Blue Earth County: Finn/Oil Gravel Project: CSAH #24 from TH 30 to CSAH 25

In 1996, Blue Earth County paved a rural, two-lane County State Aid Highway using Finn Road or Oil Gravel technology to explore its potential for providing an economical easy to maintain, and improved all-weather driving surface for the County’s 300 miles of gravel road.

Koch Oil designed the mix, and Loveall Construction of Winnebago, Minn., constructed the mix, with construction inspection and contract administration by Blue Earth County. Separate pay items for gravel, quartzite, asphalt, and produce and lay gave the County the flexibility to modify the mix design based on design information and to conduct construction tests for the highest quality pavement. High Float Emulsion 3010 asphalt binder was used. The pavement was constructed in two demonstration sections: one with 100 percent quartzite and one with 50 percent gravel and
50 percent quartzite.

Significant segregation of the mix occurred during construction, which was repaired by spray injection and seal coating. The County reports performance after one winter as good, with initial construction cost about 33 percent less than a traditional 7-ton hot mix bituminous pavement design. No maintenance experience is available to date.