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Design Slab On Grade CRSI 2

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Joe117

Mechanical
Nov 5, 2021
16
I've been trying to find the old CRSI book that has the thickness recommendations for certain loads. Been looking through old posts and have found:

This is from an older version of the CRSI manual.
sub-slabs under other slabs - 2"
Domestic or light commercial <100psf - 4"
Commercial/institutional/barns (100-200psf) - 5"
Industrial/gas stations/garages (<500psf) - 6"
Industrial (600-800 psf) - 7"
Industrial (1500) - 8"
Industrial (2500) - 9"
Industrial (3000-3500) - 10"

with the following reinf:

2" - none
4" - one layer WWF 6x6-W1.4xW1.4
5" - one layer WWF 6x6-W2.1xW2.1
6" - one layer WWF 6x6-W2.9xW2.9
7" - two layers WWF 6x6-W2.9xW2.9
8" - two mats of #4@12"o.c. ea. way (top and bottom)
9" - two mats of #5@12"o.c. ea. way (top and bottom)
10" - two mats of #5@ 8 to 12" o.c. ea. way (top and bottom)

Bought the CRSI Handbooks from 1954 and 1984 and haven't had any luck finding it.
 
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There is a reason they publish these loads like this anymore. Several threads recently have discussed, the SOG capacity is primarily a function of the foundation preparation and bearing capacity. granted, a properly proportioned and reinforced concrete section is also required. I think (nowadays) there would be concern saying a 10" slab can carry 3000 psf without any reference to the base preparation and bearing capacity of soil.

I'm curious why you are seeking these tables. I think they would be useful for planning and budgets, but a good geotech report and structural design should be carried out especially for heavily loaded slabs.
 
Joe117

I don't know this is the exact table you are looking for, but a table for that information is contained in the following volume: CRSI, Design Handbook, Working Stress Design, Revised 1963 ACI Code, page 14-11. Most of the caveats raised previously are included in the notes accompanying the table.

Jim


 
Thank y'all. and yup, old books for concepts/rules of thumb. New books for math/design.
 
I don't recall what happened with it, but a couple of decades back, I did an airport runway in India... the soil was so poor and aggregates were unavailable, the slab was 18" thick... for heavy moving point loads... so depends a lot on the soil and the type of loading. A uniform load on a SOG constructed on great soil does not generate much flexure.


So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
photo of the cover of the CRSI Handbook is attached. My copy is well used. I had a client who has several buildings that were designed using the concrete joists based on this handbook.

I had to thank my wife who found it, years ago, in a garage sale. She bought for few bucks!

Regards,
Lutfi
 
 https://files.engineering.com/getfile.aspx?folder=53596bd2-48bf-404a-8ec8-5dc62bae0834&file=IMG-4051.jpg
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