Northeast Asphalt Uses Mill and Fill on Popular Tourist Route

With the tourist season nearing its end, crews began construction in August 2009 on US Hwy 45, a primary thoroughfare from northern Wisconsin to Michigan, completing the project in October 2009. Northeast Asphalt Inc., Greenville, WI, completed the repairs of the 15.25-mile stretch of the two lane highway from Eagle River to Land O’ Lakes.

The surface of this popular tourist route was suffering from distressed and cold temperature cracking. As a result, mill and fill was chosen as the technique to repair the road. Due to the amount of traffic on the road, several other upgrades were made to enhance its safety.

Funding for this project came through the American Recovery and Reinvestment Act. The main goal of ARRA is to create new jobs and save existing jobs. “This project provided 70 company employees with work,” says John Bartoszek, regional manager with Northeast Asphalt. “In addition, this project provided work subcontracted to another 13 construction companies.”

Safety for the project, safety for the road

Safety was a key concern both during the project and after its completion. Special precautions were taken to make sure that travelers were safe when using the road during construction. As a result, Northeast Asphalt worked with the Department of Transportation to help with the route while the road was under construction.

A few additional changes were made to the original project plans to provide a safer roadway for travels during construction.

“The original project plan called for milling 4 inches of the existing asphalt pavement and placing barrels at the centerline to keep traffic confined to each lane,” Bartoszek says. “This construction plan would create a 4-inch elevation difference between the northbound and southbound lanes. Therefore, no passing would be safely possible for the traveling public within the 15.25-mile zone during construction.”

Before deciding on what method would be most effective, Northeast Asphalt initially paved directly behind the milling operation. “It was determined this method would be safer and provide better traffic flow with minimal effect to the traveling public,” Bartoszek says. “It also reduced the centerline elevation difference and provided cost savings because it eliminated the need for centerline barrels.”

Another safety focus was making changes to the existing layout of the road creating a safer environment for travelers. One major enhancement to the road was the addition of acceleration and de-acceleration lanes. With five intersections along the stretch of US Hwy 45, upgrades to the road were made to include one acceleration and de-acceleration lane at each intersection.

Completing the project

During this project, crews were able to mill and pave 1.5 miles per day.

“We used two Wirtgen 2200 mills with an 8-foot 3-inch cut working one lane at a time,” Bartoszek says. Crews milled over 269,000 square yards of asphalt at a depth of 4-inches. “After the materials were milled off, we came back in the same lane to keep the profile difference to a minimum and paved in the lane.”

Over 77,000 tons of Superpave E3 Hot Mix Asphalt was used on the project. “The asphalt was placed in two lifts,” Bartoszek says. “The lower layer was 3 inches, 19 millimeters and the upper layer was 2 inches, 12.5 millimeters.”

The HMA mix contained 12 percent reclaimed asphalt pavement (RAP) and used a 58-28 binder. The virgin aggregate consisted of crushed gravel and natural sand.

Northeast Asphalt completed the paving using a Blaw Knox 3200 asphalt paver with a Carlson Easy 4 screed. “We used automation with a duel-grade, 7.5 Blaw Control with a 50-foot ski on the centerline and on the mat reference a pan style ski on the outside,” Bartoszek says.

The paver was followed by the Ingersoll Rand DD 138 84-inch breakdown roller with high frequency, then the Caterpillar 900 B rubber tired roller loaded to 25 ton for the intermediate roller, followed by the Bomag BW11 AS 54-inch static roller used for the finish rolling.

Achieving a high IRI

Northeast Asphalt achieved an IRI index of 32.0 in the northbound lane and 31.2 in the southbound lane earning ride incentives. Northeast Asphalt took several steps to achieve a successful IRI index.

One crucial area to achieving the IRI was the crews focus on properly milling the existing asphalt.

“We paid close attention to the milling operations ensuring the material was milled evenly and uniformly,” Bartoszek says. “Another important aspect was ensuring that the RAP wasn’t oversized by using a nugget cruncher to control oversized material going into the plants. This made sure that no oversized material was used in the pavement material.”

The RoadTec 2500 Shuttle Buggy was another piece of equipment used to enhance the road.

“The Shuttle Buggy delivered mix to the paver ensuring the paver could maintain movement without starting and stopping,” Bartoszek says. “That is something you would have to do if only trucks were used.”

Bartoszek also credits experienced roller operators for the high quality mat because they did not create roller bumps.

Northeast Asphalt also earned density incentives. “The requirements for density were 91.5 for both the lower and upper layers,” Bartoszek says. “The densities on this project averaged 93+.”

Receiving both ride incentives and density incentives, Northeast Asphalt was able to complete the project on time without any reported safety incidents in the work zone.