Penn State Millennium Science Center
The Millennium Science Complex on the campus of Penn State University in University Park, PA, consists of two wings of specialized research facilities. To encourage collaboration, the two 154-foot-long wings cantilever into a dramatic “bridge” that connects the two parts of the L-shaped building over a public plaza.
The cantilever was formed using steel trusses supporting architectural precast concrete panels. The cantilevered panels, as with the rest of the façade, feature full-depth bricks along with half-bricks in a few areas. The panels are 22 feet long and vary in height from 8 to 12 feet. High Concrete provided the precast concrete components.
“The mass of the concrete helps dampen the structure-borne vibration, which is critical for the building’s specialized laboratories,” explains David Rolland, project director at RV Architects. These spaces include clean rooms, electron-microscope labs, and vivariums where experiments could be affected by minute vibrations.
The bricks complement the “Penn State brick” used throughout the campus, consisting of a mixture of deep reddish bricks with intermittent “flash” bricks distinguished by a charcoal-burnt hue resulting from a longer firing process. The flash brick was used in a reveal pattern spaced every 2 feet up the height of the building, emphasizing the façade’s scale and strengthening the horizontal lines of the building form as it steps up through four levels.
Stepping back the building from the adjacent streets established a human scale and allowed five green terraces to be built, keeping the sensitive laboratories furthest from the ground vibration caused by vehicular traffic.
The advantages offered by the precast concrete panelized construction were especially helpful in creating the cantilever, Rolland notes. “Many large pieces could be erected in a single day with a higher level of quality control as opposed to trying to lay brick in a traditional method with scaffolding.” This was particularly important due to the stack-bond pattern of Norman-style bricks, which accentuate the close tolerances at both the vertical and horizontal joints.
The precast concrete design also helped create a feeling of depth within the exterior enclosure with the use of C-shaped panels with returns around windows. This allowed the continuous horizontal glazing on each level to be recessed, with the precast panels serving as the spandrel and providing shading for the glazing. “The profile of the facade is the key reason we specified precast concrete panels for this application, as we could not have achieved that effect through traditional masonry construction.” A return also was created on the panels that produce the mitered brick joint, ensuring no joint at the edge.
The brick-faced panels consist of 6 inches of concrete supporting the brick backed with 4 inches of rigid insulation and a vapor barrier. In total, 345 precast panels were fabricated, trucked to the site, and erected from a staging area near the building.
The most challenging portion of the erection came in linking the cantilevered wings at their apex. Cranes were placed on either side of the wings, with panels hung on the facades at the same rate so the trusses could deflect simultaneously. In-place adjustment of the panels allowed tolerances to be met through the fine-tuning of panel alignment as the cantilever deflected.
The precast panels helped the building achieve LEED certification by enhancing energy efficiency with their thermal mass, being composed partially of recycled materials and producing the materials within the region. In addition, more than 90% of construction waste was diverted from disposal and at least 10% of materials were from recycled content, including the precast concrete. Sustainably harvested wood was used, and 10% of materials were regionally sourced, again including the precast concrete components.