MICROWAVE HEATERS RECYCLE HOT MIX ASPHALT

Microwaves are coming as a new means of commercially recycling asphalt with no visible emissions. A new state-of-the-art plant in Los Angeles now meets and beats the toughest environmental regulations in the nation--and it heats and treats 100 percent reclaimed asphalt pavement (RAP) as hot mix for reuse as base and surfacing on city streets and highways. Cyclean, Inc., Georgetown, Texas, has developed the new technology into a proprietary system of equipment. The process entails drying and preheating the RAP to an initial temperature of about 230 deg F on a fluidized bed conveyor. A microwave-powered heating tunnel then completes the heating to the desired final temperature before a rejuvenator is added to restore the chemical and physical properties of the original mix. Commercial proof of the new system comes from Cyclean's $4.1 million contract to produce 320,000 tons of recycled hot mix for the city of Los Angeles over a two-year schedule for $13/ton. Production started in early 1987 and continues to the end of the 1988 season. The system is still limited to a production rate of about 65 tph but with storage silos, it produces up to 1200 tpd to meet the city's paving needs. This article describes how the system works, its power requirements, environmental restrictions, and how the process copes with the problems of metal in the RAP and protecting stockpiles of RAP from rain water.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03620506
• Corporate Authors:

  Cahners Publishing Company

  275 Washington Street
  Newton, MA  United States  02158-1630
• Authors:
  • Munn, W D
• Publication Date: 1988-10

Media Info

• Features: Photos;
• Pagination: p. 66-69
• Serial:
  • Highways and Heavy Construction
  • Volume: 131
  • Issue Number: 10
  • Publisher: Cahners Publishing Company
  • ISSN: 0362-0506

Subject/Index Terms

• TRT Terms: Asphalt pavements; Demand; Electric power supply; Environmental impacts; Equipment; Hot in-place recycling; Hot mix asphalt; Microwaves; Productivity; Recycling; Technological innovations
• Old TRIS Terms: Electric power demand
• Subject Areas: Energy; Environment; Highways; Maintenance and Preservation; Materials; Vehicles and Equipment; I31: Bituminous Binders and Materials; I61: Equipment and Maintenance Methods;

Filing Info

• Accession Number: 00476856
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 31 1988 12:00AM