The Freaking Interstate Collapsed.......

Jay Honeck said:
What's weird is that PVC is resistant to combustion, and does not like to continue burning.

There was something else under that bridge.

Sent from my SM-T700 using Tapatalk
Click to expand...
A lot of PVC glue maybe?
Or a meth lab?
or both.
 
JOhnH said:
A lot of PVC glue maybe?
Or a meth lab?
or both.
Click to expand...
That would certainly get things rolling, but didn't that fire burn for quite a while?

I was just reading up on PVC. It actually releases gasses that retard combustion as it burns, which indicates that this fire should have been self extinguishing.

Surprisingly, even though they claim to have no idea what caused the blaze, they have eliminated terrorism as the cause.

Sent from my SM-T700 using Tapatalk
 
The powers that be announced it would be MONTHS before they could repair it?

OMG - we built a nuclear bomb in less time once we got it figured out - and that took a Nobel Prize.

You could get a temporary structure up in a weekend. Through enough resources at anything - you could then keep a temporary up with two lanes each way - build one side - then move the traffic over there once the one side is done - I'm not a construction engineer - but . . . .
 
MadseasoN said:
Two buildings in history is not a large enough sample size to say that 'that's how buildings like that collapse'. It's still one floor at a time regardless of how many there are.

"Personal attacks are prohibited. This specifically means any text/post that is blatantly attacking another person, on or off the forum, especially in a personal way. Make your point without calling names or casting aspersions on others."
Click to expand...

We don't need any buildings to have collapsed to know "that's how buildings like that collapse". Its well understood physics. F=ma, and in this case the "a" is 9.8 meters per second squared straight down (gravity). Any first year physics student understood that.
 
Jay Honeck said:
What's weird is that PVC is resistant to combustion, and does not like to continue burning.

There was something else under that bridge.

Sent from my SM-T700 using Tapatalk
Click to expand...

I believe it was HDPE, which is a vastly different critter than PVC.

Basically a plastic with 30% more energy density than gasoline and a lower ignition point.

So a burning cigarette or a homeless person cooking a rat probably started a grass fire and...
 
TheTraveler said:
Cement/concrete holds a lot of moisture. Heat it up fast and good, and you've got a disaster. Anyone who has a cement/concrete driveway sees the eventual cracks as the seasons change for the same reason.
Click to expand...

Ummm...no.

Properly reinforced, poured, cured and cut concrete will not crack in a lifetime, if the substrate adequately stable. Lots of unreinforced concrete, if the rest of the perimeters are met, won't crack either.

Cracks in concrete driveways are typically a result of differential settling, pouring too wet, improper curing, or a combination.

Oh, and earthquakes. Earthquakes are good at cracking concrete!
 
Last edited:
kyleb said:
I believe it was HDPE, which is a vastly different critter than PVC.

Basically a plastic with 30% more energy density than gasoline and a lower ignition point.
Click to expand...

looked to me like there might be some sort of chimney effect going on as well. all that energy plus forced ventilation.....
 
TommyTBone said:
Ummm...no.

Properly reinforced, poured, cured and cut concrete will not crack in a lifetime, if the substrate adequately stable. Lots of unreinforced concrete, if the rest of the perimeters are met, won't crack either.
Click to expand...

I'm a "floor buyer" in this conversation, but the concrete experts I've dealt with clearly explained that large slabs generate huge internal stresses due to shrinkage as the slab cures. That's why they make saw joints in new concrete - so they can pick where the slabs crack. The rule of thumb I was given was that you will see cracking if you don't have perfect pours and curing or provide saw cuts/construction joints every 10-12 feet. I've purchased a couple of million square feet of factory and warehouse floors based on those construction principles, including a 100k SF "superflat" floor in a high bay warehouse. All of that footage had provisions for cracking.
 
Jay Honeck said:
That would certainly get things rolling, but didn't that fire burn for quite a while?

I was just reading up on PVC. It actually releases gasses that retard combustion as it burns, which indicates that this fire should have been self extinguishing.

Surprisingly, even though they claim to have no idea what caused the blaze, they have eliminated terrorism as the cause.

Sent from my SM-T700 using Tapatalk
Click to expand...
I remember standing under some bridges that felt like standing in a wind tunnel. If the wind were of the right strength, it could have blown away the gasses while fanning the flames.
 
kyleb said:
I believe it was HDPE, which is a vastly different critter than PVC.

Basically a plastic with 30% more energy density than gasoline and a lower ignition point.

So a burning cigarette or a homeless person cooking a rat probably started a grass fire and...
Click to expand...

Yeah, I'm glad I'm not the guy who said, "Just put it over there under the bridge so it's out of the way."
 
TCABM said:
Looks like the opposite direction lanes could use a good inspection, too.
Click to expand...
They announced that both lanes are closed indefinitely!:eek::eek: My wife's doctor is up that way, luckily it's not that far north of downtown, but the pressure on the remaining roads is going to tremendous!! :eek: Traffic is going to suck for many months, I bet it will be August before it's finished, maybe later. :rolleyes:
 
The Army Engineers could probably have a temporary repair in place by Monday's commute.

Rich
 
Three homeless people in custody for starting the fire.
 
If they throw enough manpower at it they can get it done fairly quickly. That's a big if though.
 
kyleb said:
I'm a "floor buyer" in this conversation, but the concrete experts I've dealt with clearly explained that large slabs generate huge internal stresses due to shrinkage as the slab cures. That's why they make saw joints in new concrete - so they can pick where the slabs crack. The rule of thumb I was given was that you will see cracking if you don't have perfect pours and curing or provide saw cuts/construction joints every 10-12 feet.
Click to expand...

Exactly. All concrete cracks so you saw it to set up a weak plane and get it to crack where you want it to. The rule of thumb on spacing is actually twice the thickness of the slab in feet. i.e. cut a 4" slab into 8' squares, a 6" slab into 12' squares, etc. and maybe a bit closer if poured over visqueen (which is a very unwise thing to do unless it's a low lying area that will tend towards a wet substrate).

My point was that concrete doesn't crack simply because it contains moisture and goes through years of normal summer/winter thermal cycles. Not concrete that has the proper amount of air entrainment anyway and was properly placed.
 
No chance of screwing this fix up.

patsfalcons.png
 
RJM62 said:
The Army Engineers could probably have a temporary repair in place by Monday's commute.

Rich
Click to expand...

Yeah, but this is the south. Nothing happens fast, road contsruction projects drag for years.
 
Norman said:
I would sooner trust MSNBC to report fact. The Daily Mail is no more than a tabloid rag.
Click to expand...

I don't know. The Daily Mail is certainly a left leaning publication with a more than a hint of tabloid hysteria. But the mainstream media here in the States will simply ignore stories that don't fit their narrative.
 
Any of our Atlanta contingent have any pireps on traffic around that area today?
 
JOhnH said:
Any of our Atlanta contingent have any pireps on traffic around that area today?
Click to expand...

Piedmont still closed, this will mess up most local roads. 285 apparently pretty awful.
Weather today isn't helping either.
 
kyleb said:
I'm a "floor buyer" in this conversation, but the concrete experts I've dealt with clearly explained that large slabs generate huge internal stresses due to shrinkage as the slab cures. That's why they make saw joints in new concrete - so they can pick where the slabs crack. The rule of thumb I was given was that you will see cracking if you don't have perfect pours and curing or provide saw cuts/construction joints every 10-12 feet. I've purchased a couple of million square feet of factory and warehouse floors based on those construction principles, including a 100k SF "superflat" floor in a high bay warehouse. All of that footage had provisions for cracking.
Click to expand...

They built a new warehouse next to my POS building and they used some type of cables that ran the length of the floor, both directions and did some type of magic squeezing, to put cables under tension to the floor while it was curing. I wish I knew more details, just parroting what was on the news and what I saw. Next time I go over there, will look at see if they put stress relievers in it. Any idea what the cables did or didn't do?
 
dmspilot said:
PVC can't melt concrete beams
Click to expand...

It wasn't pvc it was HDPE. You know how the media gets facts wrong on aviation? They did it on this too.

Based on the energy density of HDPE and the amount stored down there, it was probably the equivalent of 2100 gallons of gasoline under there. 20 bundles @ 500 lb ea. = 10,000 pounds. That stuff has an energy density that is 30% higher/lb than gasoline. So in rough terms : 10,000 lbs/6lb gallon of gas X 1.3 energy density factor = 2100 gallons of gasoline.

And I think there were more than 20 bundles under there.
 
You must log in or register to reply here.
Back
Top