AWARD OF EXCELLENCE: Special Projects Category

Repair of Ramps and Concourses, Assembly Hall, University of Illinois

Chicago, Illinois

Submitted by Klein and Hoffman

The Assembly Hall of the University of Illinois in Champaign, Illinois, is constructed of cast-in-place reinforced concrete with a glass curtain wall. Resembling a flying saucer, the thin, “floating” nature of its elements give it graceful, curved lines. The principal venue on campus for large events, its seating capacity is approximately 16,000.

The top surfaces of the balconies around the dome, the ramps and pedestrian bridges, and the balustrades around the balconies and along the ramps were badly spalled and delaminated. The ramps and bridges were more significantly deteriorated than the balcony.

The concrete ramps were originally placed over earth fill between retaining walls. A gap several inches wide between the fill and the slab posed a challenge for repairs, which incorporated a bonded overlay. The slab could deflect or collapse when the top three inches of concrete was removed and a concrete overlay placed.

Shotcrete was used to repair walls and slabs. Ramps were repaired incorporating a bonded overlay. New expansion joints were installed in the structural slabs. Concrete plays such an important role in the architecture of the Assembly Hall that the restoration had to appear “seamless.”