Award of Merit: Parking Structures Category
Ottawa Towers Plaza and Parking Restoration
Submitted by Carl Walker, Inc.
State of Michigan Department of Management
Carl Walker, Inc.
Kares Construction Company
American Hydrotech, Inc.
The State of Michigan Ottawa Towers Parking Ramp and Plaza, built in 1980, encompasses two state buildings. The complex consists of an elevated landscaped area and two below-grade parking levels: one supported and one slab-on-grade parking level.
The structural system for the supported parking slabs consisted of structural steel beam and column framing, with 5 in. (13 cm) thick conventionally reinforced cast-in-place concrete slabs. Chloride contamination had progressively deteriorated the structural integrity and durability of the supported slab. Full slab replacement was chosen as the repair method. Other repairs included new lighting, new fire protection, new plumbing, fresh paint, a heavy-duty low-odor deck coating system, new traffic-control equipment, and new signage.
The structural system for the 88,000 ft2 (8175 m2) plaza consisted of cast-in-place conventionally reinforced concrete slabs. The plaza system cross section consisted of brick and asphalt pavers, cast-in-place concrete, landscaping, planters, and a subsurface waterproofing membrane bonded directly to the structural slab. The existing surface was removed, and a new system, including a complete new membrane system, subsurface drainage/isolation layer, cast-in-place floating slab, and brick paving with an insulation layer and snow melting system, was installed. The restoration included installation of a complete subsurface drainage system to eliminate internal/subsurface water ponding. A snowmelt system was installed down the center corridor of the plaza.
The project was completed in August 2006 at a construction cost of $9.95 million.