Architectural precast and structural precast concrete structures can do more to reduce your project’s carbon footprint, give you more green performance and lower costs. More than mere tweaks, these five proven techniques can help you make sure you’re getting the most out of precast concrete on your next sustainable construction project.
Location: Bloomington, Ind.
Type of Precast: CarbonCast® High Performance Insulated Wall Panels
Size: 40,000 sq. ft. (7,213 sq. ft. precast wall panels)
Striking CarbonCast enclosure sets fast-track pace for business precinct
Designing the thermally efficient CarbonCast skin
Progressive and forward thinking while emulating core campus precedents
PCI Design Award
Read the judges' comments from the 2011 competition
Striking Fast-Track CarbonCast Enclosure Sets Pace for Business Park
In September 2008, when Indiana University (IU) in Bloomington, Ind. awarded the Innovation Center project to the design-build collaboration of Messer Construction and BSA LifeStructures, three months of the 15-month design inception-to-occupancy schedule were already gone. Fortunately the University expected the design solutions to reflect it aggressive schedule, and had included precast as an option in the RFI for the team’s conceptualization.
The $10 million, 40,000 sq. ft. building is Phase One of IU’s Research Park, an emerging discovery-focused precinct for information technology infrastructure and technology transfer/economic development located adjacent to the school’s main campus. Located at the future entrance to the precinct, the LEED® Silver Certified (v 2.2) building is a business incubator dedicated to developing new technology based companies and further augmenting research activity to benefit the local community and the state. It provides modular labs and offices to emerging companies in increments as small as 300 sq. ft. Spaces can be built out quickly, and are designed for heavy research and vibration-sensitive equipment.
“Schedule was the key driver for the Innovation Center, and budget was second,” says Jackie Bieghler, project architect for BSA LifeStructures. “A precast envelope appealed because of the tight schedule. We jumped on it to explore the options and possibilities.” Further, the design had to hew to the campus master plan for the precinct and the adjacent buildings in terms of orientation, scale, and general layout. BSA LifeStructures and Messer Construction strategized and delivered on a fixed price, he notes, and chose an enclosure solution based on CarbonCast High Performance Insulated Wall Panels from the High Concrete Group LLC’s Springboro, Ohio plant.
“We worked closely with the High Concrete Group team to optimize panel dimensions and use repetition to minimize forward cost. High Concrete Group helped us by accelerating precast delivery by a month,” says Bieghler. “The CarbonCast façade also allowed us to dry in the building much more quickly, so other trades could move ahead.”
Designing the thermally efficient CarbonCast skin
The submissions form for the project entailed in-depth requirements including building orientation, serviceability requirements and discussion of the topography and the serviceability of neighboring buildings., the Innovation Center is a simple building form conveying a straightforward organizational layout with a central circulation spine/core element that anchors the north and south wings. Glass volumes mark the opposite corners of the building which comprise the approach from the university and the main entry.
The main entrance, located at the NE corner of the building, creates a dramatic and transparent entry/lobby element to both invite and engage staff and visitors to the facility, while still accommodating a future 30,000 gr. sq. ft. eastern expansion. The building provides 1,500 sq. ft. or more of office, dry lab or wet lab space that can be built out quickly and will be flexible in use for new companies.
The design team could have used precast for the frame, but settled instead on a steel frame based on Messer Construction’s relationship with its steel subcontractor after meeting all LEED prerequisites (view LEED Checklist). In deciding on the skin, the design team evaluated the pros and cons of materials based on the logistics for this site and the surrounding buildings, contractor lay-down areas and site access.
CarbonCast panels form the base of the building in a nice middle of the road module based on bay spacing of 21’. The panels encapsulate a 3” layer of rigid XPS foam insulation for continuous insulation as defined by the ASHRAE 90.1 energy code. CarbonCast technology utilizes C-GRID® carbon fiber wythe ties that provide fully composite structural performance with low thermal conductivity. “We required the carbon fiber connector to address thermal bridging concerns,” says Bieghler, noting that the thermally efficient envelope delivers an average R-15. The steel deck roof is also insulated with XPS foam and is covered with a white TPO membrane. A metal screen wall above an eyebrow conceals rooftop mechanicals.
Progressive and forward thinking design emulates campus precedents
The Indiana University campus is famous for its beautiful Indiana limestone, and the buildings of the new Research Park will pay homage to the tradition. “The Innovation Center is meant to be the first of many incubator buildings in this area of the campus, so its image sets the tone,” says Bieghler. The northeast view of the Innovation Center is important as it gives the feel for the other Research Park buildings.
“There is a layering of materials, with buff-color precast used as the dominant form on the base and in strategic locations on the second floor to highlight and counterbalance the dark brown metal and glass. The ends got more glass where the programmatic spaces are, facing the university and in the main entry,” says Bieghler.
The CarbonCast panels are heavily applied to the north and south elevations. Metal panels and continuous glass curtainwall were used predominately on the upper part of the east and west elevation. Vertical metal fins sit in front of the curtainwall break up the large expanse of the windows.
Reveals created in the precast formwork help to break down the large expanses of the precast enclosure. A result of structural spacing and panel size modules, the reveals are too large to look like stone yet nevertheless acknowledge the limestone prevalent elsewhere on campus. The curtainwall mullions bleed across to continue the line established in the precast panel spacing. In one vestibule, the precast is turned inside to provide visual continuation and also a durable surface in a high traffic area.
A canopy over the entrance was mounted using outriggers attached to embeds in the precast. The canopy implies the continuation of other metal elements on the façade; a second metal panel on the east elevation serves as a visual connector, and creates an illusion that four vertical windows are sitting on a little vertical plane.
LEED is a registered trademark of the US Green Building Council.
CarbonCast is a registered trademark of AltusGroup, Inc.
C-GRID is a registered trademark of Chomarat N.A.
PCI Design Award
The IU Innovation Center was recognized in the 2011 PCI Design Awards competition as Best University Project, Cowinner.
"This building was singled out for the ways that it uses precast concrete, both for its forming ability and for its ability to meet sustainability goals that perhaps other materials couldn't have met. It's also an interesting piece of architecture. It integrates different materials well into the overall context of the building, and it's also beautifully integrated into the landscape. It was well put together and nicely detailed. It creates a nice solution for this need."
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