Fire Effects on Steel Structures – Technical Engineering Studies and Data

After researching the collapse of the WTC towers, the 911 researchers lack data in steel structure test burns. Some researchers claim that metal is not damaged in fires which will be shown to be untrue. Much speculation is created about the temperature obtained in the steel. If you search deeper outside of the 911 truth movement, you will find that there are many structural engineering groups who have researched the effects of fires on steel structures. This was done thru researching previous building fires, computer simulations and test building fires.

The test structure fires are what we need to focus on. There is enough data here to create a good hypothesis on the failure modes of the towers. The data is extremely complex and much more than I can handle. I would encourage other engineers to look over this data and post their results. We also need to email the structural and fire engineers who performed this research for more information pertaining to the WTC buildings. Here are the main points which I found in my research.

Research Papers/ Sites :
These links are chosen since they reflect international 3rd party views outside of NIST.

Report: The Behaviour of Multi-storey Composite Steel Framed
Structures in Response to Compartment Fires Susan Lamont - 2001
http://911research.wtc7.net/mirrors/guardian2/fire/SLamont.htm

Forward from Susan Lamont:
For many years the ability of highly redundant composite framed structures to resist the effects of fire has been undervalued and largely misunderstood. This was first realized when, after a number of real fires in multi-story composite steel framed structures structural failure did not occur. The Broadgate Phase 8 fire is probably the most notable. This accidental fire happened during the Construction phase when the steel frame was only partially fire protected. Despite very high temperatures during the fully developed phase of the fire and considerable deflections in the composite slab there was no collapse. This initiated construction of an 8-storey composite steel frame at Building Research Establishment large scale test facility in Cardington. Six fire tests were conducted, of varying size and configuration, to observe and ultimately explain why composite steel-framed structures adopt very large deflections during a fire but do not collapse.

Cardington Test Fires:

http://911research.wtc7.net/mirrors/guardian2/fire/cardington.htm
http://911research.wtc7.net/mirrors/guardian2/fire/SCI.htm
Note that unprotected steel DOES deform from fire. The steel will reach temperatures in excess of 90% of the surrounding fire.

Cardington fire test powerpoints with videos, thermal photos and data:
http://www.mace.manchester.ac.uk/project/research/structures/strucfire/DataBase/TestData/default1.htm

Fire In Steel Forum:
http://fire-research.group.shef.ac.uk/steelinfire/
This site contains many structural engineer email contacts. The forums also have a lot of data related to steel fires.

Report: The Royal Society of Edinburgh: FIRE AND STRUCTURES:THE IMPLICATIONS OF
THE WORLD TRADE CENTER DISASTER - 2004
http://www.royalsoced.org.uk/events/reports/2003-2004/fire_structures.pdf

Fire Induced Collapse of Tall Buildings - Graeme Flint Thesis - 2005:

http://www.civ.ed.ac.uk/research/fire/public_html/thesis/GFThesisFinal.pdf
Very interesting thesis on the WTC fires/ collapse.

Conclusion:
From all this information I find little research into collapse mechanisms. All theories on collapse mechanisms have not been tested with experimentation. The massive First Interstate Bank fire in 1988 burned for 3.5 hours and caused no damage to the steel. The sprinkler system was not functioning like the WTC. The fireproofing however was 100% intact. We cannot assume that the fireproofing was intact for WTC even though it probably was intact for WTC7. The broadgate and cardington fires are the best cases to study since they involve a massive fire with no fireproofing on the metal. These fires also assumed to be much more severe than the WTC fires. The Cardington test fires show that fires can deform unprotected metal in fires. However the structure will not collapse. No experimentation has ever been performed to prove that the collapse theory can even occur. It’s unacceptable in the fire engineering community to not attempt a test on this theory. More research will be needed to disprove that a complete progressive collapse is possible in a large structure.