MENTION: Parking Structures Category
Repair of Continuum Parking Garage
Submitted by Wiss, Janney, Elstner Associates, Inc.
Continuum Parking Garage in Austin, Texas, is a five-level
precast concrete structure that was constructed in 1986.
The structure consists of a series of precast, prestressed
double-tee beams, supported by spandrel beams on the east
and west edges and by vertical load-bearing wall panels
along the two interior column lines.
The concrete in portions of the load-bearing precast
elements exhibited cracking and a loss of integrity, which
material testing attributed to delayed ettringite formation
(DEF). This is believed to be the first structure in the
United States that required structural repair due to DEF.
Other distress in this structure included inclined
structural cracking in the spandrel beams near the end
supports due to insufficient reinforcing of the spandrel
The distressed portions of the load-bearing precast wall
panels were repaired using cast-in-place replacement panel
sections with additional reinforcing. The deteriorated panel
concrete was removed from the top down, effectively
detensioning the prestressing tendons as the removal
The cracked spandrel beams were repaired by low-pressure
epoxy injection of the cracks followed by supplemental steel
reinforcing plates on the inside face of the beams. The
contractor’s demolition, shoring, and formwork schemes
allowed the reconstruction of the panels in place while the
garage was still in service. Furthermore, these repairs were
completed without any permanent loss of parking and without
an effect on the overall aesthetics of the structure.