Thin overlay of concrete slab

[Zulak]

I have a lightweight concrete slab on composite steel floor deck in which the contractor experienced some scaling during construction. He's proposing to rough and clean the existing slab and installing a 2" lightweight concrete overlay with a bonding agent. Assuming all the members below are sufficient for the added dead load, is this an acceptable fix?

 

[ishvaaag]

Analysis should show. If the original concrete is too weak it might not work. Then you have the replication of cracks issue. An analysis can be made for new deflections and shear stresses -and so on- to see if the conjoint repaired composite slab will work. If you see anywhere shear stresses exceeding those allowable for the weaker concrete the solution won't work midterm on.

 

[JAE]

The first thing I would do is deterimine to what depth the contractor is grinding the slab and re-calculate my beams using the shallowed depth slab and the added loads. If it works, then the bond between the main structural slab and the topping does not adversely affect the capacity. If it doesn't work, then you need to do what ishvaaag stated and check the horizontal shear stresses on the joint between main slab and topping to see what they are. The bonding agent may or may not adequately resist the shear stresses.

I would be wary of depending on bonding agent for my capacity.

Also, you might want to double check the f'c of your slab with cores as the scaling may represent problems with your overall slab strength.