Architect: Calatrava Valls, Zurich, Switzerland
Architect of Record: Kahler Slater Architects, Milwaukee, WI
Engineer: Graef Anhalt Schloemer & Associates, Milwaukee, WI (Structural and Civil)
Construction Management: C.G. Schmidt Construction, Milwaukee, WI
Concrete Contractor: C.G. Schmidt Construction, Milwaukee, WI
Concrete Supplier: Central Ready Mixed L.P., Milwaukee, WI
Reinforcing Bar Fabricator: Ambassador Steel, Waukesha, WI
Reinforcing Bar Detailing: The City Rebar, Morrison, IL
Custom Formwork: Union Brotherhood of Carpenters Locals 344 and 264, Milwaukee, WI
Total Project Cost: $120 million.
Total Project Size: 140,000 sq ft (added to existing museum)
TO CREATE: A work of art to showcase art, offering new space for traveling exhibitions and rarely seen works from the Museum’s collection.
TO MEET: The demands of the architect’s vision and the lakefront site with local ingenuity and craftsmanship.
TO GIVE: A lasting cultural gift to the people of Milwaukee – and the world.
POETIC. HEROIC. TRANSPARENT. LIGHT.
Milwaukee’s Expanded Art Museum Unites A Great Lake With A Great City.
These are just some of the impressions of those who have marveled at the 140,000 square foot addition to the Milwaukee Art Museum since its opening in 2001.
Based on a concept of Spanish-born architect, sculptor, and engineer Santiago Calatrava, the expanded museum incorporates shapes and finishes never seen before in steel reinforced concrete. The inherent beauty, strength and versatility of reinforced concrete played a vital role in bringing Calatrava’s vision to life.
The design, chosen in 1995 from among over 70 design entries, reflects Calatrava’s goal of uniting the museum with the shore of Lake Michigan. He infused the new structure with the spirit of the lake – “the boats, the sails, and the always changing landscape.”
Wind, Wave and Wing…Elements of the Architect’s Vision.
The revitalized museum welcomes visitors through its low-slung main pavilion, home to the new retail store, offices and gallery space. The pavilion leads to a grand reception hall with a soaring 90-foot glass atrium ceiling.
Gracing the atrium is the signature feature of Calatrava’s design – a brise soleil, or architectural sunscreen, which moves like the wings of a bird to control light and heat radiating into the building below. With a wingspan of 217 feet made of 72 steel fins attached to rotating spines, the 110-ton structure opens and closes on schedule each morning, noon and evening. The wings gently close whenever lake winds reach 23 miles per hour.
The building’s profile also includes a 198 foot slanting mast with 3,300 feet of locked-coil cables, which in turn secures to a 250 foot pedestrian bridge linking the museum with downtown Milwaukee. Below, a concrete ring beam secures all elements of the structure, its graceful strength suggesting the lines of a ship’s bow.
Calatrava chose steel reinforced concrete to anchor these design features while absorbing the forces of wind and water on the building. With its lowest floor 13 feet below the lake’s expected 100-year level, the museum structure must withstand 48 million pounds of buoyant pressure. Extraordinary wind stresses on the brise soleil, mast and walkway are stabilized by the building’s concrete core, which also supports the atrium and a vast garden terrace with its 500-foot water wall display.
Sculptural Art Rendered in Steel Reinforced Concrete.
Certainly strength was an element in Calatrava’s selection of reinforced concrete for this one-of-a-kind project. But he also chose the material for its ability to take on the sculpted forms that define all spaces of the newly expanded museum. Every area of the addition includes curved walls, arches and ceilings. The main pavilion features 76 graceful arches supported by a keel beam, giving visitors the sense of being inside the belly of a great ribbed ship. Even the 100 car underground garage, itself as beautiful as a gallery, has distinct curved walls accented by 22 long horizontal reveals.
Yet surprisingly, most of these concrete surfaces don’t look like concrete. The building’s smooth exterior appears bright white; the pale, glossy interior walls seem as if they were somehow formed from curved drywall.
How did crews sculpt steel and concrete into these remarkable forms? What was it like to construct a building where, as one worker put it, the concepts of “plumb” and “straight” have almost no relevance?
Quality Teams Make the Impossible Possible.
From the start of the museum project, local architects and engineers came together with general contractors, steel fabricators, reinforcing bar detailers and forming contractors to include every trade and discipline needed to complete the project. Concrete form makers, reinforcing bar fabricators and placers, glass, electrical, plumbing and painting contractors all played a role as well as concrete mix.
Each team member knew that everyone else in the room had been chosen for their expertise. This created a climate of respect, says Dave Scritsmier, general superintendent on the project for construction firm C.G. Schmidt, “The teams came up with the innovations that in the end, made it possible to do what at first seemed impossible,” he explains.
From Clay to Curving Concrete.
Designers, builders, and suppliers devised creative ways to plot the curved surfaces called for by Calatrava’s design. When the architect’s drawings didn’t provide enough detail, teams fashioned clay models as reference points.
“We worked directly from Mr. Calatrava’s ideas to bring them to three-dimensional reality,” says Bob Vaughn, president of The City Rebar. Vaughn’s company, in partnership with Ambassador Steel, created the reinforced concrete systems that hold the arches, curves and columns in the expanded museum.
The project’s complexity required two reinforcing bar detailers to work full-time for 18 months. Most of the 2,100 tons of reinforcing bar – using nine of 11 bar sizes were manually bent by Ambassador’s fabricators into the intricate cages that crews placed using specially constructed guides.
Achieving the curved smoothness called for unusual concrete forming solutions as well. Concrete forms as well-crafted as fine cabinetry were constructed using computer-designed, laser-cut wood sections – and nearly as much Bondo© as plywood. Carpenters coated the inside of the forms to achieve the silken finish desired.
Shapes Emerge from Carefully Planned Placement.
Challenges for the concrete placement throughout the new museum went beyond the extreme congestion of reinforcing bar needed to hold the unique shapes. To consolidate the rapid-setting, flowing mix, forms had to be vibrated after each placement. Most forms were filled slowly from the bottom up using specially constructed steel pipes that lifted as the level of the concrete rose.
Slow, careful work created the building’s ring beam, which ranges from 10 feet thick at its core to a mere eight inches in the section soaring out over Lake Michigan. The beam pour took weeks to prepare and 13 hours to complete, Scritsmier notes. The keel beam in the main pavilion also called for innovation – with craftspeople building a 30 foot by 60 foot rolling cart that held forms and shoring, which moved along as the beam took shape 30 feet above floor level.
Inspiring visitors from around the world.
Critics have called the Milwaukee Art Museum addition an event as much as a building, a moving work of art in an elaborate urban ballet. The museum now welcomes twice the number of annual visitors as it once had, with millions coming to see this innovative structure where the boundaries between engineering, sculpture and architecture merge.
Advances in concrete technology, Computer-Aided Design (CAD) drafting and construction techniques have continued to move the edge of reinforced concrete structures forward. The sculptural qualities seen in Calatrava’s museum design now grace many striking steel reinforced concrete structures around the world.
By The Numbers.
$120 million: Total project cost
140,000: Square feet added to existing museum
83 million pounds / 20,000 cubic yards: of specially formulated concrete
2,100 tons: of steel reinforcement
95%: Percentage of non-glass surface that is exposed concrete
8 years: From conception to unveiling in October 2001
800: Local tradespeople who contributed to this unique project
“The heroic design…gives the Milwaukee Art Museum an artistic identity that reflects the greatness of our collections inside and creates a world-class landmark for Milwaukee that will further the vibrant cultural history of the city.” – David Gordon, Museum CEO and Director.
“A bridge or building can be very steady and yet be kept right on the edge of the possible.” – Santiago Calatrava, Architect.
Milwaukee Art Museum Addition, On the Edge of the Possible — Spotlight Series