ASEE Prism Magazine  - November 2002
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- By Dan McGraw   

The architect of a new $55 million art museum in Fort Worth is winning praise for his groundbreaking use of concrete, but much of the credit goes to engineers who have developed new ways to use the age- old material.

When you walk through the new Modern Art Museum of Fort Worth, you can't help but look up, given the soaring ceilings in the lobby and the many exhibit galleries. Japanese architect Tadao Ando's design uses vertical space in a very impressive style; some of the ceilings are 40 feet high, bathed in natural light, and framed by silky and shimmering concrete. The effect is simple, yet stunning. Never have large rooms of poured concrete exhibited such warmth and charm.

But as you look up, it is what you don't see that is perhaps the most striking. The ceiling of the main lobby, which is 80 feet long and 64 feet wide, has little or no visible support. The ceiling seems to be held up by the exuberance of the space and nothing more. There are no steel cross beams holding up the concrete ceiling, no truss support systems. Two concrete pillars, very much off center, are the only visible means of support. Glass skylights run the length of the main ceiling, adding to the effect that something other than science is holding that concrete ceiling in place. Outside the building, Y-shaped concrete columns hold up huge concrete overhangs (24 feet by 56 feet) that appear to hover over the museum's glass skin.

It is almost as if the concrete is flying. But we all know that concrete doesn't fly on its own, at least not without a little help from structural engineers. The $55 million museum is winning praise from architecture critics for its groundbreaking use of concrete and glass and space. But the building, due to open in December, is also winning praise from engineers for making Ando's visionary architectural drawings a reality. The 153,000 square foot museum will be the largest museum of modern art outside of` MoMA in New York.

"Most buildings are built like Stonehenge," says David Spires, a structural engineer with Thornton-Tomasetti Engineers in Dallas. , the project's structural consultant. "You put one piece on top of the other and the bottom pieces supports the pieces above. But this building is so different. Almost everything we did had to be unique. The challenge is that everything we did here is exposed. There was no margin for error."

It is appropriate that Ando's groundbreaking design is being used for an art museum. But the building itself, with its unique use of concrete, is also a testament to the role that science has in creating art. Ando, a self-taught practitioner, relies heavily on engineers to make his designs a reality. This has created a unique relationship between the Japanese architect and his Texas engineers: Ando must think more like a scientist when creating his art, and the engineers must think like artists when coming up with complex solutions to uphold the artistic integrity of the building.

Take soaring ceilings in the lobby and in the exhibit spaces. The engineers came up with 20 different approaches to creating the vast rooms without a visible support system. Ando wanted the ceiling to be poured in concrete slabs as little as six-inches thick. The team considered cast-in-place concrete, pre-cast concrete and steel frames. Steel frames offered the easiest solution, but departed from Ando's vision of a more organic all-concrete roof system. Likewise, strengthened pre-cast concrete did not conform to Ando's view that the ceilings should have the same shimmering veneer of his specially designed 16-inch thick poured concrete walls.

The solution was a flat roof scheme, poured on site using the same Ando approved molds. The flat roof concrete molds are held in place by attaching them to concrete overhangs that extend from the walls. The overhangs have been nicknamed "longhorns" (many of the engineers on the site are University of Texas graduates), and the ceiling is held in place from the end of the horn. Many of the concrete ceilings are also embedded with metal tendons sheathed in plastic. The plastic sheaths allow the tendons to be stretched, providing extra support for the ceilings. In some cases, the hydraulic jacks doing the stretching are exerting 32,000 pounds of force and stretching the cables several inches.

Originally, the engineers thought that concrete beams would be needed to support the massive roof systems. But they found that the inherent torsional strength of the flat roof system allowed the beams to be removed, thus providing a cleaner roof system that complied with Ando's vision. "It is a fallacy that architects hand over the designs to a structural engineer and the engineer merely tells the architect what will work and what won't," says Spires, a 1984 graduate of the University of Texas—Austin in architectural engineering who also holds a master's in civil engineering from the University of Iowa. "We worked closely with Ando and the museum owners, making suggestions that would support the artistic vision, but also making sure the building would work in a practical way. There was a lot of give and take over the issues of function versus appearance. In every case, we could have taken the easy way out and put functionality first. But we knew this building was a work of art in itself, and we had to think like artists."

Oldie But Goodie

The use of concrete was an interesting subtext for Ando's vision. The award-winning architect (Ando, 60, has won the 1995 Pritzker Architecture Prize, the 2002 Gold Medal from the American Institute of Architects, and the 2002 Kyoto Prize for Art & Philosophy) likes buildings that do not "speak very much." Instead, he uses organic materials and natural light to frame the spaces in very subtle ways. For the engineers, it means taking one of nature's oldest building materials and literally casting it in a new way.

Concrete has been around since ancient times, beginning with the Egyptians and perfected by the Romans. From the arches in the Coliseum to the dome of the Pantheon, concrete became the building material of choice from the ancient to the modern world. In the 19th century, concrete became even more important when it was reinforced with steel. Reinforced concrete was the design force behind skyscrapers and housing complexes.

But concrete architecture became a dirty concept in the past 20 years. Prefab concrete structure, factory produced and assembled on site, took on a pedestrian air of a functional yet bland building material. Builders used it as the cheapest alternative, and it was considered by the leading architects to be little more than a utilitarian material that needed to be the bones of the building, but should be covered up once it was poured or hoisted into place.

"The mistakes of the 1960s and 1970s were not to do with the material itself, but often with how it was used," says Australian architect Andrew Nolan. "If concrete is used in the right architectural form and for the right reasons, the result is not only strong but beautiful, light, warm, and enduring. It's plastic, durable, permanent, and ideal for creating expansive spaces, retaining the site, and combining sympathetically with other masonry materials."

Civil engineering departments around the world are experimenting with new ways to use this age-old material. Engineers at the University of California-San Diego are combing concrete with composites to allow bridge decks to be lighter, and making longer bridge spans possible. The University of Iowa is finding ways to make concrete highways stronger. The result is that engineering departments are developing concrete that is lighter, stronger, more pliable, and aesthetically more appealing.

For the museum, Ando (who also used concrete as the major design material in the Pulitzer Foundation for the Arts building in St. Louis) needed a mix of concrete that was strong, resisted cracking, and would have a shimmer once it cured. The engineers worked closely with Ramon Carasquillo, University of Texas professor of civil engineering and concrete expert, to come up with a mix that would meet Ando's requirements. The final mix balanced the amount of fly ash and fine aggregate to achieve a fine surface density with limited water content.

The team tested Carasquillo's mix by pouring small walls on the museum site three years ago to see how the mix would hold up to the elements. The construction crews used specially designed resin coated plywood as forms for the concrete structure, a process Ando has pioneered to create a surface that would change appearances at different angles and in different light, looking mottled from the front and shiny when viewed at an angle. One can see the attention to detail immediately; the corners on the square concrete pillars are as sharp as razor blades. (Ando's attention to detail is legendary. A former boxer, he is reputed to have once punched out a construction worker who flicked a cigarette into the concrete mix.)

Spires says that the finished product has given him a greater appreciation for the artistic process. "Sometimes, we as engineers look for the cheapest and most functional solution to solve problems," he says. "In this case, we had to consider the artistic vision as well. Ando is smart enough to know that he can't get involved in every little engineering detail. But we were smart enough to know that our work was going to complete his vision and create a building that will look new and original 100 years from now."

Author Raymond Chandler once wrote: "Without art, science would be as useless as a pair of high forceps in the hands of a plumber. Without science, art would become a crude mess of folklore and emotional quackery." In the case of this museum, the artist Ando has teamed with the scientist, Spires, to create a masterpiece. Without the input of both, the building might have ended up as an empty and boring jewel box, or a 153,000-square-foot nonfunctional flight of fancy.

It is the blend of both science and art that allows the Modern Art Museum of Fort Worth to be more than just a place to hang paintings and display sculptures. By using an old material in a new way—and by coming up with creative solutions to old problems—the Texas engineers and the Japanese architect have created their own masterpiece. As a testament to their work, this concrete structure is now considered the first major work of art being displayed at the new museum.

 

Dan McGraw is a freelance writer based in Fort Worth. He can be reached at dmcgraw@asee.org.

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