Award of Excellence: Strengthening Category
SUNY Health & Science Center Brooklyn Parking Structure Restoration
Brooklyn, New York
Submitted by Carl Walker, Inc.
SUNY Health & Science Center Brooklyn
Brooklyn, New York
Carl Walker, Inc.
Cherry Hill, New Jersey
Structural Preservation Systems
Hawthorne, New Jersey
Lyndhurst, New Jersey
The State University of New York (SUNY) Health & Science Center Brooklyn Parking Structure was constructed in 1967. It has a total of 10 levels, 3 levels below grade and 7 above, each with a plan area of approximately 125 x 246 ft (38 x 75 m) totaling 360,000 ft2 (33,445 m2) of parking with space for 933 vehicles. The structural system is a cast-in-place reinforced concrete moment frame consisting of spread footings, columns, wall, girders, and waffle slab.
Immediately following the completion of construction, a structural crack developed perpendicular to the one-way joists. The crack occurred on all supported levels of the structure. Investigation revealed that a major structural error in the design and construction had occurred and a substantial amount of the negative bending reinforcing steel was not extended sufficiently past the column supports.
The final repair system selected was to shore the floor, remove the concrete overlay, inject the crack, prepare the surface, apply carbon-fiber reinforced polymer (CFRP) on the top side, and protect with an extra layer of epoxy resin and a urethane traffic bearing membrane.
The use of CFRP was a very cost-effective repair method that eliminated a serious trip-hazard liability, increased headroom in a low-headroom clearance structure, and eliminated the risk of future repairs costs on a chloride-filled concrete overlay adhered with a 30+ year old bonding agent and some mechanical pins.
The work was phased to remove a maximum of only 100 spaces at any one time. The total restoration cost of the project was $2.0 million, which included the CFRP strengthening, waterproofing, and various concrete repairs on the underside of the structural system.