Grizzly Bear
このマスクに&#
- Joined
- May 30, 2008
- Messages
- 7,963
For example:
The World Trade Center Seven is being constructed using a method called concrete core construction, in which the steel frame is set first and concrete is poured around the steel framework...
http://www.lincolnelectric.com/knowledge/articles/content/worldtrade.asp
The concrete encasement ensures much more efficient fire resistance, it doesn't really negate the effects of thermal expansion.
Kesha, thermal expansion isn't a new concept -- it wasn't then, it isn't now. The case for WTC 7 was a factor of its design which magnified the effects. I haven't read any of the code changes since that period but I would expect that any comment concerning this has been dealt with, as it should be when a design flaw is identified.