"bridge in a backpack"
"bridge in a backpack"
(OP)
This seems like an efficient way to build a bridge. I wonder what kind of spans you can cross with these?
http:/ /www.forbe s.com/feed s/ap/2009/ 04/11/ap62 80713.html
h ttp://www. maine.gov/ mdot/trans portation- research/t ransportat ion-resear ch-div.php
http:/
h





RE: "bridge in a backpack"
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: "bridge in a backpack"
The title is a bit miss leading though, the article does say you still need trucks for the concrete.
I wonder if the military is looking at it.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: "bridge in a backpack"
RE: "bridge in a backpack"
RE: "bridge in a backpack"
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: "bridge in a backpack"
Yeah, saying 'bridge in >a< backpack' is misleading.
Mike Halloran
Pembroke Pines, FL, USA
RE: "bridge in a backpack"
RE: "bridge in a backpack"
RE: "bridge in a backpack"
RE: "bridge in a backpack"
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: "bridge in a backpack"
RE: "bridge in a backpack"
I guess fundamentally they're using an exoskeleton like an insect rather than an endoskeleton like mammals etc.
I wonder how well the composite really protects the concrete, or if it degrades over time or at least if moisure can seap in somehow.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: "bridge in a backpack"
I'd think a veneer of mortar would be appropriate, else the bridge is susceptible to damage by vandals.
Mike Halloran
Pembroke Pines, FL, USA
RE: "bridge in a backpack"
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: "bridge in a backpack"
(originally posted after 14 Apr 09 13:44 post)
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: "bridge in a backpack"
RE: "bridge in a backpack"
Kenat, yes, I read that too, but it wasn't clear at first whether the tubes were truly filled with concrete, or just backfilled/overburdened with concrete (i.e. left air-filled or hollow). The photos and text in the original article weren't very clear on the sequence.
Then again, yes, I'm sometimes guilty of overthinking, and over-posting. Debated red flagging my whole string of posts. Then decided, nah, I'll add more noise with a reply to your post instead...
RE: "bridge in a backpack"
Still, seems pretty neat to me but I'd be interested to know about the durability issues.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: "bridge in a backpack"
Looks like a design which saves money on construction and generates a whole load of maintenance problems 30-50 years on.
IMHO - Rubbish.
Can´t wait to see their new take on the wheel........
gwolf
RE: "bridge in a backpack"
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: "bridge in a backpack"
RE: "bridge in a backpack"
Guffaw. Except that our current crop of highway bridges, especially in high road-salt-usage areas, pretty much follow the "rot away to the rebar" pattern in some 30 years. While for the composite arches, the vinyl ester resin is potentially a moisture and salt barrier for the concrete, the assumption is that the barrier is not breached for some period of time (to justify their claims of 50+ year life). One bum with a campfire under the bridge...bingo, no more composite.
RE: "bridge in a backpack"
RE: "bridge in a backpack"
Yes, and the damage susceptibility is a real problem there; it is managed to minimize problems, and costs are (sometimes) traded off against the performance advantages of the lightweight properties of the materials. But when a mechanic drops a wrench on a carbon fiber wing section, that section can quite readily develop hidden damage due to fiber breakage or delaminations. A lot of time and money are spent inspecting parts made of composite materials to ensure they aren't falling apart, or about to. They certainly don't park their expensive aircraft on roadsides.
RE: "bridge in a backpack"
RE: "bridge in a backpack"
do you ski? I had carbon fiber ski poles once, when they broke you can see the carbon fibers held strong but they are held together by some epoxie media which splintered - possibly from the cold. I would guess they would just hold up well against a small fire...
how big of fires do bums normally have?
RE: "bridge in a backpack"
RE: "bridge in a backpack"
RE: "bridge in a backpack"
All things considered (or at least most), I think its apparent that this type of construction has its limitations as with any. I just enjoy reading about people "thinking outside the box." Helps remind me that there is still a lot of creativity and ingenuity that goes on out there.
RE: "bridge in a backpack"
RE: "bridge in a backpack"
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.