
07-30-2015, 04:50 AM
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8 posts, read 3,885 times
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Sorry on the above post.. I meant NIST report, not FEMA. I got those two confused sometimes when I read about this topic.
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07-30-2015, 07:01 AM
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Location: By the sea, by the sea, by the beautiful sea
67,407 posts, read 50,858,925 times
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Quote:
Originally Posted by POhdNcrzy
My understanding is jet fuel burns at a low temperature and can not melt or pulverize steel.
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Steel doesn't have to melt to be substantially weakened by heat.
Last edited by burdell; 07-30-2015 at 07:14 AM..
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07-30-2015, 07:25 AM
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Location: Philadelphia
12,001 posts, read 12,251,329 times
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9/11 and the collapse of Building 7 has no historical equivalent.
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07-30-2015, 03:07 PM
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8 posts, read 3,885 times
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Quote:
Originally Posted by burdell
Steel doesn't have to melt to be substantially weakened by heat.
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But was it really heated to the point of total progressive collapse as in the 911 case? First, there may be some doubt on that since NIST's own report stated that out of all the pieces they collected as forensic evidence, the vast majority of them does not show evidence of temperature exceeding 250 degrees.
"Observations of paint cracking due to thermal expansion. Of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250 ºC: east face, floor 98, inner web; east face, floor 92, inner web; and north face, floor 98, floor truss connector. Only two core column specimens had sufficient paint remaining to make such an analysis, and their temperatures did not reach 250 ºC. ... Using metallographic analysis, NIST determined that there was no evidence that any of the samples had reached temperatures above 600 ºC. (p 90/140) "
They did state the temperature was 1000 degrees or above on the building on their models on re-enacting the incident on their computer. However, it was never explained where they got this figure from. Calculations made by independent parties based on the explosions and jet fuel fire + office materials and furniture couldn't ever reach the quoted 1000 degrees temperature. NIST never really explained how they got to this 1000 degrees or above figure on their report as far as I'm aware.
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And also, even if the temperature did reach 1000 degrees. How long was it burning for 1000 degrees inside? That heat would lose intensity because of thermal conduction of everything in the building. Most specially the 90,000 tons of steels making up the skeleton of the structure. It won't be localized to 1000 degrees at one point as the steel conductivity would spread out the heat to the rest of the structure.
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