I for one do not think it offers anything contrary since the assumption is still that the fire was hot enough
to initiate the collapse. It also would have to happen around the perimeter of the building at the same time.
The contradictions of previous posts, is that the many vertical supports per floor, only served to transfer loads of the floor above to the angle clips of the floor hangars at the central core and the out wall support structure. These multiple supports were only stabilizing in nature, to minimize floor flex and bounce for the occupants. They were NOT major structural supports. The major structural support for the building was the inner core and the outer shell, and NOT, just the outer shell and vertical floor supports/stabilizers.
As the floor joist angle clips were weakened by the prolonged heat, they deformed under the load of the floor weight increasing their angle and allowing the floor to slide down the angle. The floor movement down the angle clips (now turned into ramps) allowing the floor weight to push the outer walls outward. This put even more weight load at the edge of the angle clip instead of its root, increasing the steel deflection until the outer wall movement of the floor angle clip no longer supported the floor weight. This occurred on several floors at the same time due to the outer wall movement. The combined weight and velocity momentum of the floor weight, began over stressing angle clips on the successive lower floors. It's also not hard to expect that those vertical floor stabilizing supports, having no triangulation, for stability, rather than simply collapsing, would now introduce lateral forces as they fell over and guided the floor structure either below or above it, into the central core. The resultant progressive damage, making it unable the support the many tons of load it normally withstood, now without aid of the outer walls support structure. Once the momentum builds, counter force needed to stop it rose exponentially, and went far above design limits.
Heat is concentrated near the center of a flame. In this case, the center of the building/central core support structure. This was also where the elevator shafts were. While I don't know, couldn't the plane crash have compromised the elevator doors, allowing the fuel to be fed oxygen from the elevator shaft? This would certainly intensify the heat. Again the floor joist angle clips would be the likely weak points subject to deformation from the heat of the fire. Without floor support transferred to the central core, the floor stabilizing supports then transmit the weight of one, two, or three floors to the angle clips of a floor designed to withstand far less weight. Then with the outer wall moving outward, the pancake/crumbling process continues downward.
"at the same time", implies instantaneous. The building did not collapse instantaneously. There was a progression of events. And, the internal failure(s) leading up to and during the collapse was hidden from view by the outer walls. I don't understand your use of "at the same time". And there was no reference to "at the same time" in the link I posted.
Quick ignition which meant quick burn would not have subjected the steel to the temperature need to weaken the steel for a long enough period.
A one to two hour heat cycle with temperature spiking to "750–800°C range", is quick? "It is known that structural steel begins to soften around 425°C and loses about half of its strength at 650°C"
I'm sorry, I don't think I can accept your assertion in this regard.
Even then, I don't see the fire being sufficient to heat the entire perimeter of even one floor.
I don't think it has to all begin at once. Certainly the outer shell/support was weakened significantly from the plane crash. Why is it so hard to believe the the joist clips for the floors in this area gave way, or were distorted from the impact? Add a bit heat for an hour or so and failure does not seem unlikely to me. Then the angle clips around the perimeter would fail like a can opener rips the lid off a can. None of this action would be visible on the outside of the structure, apart from some outward motion of the exterior wall as the floor joists slipped off the angle clip.
I just don't see the evidence for a conspiracy. Both towers suffered from the same impact damage and heat distortion. They both failed in the same way. No building is able to withstand any and all possible disasters. Most are built to withstand conceivable disasters within a build budget. I expect future building designs will differ in construction from the WTC towers, for a while. Eventually, building budgets will change construction design again. OR, we will have progressively fewer buildings created as time goes on. For example, should buildings be able to withstand meteor strikes? Of what size? What about earthquake damage of 9.0?
After these are experienced, people will come out of the woodwork to blame someone else's lack of foresight.
Cheers,