County Road 12 (Kettle River, MN)
Frost-heaving problem resolved
Year Completed: 2001
County Road 12 in Kettle River, MN had a trouble spot that underwent annual surface maintenance due to frost-heaving. Later it was learned a spring in the middle of the road subgrade that constantly pumped water to the surface and damaged the road with moisture and frost-heaving.
A conventional subbase of clean class 5 aggregate was installed and the next year an edge drain was installed, and yet the water was not handled efficiently enough to prevent road damage. Class 5 could not get the water to the drains effectively enough.
Installing TDA in the subgrade solved the moisture problem because the void space within TDA allowed water to move into the drains. As a bonus, the TDA void space and hydrophobic properties prevent water from wicking up to the surface of the road and causing frost-heaving problems.
Project engineer John Sielmeier said: "Tire shreds were placed along about 700 feet of Carlton County Road 12 during 2001. In the past, this portion of the roadway had experienced frost heave and spring thaw weakening requiring excessive maintenance activities. The tire shreds were placed to increase the durability and safety of this portion of the roadway and to try an innovation technique that may have applications to other roadways in Minnesota."