OPERA 2007 annul report published
You can download it from the OPERA project Web page
OPERA Project:
Frost Boil Correction
Project title: Frost Boil Correction
Sponsor name: Gene Busacker
Agency: Scott County Public Works
Phone: 952-496-8478
Problem: Water that seeps into gravel or red rock roadbeds can cause frost boils and other road defects, as happened on heavily traveled Scott County roads on a yearly basis. These road conditions resulted in complaints and shoulder damage.
Solution: Instead of red rock or gravel, use millings and Geo-Tec fabric to seal the road bed.
Procedure: After laying Geo-Tec fabric across the road top (the entire 24-foot width and 50 feet past any bad spots to ensure a good, hard road bed), three 6-inch layers of millings are laid, graded out, watered, and compacted with a roller for a total depth of 18 inches. Two inches of class-five gravel are laid on top of the millings, and a reclaimer mixes gravel and the top 2 inches of millings. After further watering, blading, and compacting, the new road bed is ready.
Results: The fabric kept clay and mud from being pushed up into the millings layers, and the millings sealed water out of the road bed. There have been no signs of frost boils or weak spots in the road beds after two spring seasons, and there have been no complaints.
Approximate Cost: $10,000 ($5,000 approved for project)
Implementation: The county plans to use the material in future road repairs.
Status: Completed
The Exchange regularly highlights projects completed under the LRRB’s Local Operational Research Assistance Program (Local OPERA). A condensed sample from the 2007 OPERA annual report is reprinted above. For a copy of the report, please visit www.mnltap.umn.edu/opera.
Local OPERA helps to develop innovations in the construction and maintenance operations of local government transportation organizations. Learn more about the program and apply for OPERA funding online at www.mnltap.umn.edu/opera, or contact Jim Grothaus, Minnesota LTAP director, 612-626-1077, mnltap@umn.edu.