Four potholes were dug in order to evaluate a Poweray TR20 heater used for patching bituminous concrete. Each hole measured about 20 inches square and all were dug to the bottom of the existing material, 3-1/4-4 inches deep. Three of the holes were heated, the fourth was not. The heater was placed over the hole and turned on for four to six minutes then removed. The existing material around the hole was fluffed with rakes, then the patch material was put in at temperatures near 300 degrees F and compaction was employed. No densities were determined. The following observations were made: (1) the temperatures of the existing material were raised significantly by the heater. Thermocouples 1/2 to 1-inch into the sidewalls at various depths showed temperatures of over 150 degrees F after a four minute application and over 200 degrees after six minutes, all before the patch material was placed. (2) There was little difference between heated and unheated pavement in (a) penetration at 77 degrees F, (b) viscosity at 140 degrees F, and (c) viscosity at 275 degrees F. (3) There was a better knit and bond between existing pavement and patch material in the heated potholes. (4) Because of the workability of the existing surface surrounding the hole, the surface could be feathered to the patch material, resulting in a better appearance, excellent overall smoothness and riding quality. In summary, the heater did prove to be advantageous in patching potholes in windy, 50 degree F weather. /HRIS/

  • Supplemental Notes:
    • Appeared in "Special Reports on: Use of Equipment and Methods of Maintenance".
  • Corporate Authors:

    Federal Highway Administration

    Construction and Maintenance Division, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Burnett, W C
  • Publication Date: 1975-7

Media Info

  • Pagination: 1 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00126298
  • Record Type: Publication
  • Report/Paper Numbers: Evalt Rpt.
  • Files: TRIS, USDOT
  • Created Date: Oct 18 1975 12:00AM