The MissionThe mission of the non-profit Fred Hutchinson Cancer Research Center is the elimination of cancer as a cause of human suffering and death. With over 2,300 employees, it is internationally recognized for its pioneering work in bone marrow transplants.
The mission of Turner Construction, the general contractor for the Hutchinson Center, is to build a cast-in-place Public Health Sciences building on the Center’s world-renowned campus. They are to do so at an accelerated pace in the downtown Seattle location. Seven elevated slabs — two below street level and five above — is the goal.
Therefore, with the help of three square towers, a roll-and-fold 32-Meter Putzmeister placing boom is being flown on a weekly basis from pedestal to pedestal for added efficiency in placing the concrete. The placing boom even placed the slab on grade for the foundation with the use of anchor bolts.
To handle the 86,000 square feet of space, five different pours divide up each floor. A pour a week covering 10,000 to 20,000 square feet is done before moving the placing boom to the next area for placing concrete. After five weeks, the tower is pulled up via a tower crane and the process repeats itself.
“Using the three towers and flying the placing boom was the only sensible way to place concrete quickly and cost-effectively for the sheer walls, post tension slabs and decks. It was like playing leap frog, going from one process to the next to keep the project swiftly moving along,” said Russell Soeters of Conco Cement Company of Kent, Wash., who supplied the placing equipment.
Soeters added, “The contractor was especially pleased with how easy the Putzmeister was to raise and move. With its convenient four-pin connection, it is simply disconnected, picked up and the entire system moved in under 10 minutes.”
A high pressure Putzmeister 12000 concrete trailer pump remained on the ground, pumping the standard post tensioning 6000-psi mix supplied by Glacier Northwest of Seattle.
To further pick up the pace, a second shift was also added to expedite the process, and a 36Z-Meter Putzmeister boom pump helped place concrete on the lower levels, especially in spots that were difficult to reach. In addition, often a pour would occur on a Friday, allowing time to cure over the weekend before commencing work again on Monday.
Having started the concrete process last May, the crew will top off the structural portion by late March of this year ahead of the projected schedule. In the process, over 23,000 yards of concrete will have been used.
Owner: Fred Hutchinson Cancer Research Center – Seattle
General contractor: Turner Construction – Seattle
Concrete contractor: Conco Cement Company – Kent, Wash.
Pumping contractor: Conco Concrete Pumping – Kent, Wash.
Ready-mix supplier: Glacier Northwest – Seattle
Equipment: Putzmeister 32-Meter placing boom, three Putzmeister towers and a 12000 high pressure trailer pump