In the spirit of the Seattle World's Fair/Century 21 Exposition, host to nearly 10 million visitors from April to October 1962, the United States Science Pavilion marked a turning point for the precast/prestressed concrete industry. Following a decade of widespread acceptance in bridge construction, the Science Pavilion set the pace for extensive use of precast/prestressed in buildings.

The Pavilion comprises six interconnected, low-rise structures surrounding a courtyard featuring neo-gothic vaults, pools, and fountains. Inspired by romantic and classical themes of European and Asian buildings while enamored of modern minimalist construction, Detroit architect Minoru Yamasaki incorporated five 100-ft.-tall neo-gothic vaults within the Pavilion courtyard as a key visual element symbolizing man's “continual search for knowledge.” The vaults were constructed of 71-ft.-long, pretensioned columns topped by open-ribbed, lacy precast trusses.

Echoing that theme, the buildings surrounding the courtyard feature 100-ft.-high entrance arches and large exterior expanses of a repetitive pattern of vertical ribs and narrow arches. White portland cement and white quartzite aggregate used to face the wall panels lend the façade a sparkling appearance.

BUILT TO LAST

The Pavilion and adjacent Space Needle were earmarked to become the nucleus of a city cultural center following the Seattle World's Fair. Accordingly, much attention was paid to durability as well as aesthetic appeal. For the Pavilion, concrete members weighing a total of more than 11,000 tons were cast within a five-month period by Associated Sand & Gravel Co., an Everett, Wash., operator now owned by Rinker Materials Corp. Standing 32 and 52 feet tall with 3-in. flanges, ribbed wall panels double as load-bearing, S-type stud panels carrying prestressed single-tee roof members that span up to 112 ft. Prestressing adds strength to the 3-in.-thick panels and the 6-in.-wide × 15-ft.-long vertical ribs or studs.

In a 1962 advertising campaign spotlighting the U.S. Science Pavilion, Lone Star Cement Corp. noted that its 24-hour ‘Incor,’ a fast-setting cement, enabled the precast elements to attain strengths of 5,000 psi in 12 to 14 hours. Trinity White cement, milled by Lafarge predecessor General Portland Cement Co. and used in combination with Incor, permitted stripping of forms in 12 to 14 hours with steam curing. Specially outfitted lift trucks helped to meet the challenges of repeated turning, handling and transporting of the massive members. Welding or bolting served to secure the panels in place.

THE YAMASAKI LEGACY

No sooner had finishing touches been completed on the U.S. Science Pavilion than Minoru Yamasaki received a letter that would culminate in one of the grandest architectural commissions ever. A September 2002 article titled “Towering Ambition” by James Glanz and Eric Lipton, staff reporters for The New York Times, details the story behind Minoru Yamasaki's selection as architect for the World Trade Center in New York.

As of Spring 1962, Yamasaki's small Midwestern architectural firm had never taken a job in New York City, and the one high-rise office building to his credit was the 28-story Michigan Consolidated Gas tower in Detroit. So, the architect assumed an error accounted for the magnitude of the figure cited in an unsolicited invitation from the Port Authority of New York to join a design competition for a $280 million, lower Manhattan development. “An extra zero” was his reading of the offer.

Glanz and Lipton, authors of the recently published City in the Sky, relate that Guy Tozzoli, an inveterate pragmatist spearheading the WTC initiative on behalf of the Port Authority, had been uncharacteristically moved upon seeing the U.S. Science Pavilion (now the Pacific Science Center) at the 1962 Seattle World's Fair. A subsequent meeting with Yamasaki in Detroit at the Consolidated Gas tower reinforced Tozzoli's favorable impression of the architect's talent. The building's exterior of white marble columns and narrow floor-to-ceiling windows, forcing the eye skyward, provided further evidence of the grandeur and transcendental aspirations of Yamasaki's designs.

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As part of our coverage of the 50th anniversary of the Precast/Prestressed Concrete Institute, Concrete Products examines a key building among PCI's 50 Top Projects of the past 50 years. Even among the best, the U.S. Science Pavilion is outstanding not only as a landmark but for the role it played in the subsequent design of a global masterpiece — the World Trade Center.

WHAT IS AND WHAT SHOULD STILL BE

The U.S. Science Pavilion (1962) and World Trade Center (towers, 1970-71) shared the same architect and group of structural engineers: Minoru Yamasaki and Worthington, Skilling, Helle & Jackson (at the time of the latter project — Skilling, Helle, Christiansen, Robertson), respectively. The Pavilion was arguably a catalyst for the Port Authority invitation to Yamasaki to participate in a WTC design competition. The 1964-'65 process yielded a plan for the twin towers, whose eventual construction was credited primarily to Yamasaki, lead engineer Les Robertson, and Port Authority point man Guy Tozzoli.

Robertson relocated to New York City when his firm in Seattle was awarded the WTC contract. In 1983, he went on to head his own firm, Leslie E. Robertson Associates, R.L.L.P. (LERA), whose offices remain in lower Manhattan.

Adopting the name Skilling Ward Magnusson Barkshire, the Seattle operation was subsequently credited with specifying the highest-ever design strength concrete — 19,000 psi for the Two Union Square Building in Seattle. The firm exists today as Magnusson Klemencic Associates.

Fifteen years after the completion of the World Trade Center, Minoru Yamasaki died in 1986 at the age of 73.