You lot are hilarious, you question properly attributed reports and quotes, and yet you post utter fucking bullshit like this and expect people to take it seriously.Here is a summary of the enclosed video-
Nist couldn’t make up its mind for years as to the cause of collapse of Building 7 but
finally in 2008 it announced via a computer model, ie no physical testing
that the critical column 79 had failed first, claiming fires on the N.E corner of floor 12 had heated the ceiling that included the floor beams for floor 13, so causing thermal expansion of the beams and thus causing the girder at column 79 to fall off its seat.
Nist concludes column 79 buckled due to loss of support from that girder and then the whole building collapsed in seconds.
Nist claimed in 2004 that the beams in Building 7 were made composite with shears but in its final report in 2008 it backtracked and said there were no shear studs on any of the girders- this was refuted by John Salvarinas, the project manager for building 7 who confirmed there were shear studs on all the girders- in fact there were 30 shear studs on the critical girder at column 79
Nist claims differential thermal expansion caused the breakage of over 100 high strength bolts.[B] This was caused, Nist claimed, by expansion of the beam being much more than the concrete above it-[/B But it would not break as the concrete floor slab would heat and expand too, a factor not considered in the Nist computer model!
Knowing the measurements, the girder would have had to move 5.5 inches due to the expanding floor beams to fall off its seat- but what temperature did the beams reach?
This was Tricky for Nist for if the temperature is over 600 C, steel loses its strength and so is not able to extend into the girder , but if the temperature is too low, it's not enough to allow for expansion of the floor beams. So Nist settled on the beam temperature reaching 400C on the NE corner of floor 12. Under the Nits model all the bolts and steel connections then broke in 2 seconds! But at 400 C maximum expansion is only 3.3 inches- not enough to make the girder fall off its seat.
In addition, Nist claims the fires were 7 hours long but early photos don’t show fires on floors 11-13 where Nist say the first failures occurred , happening until after 2.00 pm and the building then fell less than 3.5 hours later.
Plus, requirements for fire resistance were that the steel components must be able to withstand 2-3 hours of intense fire
Finally the fire load in Building 7 only supported approx 20 mins of fire in any given area, the Nist claims of several hours of fire is misleading , the fires were not in one particular location for 7 hours!