Wtc - Concrete Pulverization Options

[hiram]

WTC – Concrete pulverization


In a lot of papers or articles about the collapse of the twin towers on the 11th of september 2001, we find the word "pulverization" associated with "concrete" and sometimes with "steel" for the more daring.

A lot of pictures and videos show the billowing clouds of dust which ressemble the pyroclastic flows of ashes, dust und gases emanating from erupting volcanoes.
For sure, there you get dust, heath and gases as an energetic propellant. Was it the same with the WTC towers ?

As everyone can learn from the available documentation the towers where mostly steel buildings.
You found reinforced concrete in foundations, probably in some subteranean levels, in the technical levels, within the core and under the roof. We are told the metal decks wich constituted by far the usable space were topped with "lightweigth concrete" probably non reinforced.

This lightweigth concrete seemed to be made of cement, sand and lightweigth aggregates (probably baked expanded clay).

When I saw the first pictures or videos, I imagined that the clouds of dust came from this lightweigth concrete but of the AAC (Autoclaved, aereted concrete) type (YTONG,HEBEL) which is rather brittle (compared with ordinary concrete), fine grained and almost white. It was not, after I had some further informations.

Also, contrary to what you could see of the heap of rubble on the first days, the debris of the towers contained a lot of "dirt" (see photographs in Joël Meyerowitz's book "Aftermath".) which partially filled voids between steel and other components.

Another set of pictures show people fleeing covered with a gray dust which also covered several acres around the site. A video shows a woman running her hand on the hood of a car covered with a thick, fluffy gray matter. It obviously contained a lot of fibers, fine elements and very few aggregates or sand which are too heavy to float in the air.

The towers contained great quantities of fine brittle elements and fibers under the form of :
suspended cielings, fireproofing and drywalls.

A very rought estimate (metric ) (1 tower, 100 levels above ground)
"." are for thousand separators and "," for decimal.

Non-concrete elements (NCE) :
Suspended cielings (3/4 ") : 7.200 m³ (254.417 ft³)
Fireproofing under deck (1") : 7.300 m³ (257.950 ft³)
Drywalls (1" 7/8) : 12.650 m³ (446.996 ft³)
Fireproofing inside ext.walls (1") : 2.312 m³ (81.696 ft³)
Total : 29.462 m³ (1.010.059 ft³)

The fireproofing thickness of 1" is somewhat "understated" but I found no precise description of the different products or surfaces that where reworked.
I also omitted the fireproofing of the core columns and additional partitions on some floors for lack of information.

Concrete components (CC):
Lightweight concrete (netto 3.3 ") : 24.158 m³ (853.639 ft³)
Reinforced concrete (5") : 8.275 m³ (292.403 ft³)
Total : 32.433 m³(1.146.042 ft³)
By lack of information on the technical level I counted reinforced concrete on 100 core levels.

We can see that NCE make 122 % of lightweight concrete in volume which given their low mechanical properties makes of them serious candidates for the forming of most of the dust clouds.
Ordinary reinforced concrete did'nt give much to them nor probably lightweight for it was covered everywhere by carpeting, vinyl … which contributed to contain the debris during the part of the fall.

If we assume that ½ of the 29.462 m³ (1.041.060 ft³) of NCE went into clouds of dust (14.731 m³ rounded at 14.000 m³ (494.670 ft³)) it could cover 280.000 m² (69 acres) with a 5 cm (2") thick layer. (For one tower) For both towers it is an area from Murray street to Edgar street (N-S) and from Broadway to NorthEnd ave (E-W). I have not found sufficient elements on the extent of the fallout but numerous videos and photos show that the dust thickness decreased rapidly. Parts of the clouds flew a lot farther but it was the finest of the dust.

Supposing that all the concrete fell straight down (and the other NCE blew away) the 32.433 m³ ( 1.146.042 ft³) volume could fill the tower section (3.998 m² ; 43.035 ft²) to 8,11 m(26,6 ft)and if we add 10 m (32,81 ft) to the "falling zone" (makes 6.924 m²; 74.532 ft²) to 4,68 m (15,35 ft) which seems a reasonable thickness in regard with the height of the rubble pile. In fact, probably some fine parts of CC blew away and some NCE fell down.


These little numbers can bring a different view on the different computations that integrate the "pulverization of concrete" as an energy sink or imply a lot of it (e.g. in the form of explosives) to crush concrete to fine dust. It also seems a lot of authors have a rather incomplete vision of what a building is made of.

The preceding computation doesn't explain how the NCE and CC were blown to dust or crushed.
It doesn't deny the use of explosives or similar devices to weaken the main core columns.
(It would be somewhat foolish to use "show making explosives" to blow what you could of NCE or CC if your intent was to make believe the towers fell by virtue of shock and fire due to the terrorists attack.)

WTC 7 is out of these ramblings.
As we say in french : "C'est une autre histoire…"

A belgian carpenter.
[size="4"][/size]

[Bruce Sinclair]

Awesome work! Wow! Welcome aboard!

[dMz]

Hello and welcome hiram,

There are many technical sources (other than FEMA and the 10,000 page NIST "draft" reports) on WTC1N and WTC2 So information that have mass and energy numbers that you might want to look at.

http://www.ae911truth.org/techarts.php

http://stj911.org/presentations/index.html

Tony Szamboti's Paper
http://www.journalof911studies.com/volume/...fTwinTowers.pdf

http://www.journalof911studies.com/

Gregory Urich Paper
http://pilotsfor911truth.org/forum//index....showtopic=13452

Jim Hoffman's page
http://911research.wtc7.net/

Jim Hoffman on Ryan Mackey's "debunking"
http://911research.wtc7.net/reviews/mackey/index.html

More on Mr. Mackey's paper
http://truememes.com/mackey.html

http://www.journalof911studies.com/letters...ackeyLetter.pdf

[rmartin01]

On the morning of 9/11, I stood on the roof of Lenox Hill Hospital, where I worked as a surgical physician assistant, and watched the second tower go down. Later that day, I went down to the "pile" after the end of my shift on 9/11. I grabbed a respirator (air was acrid), hard-hat, gloves and did whatever could be done as the moment defined the need. I will never forget how shocking it was to see that sight for the first time that evening. It was almost incomprehensible to me how such massive structures could be reduced to a pile of rubble, including the core columns, just several stories high. I watched those towers being built. I recall how massive the steel columns were that comprised the core.

Much of the time, I tended to the medical problems of the firefighters, medics, and police officers. Many of them were there at the time of destruction. I listened to them relate to me what they felt, heard, and saw, and what was perplexing was how those responsible for this could manage to get those charges in the building without being detected.

Kevin Ryan just wrote a paper that may explain this puzzle. It also may show us the complicity of certain individuals in NIST itself. He shows his skills as a chemist and as an investigator. http://911review.com/articles/ryan/nist_th...connection.html

[dMz]

Hello and welcome rmartin,

(IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/welcome.gif)

I have met another "Ground Zero" worker online this past year (an ironworker who was essentially comandeered by FEMA). When they found out he wasn't "officially there," he was debriefed for hours and forced to sign some papers without legal counsel before he could leave (I'm fairly certain that these were Non-Disclosure Agreements- I've seen plenty of those in my day).

He doesn't like to talk about those WTC experiences much, and he was a combat veteran pre-9/11.

[Bruce Sinclair]

Welcome aboard rmartin01! Thanks for your post and the excellent link provided.

[Omega892R09]

Welcome aboard rmartin01! Thanks for your post and the excellent link provided.

Indeed it was a most excellent link.

That article is worth posting up here perhaps?

Edited to remove ambiguity.

This post has been edited by Omega892R09: Jul 14 2008, 07:53 AM

[Ricochet]

And now from someone who is in the know. I will find out if this guy is legit.

July 18, 2008
Why the World Trade Center towers floors could not 'pancake' collapse as we have been told.
The typical floor structural configuration for the World Trade Center Towers spanned from the exterior wall columns to where the inner 49 columns formed support for the elevator shafts, stair towers, air shafts and mechanical systems. Thus, each floor was NOT a monolithic slab and structural system spanning across each tower from one exterior wall to the other three, as we are led to believe. Each floor, in fact, terminating at the contiguous structural core, resembled a square 'donut', with the structural core, so to speak, being the 'donut' hole. Failure of floor structural support in any quadrant of the building plan, or even in any half, thus, would have failed ASSYMETRICALLY. And at the time of failure would not, could not, have 'pancaked' symmetrically as the misleading NIST and commission reports indicate (diagrams shown in these reports are graphically out of scale, and do not accurately represent the building's structure).

See Orignal Drawings:

Floor Plan, 35th to 40th Floors, http://911research.wtc7.net/wtc/evidence/p...rA/A-A-58_0.png

Building Sections http://911research.wtc7.net/wtc/evidence/p...H/A-A-177_0.png

How do I know this? What is my personal technical reference? From 1970 to 1972 I was a young design development draftsman for the firm of Minoru Yamasaki Associates, the design architectural firm for the WTC. I was part of the team that detailed the complex aluminum cladding fenestration details for similar building's 'skins' done at the same approximate time and also worked, in part, on detailing the WTC Executive Floor interior paneling and updating the WTC plans to reflect various 'as-built' construction changes. I was quite familiar with the structural system at work on the towers, both at a technical and intuitive level, based on project experience.

The towers could not possibly have collapsed as we have been told in the 'official' reports, one floor, coincident, on top of another, without powerful external forces at work--forces other than the plane crashes and the relatively low temperature jet fuel fires. That is, explosives. The WTC towers were intentionally demolished.

R H Nigl

rhnigl @exoptica.com

Google "R Henry Nigl"

Original source. http://exoptica.typepad.com/blogoptica/

This post has been edited by Ricochet: Jul 18 2008, 06:41 PM

[Ricochet]

More from Mr. Nigl.

Most recent blog R H Nigl
Was there an aluminum cladding problem with the original World Trade Center towers?
As I mentioned in my earlier post, (see July 18, 2008 below), in 1971 I was a design development draftsman working at Yamasaki's architectural office in Troy, Michigan...forty years ago now. I was honored to be working for such a distinguished firm bursting at the seams with talent and creativity. I am still proud to have been part of that team. It was an exciting time.

One of the assignments I had at that time was to detail the study drawings for the aluminum cladding system for one of the other projects* awarded the firm after the WTC. These projects shared many of the fenestration design features used on the WTC. The elaborate aluminum cladding system, (elaborate because it performed a three-dimensional seal between the glazing, spandrels, and other finish materials that expanded at different rates based on thermal variables, while still providing weather integrity and effective moisture drainage). It was an elaborate detail, yet functionally effective and beautiful at the same time.

In retrospect, I remembering questioning the direct connection detail of aluminum to steel, and aluminum to concrete, that was, apparently, going to be used on these new projects. This was a detail that flew in the face of everything I knew about the reaction that occurs between disparate metals, like steel and aluminum. That is, an electro-galvanic reaction which will corrode and ultimately compromise the strength of the connection over time as oxidation takes place. I asked several of the senior architects and even brought it to the attention of the department head. My questions were not answered, really, and If I recall correctly, I was told that it would not be a problem because it had been tested in other structures and was a non-issue. Perhaps, ultimately, the aluminum to steel detail was not used on the project I was working on--I never saw the shop drawings or inspected the actual field connection. Nevertheless, I left the firm a few months after that, (not for that reason but for other personal reasons--I wanted to travel the U.S.).

Direct connection of aluminum to steel was probably used on the WTC towers to the best of my knowledge, and that connection's corrosive potential, among other problems, as I understand it, (having read the report in a variety of articles), was undoubtedly, some of the reasons the Port Authority, the City of New York, and the future developer, Larry Silverstein, wanted the buildings demolished. The WTC buildings were full of asbestos, (typical for construction at the time), and, looking back critically at the designs were obsolete structures in many other ways, not the least of which, was that they did not conform to the city's strict building and life safety codes applicable in our time. Of course, there was no way economical way the interested parties could renovate or, because of the toxicity of materials, demolish the structures. In fact, to renovate in accordance with standards in effect today would have cost more than the original project.

The WTC towers were 'white elephants' almost right after they opened. Space was difficult to lease, when it could be leased at all, it was at a loss, the plaza design caused a 'wind tunnel' effect that was most unpleasant to pedestrians entering the buildings at ground level...just a ton of problems. So I guess, ultimately 9/11 solved a lot of problems for some.

Aluminum to steel connection without a separating insulative barrier at the connection is bad fabrication design...it is still used, however, in many industries, automotive, signage, construction, and many others without the slightest hesitation.

*Century Plaza Hotel, Century City, Los Angeles, CA, Federal Reserve Bank of Richmond, Richmond, VA

R Henry Nigl

[dMz]

Thanks Rico.

Here's the original source of above:

http://exoptica.typepad.com/blogoptica/200...-architect.html

[dMz]

Courtesy of a spambot, although it is a topic that should be remembered:

http://en.wikipedia.org/wiki/Health_effect...1,_2001_attacks

http://en.wikipedia.org/wiki/David_Worby

"Worby represents the largest number of clients experiencing Ground Zero illnesses. According to New York Magazine: [Worby] is a New York lawyer, who filed the first lawsuit for a leukemia-stricken NYPD detective who served at Ground Zero and the Fresh Kills landfill, a case that mushroomed into a massive class action with 8,000 WTC workers. [1]. By September, 2007, the number of plaintiffs in the case reached 10,000. "I started this suit on behalf of one cop that got sick." He continued, "Nobody would touch the case with a 10 foot pole because it was considered unpatriotic to say anything against the cleanup or the EPA.[2]

A class action lawsuit has been filed by a group of at least 600 workers associated with the World Trade Center cleanup – cops, firefighters, sanitation workers, Transportation Department workers, Con Ed and Verizon employees, and independent day laborers, et al. against the WTC developer Larry Silverstein and a number of ground-zero cleanup contractors."

Lately the Wiki seems to be policing their "problems" slightly better, and I'm in a rush.

Related Giuliani thread is at:

Firefighter: Giuliani 'ran Like A Coward On 9/11', Before the Towers Fell?
http://pilotsfor911truth.org/forum//index....showtopic=10649

[dMz]

Here are a couple of resources on particulate sizes:

http://www.peakpureair.com/particlesize.htm

http://www.deq.state.ne.us/Publica.nsf/0/4...KTDY/02-125.pdf