Understanding loads on concrete floors
Understanding loads on concrete floors
(OP)
I spent most of my career designing production machinery for a manufacturer. I am sort of retired now and am trying to understand loads on concrete. If you are designing a elevated slab which has a few steel beams supporting it on columns to a footer, how do you figure the loads. You have the dead load from the concrete which will be cured before the live loads are placed on it. How would you go about figuring the deflection? Do you figure the deflection from the dead load concrete and then the live load deflection after it is cured? How do you figure the added strength of the concrete to the live load deflection? I guess you can tell I am very confused.
Thanks,
Paul
Thanks,
Paul






RE: Understanding loads on concrete floors
The deflection calculations take into account the dead loads, including the self weight of the concrete as well as the live load for the most stringent location of that load.
The concrete strength is not a (direct) factor in deflection calculations just as in steel construction. The modulus of elasticity (which is partially determined by concrete strength) and the moment of inertia are the determining factors.
RE: Understanding loads on concrete floors
Why Buildings Fall Down
Why Buildings Stand Up
Levy and Salvadori
RE: Understanding loads on concrete floors
RE: Understanding loads on concrete floors
RE: Understanding loads on concrete floors
RE: Understanding loads on concrete floors
I often feel like more of an accountant than an engineer.. tracing loads. We are building accountants! That crossed with a lawyer to interpret the ever changing design codes.
Good luck with your studies. This is a great site for questions, come back when you have more.
RE: Understanding loads on concrete floors
Thanks,
Paul
RE: Understanding loads on concrete floors
See attached sample from a decking catalog showing the dims typically provided that define the deck.
RE: Understanding loads on concrete floors
8" repetition
top flute 3 1/2 " wide
bottom flute 2" wide
1 1/4" vertical between flutes
Hope this helps
Thanks
Paul
RE: Understanding loads on concrete floors
Anyway the pans are 36" wide and 7' long.
RE: Understanding loads on concrete floors
Licensed Structural Engineer and Licensed Professional Engineer (Illinois)
RE: Understanding loads on concrete floors
Thanks for looking. I looked thru a few websites trying to id but no luck. I will look tomorrow and see if I can find any clues, I'll also try to get the gauge.
RE: Understanding loads on concrete floors
RE: Understanding loads on concrete floors
RE: Understanding loads on concrete floors
You can get as much as 400 psf capacity depending on how thick you go. If it is even 20 gauge you can make it work for a parking surface. You'll just have to control your purlin spacing and thickness of cover.
I always like those stories where someone gets about 500$ of free construction materials, and then spends $10,000 just to use it.
:p
RE: Understanding loads on concrete floors
RE: Understanding loads on concrete floors
RE: Understanding loads on concrete floors
Good on you. Its good to be semi retired and planning projects.
Incidently those books mentioned will not explain reinforced concrete, there just an introduction to structures, probably useful as an introduction to structural engineering in general.
Hang in there, the basics of rinforced concrete are not that hard to learn.