MONTEVIDEO -- Minnesota Highway 7 between Montevideo and Clara City will be available for school buses and trucks hauling sugar beets, but most motorists may need to wait two weeks before the road is officially opened.
Paul Rasmussen, regional engineer with the Minnesota Department of Transportation, told the Chippewa County Board of Commissioners on Tuesday that an opening in two weeks is his best guess as this point. Even then, motorists could face temporary delays or deal with one-lane restrictions and detours on parts of the roadway.
Engineers with the department are attempting to analyze how they can correct what are being called "anomalies" found in the concrete of the newly built roadway.
The roadway was to have been opened for general traffic on Aug. 29.
This year's construction is the second year that traffic on the road has been detoured, and it is taking a toll on Montevideo businesses.
"I don't know how long the businesses are going to handle it," said Commissioner Jim Dahlvang, a co-owner of DJ's Sporting Goods on Highway 7 in Montevideo. A delegation of Montevideo business owners and Chamber of Commerce representatives attended Rasmussen's presentation to make known their interest in seeing the highway reopened.
Federal stimulus funds made it possible for the repavement of the roadway between Montevideo and Clara City this summer. Last year's work was focused on the portion of highway in Montevideo.
Rasmussen said the department discovered that concrete laid for the new roadway was embedded with "chunks," some of them fist-sized, of more dense material, as if the concrete mix was not uniform. He said some of these embedded anomalies can be found by visually looking for small divots on the pavement, as if searching for clams.
But they are more like cavities in teeth, and it's believed they adversely affect the roadway.
The problem appears to be caused by a cement plant brought from Texas for the project by the general contractor, Duininck Companies of Prinsburg. Rasmussen said the problem has been as vexing to the contractor as it has been to MnDOT, and both have worked hard to solve it once it was discovered.
The anomalies were first found in the concrete laid immediately east of Montevideo.
The worst area is believed to be in the first 4 to 4.5 miles east of Montevideo, where Rasmussen said "a lot" of anomalies were found.
No one knows how many exist within the concrete along the entire route. MnDOT has taken the unusual step of running a ground radar unit over the roadway.
It will likely take two weeks to determine exactly how many exist, and how best to correct the problem.
Computers are analyzing the radar images, and MnDOT crews will drill into the concrete to determine how the radar images match with what actually exists. Once that is known, MnDOT can develop a strategy to correct the problem, according to Rasmussen.