Frost Heave Mitigation Using Structural Polymer Injection

Frost heave is caused by water freezing into ice lenses in silty subgrade soils. Subgrade frost heaving can cause significant distress in a flexible pavement. This paper summarizes a two- year study of a successful mitigation procedure using structural polymer injection to create a thermal barrier to reduce heat loss below the pavement. The contractor had problems breaking through a tough quartzite ridge during the construction of Wyoming Highway 70 four miles west of Encampment, WY. As an alternative, he placed three feet (1 m) of fill over the ridge and tapered the vertical alignment to match the approaching grades. The silty fill is classified as an SM/A-4/A-2-4. Greater than three inches (75 mm) of heave have been measured over a 100 ft (30 m) distance across the ridge. To mitigate the problem, a three-inch thick layer of structural expanding polymer (Uretek 486 STAR) was injected immediately below the base course at a depth of 18 inches (450 mm). This both supports the road surface and creates a thermal blanket having a significant R value to reduce heat loss. Surface surveying over two winters showed that the heave was reduced from three inches to one-half an inch, undetectable to the motorist. The thermal regime was determined by installing thermisters above and below the polymer layer at six bore holes. The data shows that the temperatures below the polymer stayed at or above 0C, hence controlling the heave. Untreated areas still showed three inches of movement.

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• Supplemental Notes:
  • This paper was sponsored by TRB committee AFP50 Seasonal Climatic Effects on Transportation Infrastructure.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Edgar, Thomas V
  • Mathis, Roy
  • McGary, Tim
  • Potter, John Christopher
• Conference:
  • Transportation Research Board 93rd Annual Meeting
  • Location: Washington DC
  • Date: 2014-1-12 to 2014-1-16
• Date: 2014

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Maps; References;
• Pagination: 12p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Flexible pavements; Frost heaving; Pavement maintenance; Polymers; Silts; Subbase (Pavements); Subgrade (Pavements); Winter maintenance
• Subject Areas: Highways; Maintenance and Preservation; Pavements; I62: Winter Maintenance;

Filing Info

• Accession Number: 01515512
• Record Type: Publication
• Report/Paper Numbers: 14-1029
• Files: PRP, TRIS, TRB, ATRI
• Created Date: Feb 24 2014 8:43AM