The building block construction style allows for concrete and steel to be installed simultaneously across the ballpark. In the case of Globe Life Field, work is progressing out of the ground at the area behind home plate, while the outfield is 50-feet below in a different phase of construction.
Sitting on 25-acres of property in Hillsboro, Texas, Gate Precast, the company responsible for all concrete precast, is pre-producing all of the concrete bowl components, including risers, rakers and columns.
"When you walk up through [the seating bowl] and sit down on your seats to watch the game, that's what risers are," Todd Petty, Gate Precast Vice President of Operations, said.
Rakers provide the solid foundation necessary for the seating bowl to stay in place. They are being produced in both steel and concrete, making it necessary for the different trades to work simultaneously in order to keep the project on schedule.
"They're pouring the rakers and we'll go right behind them. Then they'll hang steel behind us, so everything follows all the way around until you get to the top. It has to be carefully executed, there's a lot of moving parts," Petty said.
Concrete and steel each serve in a similar role to stabilize the overall structure. Concrete provides the main support from field level, while all levels above the main concourse are founded with steel.
"Steel typically takes several months of lead time before your first piece of steel shows up at the job site. So while you're waiting for that you can start with your concrete first," Texas Rangers Sr. Vice President of Project Development Jack Hill said. "So you'll see in a lot of the stadiums, foundation in the lower section is concrete. While they're waiting for steel, they get all the concrete done, which is exactly what we've done."
All of the subcontractors communicate and work together in order to maximize time on the site. Steel can't be erected until the lower bowl concrete has set, while in a similar pattern, concrete risers can't be set until the steel has been erected.
"We're trying to get a little bit ahead. It can take a week to build [one steel beam], and they can put it up [on-site] in minutes. So I have to build way ahead to ever have a chance," Irwin Steel Vice President Bryan Irwin said.
Constructing a seating bowl to hold tens of thousands of fans requires a complicated set of instructions in any stadium project, but the unique shape of a ballpark makes constructing the pieces much more complicated.
"Baseball stadiums are different because it's asymmetrical. It does add a little bit of a challenge to it," Hill said. "You can see how they need to be very precise with their measurements. All that has to be detailed so they know what to fabricate. That gives you a chance to start all your concrete."
There aren't many similar pieces on the job in either the concrete or steel spectrum. Petty estimates that with the atypical design of the ballpark, Gate Precast will have nearly 50 different types of riser profiles for the entire project, while a football or soccer stadium would have much less, simply due to the more standard elliptical shape.
Irwin Steel is responsible for all the steel rakers, which are the diagonal pieces that hold the seating area, as well as additional steel framing throughout the site. Steel takes several months of production before it's ready for installation.
"We started in January, and we didn't start erecting until June, so we had to have that much of a head start to stay ahead of the erector," Irwin Steel President James Irwin said.
Irwin Steel has been involved with several stadium projects, including neighboring AT&T Stadium, but the notoriety around Globe Life Field will be added to their list of memorable projects.
"Two years from now you can go anywhere in the United States and say 'Globe Life Field' and everybody is going to know what you're talking about. Very few jobs are known like that nationwide, but Globe Life Field is one of them and we wanted to be part of it," James Irwin said.
While the obvious workload is on the construction site, not all products can be built in Arlington. The Rangers have partnered with local companies to fabricate necessary resources at an off-site facility.
"Local production is an advantage if you can do it," Hill said. "In this area we've got some great companies. There are a lot of people in the industry in this area, so there are several advantages on this project."
The 1.7 million square foot project is built from a multitude of products, but concrete and steel are combining to bring the ballpark out of the ground and into eye level. Many of the key components are being fabricated off-site, though each has a close proximity to the ballpark, providing for an advantage when piecing together the finished product.
In the weeks following the first steel beam erection in June, progress has erupted beyond a single piece of steel, creating the outline of the ballpark. Though the steel erection has just recently been started at Globe Life Field, the steel work started way before that day in June, at a fabrication facility 35 miles away.
"We take a column that we may work on here for 150 hours of labor, and the erector will stand that in 30 minutes," James Irwin said. "So there's a whole lot of work up front to be able to work so quickly in the field."
Irwin Steel is fabricating nearly 16,000 tons of steel at their Justin, Texas facility. All of the steel starts at that facility with a flat sheet of steel. The sheet is transformed into a column, riser, or raker, and constructed together similar to building blocks.
After the pieces fit together, they are welded. Depending on if the steel is visible to the public, it is sent to be painted. If the steel will be hidden from the public, it is essentially ready to be shipped to Globe Life Field.
There are several advantages to producing products off-site. The Gate Precast off-site concrete facility allows for the product to be made several months ahead of time, so the risers are ready to be installed as soon as construction has progressed enough to support the structure.
Concrete risers can take a team 12 hours to form and another 12 hours to dry to the correct standard. At the peak, Petty estimates ten risers can be formed each day, to get to the total of 2,100 total pieces required to finish the job. Production of that magnitude can't be completed on-site at Globe Life Field.
"There's no way that you can handle the quality control outside, and on-site, that you can in a controlled environment like the plant," Petty said. "There also isn't much room available in the construction area. To have it stored [off-site] is a huge plus, to have it really close, 60 miles, is a huge plus for that."
The local production is not only cost effective and time efficient, but also allows the facility workers to see the direct impact their products have on the community.
"The guys that are actually building [the ballpark] are going to be sitting in those seats… and eating hot dogs. I think the Rangers especially recognize that and appreciate that," James Irwin said.
By the Numbers:
- 750 truckloads of bowl steel delivered to site
- 28,000 pounds: average weight of one precast riser
- 2,100 individual pieces created at Gate Precast
- 11,090 cubic yards of concrete used for precast
- 35,000 tons of steel total (16,000 for seating bowl, 19,000 for roof structure)
- 9,700 "picks"- number of times a crane will pick up a piece of stseel
- 9,200 pounds- the average weight of one steel beam
- Rakers- Diagonal pieces constructed to give stability to the seating bowl structure.
- Risers- The vertical elements in a set of stairs.
- Precast- producing concrete in a controlled environment, off-site from the construction site.