New Concrete Picked for Freedom Tower
- Jan 08, 2008
When the Freedom Tower rises its 1,776 feet above Ground Zero, it will be made, in part, with a newly patented concrete. It will be the first major project for the new iCRETE technology, which is produced by the just-founded, privately-funded, Los Angeles-based iCRETE company. The concrete provides record-breaking strength and environmental improvements and will be used for a 186-foot inner core support as well as the tower itself.Tony Arnold, president of iCRETE, told CPN “When they put the design specifications together for the tower, there were lots of safety challenges.” To meet those challenges, Arnold turned to John Quadrozzi Concrete’s team. Together they worked out the best mix to meet the various specifications. “It had to meet certain slump characteristics, temperature, PSI,and a lot of other factors,” he explained. “We were able to come up with the mixes that even surpassed some of the performance tests.” iCRETE creates the design and technology and Quadrozzi produces the cement mixes, according to the iCRETE standards, and also pours the concrete.The Freedom Tower project will require that Quadrozzi pour out 240,000 cubic yards of concrete to achieve the required 14,000 pounds per square inch of compressive strength — 2,000 PSI higher than the previous record of cement poured in NYC.iCRETE has no ingredients novel to concrete, but the mix design and the plant production practices have been tuned to yield the stronger-than-usual concrete. A lower percentage of cement is also used to make it greener, as well. With the Freedom Tower, the reduction in greenhouse gas emission will be 40 percent. Noted Arnold, “Normally to get green you have to pay more, but ours is not more expensive. Our concrete is easier to work with and requires less labor.” Other projects, he added, are now in the works.