STATE-OF-THE-ART HOT RECYCLING

Hot recycling pertains to the recycling or reprocessing of reclaimed pavement materials into hot mix asphalt in a central plant. Although reclaimed uncoated, aggregate and Portland cement concrete materials can be reprocessed into hot-mix asphalt, hot recycling is usually meant to specifically include the reprocessing of reclaimed hot-mix asphalt or asphalt treated aggregate. Reclaimed uncoated aggregate materials are reprocessed in the conventional manner as new aggregates, whereas reclaimed asphalt coated aggregates are reprocessed using slightly modified techniques. Both reclaimed uncoated and coated aggregate materials may be reprocessed into hot-mix asphalt during the same operation. In either case, the use of some additional new aggregate may be required in the recycling process for the purpose of producing a hot-mix asphalt which meets the stated quality criteria for the mix and/or for the hot-mix plant operation, itself, which requires a certain quantity of uncoated aggregate to operate efficiently and within air quality standards. In all instances new asphalt cement and/or a suitable rejuvenating agent will also be added as part of the recycling process to restore the properties of the aged asphalt and to coat reclaimed or new aggregates that have been added. Hot recycling can be done in any type of hot-mix plant including the drum, batch, and continuous types. The hot-mix plant must be modified or retrofitted for recycling, if not originally equipped when new. In terms of overall plant replacement cost, the investment is relatively small. The actual hot recycling process is not complicated, and in fact not much different from the conventional process. The technology and equipment necessary to do recycling is developed and available. What makes hot recycling seem complicated sometimes is the seemingly infinite number of ways to go about it. In addition there are numerous factors unique to the highway industry and the asphalt industry in particular, that would make one recycling technique preferable in one area and not in another. These factors need to be addressed in order to meld hot recycling into the normal operating procedures of the asphalt paving industry. The concept of hot recycling has grown from one concerned with the utilization of pavement materials being disposed of in landfills to one also concerned with finding situations where pavement material removal for subsequent recycling provides an economic advantage over other pavement rehabilitation alternatives. It is the latter that is the most difficult to identify and to accomplish. (Author)

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1980/780/780-015.pdf
• Summary URL:
  https://scholar.google.com/scholar_lookup?title=STATE-OF-THE-ART+HOT+RECYCLING&author=R.+Smith&publication_year=1980
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/030903101X
• Supplemental Notes:
  • This paper appeared in Transportation Research Record No. 780, Proceedings of the National Seminar on Asphalt Pavement Recycling. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Smith, Richard W
• Conference:
  • National Seminar on Asphalt Pavement Reycling
  • Location: Dallas Texas, United States
  • Date: 1980-10-14 to 1980-10-16
• Publication Date: 1980

Media Info

• Media Type: Print
• Features: References;
• Pagination: pp 115-124
• Monograph Title: Proceedings of the National Seminar on Asphalt Pavement Recycling
• Serial:
  • Transportation Research Record
  • Issue Number: 780
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Aggregates; Asphalt plants; Dryer drum process; Hot mix asphalt; Mixing plants; Portland cement concrete; Recycling; State of the art studies
• Old TRIS Terms: Artificial weathering tests; Continuous mixing plant; Rejuvenating agent
• Subject Areas: Construction; Design; Geotechnology; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00334557
• Record Type: Publication
• ISBN: 030903101X
• Files: TRIS, TRB
• Created Date: Oct 28 1981 12:00AM