Nice footage of skyscraper demolision..

Originally posted by Samblack
Keep in mind that these towers were not built like a steel cage,ive seen various documentaries that were made PRE-911 that state that the exoskeleton was its main source of structural integrity and not the center of the tower.

Source please. I've heard extremely different....even from NIST.

Even the floors of the WTC were not that structurally strong ,consisting of mainly concrete wich fails horribly when it gets hot.

Since concrete is a fire retardent, how does it fail horribly when it gets hot? Please do some research if you are going to claim things as fact.

If it would of been the Empire State Building that would of been hit it more then likely would of taken explosions cause those types of buildings were basically steel cages where as the WTC were basically hollow buildings with its structural integrity was mainly on the exoskeleton. Place a large whole in its exoskeleton and add a little heat=FAILURE.

These statements are false. Please look into the designs of both buildings. The Empire State had a lot more concrete (suppossedly...another time and other thread) than the WTC. So, by your logic of concrete acting horribly in fire, that building should have fallen rather than the WTC. Again, please start sourcing your "facts".

Originally posted by Slap Nuts

Originally posted by Griff

Originally posted by Samblack
The way the towers were built was so the Exoskeleton was the main support,the exoskleton took alot of damage that day.

Factually false. I've heard anywhere from 60% core to 50% core...depending on source. So, no...the "exoskeleton" was not the main support.

Sorry to say, but you are both worng on a TECHNICALITY.

Because the towers have been quoted as being 2-3x redundant by the designers, even if the load bearing was split 50/50; TECHNICALLY either could support the entire mass.

OK...on that technicallity...you are correct. I've heard that the perimeter was 5x redundant and the core 2.5-3.5x redundant. So, you would have to essentially sever over 4/5 of the exterior columns to achieve failure (not counting the core).

youtube.com...

Good film if you havnt seen it.

All it would of take is the floors to collapse to trigger the fall of the towers+the weakening of the exoskeleton and the extreme heat.

I was a witness to a bridge fire about 5 years ago,there were conduit lines running from 1 side of the bridge to the other(basically PVC pipes with cables in them.Well anyway someone set fire to the conduit lines and it got pretty intense,I could hear concrete cracking and popping(wich could be missenturpreted for explosions cause they were rather load).If a fire of that magnitude on a bridge was capable of cracking concrete I have no doubt that the floors of the WTC failed horribly considering that it was much much hotter and that a jet liner pulvurized a few of the floors .It took them something like 8 weeks to fix this bridge that was no more then 12 years old at the time.

Originally posted by Samblack
I have no doubt that the floors of the WTC failed horribly considering that it was much much hotter and that a jet liner pulvurized a few of the floors ..

Oh COME ON, now you are just making stuff up....

Pop Quiz: What material is often used to build a FORGE?

Originally posted by Griff
Since concrete is a fire retardent, how does it fail horribly when it gets hot? Please do some research if you are going to claim things as fact.

In this case you're wrong, Griff. A steady enough fire destroys concrete. Go break a chunk off somewhere and hold a lighter under it, see for yourself.

Originally posted by Samblack
If a fire of that magnitude on a bridge was capable of cracking concrete I have no doubt that the floors of the WTC failed horribly considering that it was much much hotter and that a jet liner pulvurized a few of the floors .

Cracked concrete still retains it structural strength in compression. In tension it doesn't but the floors would have remained in compression....even if sagging. Anyway, the concrete floors are not what gave the floor it's structural integrity...it was the steel trusses. Again...source/research.

Originally posted by Astygia
In this case you're wrong, Griff. A steady enough fire destroys concrete. Go break a chunk off somewhere and hold a lighter under it, see for yourself.

So, you're saying that in an office fire, the concrete cracks and breaks up into miniscule pieces? I'll search and see who is correct.

Originally posted by Slap Nuts

Originally posted by The Observer
But where are you getting your information that a 757 crashing into the towers can't bring it down, and look like...the videos we all saw on 9/11?

There are MANY threads addressing the ENERGY and FORCES required for the towers to fail and collapse as they did.

The force of gravity alone does not nearly account for all of the energy required to snap the steel core colums to pieces, pulverize concrete into powder and eject giant pieces of steel great horozontal distances.

Search and ye shall find.

Slapnuts, Follow the link at the bottom to see where I am getting my information...by people who have actually been in the respectives business (dealing with construction and demolition) for years. They say it IS possible.

www.popularmechanics.com...

Happy reading, I would recommend page 4 as being the one most concerning this discussion.

Further, though, if physics was all that was ever necessary to figure out exactly how a given...incident would unfold in the real world, there would be no such thing as "a test run" and no such thing as "test pilots." The operative word there being TEST. As in finding out if the math really tells things how they are...and the number of test runs that fail, and the number of test pilots that die would seem to indicate that the math alone isn't always a...comprehensive picture.

[edit on 20/9/06 by The Observer]

Hmmm...first google search.

ICF Fire Resistance

Fire Resistance

Ever seen concrete burn? Me neither. In tests where ICF walls were subjected to temperatures of up to 2,000 degrees Fahrenheit for as long as four hours, the ICF walls never failed structurally. By contrast, wood frame walls typically collapse in less than an hour. When considering a wood frame home for your next house, consider the countless fire fighters who have died when a wood frame structure collapsed prematurely.

Source: www.concrete-home.com...

Bolded by me. Hmmm....2,000 F? That's 1093 degrees C. Which is much higher than in the WTC fires. After four hours.....never failed structurally.

Still going to claim I'm wrong?

Those are wall tests not floor tests. At best the floors are only 6 inches thick.They got pulvarized by a jet liner.Ive seen concrete snap crackle and pop in a matter of an hour at that bridge fire and this concrete i would assume is alot thicker then the stuff used on the WTC floors.

Tests can never duplicate real life conditions.
[edit on 20-9-2006 by Samblack]

[edit on 20-9-2006 by Samblack]

Originally posted by The Observer

Slapnuts, Follow the link at the bottom to see where I am getting my information...by people who have actually been in the respectives business (dealing with construction and demolition) for years. They say it IS possible.

www.popularmechanics.com...

Happy reading, I would recommend page 4 as being the one most concerning this discussion.

This site is proven disinfo.

Also what good is this crew if they don't even show up for a debate with 9/11 scholars?
Ya that's right, they canceled a debated wit scholars 5 minutes before airtime. so that site is bunk.

Originally posted by Griff
Hmmm...first google search.

ICF Fire Resistance

Fire Resistance

Ever seen concrete burn? Me neither. In tests where ICF walls were subjected to temperatures of up to 2,000 degrees Fahrenheit for as long as four hours, the ICF walls never failed structurally. By contrast, wood frame walls typically collapse in less than an hour. When considering a wood frame home for your next house, consider the countless fire fighters who have died when a wood frame structure collapsed prematurely.

Source: www.concrete-home.com...

Bolded by me. Hmmm....2,000 F? That's 1093 degrees C. Which is much higher than in the WTC fires. After four hours.....never failed structurally.

Still going to claim I'm wrong?

One question, though. How much would stress on the concrete itself effect it's integrity under heat? It seems to me that the stress on concrete in one of the towers would be much higher then the stress on the concrete comprising a home. You may be wrong. But with not enough info, you can't be sure you're right. My father told me once to never trust a man who sells paper when he tells you they make great all-weather aircraft. Because paper airplanes don't work in the rain... And your source site sells paper, so to speak...

Tests can never replicate real life conditions I dont care how much college youve been to or what kind of engineer you are.

Originally posted by ThichHeaded

Originally posted by The Observer

Slapnuts, Follow the link at the bottom to see where I am getting my information...by people who have actually been in the respectives business (dealing with construction and demolition) for years. They say it IS possible.

www.popularmechanics.com...

Happy reading, I would recommend page 4 as being the one most concerning this discussion.

This site is proven disinfo.

Also what good is this crew if they don't even show up for a debate with 9/11 scholars?
Ya that's right, they canceled a debated wit scholars 5 minutes before airtime. so that site is bunk.

Who proved it?

And interesting, on of the sites that debunks the crap on your sig-line sites has already been dismissed as "proven disinformation." I say again, who proved it?

At this point, I'll believe my engineers, you believe your...sites. Lets leave it at that.

Originally posted by Samblack
Those are wall tests not floor tests. At best the floors are only 6 inches thick.They got pulvarized by a jet liner.Ive seen concrete snap crackle and pop in a matter of an hour at that bridge fire and this concrete i would assume is alot thicker then the stuff used on the WTC floors.

I knew someone was gonna say "nah-uh" Well, here's something about lightweight concrete. BTW, the concrete deck in the WTC was 4 inches thick lightweight concrete. Again research/source.

PERLITE INSULATING CONCRETE ROOFDECKS

Perlite insulating concrete roofdecks offer architects, contractors and building owners several important benefits which include:

* Excellent Insulating Values
* Excellent Fire Ratings
* Lightweight
* Slope to Drain
* Monolithic Roofing Base

Sorce: www.silbrico.com...

The floor decks were lightweight concrete (not sure if it was perlite but most lightweight aggregates are similar). This site is for roof decks....which are similar to floor decking.

Tests can never duplicate real life conditions.

I guess that throws out all the tests done by NIST?

Originally posted by The Observer

One question, though. How much would stress on the concrete itself effect it's integrity under heat?

One thing. The floors only transferred the lateral load from the exterior columns to the interior.....and the trusses actually did this...not the concrete deck. There were no loads (other than dead (office furniture) and Live (people) loads) on the concrete floors. It's not like the floors held up the building.

It seems to me that the stress on concrete in one of the towers would be much higher then the stress on the concrete comprising a home.

Depending on the design, you could be right.....but see above.

You may be wrong.

Not about concrete being a fire retardant, I'm not. If you can prove me wrong, then I will recant.

No the floors didnt exactly hold the building,but if you combine all of the other things going on it definatly plays a good part in the towers colapse.

I'm actually done argueing with you. I don't have the patience anymore. Until you start sourcing your "facts", I'm done with you.

I'm only saying this because I don't want people to think I am conceeding to you...which I'm definately not. Let me ask.....How many strengths of materials classes have you taken? How much concrete have you tested/done compression tests on/did quality controll tests on? Until then, at least source your information. It makes for a better debate.

Originally posted by Griff
So, you're saying that in an office fire, the concrete cracks and breaks up into miniscule pieces? I'll search and see who is correct.

I'm saying go find a piece of concrete and burn it, see what happens. It crumbles.
Not trying to throw your entire theory out the window, pretty much everything you say is right on the mark, but I know concrete.

Originally posted by The Observer
Who proved it?

And interesting, on of the sites that debunks the crap on your sig-line sites has already been dismissed as "proven disinformation." I say again, who proved it?

At this point, I'll believe my engineers, you believe your...sites. Lets leave it at that.

Go ahead read it all here.
www.abovetopsecret.com...

There are a few sites here on ATS that talk about the crap PM spews.