Chicago's Metropolitan Pier and Exposition Authority is seeking contractors to repair the suspended roof structure of the North Building at McCormick Place, the largest convention center in North America.
This 2.7 million-square-foot convention center was recently the site of President Obama’s Election Day rally and second-term victory speech and has played host to many major events such as Chicago’s Auto Show.
Bids are due March 6. Contractors interested in bidding on the project are encouraged to attend a pre-bid meeting on Feb. 15. Bidders must have a minimum of five years of experience with installing the referenced materials in the local area.
Bids are open for repairs on a suspended roof structure at McCormick Place in Chicago. The convention center is the largest in North America.
Scope of Work
Built as an addition to the existing center in 1986, the North Building has roughly 600,000 square feet of main exhibition space. Its roof is supported by 72 cables held in place by 12 concrete pylons, which also incorporate the HVAC system and give the building the appearance of a rigged sailing ship.
The project includes repairing and coating 37,000 square feet of existing concrete pylon surfaces, rewrapping all 72 roof cables with PVC sheathing or elastomeric wrap, and replacing joint sealants.
The concrete pylons will be prepared for coating application by hand and power tool cleaning (ICRI technical guide surface profile of CSP-3) methods. If, after testing the bond strength of the remaining coatings, the results are inadequate for overcoating, the remaining coatings will be removed by high pressure water-blasting at a minimum pressure of 2000 pounds per square inch. The concrete will be primed and coated with an elastomeric acrylic system.
The PVC sheathing will include the installation of weatherproofing membranes and PVC-coated metal boots. New sealants will be applied, and each cable should have gaskets at either end. The PVC-coated boot cover will be comprised of a heavy-duty aluminum component that covers and seals to the cable boot underneath.
If an elastomeric cable wrap is chosen in lieu of sheathing, the system should be based on a cross-linking chlorosulfonated polyethylene polymer. The properties should include hydrostatic resistance of 80 pounds per square inch, a puncture resistance of 70 pounds, and a shear bonded seam strength of 140 pounds.
Twenty-four hours after the wrap, the elastomeric wrap will be heated with an electric blanket to 280 degrees Fahrenheit in order to fuse the overlapping seams and shrinkage of the wrap against the underlying cable.
The 'Fireproof' Building that Burned
In 1927, Chicago Tribune publisher Col. Robert R. McCormick began a campaign to build a “world-class” lakeside convention center in Chicago, IL. Though he did not live to see his vision achieved, the $41.8 million facility bearing his name eventually opened in 1960.
According to the exhibition authority’s website, the original structure was designed by Merchandise Mart architect Alfred Shaw and boasted 320,000 square feet of exhibit space and 23 meeting rooms. The building also included a 5,000-seat theater designed by Edward Durrell Stone, making it the second-largest theater in Chicago at the time.
The structure was thought to be fireproof, due to its steel and concrete construction, according to Wikipedia, but just seven years after it opened, the exposition hall burned to the ground in a devastating fire. The combination of highly combustible exhibits, the lack of sprinklers on the ground floor, and several fire hydrants that had been turned off caused the blaze to spread quickly, taking the life of a security guard.
After the investigation, the city amended its building codes to prevent similar disasters.
In 1971, the East Building became the first to replace the 1960 center. The new design by renowned architect Gene Summers of C.F. Murphy Associates featured dark steel and glass components.
The North Building connects to the contrasting dark and flat-profiled East Building by way of an enclosed pedestrian bridge.
Today, McCormick Place is comprised of four buildings and sits atop a commuter rail station for the Metra Electric Line.
Reported by Paint BidTracker, a construction reporting service devoted to identifying contracting opportunities for the coatings community.