Xerox Corporation's 33-story, Xerox Square Tower stands high amid the downtown Rochester skyline. The elegant facade is constructed of cast-in-place exposed garnet aggregate concrete - a mix that offers extremely high compressive strengths and a dramatically decorative finish.
On Sept. 25, 1998, vibrations caused by a mild earthquake reached downtown Rochester and caused 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 contractor asked to bid on and, ultimately chosen for, the project has extensive experience in concrete and masonry restoration on high-rise structures.
The 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, 1,638 cubic feet of concrete were replaced at 1,912 repair locations; 138,000 linear feet of sealants were replaced (34,500 linear feet per elevation); 2,445 linear feet (516 locations) of existing aluminum channel sections were replaced, and 100-percent of the lockstrip T-gasket system was inspected and 36,000 linear feet 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 with pride in and dedication to craftsman-inspired work. Ultimately, by effectively teaming with the Consulting Engineer and the Repair Contractor, Xerox ensured the continued beauty and structural integrity of a landmark building.