Questio about available mass in the towers.

leftysergeant

Penultimate Amazing
leftysergeant
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While we were discussing the spray-on fire resisting coating in the towers, it occurred to me that I rarely hear it mentioned among the residues of the collapse. There are referrences to "dessicated concrete" chunks which easily crumbled when handled. The DEWers take this as a sign of exotic weaponry use, but it seems pretty clear to me that it is just a highly aerated cement product.

I see many twoofers posating that there was too much material lost over the sides of the towers for there to have been enough mass to have driven the collapses. I find this absurd on its face, in that there is no Mark I eyeball properly calibrated to weigh plumes of dust that far above the ground. Thus, noone can look at the video and say "See that? It is shedding too much mass." (Noone rational, anyway.)

It is my impression that a lot of dust seen ejected in the dust plumes and lying about NYC the next day when they started taking samples, may have been mostly the spray-on insulation. It would appear to be indistinguishable, chemically, from concrete.

I have to wonder how much of this material was present, and whether whackos like Hoffman take it into consideration in his theories regarding the collapses.
 
leftysergeant said:
While we were discussing the spray-on fire resisting coating in the towers, it occurred to me that I rarely hear it mentioned among the residues of the collapse. There are referrences to "dessicated concrete" chunks which easily crumbled when handled. The DEWers take this as a sign of exotic weaponry use, but it seems pretty clear to me that it is just a highly aerated cement product.

I see many twoofers posating that there was too much material lost over the sides of the towers for there to have been enough mass to have driven the collapses. I find this absurd on its face, in that there is no Mark I eyeball properly calibrated to weigh plumes of dust that far above the ground. Thus, noone can look at the video and say "See that? It is shedding too much mass." (Noone rational, anyway.)

It is my impression that a lot of dust seen ejected in the dust plumes and lying about NYC the next day when they started taking samples, may have been mostly the spray-on insulation. It would appear to be indistinguishable, chemically, from concrete.

I have to wonder how much of this material was present, and whether whackos like Hoffman take it into consideration in his theories regarding the collapses.
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What was the mass/volume of material used? That would be your answer but mixed in with everything else. Mass discarded by the physics of the collapse or mass discarded by beam rays/explosives = same mass, regardless. (Unless it was vapourised completely by the beam of course).

Why would anyone want to determine what a shovel full of this stuff consisted of? In light of the medical problems many have suffered since,the only reason i can see for doing so would be for medical research reasons.
 
leftysergeant said:
It is my impression that a lot of dust seen ejected in the dust plumes and lying about NYC the next day when they started taking samples, may have been mostly the spray-on insulation. It would appear to be indistinguishable, chemically, from concrete.
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drywall and ceiling tiles.

there was just as much, if not more volume of drywall and ceiling tiles than fireproofing. They are both just as friable as the fireproofing.

Also, most modern office buildouts use fiberglass batting inside drywall partions as soundproofing.
 
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leftysergeant said:
While we were discussing the spray-on fire resisting coating in the towers, it occurred to me that I rarely hear it mentioned among the residues of the collapse. There are referrences to "dessicated concrete" chunks which easily crumbled when handled. The DEWers take this as a sign of exotic weaponry use, but it seems pretty clear to me that it is just a highly aerated cement product.
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One of the first stories I got by someone who worked on the pile was from a retired FDNY fireman of my acquaintance who spent days working the pile looking for his friends.

He described "cooked" concrete and compared it to Styrofoam. He attributed it to the fire cooking the water out and made it sound like it was to be expected for concrete under those conditions.

I don't know if he knew that the concrete was "lightweight". Maybe lightweight concrete turns to Styrofoam-like material quicker than structural concrete does.

That was 9 years ago. If I meet him again, there are dozens of debunking questions I'd like to ask him but I won't. I'll be happy to see him alive and not suffering from PTSD-like effects and able to breath.
 
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BigAl said:
He described "cooked" concrete and compared it to Styrofoam. He attributed it to the fire cooking the water out and made it sound like it was to be expected for concrete under those conditions.
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That sounds consistant with what I have read about the appearance and texture of the spray-on fire protection.

I have absolutely no reason to doubt that the stuff made up a large part of the dust plumes, The whackos like Wood and Hoffman may be basing their assumption on the weight of the debris crushing downward on the appearance that this was the concrete leaving the top of the towers.

There is now also little question in my mind that it was a big part of the super-fine "concrete" dust that twoofers seem to think is so significant.
 
I was a project engineer with a large east coast company and had a three year project where I managed the demolition of over 250 buildings and bridges. Everything from large grain elevators to supply sheds.

Let me tell you, every time you demolish something that isn't brand new you are going to get dust. Took down a completely steel water tank. Dust. Concrete buildings, dust. Wood buildings, dust. Steel bridges, dust.
 
switchpoint said:
Let me tell you, every time you demolish something that isn't brand new you are going to get dust. Took down a completely steel water tank. Dust. Concrete buildings, dust. Wood buildings, dust. Steel bridges, dust.
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So we can be pretty sure that anyone claiming that the dust plume indicates that a lot of mass is being lost and unavailable to do the work of crushing down are grasping a straws?
 
Grasping at straws? More like trying to pin smoke to a wall. Really, we were just roughing up some concrete to take paint using a air gun and some "black beauty" to take maybe 1/64" off the top and the cloud of dust from that was so much that a neighbor a block away called the fire department because he thought the place was burning to the ground.

This reminds me of a poster on another forum I am going around with that likes to talk about "dustification". He/she kept using that term like it was a real word.
 
First time I picked up lightweight concrete blocks at work was wierd and my description of it at the time was that it was like picking up styrofoam, well, polystyrene was the word I used. Anyway, it's surprising how light it can be while looking like solid concrete so it may not have been affected by heat at GZ.

EDIT: Here's someone building with it:

http://www.youtube.com/watch?v=TJdYEVWVNlU&feature=related
 
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Typically we in the engineering field measure loads as a function of the surface area that they cover. This is usually in a floor load or a wall load.

Fireproofing generally averages out to 5-10psf over the floor. It's really not that much compared to the dead and live loads of the rest of the building.

Structural light-weight concrete typically comes in at around 110pcf. A 4" slab, such as that in the WTC weighs about 36psf.
 
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Newtons Bit said:
Typically we in the engineering field measure loads as a function of the surface area that they cover. This is usually in a floor load or a wall load.

Fireproofing generally averages out to 5-10psf over the floor. It's really not that much compared to the dead and live loads of the rest of the building.

Structural light-weight concrete typically comes in at around 110pcf. A 4" slab, such as that in the WTC weighs about 36psf.
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Was it structural?
 
Newtons Bit said:
The floor that people walked on? Uhh, yes. It was a composite floor deck that worked with the floor trusses to resist bending. It's the component that held the building together laterally.
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The floor yes, but considering the span I'm not so sure about the 4" concrete contributing anything to the strength of the trusses and floor pans and instead be a load on those that would want to be minimised.

4" of concrete with that span would bend and might not even support it's own weight.
 
alexi_drago said:
The floor yes, but considering the span I'm not so sure about the 4" concrete contributing anything to the strength of the trusses and floor pans and instead be a load on those that would want to be minimised.

4" of concrete with that span would bend and might not even support it's own weight.
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The entirety of the 4" section is in compression, not bending.
 
Newtons Bit said:
Typically we in the engineering field measure loads as a function of the surface area that they cover. This is usually in a floor load or a wall load.

Fireproofing generally averages out to 5-10psf over the floor. It's really not that much compared to the dead and live loads of the rest of the building.

Structural light-weight concrete typically comes in at around 110pcf. A 4" slab, such as that in the WTC weighs about 36psf.
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Wow.. That much? That seems like a lot! Is this including all gypsum and classifying it as fire protection?
 
alexi_drago said:
The floor yes, but considering the span I'm not so sure about the 4" concrete contributing anything to the strength of the trusses and floor pans and instead be a load on those that would want to be minimised.

4" of concrete with that span would bend and might not even support it's own weight.
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With what span? Did he specify a span?...:confused:
 
I'm not sure, but wasn't Questio a character in Shakespeare's The Merchant of Venice?
 
Newtons Bit said:
The entirety of the 4" section is in compression, not bending.
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Ah right. Thanks. So am I right in thinking about how the floors could fail then, the trusses were in tension and if affected by heat then the compression you talk of on the concrete would be lost and instead of serving it's original function as part of the floor the concrete would just be applying it's load to the trusses in the way I was thinking initially?


sylvan8798 said:
With what span? Did he specify a span?...:confused:
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Erm, the span that the floor covered from the outer wall to the core.
 
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