Originally posted by HowardRoark
Dr. Pal Chana of the British Cement Association demonstrated the relative likelihood of floor collapse in a steel versus concrete framed
building, using the vivid example of the Madrid Windsor Tower fire which raged over 26 hours on 14-15 February 2005. This former landmark office
block of 30 storeys featured a concrete core throughout, but with concrete columns up to the 21st floor and steel columns between the 22nd and 30th
floors. Remarkably, despite the intensity and duration of the fire, the concrete floors and columns remained intact however, the steel supported
floors above the 21st floor collapsed, leaving the concrete core in-situ and exposed.
www.concretefireforum.org.uk...
The Windsor Tower was nothing like the WTC buildings.
1. The lower, steel-reinforced sections of the building were not exposed to intense fire, only the steel sections were.
2. The core would of course remain standing because it is the strongest part of the building, as the core of the WTC towers should also have. If the
core of the Windsor Building had been steel, the truss-connected floors would still have fallen, and the core would have still remained standing.
3. The steel-supported floors collapsed in isolated pieces at a time and across the entire 18 hour duration of the raging inferno. They did not go
into global pancake collapse.
4. The sections of the building unburnt or not yet destroyed by fire did not collapse into dust down to the ground when upper floors collapsed on
them. The falling debris was deflected by the resistance of the structure beneath it, fell in a non-uniform fashion, and slewed off the side of the
building as we know is supposed to happen according to basic laws of physics. Only the sections of the building directly exposed to intense fire for
extended periods collapsed, and the trusses did not "unzip", "pancake" or flip-flop. Buildings do not collapse in this manner without the aid of
explosives.
5. The Windsor inferno made the WTC fires look like a weekend BBQ, reaching temperatures upward of 1000degC and burning unhindered for 18 hours.
[edit on 2005-11-16 by wecomeinpeace]