Moderated Steel structures cannot globally collapse due to gravity alone

[Architect]

Safety Factors

Just to prove that I'm a glutton for punishment, I've given some considerable thought to Heiwa's throwaway comment regarding safety factors in the steelwork.

NIST tested the steel recovered from WTC (which in itself is of interest, as CTers usually claim it was all whisked away to China with unseemly haste). NIST NCS STAR 1-3D (http://www.fire.nist.gov/bfrlpubs/fire05/PDF/f05158.pdf) confirms a range of actual values:

- Core webs ranged from as low as 31.1 to 41.9 ksi, ie. 86 to 116% of specificed strength.

- Core flanges ranged from 32.4 to a high 53.4 ksi, ie. 90 to 146% of specified strength.

Setting to one side the 31.1 and 32.4 ksi results, inasmuch as a small proportion of columns below failure point are unlikely to lead to any wider problem, let's take the lower maximum of 116% specified value.

Now, the NIST Demand to Capacity Ratios (DCR) are based upon specified strengths and NIST themselves note that there is effectively spare capacity up to actual (but varying) yield point/strength.

Core columns in WTC typically had a Demand to Capacity Ratio (DCR) of 0.83, ie a safety factor of 1/0.83=1.20. Now let's assume assume that the steel has an additional 16% beyond minimum yield value. This would reduce the DCR to 1.16/.83=1.4.

In other words we could increase the loads in these areas by up to 40% before yield point was reached and plastic (permanent) deformation begins. Of course this figure has lots of variables - most of the steel webs did not have such a high yield factor, some areas had DCRs well in excess of 0.83, and so on.

What we don't do is then add any significant additional allowance for tensile strength because (a) yield failure is already occuring and (b) gravity loads will be compressive, not tensile.

As I frequently mention, one thing we also have to appreciate is that the structure of WTC is complex; in addition to dead and live loads, it will be dealing with (for example) transverse and shear loadings from the wind. There will be a degree of torsion due to differential loading. And so on. We would therefore have to look at the exact steelwork design in considerable detail before we could determine a safety factor for each. That's why engineers earn a lot of cash, and why complex modelling software was developed.

Nevertheless it is clear that the actual capacity of the core is not going to be anything like 400% or 4:1 before irreversible damage and failure begin to occur.

But in any event the above calculations all assume an intact core, and we know from the various NIST studies and eyewitness evidence that the cores suffered damage - around a third. This will obviously have reduced loadbearing capacity still further, and a simple pro-rata reduction of (say) 30% is likely to be wrong because the damage is concentrated in localised areas and hence these areas will be susceptible to accelerated failure under loads.

I shall, as ever, await Heiwa's next attempt to display his intuitive grasp of mechanics and structures with the greatest of interest.

Health Warning: I'm an architect, not a structural engineer. I only need to know the big picture stuff and the basics in order than I can instruct/co-ordinate/know when to listed to real specialists.* Some of the engineers may therefore want to add to this post.

(*) I do not include Heiwa in this definition of "engineer" or "specialist".

 

[bill smith]

Heiwa

I've got a question for you.

It was evident in the "crush down" (your term, I'd be just as happy with the generic term "collapse") of the towers that the crushing happened successively at each floor as the rubble descended.

My question to you: how do you explain this. Do you believe that each floor was blown with demolitions as the upper block's debris arrived at that floor?

My ultimate question is going to be "why did each & every one of about 85 collapses happen at the upper story, and not at some lower floor?"

This phenomenon happened on both towers, for every story, after the crush down got established.

What is your explanation for this?



tom

Hello Helllo.
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well. Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?

PS; Here's a short video that puts things nano in perspective nicely.
http://www.youtube.com/watch?v=S4CjZ...ilynews?page=1

 

[L The Detective]

I like math! Math is a science of space and numbers; arithmetic, algebra, geometry, you know. I just use it as a tool. To verify physical events, e.g. ship collisions and structural failures. Math can translate them into an abstract form that can assist clarifying and understanding them.
Common sense is not a science. Nor is clear thinking. I would suggest that common sense is neutrality of estimation of facts and clear thinking promotes knowledge.

I must admit, I don't enjoy math. But as you say, it's a useful tool. We agree on that.

So to you, "common sense" is neutrality. I see. So when you are asking someone to use common sense when looking at certain facts, what you are really asking is to look at the facts in an unbiased way? Do I have that correct?

By "clear thinking," do you mean rationality?

And maths is a tool to verify the results. And problems are solved. I have worked in such manner for 40 years. So common sense will not lead you to the wrong conclusions.

I see. So what you are saying here is "being unbiased won't lead you to the wrong conclusions." Did I interpret that correctly?

But bad passions, ill will, malicious intent and confused thinking surely will. I have encountered plenty of those amongst unhappy people that produce disastrous enmities and hatred. I just feel sorry for them. They are a miserable lot.

So basically what you're saying is that negative emotions can cloud judgment and lead to the wrong conclusions... I agree with that. Although, I would go a step farther and say that applies to positive emotions too. Personally, I think that any emotions can cloud "clear thinking," or as I say it rational judgment.

I am just a happy guy that nobody can really stress. Common sense and maths work for me.

I've read many of your posts, and I certainly don't doubt this assertion! You seem like a happy guy.

I think I'm talking about a different kind of common sense from you, though. What I'm talking about, well... maybe another way to say it would be "instinct." For example, in the case of JFK and the watermelon, people wouldn't think that the watermelon would blow back in the opposite direct of the bullet that goes through it. That defies common sense, or rather, it defies people's "instinctive belief."

I bring that up, because when I see some people using the phrase "even a child would see it," to me it seems what they are talking about is "instinctive belief." In other words, what they seem to be saying is that I should instinctively know that what they are saying is true.

What do you think? Do you agree with me that our instincts can sometimes decieve us?

 

[Heiwa]

You disregard both the point to you and the understanding of a composite structure. As has been explained to you several times before, the various structural elements act together - the parallel would be a girder truss - in order to ensure overall stability. If one element is compromised then the entire building is at risk.

Moreover you disregard the role of the hat trusses. These do not simply connect the inner and outer structures, but rather serve to address issues such as the overturning moment. That the ultimately served to redistribute some of the external envelope load to the columns is of note, but not their design function.

If you fail to follow this fairly basic premise then I cannot understand how you can purport to analyse the failure sequence.

Evidently the various structural elements act together. That's what structural analysis is all about. Where does the forces go? What bending moments are produced? What happens at the joints?
Structural damage analysis is more complex as the structure changes with each failure, so you have to re-do the complete analysis after each failure. Neither NIST nor Bazant & Co has done that.
But I have!
It is of course preposterous to assume that the initial failure is that all 280+ columns fail and that part C free falls on part A, but it can be analysed ... as I have done. And the result is that the columns will damage the floors ... and after that crush down is arrested.
The hat truss should remain intact as it is not in contact with part A.
Have you ever done any structural damage analysis?

 

[Heiwa]

Just to prove that I'm a glutton for punishment, I've given some considerable thought to Heiwa's throwaway comment regarding safety factors in the steelwork.

NIST tested the steel recovered from WTC (which in itself is of interest, as CTers usually claim it was all whisked away to China with unseemly haste). NIST NCS STAR 1-3D (http://www.fire.nist.gov/bfrlpubs/fire05/PDF/f05158.pdf) confirms a range of actual values:


As I frequently mention, one thing we also have to appreciate is that the structure of WTC is complex; in addition to dead and live loads, it will be dealing with (for example) transverse and shear loadings from the wind. There will be a degree of torsion due to differential loading. And so on. We would therefore have to look at the exact steelwork design in considerable detail before we could determine a safety factor for each. That's why engineers earn a lot of cash, and why complex modelling software was developed.

Nevertheless it is clear that the actual capacity of the core is not going to be anything like 400% or 4:1 before irreversible damage and failure begin to occur.

But in any event the above calculations all assume an intact core, and we know from the various NIST studies and eyewitness evidence that the cores suffered damage - around a third. This will obviously have reduced loadbearing capacity still further, and a simple pro-rata reduction of (say) 30% is likely to be wrong because the damage is concentrated in localised areas and hence these areas will be susceptible to accelerated failure under loads.

I shall, as ever, await Heiwa's next attempt to display his intuitive grasp of mechanics and structures with the greatest of interest.

Health Warning: I'm an architect, not a structural engineer. I only need to know the big picture stuff and the basics in order than I can instruct/co-ordinate/know when to listed to real specialists.* Some of the engineers may therefore want to add to this post.

(*) I do not include Heiwa in this definition of "engineer" or "specialist".

When building ships every steel component has its certificate of testing, etc. so you know what you use. But we now and then double check. No big deal.

The WTC core structure was built with a FoS >3 so it was extremely strong. Wall perimeter was same - including dynamic wind loads FoS was still >3.

In shipbuilding we actually use smaller FoS because we use quite big design loads, particularly the dynamic ones. Where there are no dynamic loads we use FoS about 3. Good practice! But that's just for design.

Structural damage analysis is a completely different matter. When a component fail ... it cannot fail again as it does not carry any load after failure. So there is no such thing as an accelerated failure under load. No, you have to re-analyse and see where the load on the failed part has gone.

I doubt very much that you have done any structural damage analysis and conclude you do not know what you are talking about.

 

[Heiwa]

So to you, "common sense" is neutrality. I see.

1. So when you are asking someone to use common sense when looking at certain facts, what you are really asking is to look at the facts in an unbiased way? Do I have that correct?

2. By "clear thinking," do you mean rationality?

So basically what you're saying is that negative emotions can cloud judgment and lead to the wrong conclusions... I agree with that. Although, I would go a step farther and say that applies to positive emotions too. Personally, I think that any emotions can cloud "clear thinking," or as I say it rational judgment.



I've read many of your posts, and I certainly don't doubt this assertion! You seem like a happy guy.

I think I'm talking about a different kind of common sense from you, though. What I'm talking about, well... maybe another way to say it would be "instinct." For example, in the case of JFK and the watermelon, people wouldn't think that the watermelon would blow back in the opposite direct of the bullet that goes through it. That defies common sense, or rather, it defies people's "instinctive belief."

I bring that up, because when I see some people using the phrase "even a child would see it," to me it seems what they are talking about is "instinctive belief." In other words, what they seem to be saying is that I should instinctively know that what they are saying is true.

3. What do you think? Do you agree with me that our instincts can sometimes decieve us?

1. Yes, more or less! But I do not use the word unbiased. Neutral or impartial is better.

2. I said that clear thinking promotes knowledge. Rationale is similar.

3. Instinct is the opposite to rationale so instinct may deceive you, of course. But you do not use instinct when doing structural analysis. But inspecting structures, instinct may be useful! You sniff around! Is everything OK? Sometimes you just feel there is a defect somewhere. This combination of instinct and rationale is quite helpful.

You see, I started out with this WTC/911 matter as some children, having seen some videos, couldn't sleep! They thought - instinct - the house would just crush them. So I explained to them how structures work! For that very simple language was required, but they understood and now sleep well. And I published the lecture on my web site. The lecture has becomea little more advanced since but the message is the same.

 

[Heiwa]

Hello Helllo.
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well. Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?

PS; Here's a short video that puts things nano in perspective nicely.
http://www.youtube.com/watch?v=S4CjZ...ilynews?page=1

I haven't got a clue. But some sudden application of energy - high, sudden presssure on the whole surface - is required to pulverize the floors. Gravity forces/loads, e.g. steel columns punching holes in the floors cannot pulverize them.

 

[bill smith]

Hello Helllo.
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well. Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?

PS; Here's a short video that puts things nano in perspective nicely.
http://www.youtube.com/watch?v=S4CjZ...ilynews? page=1

PPS Repost of defective nanotechnology link.

http://www.kqed.org/quest/television/view/189?gclid=CKSqy9mqypgCFQZqswodF1Pb1Q nanotechnology

 

[bill smith]

the head of the hmmer

Bazant talks about a 0.9 m inital layer of compacted rubble acting as the head of the hammer so to speak.As I uncerstand it he indicates that this layer grows as the collapse progresses. But to keep a layer of rubble like that compacted you need a binder of some kind and there is no such binder imaginable at the WTC.

This compacted rubble would meet the upstanding core clumns which would break it uo further and cause the dissociated aggregate to behave more ike a liquid, flowing over, around and between the Core columnns surely ? In this fashion no coherent force could b exerted on the massive Lower columns.

 

[bill smith]

I haven't got a clue. But some sudden application of energy - high, sudden presssure on the whole surface - is required to pulverize the floors. Gravity forces/loads, e.g. steel columns punching holes in the floors cannot pulverize them.

There was extremely little concrete left in the rubble on the ground. Even if the force of the collapse had broken it up thre should have been millions of pieces of concrete strewn everywhere quite apart from the percentage that had been pulverised.
If you look at the attached animated gif- allow it to load and cycle a few times you get the impression of how little rubble there WAS on the ground after the collapse. Even more tellingly, reverse the view in your mind and watch the Two biggest Towers in the world reassemble hemselves from the paltry few sticks and stones we can see in the image. Always remembering that the inside of the buildng was full of structure as well, including 110 one-acre 4'' thick concrete floors..

http://www.acebaker.com/9-11/HTR/web-content/Images/HTRTitleAnim.gif animated gif

 

[Dave Rogers]

What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well.

Being a powder, it won't have any surface tension, so there'll be no capillary action to draw it into the pores of the concrete. If you add a liquid carrier, it might, but then you've got to get that liquid out of the concrete. I'll show you why that's an issue in a moment.

Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?

At this point it would be useful to do some calculations. Thermite has an energy density of about 4MJ/kg, which is independent of its particle size. Water has a specific heat of 4.2kJ/kg/degree and a latent heat of vaporisation of 2600kJ/kg. Let's assume thermite itself has a heat capacity of about 0.6kJ/kg/degree (iron is 0.45, I don't know alumina but silica is 0.7, so 0.6 won't be far off), which sounds reasonable because it means that the thermite would be able to self-heat to about 5700C. Concrete has a specific heat of 0.88kJ/kg/degree (remember, if your nano-thermite is impregnating the concrete it'll have to heat that as well).

That should be all the physical constants you need. Now, you just have to plug in some numbers for the water content of the concrete and the ratio of thermite to concrete, and you'll be able to find just how hot the thermite can get the water. Have fun!

One result I worked out is that, if you mix equal weights of water and thermite, there's only enough energy to heat the mixture to about 375ºC. That means that an equal mix of thermite and water won't burn, whatever else you do to it, becaue its ignition temperature is over 1000ºC. Best to use some other liquid to mix it with.

Just one question, though. Since none of the concrete in the WTC was doing anything other than holding up furniture, what was the point of going to so much trouble just to pulverise it?

Dave

 

[GlennB]

Hello Helllo.
What about the following as a theory for how the floors were pulverised ?

Suppose you sprayed a 4'' thick concrete floor slab with nano-thermite ? Being nano, it might very ell impregnate even concrete quite well. Suppose further that it could be induced to ignite ? Would it instantly boil whatever water residue was in the concrete at nearly 5,000 degrees causing it to become gaseous and to explode- even pulverise the concrete ?

You posted this before but I think the replies got lost in a lot of shouting by bob_the_analyst. Let's try again :

1) This all depends on your take on concrete "pulverisation". How much and how fine. I believe you were asked once before, but I do appreciate that as a Truther here your posts attract a lot of replies. So - what is your take on this subject?

2) Why, by all that's Holy, would anybody want to even try this? Blowing the floors to pieces would have no bearing on the collapse, and would be a pointless but massive operation that could be detected in advance or go wrong in practice.

 

[BigAl]

PPS Repost of defective nanotechnology link.

http://www.kqed.org/quest/television/view/189?gclid=CKSqy9mqypgCFQZqswodF1Pb1Q nanotechnology

What does the content of that video have to do with anything that can cause the collapse of one of the largest buildings in the world? Nothing.

All discussion of nano-anything in our context is silly.

Thermite/thermate doesn't explode. To the extent that something called nano-thermite exists and can be said to explode, it also makes the same noise associated with any explosive; BOOM. Nobody heard any explosions at WTC consistent in loudness and timing with man-made demolition

The idea that any destructive device was built into any of the WTC towers in advance is silly.

The idea that any destructive device was installed just before 9/11 is silly.

As someone that was involved with several total floor renovations on Manhattan's larger buildings, the idea of anyone doing anything involving people and materials and access with the certainty that they wouldn't be found-out is silly and it shows the complete ignorance of everything on the part of the silly people that make these claims.

 

[ElMondoHummus]

Being a powder, it won't have any surface tension, so there'll be no capillary action to draw it into the pores of the concrete. If you add a liquid carrier, it might, but then you've got to get that liquid out of the concrete. I'll show you why that's an issue in a moment.



At this point it would be useful to do some calculations. Thermite has an energy density of about 4MJ/kg, which is independent of its particle size. Water has a specific heat of 4.2kJ/kg/degree and a latent heat of vaporisation of 2600kJ/kg. Let's assume thermite itself has a heat capacity of about 0.6kJ/kg/degree (iron is 0.45, I don't know alumina but silica is 0.7, so 0.6 won't be far off), which sounds reasonable because it means that the thermite would be able to self-heat to about 5700C. Concrete has a specific heat of 0.88kJ/kg/degree (remember, if your nano-thermite is impregnating the concrete it'll have to heat that as well).

That should be all the physical constants you need. Now, you just have to plug in some numbers for the water content of the concrete and the ratio of thermite to concrete, and you'll be able to find just how hot the thermite can get the water. Have fun!

One result I worked out is that, if you mix equal weights of water and thermite, there's only enough energy to heat the mixture to about 375ºC. That means that an equal mix of thermite and water won't burn, whatever else you do to it, becaue its ignition temperature is over 1000ºC. Best to use some other liquid to mix it with.

Just one question, though. Since none of the concrete in the WTC was doing anything other than holding up furniture, what was the point of going to so much trouble just to pulverise it?

Dave

Bill's missing something else: Thermite needs iron to react. Even if someone impregnated concrete with it, how's it going to ignite? The only places it would react at would be where steel is. Someone else can apply that to the specific construction of the towers - did the concrete have steel rebar in it, or was the concrete simply sitting on top of a floor "pan"? I don't remember - but the point is that trying to "impregnate" concrete with "nano" thermite would be silly because it wouldn't necessarily be applying it to where the steel is.

This is yet another attempt to shoehorn one of Steven Jones's silly proposals into the towers collapse. Thermite needs to be applied to the steel to react. Otherwise, it's not going to react. That's just basic chemistry.

 

[bill smith]

Being a powder, it won't have any surface tension, so there'll be no capillary action to draw it into the pores of the concrete. If you add a liquid carrier, it might, but then you've got to get that liquid out of the concrete. I'll show you why that's an issue in a moment.



At this point it would be useful to do some calculations. Thermite has an energy density of about 4MJ/kg, which is independent of its particle size. Water has a specific heat of 4.2kJ/kg/degree and a latent heat of vaporisation of 2600kJ/kg. Let's assume thermite itself has a heat capacity of about 0.6kJ/kg/degree (iron is 0.45, I don't know alumina but silica is 0.7, so 0.6 won't be far off), which sounds reasonable because it means that the thermite would be able to self-heat to about 5700C. Concrete has a specific heat of 0.88kJ/kg/degree (remember, if your nano-thermite is impregnating the concrete it'll have to heat that as well).

That should be all the physical constants you need. Now, you just have to plug in some numbers for the water content of the concrete and the ratio of thermite to concrete, and you'll be able to find just how hot the thermite can get the water. Have fun!

One result I worked out is that, if you mix equal weights of water and thermite, there's only enough energy to heat the mixture to about 375ºC. That means that an equal mix of thermite and water won't burn, whatever else you do to it, becaue its ignition temperature is over 1000ºC. Best to use some other liquid to mix it with.

Just one question, though. Since none of the concrete in the WTC was doing anything other than holding up furniture, what was the point of going to so much trouble just to pulverise it?

Dave

The incredibly finely-ground thermite could have been added to some kind of sprayable gel. Something hat would hold the nanothermite layer in place. The gel itself would likely also be a nano material which would mean that it could be drawn into the concrete by capilliary action or under pressure, The gel cold hve been applied to the underside of the floors by workers or robot srayers on rails. Detonators might have been also attched to the underside of the floors too.

If you read Kevein Ryan's paper on nano-thermite you will see that it's properties are greatly enhanced qua speed of ignition and coverage. Nano materials are so small that they can enter human cells, so the much larger structures in concrete would pose no problems at all. At 5,700 degrees C the water residue would most likely boil instantly explode and pulverise most of the concrete into a fine dust upon ignition. It's good to have scientists such as yourself for plugging in the numbers.

As for why they had to pulverise the concrete I can think of a couple of possibilities. One : to shroud and conceal the nature of the collapse and Two: Two: because pulverising the floors may have promoted a more efficent demolition
There iis a third less likely possibility but that is a story all on it's own.

 

[L The Detective]

1. Yes, more or less! But I do not use the word unbiased. Neutral or impartial is better.

All right. In that case, those words are probably better to use than common sense, since that term may be a bit misleading. When I hear common sense, I think it means general knowledge, or instinct. I think most people generally have the same response. But in any case, I know what you personally mean now by those words.

2. I said that clear thinking promotes knowledge. Rationale is similar.

What do you mean by "clear thinking," exactly? I was only guessing that you meant rationality.

3. Instinct is the opposite to rationale so instinct may deceive you, of course. But you do not use instinct when doing structural analysis. But inspecting structures, instinct may be useful! You sniff around! Is everything OK? Sometimes you just feel there is a defect somewhere. This combination of instinct and rationale is quite helpful.

So it seems we agree. Instinct can be helpful, but at the same time it can lead you astray. I would say that for practical things, instinct is a good "starting place," but if those instincts should come under question we have to be prepared to re-examine them, and dismiss them if the science disagrees.

You see, I started out with this WTC/911 matter as some children, having seen some videos, couldn't sleep! They thought - instinct - the house would just crush them. So I explained to them how structures work! For that very simple language was required, but they understood and now sleep well. And I published the lecture on my web site. The lecture has becomea little more advanced since but the message is the same.

I see, that's interesting. So what you're saying is, the children's instinct about how buildings would fall was wrong, and you corrected them using science? Am I correct in understanding that?

May I ask you another question? What led you to originally suspect that 911 was an inside job? Was it rationality, or instinct? And by "originally," what I mean is, the very first time you had suspicious thoughts, which do you identify as being the cause? The reason I ask is because, it seems that for most people, the answer would be "instinct," because they instinctively knew that buildings couldn't fall that way, or some other such thing. But maybe it's different for you?

 

[bill smith]

What does the content of that video have to do with anything that can cause the collapse of one of the largest buildings in the world? Nothing.

All discussion of nano-anything in our context is silly.

Thermite/thermate doesn't explode. To the extent that something called nano-thermite exists and can be said to explode, it also makes the same noise associated with any explosive; BOOM. Nobody heard any explosions at WTC consistent in loudness and timing with man-made demolition

The idea that any destructive device was built into any of the WTC towers in advance is silly.

The idea that any destructive device was installed just before 9/11 is silly.

As someone that was involved with several total floor renovations on Manhattan's larger buildings, the idea of anyone doing anything involving people and materials and access with the certainty that they wouldn't be found-out is silly and it shows the complete ignorance of everything on the part of the silly people that make these claims.

The video gives people an opportunity to really understand
nano-technology rather than just vaguely thinking 'very small'.
If you want to have a idea about how effective and different from standard thermite the nano version is this isessential viewing, just as Kevin Ryan's paper on nano thermite is essential readng.

http://www.journalof911studies.com/volume/2008/Ryan_NIST_and_Nano-1.pdf NIST and nano-thermite

http://www.kqed.org/quest/television/view/189?gclid=CKSqy9mqypgCFQZqswodF1Pb1Q nanotechnology

 

[Architect]

When building ships every steel component has its certificate of testing, etc. so you know what you use. But we now and then double check. No big deal.

The WTC core structure was built with a FoS >3 so it was extremely strong. Wall perimeter was same - including dynamic wind loads FoS was still >3.

No. I've just posted a detailed explanation of why the actual safety factor is not 3, including facts/figures. You have blindly stated "FoS>3" without any explanation. Please clarify, in detail, how you arrived at this figure.

 

[Sunstealer]

Apparently this nano-thermite is also weightless and invisible. No one has done any calculations to show how much steel a Kg of thermite will melt even when half the calculation has been done for them. Infact truthers don't even know which parts of the structure required to be cut for collapse. Imagine if all the floors needed thermite to collapse. 1 litre of thermite weighs 2.1Kg. You'd need truckloads of the stuff. Imagine the poor NWO operatives lugging all that up the back stairs!

 

[Architect]

The incredibly finely-ground thermite could have been added to some kind of sprayable gel. Something hat would hold the nanothermite layer in place. The gel itself would likely also be a nano material which would mean that it could be drawn into the concrete by capilliary action or under pressure, The gel cold hve been applied to the underside of the floors by workers or robot srayers on rails. Detonators might have been also attched to the underside of the floors too.

If you read Kevein Ryan's paper on nano-thermite you will see that it's properties are greatly enhanced qua speed of ignition and coverage. Nano materials are so small that they can enter human cells, so the much larger structures in concrete would pose no problems at all. At 5,700 degrees C the water residue would most likely boil instantly explode and pulverise most of the concrete into a fine dust upon ignition. It's good to have scientists such as yourself for plugging in the numbers.

As for why they had to pulverise the concrete I can think of a couple of possibilities. One : to shroud and conceal the nature of the collapse and Two: Two: because pulverising the floors may have promoted a more efficent demolition
There iis a third less likely possibility but that is a story all on it's own.

With respect, this is all unsubstantiated conjecture.

On the one hand, we have a highly detailed series of models demonstrating how failure could - did - occur due to damage to structural steelwork and fire damage. It has been reviewed and discussed by learned bodies such as the universities at some length, and the results not found particularly wanting.

What you have is unsubstantiated conjecture. Perhaps it could be some sort of spray-on therm*te gel, but then perhaps it could also be a martian death-ray. Unless you have tangible evidence then it comes to naught.

Moreover in discussing the reason for pulverisation (your term) of the concrete, you completely overlook the impact (pun inteded) of a fall from a great height.