Effect of Using Fog Seals Without Sanding on Surface Friction and Durability of Open-Graded Friction Course

The Alabama Department of Transportation has customarily used open-graded friction course (OGFC) as the final riding surface on interstate and high traffic roadways because of its safety benefits. However, some OGFC sections have experienced premature failures, threatening its use as a surface course. Mixtures on those projects are raveling out after only 6 to 8 years in service. To maintain the good performance of OGFC, preventive maintenance has been considered essential. There are several approaches for maintaining OGFC, one of which is the application of fog seals. While fog seals can reduce raveling and extend the service life of OGFC, there are two trade-offs that must be considered, including decrease in the drainability and temporary loss of surface friction. The objective of this study is to evaluate the effect of using fog seals without sanding on the surface friction and durability of OGFC. The study evaluated three fog seal materials through both field work and laboratory testing. The results of this study showed that the surface friction based on the IFI parameter F60 may be reduced between 2 to 24 percent. Therefore, fog seals without sanding should be used with extreme caution on OGFC as they may cause a temporary loss of friction. Each of the fog seal products evaluated in this study appeared to improve the abrasion resistance of OGFC based on the Cantabro test, and the Hamburg test results clearly showed a trend that the middle spray rate (0.10 gal/sy) was better in enhancing resistance to rutting/moisture susceptibility of OGFC.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK40 Characteristics of Asphalt-Aggregate Combinations to Meet Surface Requirements
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Tran, Nam
  • Watson, Donald E
  • Anwer, Nadeem
• Conference:
  • Transportation Research Board 91st Annual Meeting
  • Location: Washington DC, United States
  • Date: 2012-1-22 to 2012-1-26
• Date: 2012

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 18p
• Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Durability; Friction course; Open graded aggregates; Preventive maintenance; Service life; Surface course (Pavements); Surface friction (Geophysics)
• Uncontrolled Terms: Fog seals
• Subject Areas: Highways; Materials; Pavements; I30: Materials;

Filing Info

• Accession Number: 01372816
• Record Type: Publication
• Report/Paper Numbers: 12-4544
• Files: TRIS, TRB
• Created Date: Jun 15 2012 4:04PM