3 Citizen Group 6-29-15 Notes from Conversations and Emails with Bruce HasbargenNotes from Conversations and Emails with Bruce Hasbargen, County Engineer, Beltrami County, MN
May and June 2015
Bruce Hasbargen is the County Engineer for Beltrami County, MN.
Bruce has been with Beltrami County for 6 years.
Beltrami County has 750 miles of road, 350 are aggregate and 400 are paved.
Following are Beltrami County’s current practices and observations.
1. Does not currently pave roads with less than 250-300 cars a day, but has in the past paved
roads with over 150 cars per day. In their experience, it is not cost effective to pave roads
with less than 150 cars per day.
2. Has been using bound aggregate (which they refer to as the “good gravel”) with chlorides on
their aggregate roads for 4 years.
3. Has replaced most gravel road surfacing with the “good” bound aggregate.
4. Has used “good” bound aggregate with success on 11% grades. (They are a hilly county.)
5. Grade their aggregate roads to a 4% slope to shed water efficiently.
6. Use Class 1 with 8-15% binder plus added clays (vs. Class 5 that has 3-10% binder)
7. Has good success with putting chlorides in top 3” of aggregate. Chloride run-off is not a
problem when bladed into the aggregate.
8. Blading maintenance events went from approximately 2 x per month (plus after rain events)
to 2 x per year.
9. Motor grader operators can distinguish between the “good” bound aggregate and typical
gravel. It is easier to work with and holds together better.
10. Estimate that this “good” bound aggregate is 80% more stable than typical gravel.
11. Use rock ditches alongside aggregate roads. They use rocks anywhere from 3”-24”
depending on situation. Rocks dissipate flow. The ditches are largely self-cleaning on hills
because of flow velocity.
12. Rock ditches that were installed 5 years+ ago have not needed cleaning yet.
Bruce received the MNDOT Bound Aggregate Surfacing Guide Specifications and Bound
Aggregate Gradation Specification that we are recommending. He confirmed that these
specifications are in line with the bound aggregate used in Beltrami County.
Bruce reviewed these notations and confirmed that they are correct.
Conversations and emails were with Steve Monlux and Pam Smith.
Note - Differences in precipitation between Beltrami County and Scandia are within accepted tolerance
for similar experience with bound aggregate material - Steve Monlux. Used Noaa historical precipitation
data for prior 12 months, prior 60 months and entire 20th century averages.