A design-build approach that reused steel forms from an award-winning project resulted in the 315-space Lehigh University Alumni Parking Garage in four to six months less time than typical construction. The form design was recognized with a PCI Design Award in 2002 and again in 2007 when it was repurposed for this project.

The five-level, 104,000 square foot garage for university faculty features 10- by 30-foot precast concrete elements that incorporate slender precast concrete columns and spandrel beams. The structural design eliminated tall, heavy spandrels that are traditionally associated with parking structures, replacing them with an open, lightweight concrete latticework that provides both exciting form and efficient function. The panels' slender columns correspond individually to the 7-foot 6-inch span of the 15-foot-wide structural double tee stems. In addition to bringing in light and providing an open, airy feel, the exterior lattice system blocks headlight beams from reaching into the neighborhood.

In a recent and unconventional interpretation of this concept, the New Brunswick Development Corporation (Devco) has completed Gateway Transit Village, a mixed-use, transit-oriented design consisting of a 24-story building and a new pedestrian walkway directly adjacent to a NJ Transit/Amtrak station. Located in the heart of downtown New Brunswick across from the Rutgers U

niversity campus, the new $150 million, 632,000-square-foot structure is the tallest parking garage and building in the city. A precast parking structure from High Concrete Group LLC forms its core.

Built as part of an ongoing revitalization effort, the new complex is intended to help bring renewed life to a site that is vital to the city, but that has been under-utilized for many years. With views of the Raritan River, the apartments and condos in the tower are targeted to attract people who already live and work in New Brunswick. Twenty percent of the units are set aside for moderate- and low-income owners.

The project is unconventional in several ways. "Gateway is the most urbanly dense transit village in New Jersey," notes David J. Stuart, project manager for New York City-based Meltzer Mandl Architects. "Everything that’s normally incorporated into a transit village has been combined into a single structure."

"Also, precast concrete parking garages are not typically designed to support taller and more complex structures above them; they are usually stand-alone buildings. To place a 14-story building on top of a garage is daring structural engineering," says Stuart.

Gateway Transit Village consists of a 10-story precast parking garage with 697 parking spaces, topped by a 14-story steel-frame and hollowcore residential tower containing 150 apartments and 42 condos. The structure is wrapped by 120,000 square feet of offices and a series of street-level commercial spaces for tenants, including the Barnes & Noble College Bookstore for Rutgers and offices for the New Brunswick Parking Authority and the Rutgers University Press.

Stuart notes that Gateway Transit Village doesn’t relate to its context as much as redefine it. "A typical approach would be to hide the parking garage, and disguise the precast," says Stuart. "At first we considered thin brick, to match other parts of the structure. But we decided that we wanted an exposed concrete aesthetic for the podium, to let concrete be concrete, and to show its inherent nature. Precast concrete can be quite elegant, minimalist. It was economical, fast, and gave us pleasing aesthetics."

The majority of the garage was cast in a standard High Concrete Group buff architectural mix and finished with a light sandblast. Simple reveals set up a rectangular pattern that brings scale to the horizontal spandrels and complements the openings between them on the way up. Spandrels at the top are finished with a small cornice.

The parking garage required 24-foot and 36-foot spacing between the support walls to optimize the parking spaces and 12’-wide precast double tees. The residential tower called for a different supporting grid, which had to have its column lines aligned with the garage support walls via 10-inch-thick hollowcore plank spanning up to 36 feet.

"This is a good use of precast," says J. Benji Alper, PE of engineering firm Severud Associates’ New York office. "While the precast garage is only 10 stories, the overall structure still stands at 24 stories tall, requiring the precast walls to resist the forces for the full lateral and gravity loads of the 24-story building." He discusses the approach in the Structure Magazine article,"Integration of Diverse Structural Systems and Design Delegation in a Mixed Use Space."

Alper notes that communication was critical in the project. "Immediately after the contract award, weekly meetings were conducted with the entire design team which included members from the precast manufacturer’s engineers, the structural engineer, the architect, the parking consultant, the owner, and the general contractor. Other trades, including the steel fabricator, the steel detailer, and the erector, also would often attend. The meetings were a key part of an iterative design process between Severud and High Concrete Group."

An outstanding thermal performance was achieved at Hamburg Elementary school (Tilden) with CarbonCast walls. Amid skyrocketing energy costs and heightened public awareness of green construction practices, more building owners are seeking environmentally friendly solutions without incurring higher costs.

Tilden Elementary Center in Hamburg, PA, is no exception. The school for kindergarten through fifth-grade students will save on heating and cooling costs with innovative precast high performance insulated wall panels engineered, manufactured, and erected by High Concrete Group.

High Concrete’s 10”-thick precast exterior walls on the 110,000-square foot project delivers R-15 performance. They use three inches of continuous XPS insulation (“ci” as defined in ASHRAE Building Energy Code 90.1-2007) sandwiched between a 4” interior wythe and a 3” exterior wythe. C-GRID carbon fiber shear grid connects the two wythes. With relatively low thermal conductivity, the carbon fiber prevents thermal transfer, virtually eliminating hot and cold spots on the interior wall preserving comfort for students.

High’s precast walls helped keep the project on schedule and under budget, both of which are critical for a public school. The project was completed in June 2008—in plenty of time for teachers to welcome students for the first day of school.