SPECIAL FEATURE
State of the Art Precast Stadia
S
tadium
projects
have
become
high-tech
extravaganzas in recent years, a dramatic change
from when generic bowls dominated. That trend
puts more pressure on designers to find creative solutions,
experiment with new ideas, and produce dramatic visual
statements. In many cases, they are turning to precast
concrete components to help them meet these challenges.
Precast concrete components, including architectural
wall panels, seating tubs and risers, solid wall panels for
vomitories and concourses, and hollow-core planks and
double tees for flooring, offer significant benefits that can
overcome key design obstacles. As stadium concepts
evolve, more designers are examining these attributes and
incorporating the components into their plans.
The Stadium Experience
Bill Johnson, design principal at HOK, notes that while
stadiums once served as the backdrop to sporting events,
today they are a major part of the sports experience. “The
idea now is to make every stadium serve multiple purposes
and provide part of the entertainment,” he says. (For more
on Johnson’s experience with stadium design, see the
profile article in this issue.)
‘The idea now is to make every
stadium serve multiple
purposes and provide
part of the entertainment.’
Aaron Brown, associate principal and senior project
manager at Populous, agrees. “We’re seeing clients look
for more revenue sources. That leads to party decks and
super-vomitories with more entertainment and concession
options. There are more revenue sources in the bowl than
ever before.”
In part, the need for higher quality experience derives
from expanded broadcast coverage, which allows fans
to view the event on multiple devices and enormous TVs
at home, notes Johnson. “Especially in the NFL [National
Football League], the big challenge is to convince people to
attend the event. There’s an incentive to stay away, so we
have to make attending more of an experience. Every seat
needs amenities, and we need to create gathering points
throughout the stadium to make fans feel special.”
This extends to the exterior design statement, he adds.
“Owners want to generate revenues through naming rights
and sponsorships. In the past, stadiums were seen as
civic buildings with traditional appearances. Today, to sell
sponsorships, they need more excitement and a dramatic
appearance.”
They also need robust structures from which can
be hung larger monitors, additional signage, and other
amenities that enhance the experience and generate more
revenue. “There’s a lot to think about and balance,” says
Johnson. “We have to talk with people of all generations and
expectations to learn their attitude about attending events
and what they like to do there.”
Speed Matters
In addition to the need for more amenities, there is a
driving need to create these more elaborate venues on tight
schedules. No matter when the project gets underway,
missing the opening date—usually tied to the new season—
can’t happen. “Owners want everything done faster today,”
says Brown. “They want no down time or contractors
working during the season. They’re feeling the pressure, and
we’re feeling it earlier in the process, too. We’re pushed to
get these designs out faster in the off season.”
‘Speed is everything to them.’
“Speed is everything to them,” says Jim Lewis, former
director of architectural systems at Gate Precast Co.,
which provides architectural precast concrete panels and
structural components for a variety of stadium projects.
“They absolutely need to open on time, and they’re willing
to use prefabricated materials, like precast, to give them
the results they want on a quicker timeline to accelerate
occupancy.”
Speed was a key reason that architectural precast
concrete panels were used to clad Lucas Oil Stadium in
Indianapolis, Ind., home to the NFL Colts. The 73,000-seat
stadium had a 36-month schedule for completion, leading
designers to specify insulated panels embedded with
Endicott thin brick, which were produced by Gate Precast
and High Concrete, along with structural components
including stairs, risers, and load-bearing panels, fabricated
by Coreslab Structures.
“Using precast concrete worked great for us,” says
John Klipsch, executive director of the Indiana Stadium
& Convention Building Authority, which built the stadium.
“We had a very tight schedule, and precast components
definitely were the best way to beat the deadline we had.”
Because colleges and universities offer long periods of
down time when students are not on campus, these projects
often are phased, finishing one portion during one break and
completing them the next year. Texas A&M University, for
instance, recently renovated its entire football stadium but
did half one summer and the other half the next year. In that
project, precaster Heldenfels Inc. provided larger risers and
tubs for the rebuilt alumni seating areas, to accommodate
new suites, loges and other amenities, while the student
and general-admission side were designed for typical bench
seating.
“We’re driven in college designs by meeting a wider
range of needs today,” says Gil Heldenfels, vice president.
“They are seeking to attract more donors and season-ticket
ASCENT SPRING 2016
31
SPECIAL FEATURE
Lucas Oil Stadium, home to the NFL Colts, features
architectural precast concrete panels on its façade
and structural components including stairs, risers,
and load-bearing panels. Speed was a key benefit of
using the precast concrete pieces. Photo: HKS, Inc.
holders, so there’s more variety in seating. It’s not difficult
to provide them, but it adds complexity in design and
fabrication of the components.”
Seating Needs Expand
Seating designs have become more complex owing to
the need for incorporating amenities into sections, notes
Johnson. As rows become wider and add features, it pushes
higher levels further from the field of play. “Close proximity to
the field is a priority, but we have to balance that with aisle
widths and seating needs. We use CAD systems to analyze
sight lines and clearances more than ever before.”
Designers continually experiment with tread and riser
options, he notes, but veering too far from the norm can
create loading issues. As more stadiums add retractable
roofs and require adjustable seating to change capacity
size to add more events, seating design becomes more
complex. “We’re always playing with different tread widths
and dimensions,” says Brown. The typical 33-inch width
used for plastic chairs often expands at suite and loge levels
to accommodate larger chairs, resulting in 36- and 42-inch
widths, plus drink rails.
“In-seat service is becoming popular, especially for
baseball, leading to deeper designs for the precast pieces,”
Brown says. The challenge then is adjusting seating levels
back to the 33-inch depth where they meet. “There are
different ways to do it, so the details become important.”
‘A precast concrete seating bowl
is often more desirable than
aluminum for durability and sound
transmission reasons.’
Angela Nygren, a project architect with Crawford
Architects, has looked at hybrid systems, in which lightweight
precast concrete planks are supported by aluminum risers
and structural steel framing. “A precast concrete seating
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ASCENT SPRING 2016
Photo: Coreslab.
bowl is often more desirable than aluminum for durability
and sound transmission reasons,” she says. “Using precast
planks focuses the material where needed while reducing
weight and providing more headroom under the bowl.”
Crawford designs a variety of university stadiums,
including one at South Dakota State University that is under
construction. “We looked at a hybrid system for the seating
bowl, but we chose a traditional precast concrete system
due to procurement issues,” she says. “Because of the
competitive-bidding requirements, it was more feasible in
this case to use a total precast concrete system.”
Risers have lengthened through the years, moving from
30 feet to 50 feet, notes Gary Pooley, sales manager at Wells
Concrete. “Stadiums today have unique configurations, with
less mirror-image designs than in the past, so they need
flexibility in providing long spans in different ways.” Wells
Concrete recently began fabricating components for U.S.
Bank Stadium in Minneapolis, Minn., home to the NFL
Vikings. They include risers, raker beams, beams, columns,
spandrels, stair units, and vomitory and ring walls.
Single Vs. Double Risers
Although many designs specify double and triple
risers to speed construction and minimize picks, Wells
Concrete promotes the benefits of single risers for
speedy completion. “We decided on this route even
though it’s counter-intuitive,” he says. The singles offer
more opportunities to make fine adjustments at each
level rather than facing larger ones after two or three
rows, he explains. “We’ve found we can set two singles
as fast as or faster than setting doubles because we
don’t have to wrestle with the bearing ledges and make
bigger adjustments to how they line up.”
In addition, double and triple risers are cast face-
up in forms, making it harder to control the quality
of the walking surface at the top, due to hydraulic
pressure pushing the material down. Casting singles
in a face-down position creates more consistency and
slip-resistant finishes can be cast into the pieces with
formliners. Wells Concrete uses a 500-foot-long form to
fabricate many pieces at once, using a vacuum lift to pull
pieces out that eliminates the need to strip the pieces,
erect inserts, and patch them afterward.
‘Super-Vomitories’ Proliferate
Seating designs impact the plans for corridors and
vomitories, which often are built using precast concrete
panels and planks. “Owners want to create ‘supervomitories’ that provide larger club levels,” says Brown.
That was the approach taken at EverBank Field in
Jacksonville, Fla., home to the NFL Jaguars. Populous
designers connected separate clubs on the east and
west sides of the stadium via super-vomitories. “Today,
we design the bowls traditionally, with precast concrete
seating, and then we overframe the precast concrete and
build on top of it for concourses,” he explains. “That way,
if they want to change the configuration later, the seating
is still available underneath.”
These “party decks” became popular with Populous’
designs after its work at Coors Field in Denver, Colo.,
he notes. “That went over great, so more clients began
latching onto them,” he says. “Now the notion of unusual
little decks or hangout spots connected to the seating
areas is growing, which complicates the bowl design.”
Those areas are especially important in baseball fields,
he notes, as the slower pace of the game leads patrons
to roam. “They check out the amenities, such as the gift
Texas A&M recently renovated its entire seating bowl,
phasing two halves over two seasons, using precast concrete
structural components. Suites and loges were integrated
with general seating next to each other on the middle deck.
Photos: Populous.
ASCENT SPRING 2016
33
shop, fan zone, a craft-beer concession, etc. Football
stadiums don’t need as many entertainment areas,
making the design a little simpler.”
“There can’t be any
obstructions from seating
or vomitory walls.”
Concourses need longer spans to provide better line
of vision from the corridors back to the field, notes Wells’
Pooley. “There can’t be any obstructions from seating or
vomitory walls,” he says. That often means hanging vomitory
walls off of the stair risers to avoid adding columns or shear
walls. In some cases, the vomitory walls include stair units
as a monolithic piece. “It makes casting more complicated
and creates support issues,” he says. “But designers can
count on precasters to provide the needed support for
vomitory walls and stairs in the middle of a long span that
otherwise would create an obstruction.”
“The differences in the designs today are more nuances
than dramatic changes,” says Heldenfels. “The goal is to
provide better flow and sightlines. Vomitory-wall designs are
changing in different schemes to meet those goals.”
“Clients are always looking for new ideas and
experimenting,” says Brown. “They don’t know what will
work, so we try to keep options open for adapting down
the road. Rather than rip out all the precast concrete if they
want to update, we work with it to keep it in place and build
over it where we can.”
Kit of Parts Design
In many ways, the use of precast concrete provides a
“kit of parts” that lets designers combine pieces to find
the best fit and adapt the stadium for a wider range of
needs. This approach was epitomized by the Centennial
Olympic Stadium in Atlanta, Ga., which was taken apart and
reassembled into Turner Field for Major League Baseball’s
Braves.
“We asked ourselves if we could reuse the precast
concrete pieces, since they worked so well as a kit of
parts,” says Johnson. “Precast concrete lends itself to that
well and this use maximized it. We didn’t need to build the
new stadium from scratch, we could take the seats out,
take the precast components apart and move them into
new positions. It saved enormous amounts of construction
time.” For that reason, Turner Field had a smooth, curving
outfield wall, as it consisted of some of the panels that had
been used to create the Olympic rings in the original design.
This kit of parts approach also helps with fit walls, stairs,
and treads together, he adds. “We bear the precast stairs
on the vomitory walls to make it more efficient, and we
know the pieces will fit together perfectly since they’re being
supplied by the same source.”
Fitting the pieces is more important due to the
complexities of the bowl shapes, says Brown. Smoothly
curving outfield walls in a doughnut-shaped stadium are a
thing of the past. “There’s more variation in bowl designs,
with very few 360-degree circles. By the time we add in ADA
requirements, loges, premium seating areas, more tunnels,
wider vomitories, party decks and other elements, each
design is totally unique.”
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ASCENT SPRING 2016
Precast Benefits
High-performance precast concrete can provide a variety
of benefits to stadium projects• Speed. Casting components off-site while site
preparation and foundation work is underway ensures
the stadium can be erected quickly, saving time, on
site trade parking and allowing interior trades faster
access. This helps ensure stadiums are ready for
game day.
• All-year construction. Precast concrete components
can be erected through harsh winter weather, day or
night, expanding the construction season and keeping
projects on schedule.
• Aesthetic versatility. Precast concrete’s plasticity
allows it to blend with existing campus styles or
create a singular aesthetic statement. Veneer-faced
precast panels offer many benefits like long term
durability and formliners can be used to create
texture, reveals, and other treatments. Glass,
aluminum, and other materials can interface with
these components.
• Efficiency. Having many elements, including a
full- wall assembly, created and delivered by a
single- source supplier, eliminates communication
concerns and minimizes redundant trades, reducing
construction time and materials.
• High quality control. By casting under controlled
conditions off-site, precast concrete components
achieve high levels of quality assurance and can hold
tight tolerances.
• Durability. 100 year structures. Precast concrete’s
dense mass allows for easy maintenance and
protection against water penetration or chemical
washing agents.
• Flexibility. Hollow-core plank, double tee’s and
monolithic seating/vomitory components provide
long-span capabilities, with the potential for long
spans. They can eliminate columns to open sight lines
to the field from concourses and provide easily traffic
flow.
• Stability. Precast concrete seating provides a solid,
easily cleaned material that provides a better base
for seating of all types than other materials, such
as aluminum. Its structure can easily stand up to
rhythmic vibrations and heavy loading.
• Fire protection. The inherent inorganic composition of
precast concrete prevents it from catching fire, and it
can slow the spread of flame from any incident.
• Sustainable design. Precast concrete contributes
to multiple LEED points through its use of local
materials, resources, recycled components, reduced
construction waste, and other features.
Façade Treatments Expand
The need for more exciting venues impacts stadiums’
exterior images as well as interior amenities. Precast
concrete often is used in these applications due to its
aesthetic versatility.
Precast concrete panels can have natural stones, bricks,
terra cotta and other materials embedded into them, or
they can use formliners to replicate materials and finishes.
The ability to cast multiple finishes and materials into one
panel further reduces pieces and saves construction time.
Contemporary designs also can be achieved by interfacing
easily with glass, metal, and other materials.
Memorial Stadium, Indiana University, Bloomington,
enclosed their south end zone with an insulated precast
façade. The university provided Gate Precast a piece of
natural limestone from the original stadium, this piece of
stone was used to create a formliner to replicate the original
variegated limestone facade. To achieve the proper look, the
formliner manufacturer visited the precast manufacturing
facility to take dimensions for what was required, and
handcrafted the formliners. Several mock-ups were created
with careful attention to detailing to indicate how they would
appear on the façade.
Terra cotta veneer embedded into precast concrete panels
is the material of choice at the Health & Human Performance
Complex (H&HPC) at McNeese State University in Lake
Charles, La. “It is a great clay-based material that gave us
the size and color we wanted,” says Nygren, an architect
on the project. “We had seen earlier projects that used terra
cotta, and they came out looking very nice.”
Using precast concrete panels creates efficient designs
because they can incorporate most of the components of
the full wall system into a large, panelized component that
makes construction move quickly and minimizes joints,
reducing long-term maintenance.
‘It’s always faster to use
precast concrete.’
“It’s always faster to use precast concrete,” says Brown.
“While we’re preparing the site, someone can be casting
the walls. And once you get the wall in place, you’re done.
You’re not waiting on the waterproofer or mason or glazier
or other trades to come in and finish the wall with multiple
other pieces. You put down the wall and it’s done.”
That was a key benefit at McNeese State University,
says Nygren. “We specified insulated precast concrete wall
panels for aesthetics and economy. One panel comprises
everything from the exterior façade to the interior finish,
with one trade handling everything, which simplified the
construction process. We also used the interior face of the
precast panel as the finished-wall surface. In a stadium or
arena situation, this level of finish is very durable, efficient,
and aesthetically pleasing.”
At Lucas Oil Stadium, the panels saved significant time
over erecting scaffolding and having masons work on the
façade, which was more than 200 feet tall. The 8-inchthick insulated sandwich wall panels provided the exterior
envelope, 2 inches of Rigid XPS insulation, vapor barrier,
and paintable back surface in one piece.
“Precast concrete panels embedded with thin brick
afforded the construction team the comfort that the
exterior skin would not be any cause for construction
delays on the project,” says John Hutchings, principal at
HKS Inc. in Dallas, Texas, which designed the stadium.
“This approach allowed critical finishes to meet the
proposed completion date.” The insulated panels also
saved time, he notes. “The thermal sandwich, energyefficient panels with thin jumbo bricks created a detailed
and elegant exterior façade.”
Precast concrete bowl designs and structural elements are being integrated into
the architecture of the stadium more often today, as is the case at Citi Field in
New York, N.Y., home to Major League Baseball’s Mets. Photo: Populous.
Complement College Campuses
University stadiums and arenas often make use of
precast concrete to satisfy contextual requirements
on college campuses. “Colleges always provide a
challenge because the look has to tie in with the rest of
the campus,” says Nygren. That was part of the reason
that terra cotta-faced panels were used on the H&HP at
McNeese State University, as it complemented the brick
found on nearby buildings.
‘Sports facilities on college
campuses often have a set style
that has to be met.’
“Sports facilities on college campuses often have a set
style that has to be met,” she continues. “But you still want
to create an iconic look. Sometimes in university projects,
the other buildings on campus determine your range of
style, and precast concrete offers an economical way to
meet those challenges.”
At McLane Stadium at Baylor University, designers had
some leeway because the stadium sat across a river from
the campus, providing separation between the two. Two
pedestrian bridges now connect the locations, “creating
opportunities for new traditions and game-day pageantry
that shapes the experience of attending a football game,”
says Tristan Anderson, senior architect at Populous.
The stadium’s design responds to the campus’ Georgian
architecture, he explains, “But we interpreted those
traditional elements in a nonconventional way, framing
views of campus and the river through a horseshoe form
with serrated brick walls and abstract viewing portals.”
The stadium features a rhythm of large columns that reflect
those on campus, giving scale and majesty to the facility.
Looking to the Future
Technology is rapidly advancing and sustainable
capabilities are being used more often. We need to
remain forward-thinking and not dwell on the past. I prefer
to look at European designs that offer contemporary,
exciting concepts. I don’t see us going back to the old
designs.”
That was the driving force behind his work on
Mercedes-Benz Stadium, home to the NFL Atlanta
Falcons. It features precast concrete insulated wall
panels on the first 40 feet of the façade, where fans will
interact with the stadium most. The panels feature a gray
tone that complements the rest of the materials on the
façade.
‘We’d much rather use precast
concrete …It has better lifecycle costs and lower long-term
maintenance needs.’
“It provides a very modern look that helped the
aesthetics,” Johnson says. “We try to use precast
concrete whenever it offers the look that we want to
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ASCENT SPRING 2016
create in an economical way. We’d much rather use
precast concrete than an EIFS or other material. It has
better life-cycle costs and lower long-term maintenance
needs.”
In some ways, he notes, the college market has fewer
demands, owing to the different college traditions. But
we are seeing more boxes and suites, and ticketholders
are paying almost the same prices as NFL stadiums, so
they’re expecting the same amenities. Their demands
are driven by the expectations based on what they see
at other stadiums.”
While
college
traditions
sometimes
restrain
expectations, they also can create unique challenges. At
Baylor’s McLane Stadium, special risers were installed
in one specific section to meet the band’s needs, says
Heldenfels, whose company fabricated the precast
concrete components, including risers, stairs, panels,
tie beams, and slabs. “They needed wider risers to
accommodate their instruments and give them room to
maneuver,” he says. “It was important to the University
to showcase that tradition and build it into their stadium.”
Community Impact
Stadium development and the activity they generate
has a tremendous impact on the area they’re located
in. That was the case with McLane Stadium, says
Anderson. “Since opening in the fall of 2014, the
stadium has helped revitalize the downtown, spur
development along the riverfront, attract visitors
to the campus, and create a cohesive and unique
experience for the fans. With its connectivity to
campus and downtown, it has become an authentic
representation of Central Texas and of what the
university, city, and region will become.”
Athletic organizations of all sizes are taking note.
Heldenfels is working on a precast design for a
stadium at Abilene Christian University in Abilene,
Texas. As part of its move to NCAA Division 1, the
university is building Wildcat Stadium, an on-campus
8,500-seat football stadium with precast concrete
components including seating, walls, and façade.
The stadium brings football onto campus to make
it a bigger part of the school’s tradition, a school
spokesperson said. The $30-million facility will
include a number of amenities, including premium
seating and accommodations for special Game Day
activities.
The desire for improvements—and precast
concrete components—extends further. “We’re
getting questions from a number of high schools
in the area,” says Heldenfels, pointing to a recent
project in Houston, Texas. “Precast concrete seating
is considered a premium amenity for high school
stadiums. They prefer it over aluminum bleachers.”
As the demand grows for more amenity-laden
stadiums, designers will continue to innovate to
balance all of the needs on tight budgets and
schedules. “It’s important to continue to push
forward with new design ideas,” says Johnson.
“There is a fear of failure, but there also is a fear of
not moving forward and making a change.” A
— Craig A. Shutt