A method (which is seen as a means of stretching available funds in this time of economic crisis) is described of restoring badly cracked pavements through a process of heater scarification followed by an asphaltic concrete finishing course application. The surface of the existing crack-up and usually dried-out pavements will be heated and scarified to a depth of approximately 0.75 inch, the scarified material will be rejuvenated and recompacted followed by the placement of an asphaltic concrete finishing course. Pavements of this type of rehabilitation have been in service for 2 or 3 years and the performance is judged exceptionally good. The procedure is outlined, and the characteristics of the heater unit used in the operation are discussed. The required depth of heat must be accomplished before any scarification is attempted, for once the surface is scarified, the fluffed up material acts as an insulator opposing any subsequent heat that might be applied. It is not effective to have a heater searification combination followed by a second such unit. With proper balance of heater units to pavement conditions, with the flame sheilded and/or positioned other than directly upon the pavement surface, the heating phase can be accomplished effectively and without emission control problems. Specifications require that in addition to scarifying the pavement to a depth of approximately 0.75 inch, the system should be designed that a tumbling action of the scarified material is effected. This will break and cause some mixing of the material. The leveling device is discussed. It has been found effective to accomplish the compaction while the material is still hot and before the rejurvenating agent is applied. Pneumatic tired rollers are used and the specification is made that the rolling shall be completed within one hour from scarification. The asphaltic concrete finishing course is described and the results of a cost study are discussed.

Media Info

  • Features: Figures; References;
  • Pagination: p. 52-59
  • Serial:
    • Issue Number: 491

Subject/Index Terms

Filing Info

  • Accession Number: 00260980
  • Record Type: Publication
  • Created Date: Aug 16 2004 6:57AM