Before recycling could become a standard procedure for highway agencies, many questions had to be answered through the application of research. These questions included: How can the recycling potential of existing pavement be evaluated? How much virgin aggregate and asphalt should be added to the recycled mix? Are rejuvenating agents required to restore "life" to weathered asphalt and, if so, whhat types and amounts? What are the relative merits of hot and cold recycling and when is each appropriate? How is construction quality control to be conducted? State, federal, and other highway research agencies undertook an extended sequence of research projects to answer these and other questions. The result was the development of current recycling methods. The cost of research, development, and demonstration of recycling by the Federal Highway Administration (FHWA) and the 41 participating states is estimated at about $5 million. Cost savings of about $2.50 per ton for 5 million tons of asphalt paving mixtures were recorded in a data bank maintained by the FHWA through 1981. Assuming that only half of the recycling jobs of thaa period were included in the data bank, a yield of $25 million savings, or a 5:1 cost/benefit ratio, for recycling research can be extrapolated. On the basis that recycled mixtures will probably be used in rehabilitating most of the distressed asphalt pavements, and that improved equipment and techniques are now available, the current savings could amount to more than $100 million - by the most conservative estimates. (Author) (Author)

Media Info

  • Features: Photos;
  • Pagination: p. 16-17
  • Serial:
    • TR News
    • Issue Number: 119
    • Publisher: Transportation Research Board
    • ISSN: 0738-6826

Subject/Index Terms

Filing Info

  • Accession Number: 00450664
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Mar 31 1988 12:00AM