The examples before us are the Twin Towers and WTC7. The Twin Towers were anomalous from the standpoint of a lot of fuel being available to feed the fires, along with the potential of burning aluminum vapor, which is far more exothermic. WTC7 did not have burning airplanes to deal with, but it did have internal carbon-based fuel and a disabled extinguishing system, and took a prolonged time to develop a crisis.
I'm not a skyscraper architect, so I am unacquainted with other cases, but these are quite unique. It does open up a significant vulnerability in the way we construct skyscrapers. There may be no practical defense. (Or we build tall buildings as ziggurats or pyramids.) I think it would be rational to make sure that approach and departure corridors to airports do not go over urban high-rise building districts.
So this new theory of office fires causing structural steel to lose its strength so catastrophically that it resulted in the building falling straight down into the path of most resistance at free fall speed (for a few seconds) should have a major effect on the field of architecture. Given this new information architects must have studied this and changed how they design buildings so they don’t just collapse during an office fire.
What has the industry done with this new information?
There may not be much to do. The special case is aluminum catching fire. It is extremely energetic (used for rocket fuel) and would ordinarily not be present---unless an airplane crashes into your building. I don't see that there is much that can be done. The materials in use are arguably suitable and well-performing.
https://www.engineeringtoolbox.com/metal-temperature-strength-d_1353.html
Are you talking about the aluminum in the air plane? That makes no sense because even if you too all the the aluminum in that air plane and assumed a 100% conversion to energy and then looked at the energy requirement to pulverize all the concrete, it's nothing. Don't forget, the pyroclastic cloud that was generated. The resulting dust blew away on the wind and settled into a blanket all over that area of new york. I remember that dust layer being reported as 12 to 18 inches thick.
This is on the WTC 7 page "Furthermore, there are huge pyroclastic flows of dust, resembling a volcanic eruption, that poured into the streets following the final collapse of the building."
Talk of aluminum was to point out sources of heat (and potential temperatures) in the conflagration. Your claim about the energy available from the aluminum is arm waving; it would be interesting if you actually were able to produce numbers. And it would be beside the point, because the main energy involved in the destruction of each of the Towers was gravitational potential energy. Failure of concrete in compression leads to fragmentation, shattering, crumbling, and spalling. I've seen this in a materials testing laboratory. No mystery that a cloud was produced. What are we talking about, now? The Twin Towers or WTC7? I've seen structural wreckage from both. If you are going to call it a pyroclastic cloud, you can hardly deny its origins in a combustion environment. Otherwise, it is simply a cloud. I've seen that, too (Mount St. Helens eruption).
“ I'm not a skyscraper architect, so I am unacquainted with other cases,”
Nor am I, but I have listened to lectures by architects looking precisely at this issue. There are a couple of other examples of modern concrete and steel high rise building burning for extended periods of time. No collapse. No loss of structural integrity.
Not burning with a profusion of aviation fuel and the prospect of burning aluminum vapor. The flame temperature of kerosene is 2,093 deg C. But the flame temperature of aluminum (vapor, in oxygen) is 3,732 deg C. That ups the ante considerably.
My apology. Bad mental transfer. I've been laboring under a regime of very high blood pressure and it interferes with my concentration. In any case, the point was that the flame temperature of available combustibles was adequate to melt steel and produce the tiny spheres.
The examples before us are the Twin Towers and WTC7. The Twin Towers were anomalous from the standpoint of a lot of fuel being available to feed the fires, along with the potential of burning aluminum vapor, which is far more exothermic. WTC7 did not have burning airplanes to deal with, but it did have internal carbon-based fuel and a disabled extinguishing system, and took a prolonged time to develop a crisis.
I'm not a skyscraper architect, so I am unacquainted with other cases, but these are quite unique. It does open up a significant vulnerability in the way we construct skyscrapers. There may be no practical defense. (Or we build tall buildings as ziggurats or pyramids.) I think it would be rational to make sure that approach and departure corridors to airports do not go over urban high-rise building districts.
So this new theory of office fires causing structural steel to lose its strength so catastrophically that it resulted in the building falling straight down into the path of most resistance at free fall speed (for a few seconds) should have a major effect on the field of architecture. Given this new information architects must have studied this and changed how they design buildings so they don’t just collapse during an office fire.
What has the industry done with this new information?
There may not be much to do. The special case is aluminum catching fire. It is extremely energetic (used for rocket fuel) and would ordinarily not be present---unless an airplane crashes into your building. I don't see that there is much that can be done. The materials in use are arguably suitable and well-performing. https://www.engineeringtoolbox.com/metal-temperature-strength-d_1353.html
Are you talking about the aluminum in the air plane? That makes no sense because even if you too all the the aluminum in that air plane and assumed a 100% conversion to energy and then looked at the energy requirement to pulverize all the concrete, it's nothing. Don't forget, the pyroclastic cloud that was generated. The resulting dust blew away on the wind and settled into a blanket all over that area of new york. I remember that dust layer being reported as 12 to 18 inches thick.
This is on the WTC 7 page "Furthermore, there are huge pyroclastic flows of dust, resembling a volcanic eruption, that poured into the streets following the final collapse of the building."
https://www.ae911truth.org/evidence/technical-articles/articles-by-ae911truth/101-free-fall-and-building-7-on-9-11
My understanding of the pyroclastic cloud is that the concrete was pulverised mid air and the resulting concrete dust formed the pyroclastic cloud.
Other wise, please show photographic evidence of the concrete slabs and chunks. I have not seen any of that in the photos.
Talk of aluminum was to point out sources of heat (and potential temperatures) in the conflagration. Your claim about the energy available from the aluminum is arm waving; it would be interesting if you actually were able to produce numbers. And it would be beside the point, because the main energy involved in the destruction of each of the Towers was gravitational potential energy. Failure of concrete in compression leads to fragmentation, shattering, crumbling, and spalling. I've seen this in a materials testing laboratory. No mystery that a cloud was produced. What are we talking about, now? The Twin Towers or WTC7? I've seen structural wreckage from both. If you are going to call it a pyroclastic cloud, you can hardly deny its origins in a combustion environment. Otherwise, it is simply a cloud. I've seen that, too (Mount St. Helens eruption).
“ I'm not a skyscraper architect, so I am unacquainted with other cases,”
Nor am I, but I have listened to lectures by architects looking precisely at this issue. There are a couple of other examples of modern concrete and steel high rise building burning for extended periods of time. No collapse. No loss of structural integrity.
Not burning with a profusion of aviation fuel and the prospect of burning aluminum vapor. The flame temperature of kerosene is 2,093 deg C. But the flame temperature of aluminum (vapor, in oxygen) is 3,732 deg C. That ups the ante considerably.
We are talking about wtc 7? Where is this aluminum coming from?
My apology. Bad mental transfer. I've been laboring under a regime of very high blood pressure and it interferes with my concentration. In any case, the point was that the flame temperature of available combustibles was adequate to melt steel and produce the tiny spheres.