composite steel beams

[bjb]

I am a structural engineer from the Albany, NY area, but I've just moved into the area. Can anyone tell me, if it is generally cheaper to use composite steel beams instead of non-composite beams for office/school buildings around here? I know that composite beams result in lower material costs, but I wonder if the increased labor costs wipe that out. At my old place, we assumed the extra labor costs for installing the studs negated the benefit of lighter steel beams.

Can anyone direct me to some good design aids for composite steel beams?

 

[Taro]

I am not familiar with local conditions in Albany. But unless labor is uncommonly expensive, I would use AISC's rule of thumb that a single shear stud is equivalent to 10 pounds of steel. Use composite beams if the total weight of the composite beam plus 10 times the number of studs is less than the weight of the non-composite beam.

 

[dik]

If you have enough of them, then run for 50%-60% composite action; composite beams often are more economical...

 

[bevoengineer]

I have designed a lot of multi-story buildings and always felt that the reduced floor to floor height often decreased the cost architectural items, such as exterior facade. It also can allow easier access for mechanical. So, I think the advantages goes beyond just steel tonnage. If you have a low story building this will probably not be as important.

 

[dik]

right on McDuff... er, bevoengineer...

 

[Lutfi]

A point I want to share with you:

I found that using LRFD yields more economical designs than the ASD when designing composite steel and concrete.

Good luck

 

[bjb]

Lutfi, do you have any good design aids for composite steel beams and girders using LRFD? The stuff that I have is for ASD. Thanks

 

[Lutfi]

Try

http://www.digitalcanal.com/index.shtml

They used to have a great one under the name of Eagle Point. A good friend of mine had the LRFD composite software and he liked it a lot.

Good luck