Questio about available mass in the towers.

[sylvan8798]

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?




Erm, the span that the floor covered from the outer wall to the core.

The concrete slab spanned from joist to joist. The joists spanned from outer wall to core (or to other beams). The slab spans were on the order of 6 feet.

 

[Newtons Bit]

The concrete slab spanned from joist to joist. The joists spanned from outer wall to core (or to other beams). The slab spans were on the order of 6 feet.

The metal decking is what actually spans between the floor trusses. The steel deck is non-composite and doesn't engage the concrete to help resist bending. The concrete just goes along for the ride.

The floor trusses have knuckles that protrude up and into the concrete. These engage the concrete deck as the floor truss bends and makes the entire section act compositely.

 

[alexi_drago]

The concrete slab spanned from joist to joist. The joists spanned from outer wall to core (or to other beams). The slab spans were on the order of 6 feet.

This is to do with the point I was trying to make before being corrected by Newtons Bit. I was suggesting the a 4" concrete slab spanning from the outer to inner columns on it's own would bend and possibly not support it's own weight and that putting the slab on top of the floor assembly would only add a load to the floor pans, joists and trusses.

 

[leftysergeant]

I'm not sure, but wasn't Questio a character in Shakespeare's The Merchant of Venice?

For some strange reason, what I see on my monitor does not always get up onto the website unaltered. In proof-reading, I sometimes miss stuff.

I blame the bone-headedness of school boards who thought that typing classes were for girls.

 

[aggle-rithm]

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.

And at the same time, they KNOW it was controlled demolition because the towers collapsed into their own footprint.

It must be nice to not have to sweat internal consistency.

 

[leftysergeant]

Okay, we have established that the fire resting coating was chemically similar to concrete, and that that coating, along with the drywall was highly friable. Hoffman andother nutbars seem to think that the dust is mostly concrete, and that there must have been more than just the mechanical action at work to produce that much dust. I think he is making a major mistake in assuming that even a large part of the dust was concrete, and that the fact that so much of it was other than concrete invalidates any of his work based on how much mass, in the form of concrete rubble, was avaialble to perform work on the towers.

Hoffman goes to great lengths to demonstrate how explosivies would be needed to produce all of the dust, but this just makes him look like an idiot, in my opinion, because he has attempted to prove what need not have been proven in the first place.

He may have proven that it would take explosives to produce that volumn of concrete dust, but there is now evidence that most of it was not even concrete dust in trhe first place. The proportion of the dust that is chemically identifiable as concrete is not even relevant. The actual amount of concrete in the dust is far lower than Hoffman thinks.

 

[Sam.I.Am]

You know, come to think about it I haven't seen any large chunks of drywall in the pile. Maybe it was made out of nanotermites...