Unreinforced Slab on Grade Small Overturning Moment Checks

[mountaineers19]

I am more of a steel guy but I am starting to get into some concrete stuff so I wanted to get some guidance on the proper checks for unreinforced slabs subjected to light moment loads from a steel column. I know I need to check punching shear, concrete breakout strength of a single anchor and of the bolt group and compare that to the tension developed by the over turning moment. But as besides that what other checks do I need to perform. I know most people will say a footer is needed but the loads I am talking about are around 2-3 kip-ft on 8" fiber reinforced slabs.

 

[DaveAtkins]

You need to check flexure. ACI 318 has a chapter which deals with plain concrete, and the nominal moment capacity (and punching shear capacity for that matter) are quite a bit lower than what is allowed for reinforced concrete. The axial load from your column will cause bending moment in the slab in two directions, similar to a spread footing.

DaveAtkins

 

[CDLD]

PCA "Concrete Floors on Ground" is a good reference.