Masonry Magazine October 1995 Page. 13
THE ALL-CONCRETE PRISONER holding facility at the Will Rogers Airport in Oklahoma City combines poured-in-place structural concrete with block walls that are grout reinforced (above). Two fixed pipelines and two portable pipelines are fed by trailer-mounted concrete pumps working continuously on the project (lower right).
walls. The complex operation required seven crews of four block layers, and two concrete pumping crews to introduce the consolidating mix.
Structural Concrete is Pumped
The six-inch foundation mat, a footprint for the hexagon, was poured by CPI at fifteen feet below grade atop concrete piers. The concrete contractor then poured columns, beams and decks to the sixth level with a thirty six meter 1200 concrete pump. A concrete miniplacer circled the rising core, puddling high-strength mix around the pumped twelve-inch core walls. The pumping unit pumped through slickline up to 300 feet horizontally for column and deck pours. At the seventh level a forty-two meter boom pump replaced the thirty-two meter pump. The bigger boom reached out for 138 feet horizontally to place beam and deck concrete at pour rates that averaged fifty-five cubic yards per hour. Peak production hit 100 yards per hour, even during top-out of the seven floor structure.
The Blount contract was for $48.3-million. An apron, taxiways and enclosed bridges at the airport perimeter brought total costs to about $50-million. Funded by the Federal Bureau of Prisons, the city of Oklahoma City is designated as project owner.
Following completion of the non-reinforced fifteen foot high basement walls, G.A. Masonry started exterior wall construction. The contractor used standard 8 x 8 x 16-inch block, each weighing twenty-eight lbs. Walls are one block (eight inches) thick, but were additionally strengthened with an exterior brick cladding. All ready-mix and block for the entire project was supplied by Dolese Brothers Company.
G.A. Masonry selected a small concrete pump to begin the continuous feed of mix into each of the two cells, or holes, of each block. Crews laid a six block course to create a four foot high wall section before pumping began to fill the blocks. G.A. began the process with a newly purchased concrete pump built for smaller-volume efficiency.
The pump is a mechanically operated ball-valve unit. It is designed for effective cellular-concrete pressure grouting of masonry mix, lightweight concrete and shotcrete at low operating costs. Under optimum conditions, the unit has an output of thirty-six cubic cards per hour. Pouring into a pair of six inch cells in each block, however, was a meticulous procedure. "We could tow the pump easily to Continued on Page 42
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