i found this post that really explains why jet fuel cannot be the cause of the steel failing.
"LRRP 1968 Says:
July 16th, 2009 at 5:56 am the World Trade Center buildings collapsed as a result of fires ignited by jet fuel.
The above is absolutely and physically impossible. Thermodynamics 101.
Weakened steel does not fail explosively. It gradually loses strength along its stress-strain curve and then only in the areas that attain the temperatures required to fail. Steel is an excellent heat conductor and will conduct heat away from the point of application. The materials specific heat will show you how much it has to absorb in order to get hot. This is measured in BTUs / mass. You can have flames as hot as you like but if there is not enough heat energy available to heat up the material you will do nothing.
An example of this is your stove at home. A gas range burns propane at 3254 F. An aluminum pan melts at 1220 F. This should make it impossible to cook on a gas range, as the pan would melt or at least soften into putty, but it does not because heating materials is complex and actually pretty difficult. Heat goes away very fast and you have to continue to pour BTUs into it above the rate that it loses the heat. This is not easy.
I just made myself a omelet, the pan miraculously didnt melt.
There was not enough heat value in the jet fuel to come anywhere close to making the steel hot enough to fail. You will run out fuel long before that happens and the math is straight forward.
You simply take the tons of steel in question, the amount of BTUs it would take to make the steel hot, including the concrete and the air and you just cant do it.
In fact it is so far from possible, the fires cannot be a factor, the temperature would not have even come close to the starting of the elastic region.
Anyone who repeats the jet fuel burns at xxx and steel loses yy% of it strength at xxx temp is an idiot or a liar or just cannot understand the physics involved here.
That this was an official explanation tells me that they are lying. When a suspect lies, ask any cop what that tells him.
as an aside, jet fuel burns at 1800 degrees all right IN A JET ENGINE. A jet engine forces air through a compressor to get enough volume and mass of O2 to support the combustion. You cannot get the fuel to burn at anywhere near that temp in open air, there is not enough mass air flow for an optimal stoichiometric ratio.
Even if you could, which you cant kerosene only yields 18,500 Btu/lb in perfect conditions.
In open air youd be lucky to get 20% of that efficiency, but even at 100% efficiency there arent enough BTUs to heat up the steel past about 700 degrees.
If you use a full fuel loading with zero gallons burned in the fireball and zero gallons sent down the elevator shaft to blow up the lobby you still only have enough fuel to to get the steel up to 500 degrees or so. Thats with optimal heat transfer into the steel, best case conditions of delta-T and R values, with worst case delta-t for the heat LOSS from the steel. As material heat up they radiate and conduct heat AWAY at a rate governed by the temperature and ambient factors. So the hotter the steel gets the more heat it LOSES. This is why steel mills use crucibles to hold the steel as well as the heat.
The specific heat of steel is 240 btu/ton per degree > to raise the temp from ambient to 1800 degrees would require 432,000 btu/s ton at OPTIMAL efficiency. The concrete requires even more over 800,000 btus.
The the air also has to heat up, and air being a poor conductor and all the humidity in the air, the specific heat of water is 8 times higher than steel and 5 times high than concrete.
Its a rather long equation but not really complex. Bottom line, not enough BTU to make the steel hot enough to fail. Cant be done. Something else brought the buildings down. If they didnt fall immediately after the impacts there is now way the fires could have triggered it as the tensile and compressive strength of the steel did not change at all ( reference the stress-strain diagram for structural steel) after the fires did their work. It never exceeded its maximum working stress, if it did, the top would have fallen over towards the point of maximum damage. It would have done this slowly as the stress progressed along to top of the curve to the point of maximum or ultimate strength. The metal would be very deformed at this point.
From the the origin to the point called proportional limit, the stress-strain curve is a straight line. This is called Hookes Law that within the proportional limit, the stress is directly proportional to strain up to the elastic limit. That is the limit beyond which the material will no longer go back to its original shape when the load is removed, or it is the maximum stress that may be developed such that there is no permanent or residual deformation when the load is entirely removed.
The structural damage by the impact either failed the structure right away or the it brought it past the elastic limit. If it reached a certain point the curve here is actually longer that the portion from 0-the EL, the steel will start to deform plastically, that is bend like taffy. There was zero evidence of this.
The diagram for the temperatures tells us that the steel would have to attain a consistent temperature across the entire beam of way over 1500-1800 degrees, a point stress is not enough to induce failure, and there is no way to a localized temperature peak this high without the heat conducting to the rest of the beam. This is shown by the transfer equation is governed by the composition and shape of the beam, Shape is vital in that an I-beam or box had a high surface area to volume ratio, This means heat loss radiated away form the source of the heat is going to be very high, also humidity in the air will absorb the heat faster as water can take a lot of heat before raising its temperature so initial heat transfer AWAY form the steel will be even higher.
If as they will say that the fireproofing was all blown away by the impact makes it even harder, as the steel can radiate more heat if it is uncovered.
We can also calculate the rate of heat transfer INTO the steel beams. It is a function of the differential temperature, the specific heat of the steel, the surface area of the expose material and the R value of the air or any remaining building materials between the flame and the steel, as well as the airflow ( mass flow rate of hot air).
Al these factors except R can be definitively identified. using the maximum value for R, youd run out of fuel ( assuming 100% fuel loading on the plane with zero for elevator shaft and fireball) before you got a 700 degree T-rise anywhere.
But the Kean Commission weenies also state that vast amounts of fuel poured down the elevator shafts to account for the damage to the ground floor. So where that that leave us?
Youd be lucky to be able to do a marshmallow roast with what was left after the fireball anyway.
It doesnt work and there is no way to make it work. the official story is a sham and any one who believes it is an ignorant fool. "
What you think???? Don't you just love science?