Thermal expansion examples

[Confuseling]

Got pictures of / articles about things falling apart due to thermal expansion? Post 'em here...



[I saw some really neat photos of train tracks rippling in the European heatwave a few summers ago. Can't blooming find em though... anyone?]

 

[Furi]

I suppose Thermal expansion of engine components, or the old Ball Hoop physics example pics would be quite fun as well.

or the way of banding materiats by heating a metal Band/hoop around something to draw it together.

Or we could also have ways to open a tasty jar of Piccalily using a hot water tap and this newly invented thermal expansion

 

[Travis]

Since this "crazy idea" that metal expands when it gets hot was invented by NIST there can't be any "true" examples of this and anything presented showing such is obvious disinfo.

Next thing you know "Government" scientists will tell us ice floats.

 

[Grizzly Bear]

Here's an interesting little article Bridge Girder Failure During Construction

"The Exponent investigation determined that each girder was restrained by a frictional force at the hanger beam end and with pedestal concrete at the hinge end. When thermal expansion occurred in the girders, the friction force limited the amount of expansion that could occur. This caused one girder to buckle laterally, causing a chain reaction in the other girders."

Not a building but it does illustrate that if the expansion imparts enough force against a structural member it could lead to a disproportionate amount of damage.

 

[WildCat]

The whole principle behind how a thermostat works is thermal expansion.

And here's a page from a grade school displaying thermal expansion information for various metals: http://www.schenectady.k12.ny.us/users/pattersont/IBDT%20Website/Page_Generators/ThermalExpansion.html

But grade school math may be beyond the abilities of truthers to understand...

 

[WildCat]

A video showing repairs on roller bearings on a viaduct in the UK. Roller bearings are necessary to allow the for thermal expansion of the viaduct.

 

[Norseman]

Two examples of thermal expansion in concrete structures causing collapse:

The Katrantzos Sport Department Store was an 8-story reinforced concrete building. Its fire started at the 7th floor and rapidly spread throughout the building, due to lack of vertical or horizontal compartmentation and the absence of sprinklers. Collected evidence indicated that the fire temperatures reached 1000°C over the 2- to 3-hour fire duration, and the firefighters concentrated on containing the fire spread to the adjacent buildings. Upon termination of these fires, it was discovered that a major part of the 5th to 8th floors had collapsed. Various other floor and column failures throughout the Katrantzos Building were also observed (see Figure 1). The cause of these failures was considered to be restraint of the differential thermal expansion of the structure that overloaded its specific elements or connections.

And:

On May 21, 1987, Sao Paulo had one of the biggest fires in Brazil, which precipitated a substantial partial collapse of the central core of the tall CESP Building 2.5 This was a 21-story office building, headquarters of the Sao Paulo Power Company (CESP), after whom the building was named. Buildings 1 and 2 of this office complex were both of reinforced concrete framing, with ribbed slab floors. T
.................
Approximately two hours after the beginning of the fire in CESP 2, its structural core area throughout the full building height collapsed. This collapse was attributed to the thermal expansion of the horizontal concrete T-beam frames under the elevated fire temperatures, which led to the fracture of the vertical framing elements and their connections in the middle of the building, and the consequent progressive loss of gravity load-carrying capacity (see Figure 2).

Both from Fire Protection Engineering - Historical Survey of Multistory Building Collapses Due to Fire. See the article for pictures.

Of course the truthers will complain that this was not steel structures. But it just shows that even concrete is vulnerable to thermal expansion in fire.

 

[Lennart Hyland]

Why does NIST call this a new phenomenon?

 

[Travis]

Why does NIST call this a new phenomenon?

Where in the report did NIST say that because I don't remember reading that?

 

[Lennart Hyland]

Where in the report did NIST say that because I don't remember reading that?

I havent read the report. Shyam Sunder said that during the press conference.

 

[mrbaracuda]

Why does NIST call this a new phenomenon?

Okay, someone tell me I am wrong when I say this: NIST does not say thermal expansion itself is a new phenomenon, but thermal expansion causing a progressive collapse is new, or a new phenomenon.

Our study has identified thermal expansion as a new phenomenon that can cause the collapse of a structure.

See the press conference transcript for example.

Let's actually get all of the phenomenon sentences out of there:

It fell because thermal expansion, a phenomenon not considered in current building design practice, caused a fire-induced progressive collapse.

And as we dug into it, we figured out that there was a phenomenon that we had not previously recognized in current practice, the issue of thermal expansion, which actually could cause this particular problem to happen.

It simply says we have identified a new phenomenon that previously has not been caused -- seen to have caused building collapse.

What we found was that a phenomenon that previously here had not yet -- had not caused a structural collapse, actually was important enough to actually to have caused the collapse of this particular building.

 

[Lennart Hyland]

Okay, someone tell me I am wrong when I say this: NIST does not say thermal expansion itself is a new phenomenon, but thermal expansion causing a progressive collapse is new, or a new phenomenon.



See the press conference transcript for example.

Ah I understand! I guess some truther just took it out of contex again

 

[Horatius]

And let's not forget thermal expansion joints.

 

[ElMondoHummus]

Shades of Arup's stance in the WTC 7 findings, don't you all think?
http://www.arup.com/fire/newsitem.cfm?pageid=7056

Granted, Arup's talking about the main towers, not WTC 7, but still... do we think that Arup's (and possibly the University of Edinburgh's) theses had an effect on the direction NIST went with the WTC 7 report? That's the way it looks to me.

 

[Crazy Chainsaw]

Got pictures of / articles about things falling apart due to thermal expansion? Post 'em here...



[I saw some really neat photos of train tracks rippling in the European heatwave a few summers ago. Can't blooming find em though... anyone?]

Sure hope someone invents a device soon to tell people which way my car is going to turn, you know a turn signal, or how about something to replace those pesky fuses that are all ways blowing in my house with something that will break the Circuits.

 

[Grizzly Bear]

Okay, someone tell me I am wrong when I say this: NIST does not say thermal expansion itself is a new phenomenon, but thermal expansion causing a progressive collapse is new, or a new phenomenon.

Your right from what I understand, however what some major players in the truth movement have made it sound like was that thermal expansion is an entirely new phenomenon all together, not simply the first major player in contributing to a building collapse

 

[mrbaracuda]

Ah I understand! I guess some truther just took it out of contex again

Your right from what I understand, however what some major players in the truth movement have made it sound like was that thermal expansion is an entirely new phenomenon all together, not simply the first major player in contributing to a building collapse

Yes, the lack of comprehension and inability to comprehend the easiest texts is showing again as a trait inherent to the troof movement. I think parts of their 'leaders' understand it fine though and you know the rest.

 

[ElMondoHummus]

Okay, someone tell me I am wrong when I say this: NIST does not say thermal expansion itself is a new phenomenon, but thermal expansion causing a progressive collapse is new, or a new phenomenon.

You know, I'm not sure that it being novel as a primary cause of structure collapse is true. I hope Architect comes around and comments on this, because I think he'd be in a position to definitively speak about it. But from what little I've read - and disclaimer: I'm not anywhere near the structural engineering or architectural fields - it seems as though Arup and European agencies are all over that sort of building failure mode. I get the impression that they think US standards are lacking in regards to thermal expansion considerations. Of course, I may be wrong about this - again, not my field -but that's the impression I get, possibly shaped by the fact that I've only looked into this in the context of the 9/11 events. Anyway, my point is that I'm wondering if there aren't collapses induced by thermal expansion that European engineering firms and government agencies concerned with building codes would know about that NIST wouldn't.

My 2 cents. Architect: You reading this thread? Mind speaking towards this issue? Or anyone else who'd be in the know? I'm very fuzzy on this, seeing as how it's not my field, and would appreciate clarification, or outright correction if need be.

 

[mrbaracuda]

I could have a look at German or maybe even EU-wide standards I guess.
At least the EU-wide regulations should be available in English.

ETA: No luck so far since I don't really know what to look for. I'm considering calling or e-mailing a (local) high rise building firm now.
Maybe you (as well as others) can do the same.

 

[mrbaracuda]

You know, I'm not sure that it being novel as a primary cause of structure collapse is true.

I think the main problem here, and not only with truthers, is that you really have to keep in mind that those guys at NIST are technical nerds. And Sunder is the lead nerd so to say.

So if Sunders says "It fell because thermal expansion, a phenomenon not considered in current building design practice, caused a fire-induced progressive collapse" he means just that. It is very specific in my opinion and not talking about any collapse, but a fire-induced progressive collapse.

And as we dug into it, we figured out that there was a phenomenon that we had not previously recognized in current practice, the issue of thermal expansion, which actually could cause this particular problem to happen.

The recommendations for improving the building codes are pretty specific as well:

Does this mean there are hundreds or thousands of unsafe tall buildings with long span supports that must be retrofitted in some way? How would you retrofit a building to prevent this problem?

While the partial or total collapse of a tall building due to fires is a rare event, NIST strongly urges building owners, operators, and designers to evaluate buildings to ensure the adequate fire performance of structural systems. Of particular concern are the effects of thermal expansion in buildings with one or more of the following characteristics: long-span floor systems, connections that cannot accommodate thermal effects, floor framing that induces asymmetric forces on girders, and composite floor systems, whose shear studs could fail due to differential thermal expansion (i.e., heat-induced expansion of material at different rates). Engineers should be able to design cost-effective fixes to address any areas of concern identified by such evaluations.

Several existing, emerging, or even anticipated capabilities could have helped prevent the collapse of WTC 7. The degree to which these capabilities improve performance remains to be evaluated. Possible options for developing cost-effective fixes include:

More robust connections and framing systems to better resist effects of thermal expansion on the structural system.

Structural systems expressly designed to prevent progressive collapse. Current model building codes do not require that buildings be designed to resist progressive collapse.

Better thermal insulation (i.e., reduced conductivity and/or increased thickness) to limit heating of structural steel and minimize both thermal expansion and weakening effects. Insulation has been used to protect steel strength, but it could be used to maintain a lower temperature in the steel framing to limit thermal expansion.

Improved compartmentation in tenant areas to limit the spread of fires.

Thermally resistant window assemblies to limit breakage, reduce air supply and retard fire growth.