Interstate 29 runs from Missouri north and transitions into Highway 75 as it crosses the border on its way to Winnipeg, Canada. At roughly 750 miles long, about 217 miles of it passes through North Dakota.
Winter runs long in the northern portion of the U.S. with the climate typically forcing a short construction season. For example, the North Dakota Department of Transportation’s construction season officially kicked off on May 27. According to the state’s DOT website, approximately $500 million in projects were scheduled to “enhance the state’s highway system.”
Northern Improvement has been building roads since 1935. This experience allowed the team to identify that sourcing an ultramodern concrete placer and spreader would improve productivity and create a smoother road. WIRTGEN Group Product Manager Erik Sahr at RDO Equipment Co. explains that when Northern Improvement came to the RDO team, they were specific in their requests to find a dependable concrete placer/spreader.
In fact, Greg McCormick, Northern Improvement’s President, and Executive Vice President Molly Barnes emphasized that they looked at every placer on the market, its price, availability, and capabilities.
“The WIRTGEN GROUP’s equipment would allow us to pave stringless, place faster, and achieve a smoother ride,” McCormick says.
This road construction project was created by a larger flood protection plan, so this road needed to be reconstructed to raise the road out of the flood plain within two construction seasons. As with all projects, Northern Improvement and RDO worked together to identify the goals of the project, along with the mitigating factors including the need to pave efficiently to produce equipment solutions.
“We don’t have many of these placers laying around if something goes wrong,” says Sahr. “We work with the WIRTGEN GROUP and the customer to ensure we have the parts on hand at the dealership.”
While the RDO team members ensured the necessary placer/spreader and its parts would be on hand, the Northern Improvement team worked on securing their materials while dealing with supply chain shortages. Northern Improvement’s Vice President, Concrete Paving Division Manager Steve Schmidt explained that the team purchased steel products in 2021 to ensure they would be available, but the cement was in short supply. Their team had to carefully schedule their paving days along with constant communication with cement suppliers and aggregates delivery.
After both teams secured materials and equipment, Sahr explained how they all focused on training.
“When they first started in early July, we had three WIRTGEN GROUP technicians supporting the WPS102i placer and spreader,” he says. “It’s important to us that our customer’s equipment stays up and running. “
With time of the essence, any machine that Northern Improvement used needed to be consistent, fast and create a smooth pave. The 4 miles (approximately 21,000 ft.) of I-29 needed to be reconstructed.
The WIRTGEN WPS 102i Placer/Spreader caught their attention. It can travel over pre-placed dowel baskets and tie bar baskets placed ahead of the slipform paver and texture curing machine but can be programmed to place and spread a 12 to 40 ft. wide concrete road, up to 20 in. thick.
Sahr calls the WPS 102i “truly adaptable to numerous roadbuilding projects’ needs.” For this project, WIRTGEN’s placer/spreader can travel over pre-placed reinforcement and concrete can be fed via a conveyor from the side, then quickly folded away for the next truck delivery.
Jill Berger, a foreman for Northern Improvement with 20+ years of experience was amazed by the power and speed. She says that they were able to dump six trucks in 6.5 minutes.
According to Sahr, the project marks the first running use of the machine of its size in the world. The equipment's serial number is 01.
Safety is a key role for any concrete contractor, and Northern Improvement is no exception. The crew benefited from the safety and technology features found in the WPS 102i. Features like an automatic safety shut-down system, machine monitoring, and GPS allowed increased productivity and efficiency for the project.
“Safety is especially important for both Northern Improvement and RDO Equipment Co. So, the WIRTGERN Group ensured the concrete placer and spreader would have an open platform system so alarm codes and auto shutdowns could be programmed by the WIRTGEN GROUP technicians,” Sahr says.
“While we can’t estimate how the project would have gone without this type of technology, we can assume that because it’s been used, Northern Improvement has been able to meet the project’s needs, and stay on schedule,” he adds.
The Northern Improvement team uses Holcim Type 1L cement – which reduces carbon emissions - with locally produced natural gravel as their aggregate. Schmidt said they used the ND DOT AE Well Graded mix that is specified for paving all North Dakota Roads. Schmidt highlights that this mix is both low slump formed and hand-place into forms.
Schmidt explained that North Dakota’s DOT curing time is 3,000 PSI compressive or 450 PSI Flexural in seven days. Although Schmidt underlines that their reconstructed roads for this project had full strength in under three days. The Northern Improvement team uses AMS curing compound as protective coating while following the DOT’s specifications for air-entrained concrete, fly ash, and well-graded aggregates.
All this work created a very smooth roadway according to the International Roughness Index, Schmidt explained.
Because of Northern Improvement’s work with their WPS102i Series 1 Concrete Placer and Spreader, they will be able to complete the project in the Fall of 2023.
A special thank you to Northern Improvement and the RDO Team for their contributions to this article.