Highway department uses new material
The pavement being put down this week on the under-construction area of County Road Z, south of Hammond, is not going on top of typical gravel. Jeff Durkee, St. Croix County Highway engineer, said the road contains an additive chemical that strengthens the gravel.
Durkey said County Road Z is one of four roads so far on which the St. Croix County Highway Department has used this road additive, "Base ONE aggregate base stabilizer."
"It allows us to keep it (the road) wide at less of a cost," said Durkee.
When roads are strengthened, gravel is typically added to improve the road. However, road material is sloped as it rises off the ground, for stability, and each new layer is slightly smaller than the last. If more gravel is added, the road becomes higher, and the higher the blacktop level then becomes. And the higher the road is, the more it needs to be sloped down the sides. So adding more gravel actually gives the road a smaller width, Durkee said.
"Base ONE" allows the highway department to keep the road at a lower level, and use less gravel, said Durkee, therefore allowing the blacktop surface to stay wider than it otherwise might be.
"Base One", Durkee said, is applied to roads via a water truck. The product is mixed half-and-half with water, and then sprayed onto the grated pavement. Then the chemical is mixed with the top four to five inches of road material. Finally, Durkee said the road is compacted, and then paved.
County Road Z has been compacted and the paving process should begin this week, Durkee said.
He said the process of using "Base One" is "very easy."
"We have trucks with spray bars that distribute water anyway," said Durkee. "The additional cost of our labor and equipment isn't extremely large."
Durkee said this is not the only chemical that can be added to pavement to strengthen it.
"This is the one we chose," Durkee said. He said the Highway Department selected "Base One" because they had heard of its use on some roads in Minnesota.
"I had heard good things about it," Durkee said. "I had even driven on some roads it had been used on in Minnesota."
However, Durkee said the highway department was not without its misgivings when they first began using "Base One".
"We were hesitant at first," Durkee said, "because the material we use is a trademark material, but patent pending. They're a little secretive of their formula."
Despite initial misgivings, Durkee said the highway department is now very pleased with the way "Base One" has worked on the roads they maintain.
So far, Durkee said "Base One" has been used on the first mile of County Road T, north of its intersection with Highway 64; between County Road T and County Road J, south of Hammond; on 140th Avenue; and on 190th street in the Town of Hammond. And, of course, on County Road Z.
Durkee said the highway department used "Base One" for the first time around a year ago, and have had positive results and positive support from top management, including Highway Commissioner Tim Ramberg.
"We've enjoyed our experience with it so far," Durkee said.