New York and California are continental opposites, but their zoos are on the same wavelength by using precast concrete.
By Bridget McCrea
They may be located on opposite sides of the continent, but two recently opened zoo projects in North America have at least one thing in common: They’re constructed from precast concrete. The first is an elephant exhibit at Seneca Park Zoo in Rochester, N.Y., and the other is a center for endangered species at the San Diego Zoo – and both projects serve an important purpose in their respective environments.
Seneca Park Zoo opened its new exhibit in late April for adult elephants Genny C. and Lilac, whose new home comprises a 10,000-square-foot barn and 22,000-square-foot yard that’s five times the size of the old yard. Coming this summer is a visitor enclosure, which is currently under construction, designed to provide “year-round” shelter to visitors.
Involved in the project since early 2005, James Boyce, project manager with Empire Precast in Pittsford, N.Y., said his firm worked closely with architectural-engineering firm Stantec of Rochester, N.Y., to develop the precast concrete structure that would come to be the elephants’ new home. After completing the preliminary designs, which involved creating a building that would resist elephant loads, the precaster was awarded the project in May.
At the heart of the matter was a zoo looking to expand and upgrade its facilities, and wanting to better accommodate a pregnant elephant (which subsequently lost her calf). Part of an overall zoo upgrade plan, the new elephant facility was “the first major exhibit that the zoo has added in quite a few years,” Boyce said.
Precast was specified as a way to get the facility up and in place quickly, said Boyce. Also attractive was the durability of the precast product and its overall versatility. The exterior of the building, for example, would include cut granite in order to create an Africa-like setting for its inhabitants and visitors. “I don’t think cast-in-place concrete or any other material would have been able to result in the ‘rough look’ that the zoo was looking for in the form liner,” Boyce said.
Comprised of about 75 12-inch-thick, insulated precast walls and a hollow core roof and mezzanine area, the building is supported by columns that are positioned in the middle of the structure.
Being a part of the design-build process presented a few challenges for Empire Precast, which quickly found itself caught up in the fast-paced frenzy of getting the project engineered and built in a compressed amount of time. “We cast every opening so we didn’t have to cut anything in the field,” Boyce said. “That alone was a challenge, in terms of making sure that all mechanicals and electricals were coordinated prior to getting into the casting.”
Construction was handled by The Nichols Team of Henrietta, N.Y., whose past Seneca Zoo projects included both a python and cougar exhibit. Other than a two-week construction delay caused by delivery problems, Jim Burm, project manager, says the project went smoothly and that precast worked out to be a good choice of materials for what the zoo was trying to accomplish.
Richard Napoli, associate and senior architect at Stantec Architecture in Rochester, N.Y., concurs, saying that precast not only allowed for quick completion of the project, but also served as a viable upgrade to a much smaller standard masonry construction building previously used for the elephants.
From the engineering perspective, Napoli says designing a building that took into account the animal’s size (up to 14,000 pounds) and trunk reach (up to 23 feet) was a challenge. “We needed a building that could not only contain that volume, but also be erected quickly,” said Napoli, who considered both steel and conventional masonry before selecting precast.
“We were able to get the 30-foot vertical height that we were looking for by using a plank roof, since we didn’t need very deep beams,” Napoli said. “Overall, precast really helped us in terms of a volume that we needed to create for a specific animal’s requirements.”
Being able to have large surfaces with few joints was another draw, as was the “low maintenance” factor. The project owner also saved on labor expenses, says Napoli, who estimates the project costs at $4.4 million. Whereas masons would have to be paid daily wages to erect the building, precast allowed for quick installation with minimal hands on deck.
The finished product was well received by the zoo, say Napoli and Boyce, who credit precast with helping them engineer and build a very important structure for a zoo that’s in the midst of an overall plan to upgrade its facilities over the next few years. “In the end,” Boyce said, “it worked out very well, and the owner is very pleased with the home for its elephants.”
Protecting the endangered
Across the country in San Diego, the Beckman Center for Conservation and Research for Endangered Species (CRES) moved into its new precast concrete digs two years ago at the San Diego Zoo, moving from its previously cramped quarters. Founded in 1975, CRES is one of the largest zoo-based research centers in the world.
Dedicated to preserving and protecting rare and endangered wildlife and their habitats, the research conducted at CRES is critical in the war against extinction.
At the zoo, more than 75 CRES researchers gather scientific knowledge about the unique needs of wildlife, then translate this data into strategies to better manage the captive species while protecting populations in the wild. Scientific research at CRES takes a variety of forms – from behavioral studies at the San Diego Zoo’s Giant Panda Research Station to banking endangered plant seeds at the Wild Animal Park to high-tech genetic studies at the Frozen Zoo.
And much of that work is completed in a facility made largely of precast concrete. Designed by McGraw/Baldwin Architects, constructed by Turner Construction and fabricated by San Diego Precast (all based in San Diego), the project began in mid-2003 and wrapped up in October 2004.
Gordon Pettis, senior estimator and custom project manager at San Diego Precast, says the precast portion of the project includes three buildings that are connected by four 29-foot-long precast columns, which create a walkway between the three units. Made up of 300 individual precast pieces, the building is encircled by a ring of precast that includes a midsection, top, all decks and all windowsills. A structural band running through the concrete masonry (where rebar was passed through) aligns with the windowsills.
From the precaster’s perspective, Pettis says fabricating that structural band to accommodate the rebar was a challenge. “Masons stick the rebar in the cell, and while it was designed to be blocked out exactly in the center of the cell, the likelihood of that ever happening is pretty small,” Pettis said. “So we had to increase the size of the hole in all the blocks.”
Carmen Vann, project manager at Turner Construction, says interfacing the precast with the masonry construction posed challenges for the contractor, which used a combination of eyebolts, cranes and forklifts to tie the bottom and top levels together into one cohesive structure. A green building that achieved Silver status from the U.S. Green Building Council (see the article “Sustainable Development: Precast LEEDs the Way” on page 28), CRES’ new home included an intensive landscaping package complete with full-grown palm trees, river rocks and meandering pathways.
Along with providing the cornerstone of the building, precast also brought to the table a dramatic architectural design that “lifts up” the spaces of the building, based on the fact that the second level sits on the precast elements themselves. “It gives the sense of one large building, even though there are two stories inside,” Vann said.
Calling the project “pretty straightforward,” Pettis said the zoo was also looking for a specific texture and look to the building. Achievable through the use of precast, which was originally specified by the project’s architect, the end result was an aesthetically pleasing building that exceeded owner expectations. “They were just ecstatic to see CRES leave a small, cramped building,” Pettis said, “and move into this new, appealing facility that better meets their needs.”