The new Glassell School of Art building in Houston, Tex., is itself a work of art. The defining geometry, sloping plane, and elegant use of light and space all come together in a structure that will be an anchor for the Houston community.
Much of the design was made possible through the use of precast concrete, says Olaf Schmidt of Steven Holl Architects. "The precast concrete structural elements hold up the floors and define the exterior, incorporating the angle of the main incline."The precast concrete facade design alludes to the adjacent sculpture garden walls created by Isamu Noguchi, a noted artist and landscape architect. "The simple planar structural pieces of the sandblasted precast concrete plane give character to the inner spaces of the building in the spirit of simplicity and directness," Schmidt says.
Flexibility and control
From a structural perspective, the main challenge on the project was to ensure continuity between the different types of structural components. The building’s geometry is characterized by individual panels that rotate, twist, and incline to varying degrees at random locations, requiring detailed attention to the load path. "The precast concrete walls allowed for precisely prefabricated load-bearing walls whose finish could be closely controlled and was therefore consistent for the entire building," Schmidt says.
The use of precast concrete also allowed for the minimization of wall thickness in some key locations and provided control over placement of the reinforcing steel. Connections between precast concrete panels; cast-in-place, mild steel-reinforced concrete, hollow-core planks; and post-tensioned concrete are located throughout the structure. "Ensuring that forces transfer properly from one component to another was critical for the structure as a whole," Schmidt explains.
Precast hollow-core concrete planks frame the floor systems and span between the cast-in-place concrete perimeter beams. "These made a relatively lightweight, long-span floor framing system possible—up to 40-ft-long spans with a depth of only 16 in.—and were surprisingly flexible, allowing for embedded systems and field-installed penetrations," Schmidt says.
The wall panels vary in size and geometry and are spaced along the perimeters so full-height, glazed panels could be installed between adjacent precast concrete panels. This structure of alternating concrete panels and large, translucent panels exposes the internal art studios to diffuse natural light while achieving a distinct external design that draws in passersby. "The precision of the precast concrete panel design allowed for the simultaneous fabrication of the glass windows based on drawings rather than field measurements" Schmidt notes. The panels all touch each other due to the placement of the glass; therefore, once set, each panel had to be braced and set with a "ring beam" on top.
Schmidt emphasizes that the flexibility and performance of precast concrete made the design possible. "Precast concrete for the exterior structure provided a superior finish and consistency over cast-in-place concrete," he states.