Award of Excellence: Parking Structures Category
Rehabilitation of 55 E. Monroe Street Parking Garage
Submitted by Klein and Hoffman
Glenstar Properties, LLC
Des Plaines, Illinois
Klein and Hoffman, Inc.
BASF Building Systems
Lyndhurst, New Jersey
The rehabilitation of the nine level parking garage in a downtown Chicago commercial building presented numerous structural and construction challenges. The 52-story structure, constructed in 1970-71, needed to be repaired due to severe deterioration. The owner also needed to update the garage to accommodate future residential tenants as the top 15 floors were being developed into condominiums.
The suspected cause for much of the repairs was due to the “halo effect” or anodic ring effect around the perimeter of the patches. Other factors contributing to the deterioration were insufficient bar coverage at various locations, extremely high chloride levels, and buried electrical conduits.
Some of the challenges of this project included:
- The retail space beneath the parking decks and the tower above the garage was to remain open throughout the duration of the repairs;
- Code issues had changed since the garage was built;
- The structure was built using lightweight concrete with aggregate that was no longer available. The repair material had to closely match the original substrate concrete, especially the thermal properties, as the garage was unheated. Thus, substantial testing of potential aggregates had to be completed; and
- The scheduling of work was extremely complicated because the garage had to remain open with a maximum number of available parking spaces.
As a result of thorough concrete testing, development of a repair strategy (various corrosion mitigations were used in addition to water proofing membrane), extensive quality assurance testing, and ongoing exchange of information between all team members, project challenges were solved and the project was completed on time and within budget.