Precast & UHPC: A Winning Combination

Interstate 290 in Chicago – locally known as the Eisenhower Expressway or Ike for short – is a bustling roadway used by thousands of drivers each day. In addition to functioning as a main artery for travelers, the Ike also contains several pedestrian bridges that cross over the expressway. They provide access to the city’s many public transportation offerings.

The Peoria Street Pedestrian Bridge is a particularly important component, linking students on the campus of the University of Illinois at Chicago with the city’s main train system. The bridge has performed well, but deterioration over the years led it to be marked for reconstruction as part of the larger Circle Interchange Project.

Improvement is great, but adding a construction project to a busy roadway will inevitably result in increased traffic and driver headaches. Thankfully, the use of 52 precast concrete deck panels in combination with ultra high performance concrete reduced construction time while simultaneously offering a durable, effective solution for the new, 271-linear-foot bridge.

Photo courtesy of Utility Concrete Products.

Utility Concrete Products, an NPCA Certified Plant located in Morris, Ill., manufactured the more than 15,000 square feet of 8-inch thick deck panels that were placed for the new bridge. Each of the panels was set transverse to the bridge’s steel beams in just four days. Tom Heraty, UCP’s vice president of sales and engineering, said the decision to use precast brought many advantages to the project.

“Precast speeds up the schedule and limits the traffic impacts below,” he said. “It’s also made in a controlled environment, which allows you to bring it in, set it and be done. That equals a safer job site.”

Heraty explained that, like with any modular project, joints are necessary to connect the precast pieces together. But because the project called for the use of ultra high performance concrete – a first for the Illinois Department of Transportation – the gap between the components could be minimal.

“The ultra high performance is so strong and bonds so well that you can (join the pieces) with minimal disruption to the precast,” Heraty said. “You don’t have to have a huge hole. You can do it with really small pockets and joints.”

Each of the precast panels was also manufactured with an exposed aggregate finish at the joints, helping to further increase the bond.

Photo courtesy of Utility Concrete Products.

Paul White, P.E., bridge engineering manager for Lafarge, noted that the interplay between the precast components and the UHPC was crucial for the success of the project.

“When you want to accelerate bridge construction and you want a higher quality product – which you get with precast over cast-in-place – the trick is to get precast and (the UHPC) to act as a unit,” he said. “Conventional materials have not been adequate to transfer the load without bond failure. UHPC stands apart from anything else out there right now in terms of proven success.”

The project, which was completed in the summer of 2015, opens up new possibilities for the combined used of precast concrete and UHPC moving forward. Continued use of the two materials will allow DOTs to efficiently upgrade aging infrastructure systems while keeping extended traffic disruptions at bay.