Whether it's during the Super Bowl or the World Series, precast concrete is regularly on display to thousands of fans in the stands and tens of millions more watching at home on TV. The explosion of stadium projects throughout the country is an ideal stage for the industry to put its best foot forward.
Precast concrete risers have long been a standard for stadiums and indoor arenas, offering benefits for seating units that most designers have come to recognize. But today, precast concrete components are being used for a wider range of design elements that are both structural and architectural. Designers anticipate that trend to continue in this steadily growing market.
“The amount of precast concrete used in any stadium project depends on the specifics of the project, its location, and how early we can get involved in it,” says Tom D'Arcy, head of the San Antonio, Texas, office of The Consulting Engineers Group. “We've done entire stadium structural systems with precast concrete, and it works quite well. It depends on the designer's goals and experience.”
The ability to cast components off-site through any kind of weather has boosted the use of precast concrete. This not only speeds construction by eliminating weather delays but helps keep the site clear, which is receiving more focus, says Fred Heldenfels IV, president of Heldenfels Enterprises Inc. in Corpus Christi, Texas.
The producer fabricated 3000 components, mostly seating risers, tubs, and solid walls, for the new 80,000-seat Dallas Cowboys stadium under construction in Arlington, Texas. (The facility can be expanded to 100,000 seats for other events.)
“Construction on this stadium is the same as in the past, but the safety program is the most rigorous and most disciplined we've ever had,” Heldenfels says. When work began, access to the site was restricted to those who had undergone a three-day safety-training program. That process now has been streamlined to two days.
“There are a lot of trades and individual crews working on fairly intense schedules in a compact area,” he explains. “It's becoming a trend with large sites of all types to create more safety awareness.”Standard precast seating
Precast concrete seating is used in virtually every project. These riser units previously were designed as single-level modules, but precast producers now manufacture them as double and even triple units to save erection time. “The double units have become most common,” D'Arcy notes. “Triple units tend to be difficult to cast. The forms are too high for caging and finishing.”
Double precast concrete seating units probably will remain the standard well into the future, says Mike Achilles, northern regional sales director for High Concrete Group in Denver, Pa. “The seating technology has been the same for a long time, and it's not going to change because it works,” he says. High Concrete has worked in numerous new stadiums and arenas in metropolitan New York.
Precast producers also are seeing more interest in other framing components, such as raker beams to hold the seating units, vomitory walls at exits, and stairs. “Some parts of the country have used these for a long time,” says Roger Becker, vice president of the precast division of The Spancrete Group in Waukesha, Wis. “But in the Upper Midwest, we're seeing a transition from other materials to precast concrete for the primary framing elements. Designers are better appreciating the benefits of prefabricating these units.”