Intersection of SH-51 (6th Street) & US-177 (Perkins Road), Stillwater, OK
Contractor: Duit Construction Company, Inc.  
Owner: Oklahoma DOT
Engineer: Benham

Stillwater, OK, is home to more than 49,000 people, but thanks to Oklahoma State University (OSU), the population increases by almost 26,000 students every August.

The intersection of SH 51 and SH 177 was the site of a test section of 4 in. fiber-reinforced concrete placed on asphalt pavement. The section was in service for 19 years, but with ADT of 21,167 ADT and 4% trucks, the owner to replace the intersection as part of a plan to increase capacity and upgrade the bridges adjacent to the intersection.

The Oklahoma DOT (ODOT) and City of Stillwater chose concrete because of how well it performed for them at in the 4 in. section. In addition to increasing the capacity and reconstructing the pavement, Duit Construction had to reconstruct all the water and sewer lines in this intersection, along with the entire storm sewer.

Because of the large volume of traffic on the intersection, ODOT and the city put internal milestones in place to ensure that traffic was flowing during all the OSU football games. Knowing that as many as 60,000 fans could be drawn to the area during football games, ODOT wanted to make sure this intersection was open in time for the beginning of the season. Duit was required to start the day after the final football game in 2016 and to ensure the pavement was operating at full capacity by the first game in September for 2017.

Thanks to the team efforts between Duit, ODOT, the City of Stillwater, and the Benham Group, the team was able to complete the project in time for the first football game.

Along the way, there were several challenges, beginning on the first day of the project. Telephone and power utility issues were quickly identified. There were also two bridge boxes located within 75 feet of the intersection that needed to be constructed.

The original drawings indicated the bridge could be demolished in two phases, but the team discovered the bridge was built on four footings. If two of the footings were removed as indicated in the plan, the bridge carrying traffic would have an increased chance of tipping over. Duit revised the plan that would enable them to construct the project and demolish the bridge all in one phase—and without closing the road.

Although Duit worked to thread sewer and water lines through fiber optic lines and phone lines that were not identified by the phone company. ODOT, the city, and the contractor decided the best solution was to close SH 51 west of SH 177.

To proceed with the plan, ODOT officials had to talk to all the businesses in the area to get consensus agreement. Afterward, it was decided that an internal milestone would be added to the contract to allow Duit to close the road, but to reopen it within 40 days. Within that time frame, the single-span bridge had to be removed and the triple barrel box structure had to be demolished. Within the same time frame, two triple barrel box structures had to be reconstructed, and crews had to backfill, stabilize soil, and place the asphalt base. ODOT offered Duit an incentive of $100,000 to achieve this. With the help of subcontractors, Duit was able to complete the required work within the 40 days.

Even so, the utility delays impacted the overall project schedule, so the contractor developed a plan to move traffic onto the 3 in. asphalt base so the intersection could be open to traffic during football game weekends. During the week, Duit closed the lanes to continue the concrete paving, opening the intersection to traffic only on the weekends.

For the paving, Duit placed more than 18,800 SY of concrete 8 in. thick, jointed reinforced pavement, equaling more than 2.8 lane miles. Duit used a central mix plant, but it had to be 8 mi. from the project because of limited space and permitting issues. As such, the mixture had to be dialed in precisely to handle the relatively long haul and traffic delays.

In spite of the utility delays, the project was completed on time. Now “Stilly” residents, business owners, and OSU students and football fans can travel through this area on a project that was built to last.