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Old Posted Jul 23, 2013, 1:00 PM
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dchan dchan is offline
Mandate...get it on.
 
Join Date: Dec 2007
Location: Fresh Meadows, NY
Posts: 2,546
How come "truther" websites are the only ones that claim that WTC 1 and 2 had a "reinforced cast concrete tubular core"? Everywhere else, I read that the towers had a steel core with drywall fireproofing.

Also, let's get this misconception out of the way. Concrete is NOT stronger than steel, technically speaking for equal volumes of each material. Concrete, however, can be made as strong or stronger than steel with enough volume. It is stronger still when it is reinforced with steel rebar or other steel reinforcing methods.

And yes, concrete strength is indeed affected by heat exposure. But this will typically only affect the outside layer of the concrete. The rest of the concrete as well as the steel reinforcement should be below 500°F at 2 hour fire exposure, which is below the the yield temperature for steel.

http://www.cement.org/tech/basics_fire.asp

In any case, the point of using a reinforced concrete core is not so much to allow the building to remain unscathed in a terrorist attack, but to allow the occupants of the building to exit the building safely through the stairs within the core.
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