IS YOUR ASPHALT FRETTING (WHILST YOU AREN'T)?

Fretting is the loss of the matrix of new hot rolled asphalt which after a few weeks of trafficking can leave the chippings proud of the surface. The author claims that it is often unrecognised as such and other factors are blamed. The course of action is to leave the material with a consequent loss in skid resistance and reduced life, or the costly replacement of the material. From a selection of cores taken from sites constructed in the summer and winter the author was able to deduce that densities were even throughout the layer during warm weather but a density gradient existed in winter construction. The density was found to be lowest at the surface, increasing with depth, reaching a maximum and then falling away towards the basecourse interface. Under unfavourable circumstances the density to a particular level is low enough to allow traffic to abrade the matrix of the asphalt. The author gives evidence to suggest that the reduced density is caused by heat transfer from the hot asphalt to very cold chippings. Fretting could be avoided by protecting chippings before use thus preventing the application of cold chippings. The use of a vibrating roller instead of the normal dead-weight version also gives better compaction. (TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01426168
• Corporate Authors:

  Embankment Press Limited

  Crown House, 60 North Circular Road
  London NW10,   England 
• Authors:
  • Hunter, R N
• Publication Date: 1982-11

Media Info

• Pagination: p. 32
• Serial:
  • Highways and Public Works
  • Volume: 50
  • Issue Number: 1871
  • Publisher: D.R. Publications Limited
  • ISSN: 0142-6168

Subject/Index Terms

• TRT Terms: Binders; Chippings; Core samples; Density; Heat; Heat transfer; Hot coated materials; Hot rolling; Rolled asphalt; Rollers; Skid resistance; Stripping (Pavements); Traffic; Transfer characteristics; Vibratory equipment; Wear; Wearing course (Pavements); Winter
• Uncontrolled Terms: Laying
• Old TRIS Terms: Fretting
• ITRD Terms: 4585: Chippings; 5700: Core (boring); 5908: Density; 6743: Heat; 4997: Hot coated material; 3623: Laying; 4989: Rolled asphalt; 5287: Stripping (binder); 755: Traffic; 6731: Transfer (phys); 3692: Vibrating roller; 5293: Wear; 2980: Wearing course; 2575: Winter
• Subject Areas: Construction; Highways; Materials; Operations and Traffic Management; I31: Bituminous Binders and Materials; I52: Construction of Pavements and Surfacings;

Filing Info

• Accession Number: 00373336
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Jul 30 1983 12:00AM