High Concrete Group LLC has introduced ThinCastTM, the thinnest precast concrete rainscreen panel available on the market. Designed for use in commercial, institutional, retail, and low- to high-rise construction, this innovation provides architects with the natural beauty and character of concrete in lightweight panels that accomplish their rainscreen design goals.
Location: Cincinnati, Ohio
Type of Precast: CarbonCast® High Performance Insulated Wall Panels
Square footage: 84,144 sq. ft. (40,200 sq. ft. load bearing sandwich walls; 97,000 sq. ft. structural precast)
Precast school blends seamlessly with historic neighborhood
When architects at glaserworks were designing the Fairview-Clifton German Language School, blending into the surrounding streetscape was essential. Situated on a prominent corner of a historic neighborhood, the new school would face the century-old Clifton Public School and a city recreation center, both faced in yellow brick. In addition, a beautiful 1800s carriage house resides on the site. Glaserworks sought to make the new school the centerpiece of a neighborhood campus by selecting colors and materials compatible with the existing structures.
But the material selection process did not stop with aesthetics. The project required a quick-to-erect structure that would ensure operation by the upcoming school year. The building team initially considered masonry construction, but ultimately opted for precast to simplify the construction process and deliver the desired look.
“We knew the problems of traditional masonry. The bits and pieces make for a very complicated assembly,” said Paul Duffy, principal, glaserworks. “Precast concrete reduces liability and provides a quality product.”
The extensive use of precast on the school provided the building team with superior predictability and quality during erection. In fact, the only steel used in the project consisted of trusses over the cafeteria and gymnasium for aesthetics.
The $3.4 million precast contract included hollowcore floor and roof planks, precast interior walls, stairs and beams. For cost efficiency, the building design was based on panel widths averaging 8-2/3 feet and repetitive panel layouts. (Repeatability saves precast manufacturers the time and expense of producing multiple forms.) Window openings were made as large as possible without requiring special reinforcing.
High Concrete Group used 219 CarbonCast® High Performance Insulated Wall Panels for the exterior. The CarbonCast panels feature 2-2.5 inches of XPS insulation between two concrete wythes connected with C-GRID® carbon fiber shear grid. The non-thermally conductive carbon fiber prevents thermal transfer, keeping occupants comfortable year round.Four times stronger than steel by weight, C-GRID shear trusses can also be used to deliver fully structurally composite action in load-bearing panels, increasing square footage without adding to the building’s footprint.
The CarbonCast High Performance Insulated Wall Panels deliver superior thermal performance compared to brick-and-block systems or even conventional precast. Carbon fiber grid has low thermal conductivity, thereby preventing hot or cold spots from forming. The sandwich wall panels deliver 100% of the R-value of the insulation. Significant heating and cooling savings are expected over the life of the school.
To achieve the desired appearance without compromising performance, glaserworks turned to High Concrete Group LLC. Precast walls were selected in part because, “we liked the rigor precast brought to the project,” said Duffy.
For a swift, economical solution, modular size thin brick was incorporated into the panels, eliminating the cost and unpredictability of masonry field work. An acid-washed aggregate finish created different colors and textures, achieving a traditional look consistent with the neighboring structures. Budget constraints limited the amount of modular brick as the project moved forward. High Concrete Group was able to incorporate design changes along the way easily, providing flexibility unmatched by masonry. Finally, details were added around windows to complete the façade of the structure.
The precast elements were fabricated off-site and delivered for immediate erection without concerns for the material and equipment storage had the designers opted for field-construction methods, not to mention the coordination of various trades. In addition, because precast concrete is manufactured in a controlled factory environment, the school district avoided weather delays and costly setbacks in the field.
Extensive planning was required to make sure the precast walls would accommodate other building systems. The building was designed utilizing modules with input from High Concrete Group to create the largest pieces that could be transported. This kept costs and complication down. In addition, High Concrete Group facilitated early and extensive sessions twice a week for several months with MEP primes to make sure wall and floor penetrations were correct. When the panels and plans arrived at the site, this coordination paid off. The primes knew whose penetrations were whose, enabling them to quickly install their work with few field corrections.
Precast also mitigated the risk of mold and mildew – a major potential liability in a structure housing children. The precast insulated wall panels nearly eradicate the mold risk because concrete inhibits water penetration unlike traditional brick and block methods. In addition, precast wall panels eliminate the need for drywall, a potential food source for mildew and mold. As an added bonus, the school is resistant to insects, pests, and fire. Precast provided a finished, ready-to-paint interior that saved time at the back-end of the project as well.
Precast concrete provided the Fairview-Clifton German Language School with significant benefits in aesthetics, performance and coordination. It’s safe to say the new educational facility will leave an enduring mark on this historic Midwestern neighborhood—and on the thousands of students who will pass through the precast structure in the decades to come.
CarbonCast is a registered trademark of AltusGroup, Inc.
C-GRID is a registered trademark of Chomarat, N.A.