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Recommend Concrete Codes/Standards

Recommend Concrete Codes/Standards

Recommend Concrete Codes/Standards

(OP)
Concrete is not a strong suit for me but I would like to become more proficient. What are the required ACI standards that I should have in my library?

To a more specific question, is ACI 318 sufficient in designing a 2-way bending slab (roof or floor) with penetrations supporting concentrated loads? I have a client that wants me to do more detailed concrete work, but I am turning it down because I am not that strong in it. Simple beam spans are fine, which I am comfortable doing (and I currently assume for the roof, walls, and floors for doing the current work) but once a semi-large penetration is put in the roof/floor, I just don't know where to go. Also, shear and shearwall analysis does not scare me either. Finally, is this type of analysis something I can easily do without software help? If not, I only have RISA-3D.

Thanks!

Juston Fluckey, SE, PE, AWS CWI
Engineering Consultant

RE: Recommend Concrete Codes/Standards

ACI 318 would be sufficient but I'd also get a textbook (MacGregor is my go to book) and download a copy of PCA notes on ACI 318 (free).

There's a bunch of good articles and references online regarding 2-way slabs. I'd also search here on eng-tips and bet you could find a lot of good info on floor penetrations.

The biggest note is, depending on your local, PT slabs may be something you would want to look into learning; but that's complex and I'd do that only after getting comfortable with regular concrete design.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries
www.americanconcrete.com

RE: Recommend Concrete Codes/Standards

(OP)
Thanks Mighty! I appreciate you tackling my broad question. Thanks for the recommendation of the PCA notes. I forgot about those so I am downloading now.

I said 2-way because I assumed it had to be 2-way because of the penetration. For more information, these are factory built concrete buildings (usually 14'x20' or smaller) and the penetrations are probably 2'x'2. Is there a way to do the analysis using a conservative approach using simple spans? Walls, roof, and floor are poured monolithically and then welded together with embeded weld plates. I will dig into my

Juston Fluckey, SE, PE, AWS CWI
Engineering Consultant

RE: Recommend Concrete Codes/Standards

I can't say enough good things about the book below. It's concise, practical, code based, and covers all the important aspects of both the design and the technology. Lots of hand calc method stuff too. It's out of date but that barely matters at all in my estimation.

Also, I agree with TME. Post your problems here and we'll walk you through them as required.

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.

RE: Recommend Concrete Codes/Standards

You're correct that it will always be "two-way" as obviously your loads must transfer around the opening one way or another.

However, you can definitely idealize the slab as strips that span between other strips giving you a lower-bound approach to the capacity of the slab. Regarding RISA, I do a lot of our flat precast slab designs using the FEA in RISA and they often have openings or other geometric issues. I wouldn't attempt to do a large two-way building slab with this method but for the buried structures and simple slabs I typically design it's sufficient in my mind. I would think that you might be able to make it work for a 14'x20' building.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries
www.americanconcrete.com

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