Reply #31: Umm... [View All]

[zforce]

Careful stated...

The case of the perimeter panels is closer to being significant but the results (~10% above 250C) are consistent with NIST's fire models.

Yet the fact of the matter is, the NIST actually doesn't have one perimeter column conclusively attesting to temps above 250c.

Furthermore, you neglect the fact that the NIST had omitted two investigative tools- Metastable Phases in Weld Metal and Relaxation of Residual Stresses in Welds. These two forensic tools would have determined in themselves the exact temps most of the steel had reached(between 300c and 500c), including steel lacking paint and the 3 pieces of steel with paint that MIGHT have exceeded temps of above 250c(mudcracking).

Also you should note the "discrepencies".

See Nist Appendix D

Comparing the results from the two analyses, some discrepancies exist where the visual observations made by WJE were in opposition to that of the results of the paint mapping technique utilized by NIST. As most of the observations of sooting and paint damage made by WJE were corroborated by the fire exposure-time sequence maps, it may be that a degradation mechanism exists where the primer paint exposed to the pre-collapse fires was damaged (resulting in the visual patterns) without increasing the local temperature of the steel above 250 °C.

Z: The above statement is explaining the discrepency with regard to what the WJE had observed (soot and paint damage) and what the NIST had mapped..In other words, the NIST had mapped an area that the WJE had observed to be damaged, as an area where there shouldn't of been steel temps of above 250c. Hence the nist goes onto explain that maybe there is a "degrading mechanism" that can damage the paint faster and keep the steel temps from increasing above 250c.

From there, we move onto another discrepency, and in all actuality, quite opposite of the preceding one...

Additional to the discrepancy between the visual observations of WJE and the paint mapping technique of NIST, there were seven panels where precollapse fires were observable, yet neither analysis technique indicated the exposure on the recovered panel. One example of this was from piece M-2 where images show fires/external flaming for over 16 continuous minutes on the 98th floor (Sec. 2.3.1).


Fires for 16 minutes on 7 panels, yet no evidence of exposure over 250c?

In all reality, just one panel of steel from the fire area should/could be representative of all the steel in the Fire Area, since all the steel was primarily affected in the same way by the fires, that is to say..Fires for almost the same amount of time(give or take a few mins (16 to 20 minutes-dwell times).