JOB: Wacker Drive and Damon Avenue Bridge Projects, Chicago, Illinois
CONTRACTOR: Walsh Construction, Chicago, Illinois
Bid-Well Pavers Play a Key Role in Restoring History and Making History on Two Paving Projects

Downtown Chicago is a historic place, with buildings, roadways and bridges that contain rich history and meaning for the city. Two projects, one the reconstruction of Wacker Drive, the other the Damon Avenue Bridge project, used Bid-Well 4800 Pavers to meet and exceed goals.

The $200 million reconstruction of Wacker Drive is underway with Walsh Construction of Chicago as the prime contractor. The project involves the complete reconstruction of the double-deck roadway originally built in 1926. One of the focal points of the project is the bridge decks along Wacker Drive. That is where the Bid-Well 4800 Pavers came in.

Each pour was about 1,200 yards. There were 10 segments on the contract, each segment 1,200 yards, 240 feet long. The Bid-Well pavers completed the bridge deck finishing over a period of 10 hours for each deck pour. Bid-Well finishing bridges trailed the pavers. A high performance concrete mix with a spec of 6,000 psi was used. Walsh pumped about 220 yards per hour with two 53 meter pumps. The span was 115 feet across and maintained the tolerance on the deck 131/2” and 24” at the ribs over the columns.

“The pavers did a good job of keeping up with the pumps and keeping us on target,” David Hurley, Project Manager for Walsh Construction said. “It was a traffic sensitive area. All traffic was diverted during the project. Most of the pours were at night to make sure the delivery of concrete could be maintained and not disrupted
by traffic.”

Another challenge along the road was the grades between the intersections. There were five major intersections along Wacker Drive: State, LaSalle, Dearborn, Clark and Wells. Each presented a unique paving challenge.

“All the grades came up pretty steep,” Hurley said. “At the beginning of a pour you could be going upgrade and when you reach the center of the cross street you could be going down. We had to make auger adjustments during the pours so you’re not pushing concrete forward with the augers or pulling it back, depending on whether you were going upgrade or downgrade. The Bid-Well machines were built so you easily accommodate those changes and keep paving.”

To date, the project is running ahead of schedule, another positive for Walsh Construction.
“We reached a bonus incentive on the ‘A’ part of the contract because we were supposed to do seven sections this year and we did nine,” Hurley said. “There were three different incentive packages we could have received this year and we got the second highest. The Bid-Well machine definitely helped us make our schedule.”

History of another kind was made on another street in the downtown Chicago area where the Damon Avenue Bridge was built. Walsh Construction was the prime contractor on this unique project too.

The post tension, cable supported deck was the first bridge of its kind that didn’t have any ties between the arches that support the bridge.

“It was an interesting bridge, difficult to erect,” Dan Sieve, Walsh’s Project Manager for the project said. “We hung the bridge deck from the bridge itself, from the lateral beams across the span that actually supported the falsework. We had to pour the bridge deck symmetrically from the center out so we didn't overload one end of the bridge or the other.
“We had to use two separate Bid-Well 4800 pavers working from the center of the deck out. Neither one could advance more than 20 feet symmetrically from the center because we had to keep things balanced. We used the outriggers on the wheels to offset them because from edge to edge of pipe was 48 foot six inches, so the Bid-Well just barely fit between the pipes. We had an offset device for their bogies that was pre-made for it and it worked well.” Pouring and paving concrete on such a flexible structure carried a new set of challenges for the Walsh team.

“To compensate for the deflection in the bridge we adjusted the crown and adjusted it in the machine,” Sieve said. “The formwork was deflecting as you were pouring the bridge and the bridge was deflecting as you were pouring it, so we had to take everything into account. It wasn’t like a regular form on structural steel; it was like pouring a moving project.”

The versatility and light weight of the Bid-Wells made a difference on the project, as both the 4800 pavers took to the air.

“We had to fly the machines in from the riverbank with a ringer crane,” Sieves said. “We picked them up and set them down in the middle of the bridge at a radius of about 150 feet. It would have been very difficult if we had to use anything heavier.”

The unique project turned out to be an award winner for the contractors and the designer.
“We won bridge contractor of the year and contractor of the year from the Chicago Department of Transportation for the project,” Sieves said. “We also won a public works award for the design of the bridge."