What load would these carry

[Fury5]

Ive never worked with aluminum I-beams before. Any idea what sort of load these would carry? (Link below). Thinking of using them for a one lane bridge over a stream here on the farm that tractors and trucks would use. Span would be about 12 feet.

http://hudsonvalley.craigslist.org/hvo/4273756886.html

Thanks.

 

[johninct]

You ask a very complicated question and provide not enough information .

 

[ambenz]

Depending the size and thickness.....
Specifications: ASTM B308, QQA-200/16, 6061-T6, ASME - SB308
AKA: structural aluminum beam, aluminum I Beam
Applications: frame work, rails, overhead support, trolleys, supports, trailers, truck beds, etc.
Workability: Easy to Weld, Cut, and Machine.
Mechanical Properties: Brinell = 95, Tensile = 45K +/-, Yield = 40K +/-


See.... http://www.metalsdepot.com/products/alum2.phtml?page=aluminum beam&LimAcc= &aident=

 

[bczygan]

15,750# ea. .....but then I am guessing on exact material and web thickness.

http://www.sapagroup.com/pages/522511/Answer%20Book/07_Section%20Properties.pdf

But it might not be far off.

This is total uniformly supported load, and laterally supported beams. Not point and rolling loads.

You need to find out exactly what they are.

 

[Fury5]

Thanks for all the replies. I realize there isn't a lot of information to go on. But I don't know any more than what is in the Craigslist ad. The stated dimensions are 20 feet long, 8 inches high, and 5 inches wide, with no information (and I know this part is important) about the thickness of the aluminum. What I had in mind was using them to span a 12 foot span, spaced on 24" centers with 4X6" decking to use as a bridge. Heaviest traffic on the bridge would be a 8,000 lb truck (fully loaded). Is this a "no worries," "maybe," or "heck no" kinda situation?

Thanks again.

 

[JayCrash450]

They're aluminum shoring beams, frequently used for concrete forming or shoring of structures. We use those beams all the time, I could even give you some specs on those exact beams.

I work for a commercial/industrial scaffold contractor. We also do quite a bit of reshore, when buildings need to be supported during modifications. We've used those beams for all sorts of unique situations, supporting scaffold over large areas, attaching beam lifts to the bottom flange, cantilevering scaffold out structures 200' in the air, etc.

Put those beams a foot and a half on center (one foot center would be preferred but probably give you enough width) and a double layer of 3/4" ply on top. With that arrangement those beams will virtually support anything you would want to drive across that stream. I have constructed setups like that for pettibones, boom lifts and dump trucks to drive across. Recently designed (with an engineer) a 21' beam span with about 15 of those beams to support a 20k point load on the center to allow some escalators and fire stairs to joist from.

 

[JayCrash450]

Thanks for all the replies. I realize there isn't a lot of information to go on. But I don't know any more than what is in the Craigslist ad. The stated dimensions are 20 feet long, 8 inches high, and 5 inches wide, with no information (and I know this part is important) about the thickness of the aluminum. What I had in mind was using them to span a 12 foot span, spaced on 24" centers with 4X6" decking to use as a bridge. Heaviest traffic on the bridge would be a 8,000 lb truck (fully loaded). Is this a "no worries," "maybe," or "heck no" kinda situation?

Thanks again.

No worries! Although a shorter distance between beams is preferable.

 

[Fury5]

Jay -

Thanks a bunch. That's just the kind of info I was looking for.

Cheers.

 

[bczygan]

Just one more note.
The loads I gave above came from a table that only showed 2 aluminum beams that were 8x5. I used the one with the thinner web and flange. It looks like those are the 2 standard sizes for structural aluminum. You could talk to a manufacturer to make sure.

And do get some advice on how to space them and laterally brace them. The devil is in the details.

 

[NUTTSGT]

At about 7 lb/ft, that makes them about 140 lbs each. What are scrap aluminum prices in your area ? Even though the ad states the price is firm, I'd look at them first to make sure they are straight and are aluminum (The middle and back one almost look to have surface rust on them) and make an offer that is slightly over scrap price.

I doubt they move very fast.

 

[BD1]

Check out Wallace Cranes, this may help.

http://www.wallacecranes.com/thrftalu.htm

 

[BRIANBB]

Could be galvanised steel beams? Like stated above one or two appear to have rust?

 

[BLUE72CAMARO]

Looks like the front beam is a W beam and the back 4 are I beams to me.

 

[BFBOB]

Looks like the front beam is a W beam and the back 4 are I beams to me.

I think you're right. Comparing the beams with dividers on the screen, it looks like the front beam is a 5x8" as stated (I'd call it an H beam) and the other four are 4x8". The flange shape is different- so the amount of material in the flanges is probably about the same. I'm not enough of an engineer to say how this effects strength - more homework is needed!

You might also bring a scale- the weight of a beam per unit length is also a spec; weigh one end and double. The supports aren't quite at the ends, but close enough for a first approximation.

My first thought was galvanized steel too, but the color of weathered aluminum and weathered galvanized is so similar it's impossible to tell from a picture that's been filtered through who knows how many computers and monitors.

(also, some people can't tell the difference or don't accept that there is a difference. One post here a member talked about aluminum framing studs and got downright huffy when I questioned that, having never seen any metal studs but galvanized and plain steel)

I'd suggest getting load charts from several manufacturers based on your best guess of size and material, take the charts (along with a magnet!!) and go see the stuff in person. Be prepared with a trailer and suitable supply of Benjamins - no deal beats cash and carry.

 

[mechan]

Looks like the front beam is a W beam and the back 4 are I beams to me.

One AA I-Beam (Front) and four ASA I-Beams (Rear). Would be my guess ... http://www.alascop.com/pdf/al/6061_Ibeam.pdf

FWIW Op, taking engineering advice from the internet is a bit like asking a ****** about celibacy groups, but without knowing the full cross section dimensions you are ******* in the wind because everything will just be a "guess". Go look at the beams, measure the cross sections, and have the numbers for each cross section for that size(s) beam to see if they meet you needs. Aluminum has fairly horrible elastic deformation properties, so I would *really* want to take a string line and make sure that these beams aren't wracked or bent. If they have any sort of plastic deformation realize that it basically "is what it is" and you are not going to get that out of aluminum members.

 

[mechan]

I think you're right. Comparing the beams with dividers on the screen, it looks like the front beam is a 5x8" as stated (I'd call it an H beam) and the other four are 4x8". The flange shape is different- so the amount of material in the flanges is probably about the same. I'm not enough of an engineer to say how this effects strength - more homework is needed!

You might also bring a scale- the weight of a beam per unit length is also a spec; weigh one end and double. The supports aren't quite at the ends, but close enough for a first approximation.

My first thought was galvanized steel too, but the color of weathered aluminum and weathered galvanized is so similar it's impossible to tell from a picture that's been filtered through who knows how many computers and monitors.

(also, some people can't tell the difference or don't accept that there is a difference. One post here a member talked about aluminum framing studs and got downright huffy when I questioned that, having never seen any metal studs but galvanized and plain steel)

I'd suggest getting load charts from several manufacturers based on your best guess of size and material, take the charts (along with a magnet!!) and go see the stuff in person. Be prepared with a trailer and suitable supply of Benjamins - no deal beats cash and carry.

Don't bother weighing the beams, just measure the cross sections. Agree on the magnet!