William Staffeld / AAP
September 28, 2010An hour before sunrise this morning, more than 30 carpenters, laborers, and masons started the 12-hour continuous pour to form Milstein Hall’s signature concrete dome. The quality and consistency of the pour is especially critical because the entire underside will be exposed as the ceiling for the critique space below. The engineering that went into the planning is equally as important as the completed dome will weigh approximately 900,000 pounds — or about 175 pounds a square foot.
To get the 200 yards of concrete flowing this morning, one pump truck and two conveyor rigs, on different corners of the building, poured the low-viscosity material from the top. Tradesmen crawled on the structure moving the concrete into place with vibratory tools to help ensure a smooth surface on the bottom and used hand floats to smooth the top. The layer poured today is the bottom half of what will be a double shell sandwiching a layer of insulation and utilities.
In preparation for the pour, workers have been on site since June building wooden falsework to establish the dome’s shape and provide support. On top of the falsework, plywood sheathing was installed and precisely caulked to keep the surface smooth. Woven on top of the wood form, approximately 71-1/2 tons of reinforcing rebar was put in place. The falsework will be removed in about two weeks, depending on conditions.
The Pike Company of Rochester, New York, is the subcontractor handling the dome pour and other concrete for the building. Welliver McGuire of Montour Falls, New York, is the construction manager on the project. Milstein Hall was designed by Rem Koolhaas and the Office for Metropolitan Architecture’s New York City office. Engineering consultation for the buildings cantilevers and the dome was done by Robert Silman Associates, headed by Robert Silman ’56.