CONCRETE ONE-WAY SLAB

[vincentpa]

I am analyzing a concrete one-way slab in an old nuclear facility that was contaminated in a melt down. The clear cover is 3/4", span is 10', and the thickness is 8". The one-way slab system is continuous with 6 bays supported by 20" x 36" deep concrete beams poured integrally with the slab. The remediation might require the concrete cover on top of the slabs to be removed to 2" below the top of slab and effectively remove the top steel in the slabs. I am trying to determine if considering a model of the slab is assuming a crack at the slab/beam interface results in a hinge. The slab would then be connected to the beams through shear friction of the bottom steel to transfer the shear between the slab and the beam. We would then lower the capacity of the floor based on simple bending of the slab between the concrete beams and shear friction. Is this model acceptable or does it have flaws? If we have to remove the top layer of steel in the slabs, do we have to demo the slabs entirely and reconstruct?

 

[civilperson]

I would shore from below during removal of the top steel and then the replacement top reinforcement could be encased with the replacement concrete. Check shear across the cold joint created by removal and replacement.