Reconstruction of this double-decked roadway, which carries more than 60,000 vehicles and countless pedestrians each day, was completed in just 23 months. Directed by Walsh Construction, the project replaced both levels of a critical 2-mile stretch in the heart of the city's business district.
Lower Wacker Drive provides service access for 57 high-rise buildings, while the upper level handles traffic flowing in from 16 major streets. CDOT specified crack-resistant, high-strength concrete designed to deliver up to 100 years of service. Engineers with Wiss, Janney, Elstner Associates researched 40 high-performance mixes used in other states and worked with experts at The University of Chicago to develop and test performance criteria for the mix, which was designed to reach 6,000 psi in 28 days and attain a final compressive strength of 9,500 psi. Specifications also called for air voids with maximum spacing, a low water/cement ratio and strict consistency of aggregates, materials and admixtures from load to load. Prairie's quality control team tested 14 mixes before coming up with the bid-winning design.
Crews began the massive project in February 2001 and continued their work year-round, with the single largest pour incorporating 2,100 cubic yards delivered in just 12 hours. The job included the repair of 8 Bascule bridges and rebuilding of 6 elevated train bridges, as well as replacement of 16,500 feet of storm sewer and 6,300 feet of water main.
Wacker Drive represents the first use of high-strength, high-performance concrete in Illinois.
Location: Downtown business district, Chicago, Illinois
Size: 2-mile segment incorporating upper and lower levels
General Contractor: Walsh Construction, Chicago
Engineering Firm: Wiss, Janney, Elstner Associates, Inc., Chicago
Concrete Provided: More than 233,000 cubic yards (over 33,000 truckloads), including: