The 'WTC Had a Concrete Core' Hoax

Originally posted by Wizy
it wouldn't make sense to have a complete concrete core in a high rise of that size.

Since of course that is not what the article or myself have claimed then you have shown NOTHING! Did you read the thread at all? The claim is that it is a steel reinforced cast concrete tublar core that housed stairwells & elevators, among other things.

Both the WTC 1 & WTC 2 towers had a rectangular cast concrete core structure formed into rectangular cells that had elevators and stairways in them.....

The design was a "tube in a tube" construction where the steel reinforced, cast concrete interior tube, was surrounded with a structural steel framework configured as another tube with the load bearing capacity bias towards the perimeter wall with the core acting to reduce deformation of the steel structure maximizing its load bearing capacity.

More on skyscrapers and sway:
library.thinkquest.org...
www.newton.dep.anl.gov...
science.howstuffworks.com...
some buildings have concrete cores, but its based on their design. today and those that were built around the time of the WTC towers, steel trusses and beams were used to help with the "sway". Now, dampers are used to control the sway. The chrysler building, empire state building were built with concret cores, as that was the only available technology back then to handle sway.

Once again you have showed nothing since NOBODY has claimed it was a solid concrete core. Unless you have a pre-911 source that describes the WTC core construction in detail and doesn't mention concrete at all......you look almost as ridiculous as howard!

i have a quick question for yall

can concrete act as a good heat insulator?

Originally posted by Jack Tripper

Am I reading this right? 17 foot thick concrete walls? Just want to clarify before I respond.

Originally posted by blatantblue
i have a quick question for yall

can concrete act as a good heat insulator?

Yeah, but so would be lots of steel (conducts heat away from source). But we *know* from so many past cases that reinforced concrete skyscrapers do NOT suffer major structural damage without insane fires, like the Windsor Tower. The best argument for an all-steel core would be that there is simply no precedent, which is obviously still not much of an argument since the effects of heat upon bare, unprotected steel are well-documented anyway.

Notice NIST didn't analyze the WTC Towers with concrete cores, but all steel, despite being able to clearly see concrete on the cores as they stood after the rest of the collapses. In fact, NIST didn't even mention that the cores remaining standing, and did NOT pancake with the rest of the floors as all government agencies and official supports have hereto asserted. There's just to much for them to try to explain already, without being honest about the concrete cores.

Sorry Tripper.

I never feels good to be wrong. But you are.

I suggest you not cherry pick your "sources"..And use some common sense.
Sometimes common sense is better than any "online source" so my post about the documentary stands..as does the newspaper clipping, it's just wrong. It was an article that GENERALIZED The construction of skyscrapers, it wasn't a blueprint.

The google searching, I referred to, provided me with more links DISPROVING your
concrete core THEORY, than proving it.

I could post all of those links, but it could be construed as cherrypicking..I suggest
anyone reading this thread, just peruse a list of search engine results, and figure it out for themselves.


So, as I said. I vote NO on the concrete core theory.

thanks bsbray (kldfj making post long enough)

Originally posted by spacedoubt
I suggest anyone reading this thread, just peruse a list of search engine results, and figure it out for themselves.

Put this into context:

Before 9/11, probably only engineers and the like showed much interest in the exact structure of the WTC Towers. Such people typically reported a concrete core.

After 9/11, we were quickly saturated (especially by government agencies such as FEMA) with the assertions that the buildings were all steel, save the concrete floor slabs. We're also yet to see any construction drawings.

And yet how did the cores remain standing in both towers have the rest of the collapses, and what was all of that gray stuff all over the steel columns, sticking right up in the air with the rest of it?

www.unc.edu...

It is known as a tube frame structure, please read the above article. Here is a small excerpt. It is not about cherry picking, but finding the truth from someone with nothing to gain from the outcome.

Most buildings before the 1970's would use heavy interior bracing and heavy exterior masonry. In addition to this, most of the buildings in New York used interior "X" bracing frames for support against wind. The World Trade Center was different. It used light materials on the outside, and heavy materials on the inside. Yamasaki decided to make his frame a cantilever up (meaning the support came from vertical beams) from the foundation. To use a cantilever up system, though, Yamasaki had to make the frame strong enough to withstand the winds from Caribbean hurricanes that travel up the East Coast (Yamasaki, 116). After much research, engineers were able to conclude that the best way to apply the cantilever up was by using the exterior walls as the main frame. This was the most technological and efficient way, because it used the entire perimeter of the building for support rather than just the interior core. Building's of this structure are often referred to as "tube buildings". The building's 208 foot wide face was threaded by steel columns, 61 on each side (Building Big). Every one of the 61 columns was eighteen inches wide, and there was twenty-two inches between each of them for a window. To save energy on cooling and heating Yamasaki had the columns go twelve inches deep from the outer aluminum face of glass. This provided shading during the summer, and the low amount of glass surface saved heating in the winter (Yamasaki, 117). The choice to use the external frame or tube building system had many benefits, and saved a lot of money because of the low amount of materials needed.


While the exterior provided protection against the winds, the interior served as the main support for the building. The internal columns formed a core that took care of the weight. The exterior columns, however, were not able to stop the sway caused by the winds. This was a problem with the light outside framed buildings. Other skyscrapers, such as the Empire State Building, absorbed most of the wind in the heavy exterior masonry. A study was begun in both Colorado State University and London to develop wind-engineering techniques to decrease any lateral movement. A method was discovered that used the floor beams as shock absorbers. The floors acted as a diaphragm that stiffened the outside walls against lateral buckling forces from wind-load pressures (Great Buildings). In a one-hundred mile per hour wind, the towers would move only eight inches, which is nothing in comparison to the building's size (Yamasaki, 116) The floors construction was a networks of steel trusses that ran between each column to the building's core 60 feet in, where the elevators were located. These steel trusses held up each of the concrete floors that strengthened the building.


95% of the building's frame was steel. Yamasaki discovered that steel was much stronger than it had been in the past. He knew it would be able to support the building for a longer period of time. By using steel, the tower floors were free of interior columns (With the exception of the core), making for more internal space.
Floor space was just one of the factors that Yamasaki had to take into consideration when planning the elevators. First, because the capacity of the building provided room for around 50,000 people, Yamasaki knew he had to put in enough elevators (about 100 in each tower) to keep people from waiting too long. The tricky part was to avoid using too much floor space. To save room, Yamasaki used a sky lobby system that divided the building into three vertical zones. The express elevators that would travel at 1600 feet per minute would take passengers to the sky lobbies on the forty-fourth and seventy-eighth floors. Here local elevators would go to any floor with-in its third of the building. There was never much of a wait because the express elevators could hold around 55 people, and the regular elevators could carry about 20 (Yamasaki, 118). By using the sky lobby system, the elevator shafts for each third were stacked above the one below. This freed 15 to 17 percent more rentable floor space. If a conventional elevator system had been used it would have been considerably less. Second, Yamasaki had to make sure the air pressure generated by the express elevators would not buckle the elevator shafts. The engineers of Otis Elevators came up with a solution to this problem. By using a drywall system fixed to the reinforced steel core, the shafts were strengthened enough that air pressure was not an issue.


The exterior was made up of a silver aluminum. Aluminum had to be used because any heavy materials would put to much stress on the building. Ordinarily, a sealant would be applied to the outside walls, but Yamasaki did not like sealants because he thought they dried out and cracked building walls (you can only imagine what kind of a maintenance nightmare this would be on such large buildings). Another way had to be figured out. Cupples Products was assigned the task of finding a solution. Cupples discovered a new method known as the pressure-equalization system. the pressure-equalization system prevented water from getting in by having the aluminum sheets overlap one another. The cavities created by this overlap had an air pressure equal to the wind outside. This prevented the water form ever getting in and causing a problem. as Yamasaki put it, "Thus the most economical, lightweight, maintenance free cladding wall possible was developed and used (Yamasaki, 118).

[edit on 19-5-2006 by esdad71]

and it goes on

The twin towers of the World Trade Center were essentially two tubes, with the north tower (1,368 feet) six feet taller than the south tower (1,362 feet), and each were 110 stories tall. Each tube contained a concrete core, which supported only the load of the central bank of elevators and stairwells (Snoonian and Czarnecki 23). Also, the exterior of each tower had closely spaced columns made of aluminum and steel that provide the most support for the tower. To buffer extreme winds that come from the Hudson River and the occasional tropical storm, a shock-absorbing system was developed where the ends of each floor beam acts like an automobile's shock (Yamasaki 116).

[edit on 19-5-2006 by esdad71]

Lmao, Esdad. You're supporting us, and you don't even realize it.

Look what you just posted:

By using a drywall system fixed to the reinforced steel core, the shafts were strengthened enough that air pressure was not an issue.

Reinforced? Hmm..

Each tube contained a concrete core, which supported only the load of the central bank of elevators and stairwells (Snoonian and Czarnecki 23).

And it even cites a further source for us!

[edit on 19-5-2006 by bsbray11]

Esad71,

I understand. Concrete, no concrete.

From yet another (maybe) article, it's probably been linked somewhere back in the thread.

The twin towers were the first supertall buildings designed without any masonry.

The full article is here:
www.nyc-architecture.com...

I guess nobody is sure how it was built then eh?

This is why, I think, in this case..Opinions are as valuable as links.

spacedoubt:

Yes that article was already linked by Howard.

As I stated earlier and as bsbray pointed out about the article posted by esdad71......

THIS SUPPORTS OUR CONTENTION!

Also unique to the engineering design were its core and elevator system. The twin towers were the first supertall buildings designed without any masonry. Worried that the intense air pressure created by the buildings’ high speed elevators might buckle conventional shafts, engineers designed a solution using a drywall system fixed to the reinforced steel core.

What do you use to reinforce steel?

Gypsum?

Of course not!

Concrete.

Everybody knows this which is exactly why Howard is silent because HE knows this.

Even the articles you guys cite support our contention!

YOU CANNOT FIND A SINGLE ARTICLE, DISCUSSION, OR STUDY TO DEBUNK THE FACT THAT THE CORE OF THE WTC WAS A REINFORCED STEEL AND CONCRETE CORE!

Howard clearly loses and has made a tin-foil hat conspiracy nutter of himself in the process by screaming "hoax"!

Jack Tripper.

You use Steel to reinforce concrete. They call it "reinforced concrete".
Not reinforced steel.

Here is one example of reinforced steel

peer.berkeley.edu...

It looks like, in this case, they were evaluating a type of reinforced steel for it's earthquake resistance qualities.

So, REINFORCED STEEL, does not have to mean concrete was invloved at all..



[edit on 19-5-2006 by spacedoubt]

Originally posted by TxSecret

Howard Roark

Does anyone think that the methods and sequencing of the construction of the core and the elevator shafts as presented here make sense?

Why don't YOU explain why they wouldn't make sense?

I beleive that I did on the third post of this thread.

The tops of the interior walls of the concrete core served as the support for the steel interior concrete forms that had to be disassembled and lifted 40 feet to be set for the next pour. Exterior forms were plywood.

No mention of where this information comes from, it is basically pure speculation of the part of the site author, who then goes to speculate even further:

What you see in the photos of tower construction within the official story are the kangaroo cranes used to move material, the interior forms, and elevator guide rails, or to position the rebar hanging into the concrete pour. The steel framework was built up to 7 floors over the top of the concrete core being constructed inside of the steel frame obscuring the core construction from view. Other photos when the construction is lower show elevator guide rails. These are being mis identified as "core columns" on some web sites.

Elevator guide rails? So the author of the concrete cores page is suggesting that the elevator guide rails were actually installed first and the core walls poured around them.



This is the photo provided to support this claim:

Before another core tier could be formed, the elevator guide rails had to be lowered and set in place to a level 2 floors lower than the top of the present concrete pour. They are what is shown in the diagram at the top of this page, the FEMA core. The guide rails are presented as multiple, narrow rectangular tubes that supposedly ran full length for the tower.

OK, let me see if I have this straight.

The elevator guide rails were installed, sticking up in the air before the core walls were poured,

then the forms were put in place between the corner box columns and the elevator guide rails,

then the core walls were poured, then after the walls set, the forms were somehow removed from between the guide rails and the concrete walls and moved up for the next pour? Is that right?

No wait, you then state that “Before another core tier could be formed, the elevator guide rails had to be lowered and set in place to a level 2 floors lower than the top of the present concrete pour.”

But your picture shows them sticking up in the air.

This is confusing, so now is it that the rails and the core were pre-assembled, supported on God knows what, hanging in the air, then lowered into place after the core walls were poured?

Originally posted by Griff

Originally posted by Jack Tripper

Am I reading this right? 17 foot thick concrete walls? Just want to clarify before I respond.

So you noticed that too?



Those "3 inch thick high tensile rebars" look like electrical conduits to me.

17 foot thick max at the BASE of the core.

Could be. You certainly havent shown otherwise.

He most certainly DOES give a source for the things that he claims. You simply choose not to believe it because you prefer the "hoax" explanation!

I've met numerous people that remember the early and very technical 2 hour show. One was a civil engineer who remembers the documentary aired on another cable educational channel in 1995 and remembers the concrete core as they are shown below and labeled "ACTUAL CORE OF WTC TOWERS", but as yet, is not willing to provide a declaration certifying such. The documentary showed us the true concrete core structure of the trade center towers. It aired in 2 segments on consecutive nights. I missed the first 20 minutes of the second one, otherwise I watched it all. Yamasaki's design for a torsion resistant core structure made from non flexible material, steel reinforced cast concrete, won a competition in strength with several others. All steel towers failed high winds because the steel perimeter columns could take the weight but were prone to flexing and the twisting.

The documentary focused on the concrete core because the construction of the core was a big slowdown and substantial challenge.

So it is not based on "pure speculation" it's based on information he got off this documentary which I am not surprised isn't easy to find any longer.

Bottom line.....he has provided numerous studies, referrences, and discussions, virtually all of them much more qualified sources then yourself yet you have provided ZERO sources to back up your claim.

In fact your main source actually backs up OUR claim by calling it reinforced steel!


I think it's quite obvious who is working off of "pure speculation" on this one!

Unless you can provide pre-911 detailed discussion of the wtc core construction that DOESN'T mention concrete as an element.......you clearly lose and your "hoax" is quite obviously a hoax!

Originally posted by Jack Tripperspeculation" on this one!
Unless you can provide pre-911 detailed discussion of the wtc core construction that DOESN'T mention concrete as an element.......you clearly lose and your "hoax" is quite obviously a hoax!

Yeah, I agree that this is important Howard. It'd have to be a good deal of detailed discussion, too, because all of the pre-9/11 info I've seen, and even a lot of post-9/11 stuff says there were concrete cores.






I'm pretty sure I'm looking at concrete in those pics, too. Your suggestion of that being fireproofing is bull.

As I mentioned a few posts back.

"Reinforced Steel" does not mean there was concrete invloved.
And in my opinion, goes further to prove that concrete was NOT involved.
Otherwise they would have said reinforced concrete.

So this does nothing for your argument of concrete.

I'm sure you understand my point here..
Do you have anything to add?

Originally posted by spacedoubt
"Reinforced Steel" does not mean there was concrete invloved.
And in my opinion, goes further to prove that concrete was NOT involved.
Otherwise they would have said reinforced concrete.

Are you referring to this quote, mate?:

By using a drywall system fixed to the reinforced steel core, the shafts were strengthened enough that air pressure was not an issue.

Because if you are, the exact same page later says this:

The twin towers of the World Trade Center were essentially two tubes [...] Each tube contained a concrete core

I think that's pretty clear, unless you're referring to another article.

[edit on 20-5-2006 by bsbray11]

Why would there be rebar if there was no concrete??
Is rebar used by itself?
Or is that not rebar?

Originally posted by ANOK
Why would there be rebar if there was no concrete??
Is rebar used by itself?
Or is that not rebar?

Howard already tried to prempt that by saying it looks like electrical conduit.

Of course he didn't back it up.