Reply #46: from your link

[Snivi Yllom]

apples and oranges again. Steel reinforced building with multiple transfer trusses, greatly reduced structural rendundancy.

vs.

reinforced concrets building including a solid concrete core and waffle slab but with steel columns at the perimeter. The steel columns at the perimeter did in fact fail. The floor slabs pulled down the curtainwall in a manner very similar to the WTC by the way. In the photo below the floor failed after perimeter steel columns and beams failed in the heat. The inner floor closer to the core was reinforced concrete waffle slab and did not fail. Good example showing a similar floor failure as the WTC.




See this link for more fact, less tinfoil.

http://www.arup.com/fire/feature.cfm?pageid=6150


from your link:

In fact, comparisons between the Windsor tower and the WTC towers are limited because of the very different structures of these buildings. The Twin Towers and Building 7 were both 100% steel-framed, with columns consisting of box-beams and I-beams as much as three feet wide and of steel up to several inches thick. In contrast, the Windsor building was framed in steel-reinforced concrete, with columns of concrete reinforced by thin sections of rebar. 3 The concrete pillars in the Windsor building are clearly visible in the photographs showing the intact core exposed by the collapsed facade. It is not clear what materials were used to frame the perimeter, but their apparent thinness indicates that the the core was the main load-bearing component of the building.


Compare these photographs of the Windsor building fire to photographs of the Twin Towers' fires and Building 7' fires
Steel-framed and steel-reinforced-concrete-framed structures behave very differently in fires.

Steel is a good conductor and concrete is a poor conductor of heat. Thus in a fire, a steel frame will conduct heat away from the hotspots into the larger structure. As long as the fire does not consume the larger structure, this heat conductivity will keep the temperatures of the frame well below the fire temperatures. The same is not true of steel-reinforced-concrete structures, since concrete is not a good thermal conductor, and the thermal conductivity of the rebar inside the concrete is limited by its small mass and the embedding matrix of concrete.