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Robert Purcell Community Center
	Where:	Cornell University, Ithaca, NY
	Problem:	Load bearing cantilevered beams suffered extensive damage from ASR jeopardizing the structure.
	Solution:	Balvac’s Vacuum Impregnated the beams restoring structural integrity without impacting the buildings operating schedule

Removal of the ASR damaged structural frame was avoided - The building maintained daily operations

“Two repair options were considered to address the concrete deteriorated by alkali-silica reaction. The first was a "conventional" method based on mass removal and replacement… An alternative method proposed by J. P Stopen was based upon a process of vacu¬um injection / vacuum impregnation.”

A pilot repair program using the Balvac Process of vacuum injection/im¬pregnation was performed. In order to assess the efficacy of the process, a trial repair project was undertaken. Although not a 100% success, the trial repairs were positive enough to accept the vacuum injection/impregnation repair method for the remainder of the building with some modifications to the protocol.

Cornell University resolved concerns for repairs that would create extensive shoring requirements and in-turn significantly affects the operations to the Robert Purcell Community Commons on the Ithaca, NY campus.

An investigation in 1983 of the exterior identified map-pattern cracking of the reinforced concrete structural frame. This condition was found to be most prevalent on exposed faces of the cantilever beams. Damage was attributed to poor quality concrete exposed to the severe freeze-thaw elements of Western New York winter. An updated study was made in 2001. This involved a comprehensive NDT program. The results of this testing identified advanced Alkali Silica Reaction. Repairs implemented between building studies of 1983 and 2001 addressed water intrusion with the application of protective coatings.

The engineering studies determined that the massive cantilevers beams and spandrels appeared to have adequate structural strength to support imposed building loads. However, left in disrepair, deterioration will continue to accelerate, in loss of integrity and ultimately structural collapse.

The “vacuum” injection/impregnation method for the repairs of the damaged exterior concrete framing was chosen as the only reasonable repair technology in conjuction with conventional cementitious patching of spalled concrete.

“The repaired concrete has been in place for 12 to 18 months and has experienced winter and summer weather extremes. To date, the performance is good and no mirror cracking is occurring through die elastomeric coating. Ongoing monitoring of the structure will continue.”

Peter Paradise P.E., Civil Section Leader
Planning, Design and Construction
Cornell University in Ithaca, NY

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