The George Washington University, Ross Hall

The George Washington University, Ross Hall

Location Washington, DC

Category Education

Parking Structure, Plaza, and Facade Rehabilitation

International Concrete Repair Institute Award of Merit

Designed by Mills, Petticord & Mills and completed in 1970, Walter G. Ross Hall encompasses an entire city block. The seven-story, Z-shaped, cast-in-place concrete structure, with massive board-formed concrete columns and beams bracketing concrete masonry unit infill walls, houses the George Washington University School of Medicine and Himmelfarb Medical Library. To the north is a brick-paved, concrete slab plaza above a sub-grade, bi-level parking garage that also extends under the building. Concrete delamination and exposed steel reinforcing at the facade and garage had led to aesthetic and structural concerns, while leaks so plagued the garage that waterborne mineral deposits had formed stalactites and stalagmites.

Hoffmann Architects + Engineers conducted a parking structure investigation that pointed to improper expansion joint detailing of the overlying plaza deck and waterproofing membrane. The initial installation did not allow for expansion/contraction of the plaza deck and so served only to exacerbate leaks. Poor drainage compounded the problem by saturating the compromised waterproofing system and funneling water through the open expansion joints. As water entered the garage, it mixed with de-icing salts and caused corrosion of embedded reinforcing steel, which expanded to damage the surrounding concrete in a self-perpetuating cycle.

Hoffmann facilitated testing and petrographic analysis to assess the strength, quality, carbonation, and corrosion rate of the concrete. To minimize the potential for deterioration, our architects and engineers specified protective products at drive surfaces, in repair areas, and at the undersides of the concrete. The project team designed a new plaza waterproofing, drainage, and paving system that accommodates structural movement, functions as a watertight roof for the garage below, and provides an inviting open pedestrian area.

At the facade, Hoffmann addressed shallow reinforcement placement and poor concrete quality, while protecting against the damaging effects of weather and pollutants. To allow for differential movement, deteriorated mortar and sealant joints were replaced with more suitable materials. The phased program of repairs restored the weather integrity and appearance of Ross Hall while accommodating practical, logistical, and budgetary demands.

GWU Ross Hall Concrete

International Concrete Repair Institute Award

Ross Hall, The George Washington University

The rehabilitation project at Ross Hall was recognized for outstanding concrete repair design and execution by the industry leader in concrete restoration practice, the International Concrete Repair Institute (ICRI).