CalPortland’s flagship concrete business, Catalina Pacific mustered 208 mixer trucks and 235 drivers across eight plants, located four to 20 miles from the site. Concrete contractor Conco Cos. staged 13 of its pumps—from a total of 19 machines deployed on site—to place mixes for a 17.5- to 18-ft. thick mat as far as 100 feet below grade. The foundation mix is designed with a 25 percent fly ash binder and required to meet 6,000 psi compressive strength at 90 days. Headwaters Resources supplied Catalina Pacific 1,800 tons of fly ash from its Pomona, Calif., terminal.
|Gauging the heat of hydration in a concrete mat at least 18 feet—even with a 25 percent fly ash binder component—engineers specified plastic piping to circulate chilled water through the mass concrete supporting the new Wilshire Grand Center.|
With a finished thickness up to 20 feet, the foundation will support a Korean Air-developed $1 billion office and hotel rising 1,100 feet. Beyond the foundation phase, Catalina Pacific and Conco will supply, place and finish concrete for the structural steel tower’s core and floor decks. When completed in 2016, Wilshire Grand will be the tallest building west of the Mississippi River. Catalina Pacific and Conco are part of a design and construction team headed by AC Martin and Turner Construction Co., both of Los Angeles.