Wild Concrete

When visitors to the Jacksonville (Fla.) Zoo’s new Range of the Jaguar exhibit see what appears to be a 400--year--old Mayan ruin, they probably don’t realize that almost everything they’re looking at is made of concrete.

Built as part of a zoo master plan originally conceived in 1992, the $15.4 million 4.5 acre exhibit, which opened in March after 18 months of construction, houses about 100 different species of animals, including four jaguars.

There are four main public buildings in the exhibit: the Lost Temple, the aviary, the jaguar enclosure, and the cafe and market. Different concrete techniques were used depending on the needs of each facility as well as environmental and budgetary considerations.

Concrete is considered an ideal material for constructing zoos. It is durable, easy to clean and able to take on almost any shape or color. “We build hospital--quality facilities outdoors,” director of biological programs Karl Kranz explains. “The concrete work needed to be well done in order to meet our caging tolerances, where we ask that the floors be roughened so that animals will have good traction. It needed to be smoother in pools so when they go swimming, they don’t hit something rough on the side of the pool and damage their skin. We really like the drains to be at the lowest point of the floor.” This allows the floors to gravity drain without puddles, but is not easy to achieve.

Concrete was also used extensively in nonpublic areas. “In terms of long--term maintenance and wear, concrete is the most durable and cost--effective product that could be used,” notes Steve Wetherell, director of project development for general contractor, The Stellar Group. “The use of concrete slabs in behind--the--scenes spaces, keeper areas and animal holding areas permits a greater level of sanitation, and its use in public spaces allows flexibility in finish and appearance. Concrete was used to construct and create the illusion of mud paths, trees, stone, wood decking and wood timbers.”

The zoo is within 750 ft. of a bald eagle nest. Because these birds are a threatened species protected under federal law, they cannot be disturbed during their breeding season. As a result, Stellar suggested building the Lost Temple – which houses the reptile, amphibian and fish collections – using tilt--up concrete panels. “One reason we decided to go with tilt--up is because the building could be put up very quickly so it would be up before the eagles came back for the nesting season,” Kranz says. “We had to prepare a month--by--month book for the U.S. Fish and Wildlife Service to tell them what we were going to do. We even had to change access points for the concrete trucks depending on where we were in the nesting season. We were allowed to work inside the building after the eagles returned. It was quite a challenge to meet the deadlines and budgets without disturbing the eagles.” Some work was done out of the normal sequence in order to meet deadlines while accommodating the eagles, notes Wetherell. Breeding was unaffected, with the eagle pair raising two chicks during both nesting seasons while construction was underway.

Using tilt--up had other benefits. “This approach allowed wall fabrication to occur on the opposite side of the temple building footprint from the eagle nest site, outside the zone of influence,” says Wetherell. “Manpower, formwork and equipment in the areas adjacent to the nest were very limited with tilt--up as opposed to erecting scaffold for masonry or large formwork sections for cast--in--place concrete, and having material lay down occur at multiple locations around the building.” This meant quicker completion of the work and reduced construction cost.

In decorating the 4,000--sq.--ft. Lost Temple, Cemrock Landscape, Inc., of Tucson, Ariz., did research so the sculptures and carvings would realistically portray the Mayan influence. The building’s interior contains walk--through exhibit areas including nine water filled pools.