The way Tim Hensen sees it, the first steps of a 28-story, nine-month climb are just part of another day's work. He is the general manager of Ralph's Concrete Pumping in Seattle, a company that literally gets in on the ground floor of major construct

Bellevue's newest high-rise relies on the country's biggest pump

The way Tim Hensen sees it, the first steps of a 28-story, nine-month climb are just part of another day's work. He is the general manager of Ralph's Concrete Pumping in Seattle, a company that literally gets in on the ground floor of major construction projects across the Northwest.

During the first week of April, Hensen and about 40 concrete workers began the task of laying the foundation of Bellevue's newest office tower, Three Bellevue Center. However, to anchor the 28-story building to the ground, they needed to pour a 6-foot-deep concrete foundation – filled with 188 tons of reinforced steel.

"We're known for tackling some of the tougher construction jobs," said Hensen. "So when we were faced with pumping almost 2,750 cubic yards of concrete, we brought in the biggest concrete boom pumps we could find." This included a 55-Meter Putzmeister truck-mounted concrete pump, the largest in the country, and two 42X-Meter Putzmeister pumps.

They began pouring concrete at 2 a.m. According to Hensen, the three pumps were fed concrete by nearly 275 ready-mix trucks. Seven hours later, the 110-square-foot foundation mat pour was completed.

Even though all of the concrete boom pumps were positioned at street level for the pour, reaching down 65 feet into the construction site was simple. The 42X-Meter has a horizontal reach of more than 124 feet, and the 55-Meter has a 167-foot horizontal reach. These high-volume units also have the capacity to pump 210 cubic yards of concrete per hour.

"This huge mat pour was just the beginning of the job," said Hensen. To construct the 28 floors that rise above the foundation, Ralph's will use a tower-mounted 28-Meter Putzmeister placing boom. "It'll reach more than 90 feet horizontally, which is perfect for this building. Plus it'll handle the additional 15,000 to 17,000 cubic yards of concrete needed to finish the job."

If all goes according to schedule, Ralph's will top out the 471,635-square-foot building in January 2000 so it can open its doors for business in May.