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Xerox Corporation’s 33-story, Xerox Square Tower stands
high amid the downtown Rochester, NY, skyline. The
elegant façade is constructed of cast-in-place
exposed garnet aggregate concrete—a mixture that
offers extremely high compressive strengths and a dramatically
decorative finish.
On September 25, 1998, vibrations caused by a mild earthquake
reached downtown Rochester, causing delaminated concrete
to fall from the building’s façade. A subsequent
inspection revealed corrosion-induced delaminations and
cracks in the concrete, as well as extensive interior
honeycombs. Water was also penetrating the building through
sealant joints at various locations. Recommendations were
made for repairs to the building’s structure, sealants,
and curtain wall system.
The repair project began in June 2002 and concluded in
October 2005. Mobilization took place each spring and
demobilization each fall for four consecutive years.
During each phase, crews operated 24 hours per day,
5 days a week. In total, 1638 cubic ft (46.4 cubic meters) of
concrete were replaced at 1912 repair locations; 138,000
linear feet (42,062 meters) of sealants were replaced (34,500 linear feet
[10,515 meters] per elevation); 2445 linear feet (745
meters) (516 locations) of existing aluminum channel sections were replaced,
and 100% of the lockstrip T-gasket system was inspected,
and 36,000 linear feet (10,973 meters) were replaced.
In addition to the magnitude of the work, the difficulty
in matching the exposed garnet aggregate, the extreme
height of the work areas, and the diligence required to
protect the public and property presented challenges and
learning opportunities.
The contractor’s significant preplanning and thorough
coordination of continuous operations created a unified
team. Ultimately, by effectively teaming with the consulting
engineer and the repair contractor, Xerox ensured the
continued beauty and structural integrity of a landmark
building.
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Owner
Xerox Corporation
Webster, New York
Project Engineer/ Designer
STS Consultants
Vernon Hills, Illinois
Repair Contractor
Structural Preservation Systems, Inc.
Trenton, Michigan
Material Suppliers/ Manufacturers
King Materials
Burlington, Ontario, Canada
Dow Corning Corporation
Louiston, New York |