ACI 360r-10 question

[Bammer25]

Looking at a simple slab on grade for concentrated loads. I see the equations in section 7.2 give you stresses and attempt to give back credit for the larger footprint, which makes sense. However you get to a point where your stress keeps going down for a larger footprint and you get a large negative stress, which I dont think means tension in the top.

Can I just say stresses are negligible or am I missing it?

 

[DaveAtkins]

I am not familiar with ACI 360r-10, but when you place a concentrated load on a slab, there will be tension in the bottom of the slab directly below the load, reversing to tension in the top of the slab away from the load. This is due to slab continuity.

DaveAtkins

 

[r13]

If you have used spring as support, stress reversal is possible for locations farther away from the concentrated load. If this is the case, yes, the top face experiences tension.

 

[Bammer25]

They use empirical equations to approximate stress and compare it to modulus of rupture. I think I’ll just model it in STAAD