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Date: 05 Aug 2007 16:02:06
From: Crescentius Vespasianus
Subject: Carbon fiber bridges.....
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Heard a report that the Minneapolis
bridge collapsed due to the effect on
steel that the extreme temperatures in
that area produces. If steel breaks due
to contraction and expansion maybe they
should use some other material, like CF.
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Date: 07 Aug 2007 19:18:58
From: PiledHIgher
Subject: Re: Carbon fiber bridges.....
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On Aug 8, 5:05 am, "b...@mambo.ucolick.org" <b...@mambo.ucolick.org >
wrote:
> On Aug 5, 4:02 pm, Crescentius Vespasianus <jazzyb...@hotmail.com>
> wrote:
>
> > Heard a report that the Minneapolis
> > bridge collapsed due to the effect on
> > steel that the extreme temperatures in
> > that area produces. If steel breaks due
> > to contraction and expansion maybe they
> > should use some other material, like CF.
>
> Nonsense. Everybody knows that steel bridges are
> best when lugged and constructed by a reputable
> builder, but steel bridges/frames of unusual design
> (which this one was) may require extra gussets to
> avoid fatigue at the joints. Bontrager pointed this
> out. CF bridges ride exceptionally smoothly but are
> expensive and monocoque construction requires a
> prohibitively large mold. Nobody uses aluminum
> bridges because they ride too harshly.
>
> Ben
But seriously,
There are a number of all-composite bridges (do a google search -
mostly using glass fibres but cheaper carbon fibre makes it likely
eventually) and carbon fibre wrapping of concrete pillars is used as a
repair/risk mitigation application.
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Date: 07 Aug 2007 19:05:29
From: bjw@mambo.ucolick.org
Subject: Re: Carbon fiber bridges.....
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On Aug 5, 4:02 pm, Crescentius Vespasianus <jazzyb...@hotmail.com >
wrote:
> Heard a report that the Minneapolis
> bridge collapsed due to the effect on
> steel that the extreme temperatures in
> that area produces. If steel breaks due
> to contraction and expansion maybe they
> should use some other material, like CF.
Nonsense. Everybody knows that steel bridges are
best when lugged and constructed by a reputable
builder, but steel bridges/frames of unusual design
(which this one was) may require extra gussets to
avoid fatigue at the joints. Bontrager pointed this
out. CF bridges ride exceptionally smoothly but are
expensive and monocoque construction requires a
prohibitively large mold. Nobody uses aluminum
bridges because they ride too harshly.
Ben
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Date: 07 Aug 2007 06:10:33
From: RicodJour
Subject: Re: Carbon fiber bridges.....
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On Aug 6, 7:30 pm, "Tom \"Johnny Sunset\" Sherman"
<sunsetss0...@invailid.com > wrote:
> RicodJour who? wrote:
> > On Aug 5, 7:02 pm, Crescentius Vespasianus <jazzyb...@hotmail.com>
> >
> >> Heard a report that the Minneapolis
> >> bridge collapsed due to the effect on
> >> steel that the extreme temperatures in
> >> that area produces.
>
> > Don't believe everything you hear - or read. The coefficient of
> > expansion for common building materials is well known and taken into
> > account when the structure is designed. That's why you see and feel
> > the bumps from all of those expansion joints when you drive across a
> > bridge.
>
> Some bridge expansion joints are wide enough to trap a typical road tire
> - instant header. :(
They're put there so you can practice bunny hopping your bike.
R
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Date: 06 Aug 2007 19:00:54
From: Tom \Johnny Sunset\ Sherman
Subject: Re: Carbon fiber bridges.....
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Crescentius Vespasianus who? wrote:
> Heard a report that the Minneapolis bridge collapsed due to the effect
> on steel that the extreme temperatures in that area produces. If steel
> breaks due to contraction and expansion maybe they should use some other
> material, like CF.
The only places where carbon fiber reinforced polymer (CFRP) generally
makes sense is where lower weight is a primary goal (e.g. racing
bicycles) or where the use offsets a greater expense (e.g. CFRP cost
more than aluminium alloy for aircraft construction, but results in
lower fuel consumption).
A CFRP bridge superstructure would only result in some savings in
foundation size (however, less than proportional to the weight reduction
due to similar wind overturning loads). The additional superstructure
cost of replacing steel with CFRP would be far greater than the lower
foundation cost.
--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful
--
Posted via a free Usenet account from http://www.teranews.com
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Date: 06 Aug 2007 17:26:33
From: Kinky Cowboy
Subject: Re: Carbon fiber bridges.....
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On Sun, 05 Aug 2007 16:02:06 -0700, Crescentius Vespasianus
<jazzyboss@hotmail.com > wrote:
>Heard a report that the Minneapolis
>bridge collapsed due to the effect on
>steel that the extreme temperatures in
>that area produces. If steel breaks due
>to contraction and expansion maybe they
>should use some other material, like CF.
Even if we swallow the unlikely premise, the only bridge design which
would make use of Carbon fibre's virtue would be one requiring high
tensile strength and stiffness per weight. It has been proposed to use
CF cables for extremely long span suspension bridges.
Kinky Cowboy*
*Batteries not included
May contain traces of nuts
Your milage may vary
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Date: 06 Aug 2007 06:57:00
From: RicodJour
Subject: Re: Carbon fiber bridges.....
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On Aug 5, 7:02 pm, Crescentius Vespasianus <jazzyb...@hotmail.com >
wrote:
> Heard a report that the Minneapolis
> bridge collapsed due to the effect on
> steel that the extreme temperatures in
> that area produces.
Don't believe everything you hear - or read. The coefficient of
expansion for common building materials is well known and taken into
account when the structure is designed. That's why you see and feel
the bumps from all of those expansion joints when you drive across a
bridge.
R
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Date: 07 Aug 2007 00:51:33
From: Clive George
Subject: Re: Carbon fiber bridges.....
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"RicodJour" <ricodjour@worldemail.com > wrote in message
news:1186408620.462989.299600@w3g2000hsg.googlegroups.com...
> On Aug 5, 7:02 pm, Crescentius Vespasianus <jazzyb...@hotmail.com>
> wrote:
>> Heard a report that the Minneapolis
>> bridge collapsed due to the effect on
>> steel that the extreme temperatures in
>> that area produces.
>
> Don't believe everything you hear - or read. The coefficient of
> expansion for common building materials is well known and taken into
> account when the structure is designed. That's why you see and feel
> the bumps from all of those expansion joints when you drive across a
> bridge.
It's something railways people still get caught by though - and not just UK
ones!
cheers,
clive
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Date: 06 Aug 2007 18:30:23
From: Tom \Johnny Sunset\ Sherman
Subject: Re: Carbon fiber bridges.....
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RicodJour who? wrote:
> On Aug 5, 7:02 pm, Crescentius Vespasianus <jazzyb...@hotmail.com>
> wrote:
>> Heard a report that the Minneapolis
>> bridge collapsed due to the effect on
>> steel that the extreme temperatures in
>> that area produces.
>
> Don't believe everything you hear - or read. The coefficient of
> expansion for common building materials is well known and taken into
> account when the structure is designed. That's why you see and feel
> the bumps from all of those expansion joints when you drive across a
> bridge.
Some bridge expansion joints are wide enough to trap a typical road tire
- instant header. :(
--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful
--
Posted via a free Usenet account from http://www.teranews.com
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Date: 06 Aug 2007 06:05:32
From: jim beam
Subject: Re: Carbon fiber bridges.....
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Crescentius Vespasianus wrote:
> Heard a report that the Minneapolis bridge collapsed due to the effect
> on steel that the extreme temperatures in that area produces. If steel
> breaks due to contraction and expansion maybe they should use some other
> material, like CF.
bridges have expansion joints, so that's not the issue. [cold
temperature] brittle transition can be an issue, but that's /most/
unlikely to be the case in summer.
much more likely, the combined effects of poor maintenance, subsequent
corrosion, and when sufficiently advanced, fatigue. preventable.
lamentable. shameful.
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Date: 06 Aug 2007 06:58:43
From: Artoi
Subject: Re: Carbon fiber bridges.....
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In article <13bd7rb9kdpn3f8@corp.supernews.com >,
Crescentius Vespasianus <jazzyboss@hotmail.com > wrote:
> Heard a report that the Minneapolis
> bridge collapsed due to the effect on
> steel that the extreme temperatures in
> that area produces. If steel breaks due
> to contraction and expansion maybe they
> should use some other material, like CF.
Don't give them ideas. Or CF prices would go further up and affect our
bike affordability.
--
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Date: 06 Aug 2007 06:01:26
From: jim beam
Subject: Re: Carbon fiber bridges.....
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Artoi wrote:
> In article <13bd7rb9kdpn3f8@corp.supernews.com>,
> Crescentius Vespasianus <jazzyboss@hotmail.com> wrote:
>
>> Heard a report that the Minneapolis
>> bridge collapsed due to the effect on
>> steel that the extreme temperatures in
>> that area produces. If steel breaks due
>> to contraction and expansion maybe they
>> should use some other material, like CF.
>
> Don't give them ideas. Or CF prices would go further up and affect our
> bike affordability.
> --
bs. $120 for a carbon fork is not too expensive.
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