Flat Slab

[drago8]

Hello All,

Just to have a discussion regarding flat slab. What I understand of flat slab that it is supported by column instead of beams. So for the ground floor construction of flat slab, how is the arrangement of the reinforcement in flat slab? If there are perimeter beams around the flat slab, will the slab reinforcement still goes into the beams?

Furthermore, when I did a design for the flat slab at ground floor (but I ended up using solid slab instead) some told me that the slab reinforcement can be reduced as long as the ground is well compacted. They also said there is no need to worry much about the punching shear check from the column as the slab will lay on the ground. Only if the slab is at the first floor, or above, will it become critical.

Could someone explain this to me.

Thanks.

#LoveWins

 

[KootK]

It sounds as though you're struggling with the difference between a sub-base supported slab on grade and a suspended slab at grade. Which path are you taking and, if you're going with a suspended slab, what are your reasons for pursuing that strategy?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[TXStructural]

A slab supported (more or less) continuously on soil is not a flat slab, rather it is a slab on ground (aka, slab on grade.) The rules are entirely different and the design strategy is completely different. Also, depending upon soils and foundation type, designing a soil-supported slab as an integrally-connected, structural slab could compromise the structure when soils move.

 

[drago8]

@KootK: It is a sub-base supported slab, and from what I read here, it is not called flat slab anymore and the way to design is totally different?

@TXStructural: Only now that I know it is called slab on grade. In what way is the design different? Oh it has to take consideration of the soil properties?

#LoveWins

 

[KootK]

it is not called flat slab anymore and the way to design is totally different

Totally different. For one, your walls and columns will probably pass through openings in your grade supported slab as they extend down to their supporting foundations.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[drago8]

@KootK: This is totally new to me. Thank you! I will try to look for materials regarding this matter.

#LoveWins