these pavements was measured.


  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 173 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00725533
  • Record Type: Publication
  • Report/Paper Numbers: Final Project Report, FHWA-SC-96-02
  • Contract Numbers: SPR 554
  • Created Date: Sep 6 1996 12:00AM