Conduit Cast into Composite Slabs 1

[NashEng]

The contractor would like to cast electrical conduit into the ribs of a composite slab. The UL assembly rating technically doesn't provide an allowance for it, and if the conduit projects up past the ribs it will reduce the effective area of concrete.

Does anyone have any references on this subject, what is allowable and what isn't?

What is the state of the practice? Are you allowing it on your jobs?

 

[jike]

Some small, minimal conduit can be put in the slab as long as:

it does not affect the composite action of the beams or slab

it does not displace the reinforcing

it is not so closely spaced that it creates a weak spot.

it does not affect the fire rating

sufficient cover is provided top & bottom

In general, the placement of conduit or pipes shall comply with ACI 318, section 6.3.

For thin slabs, it is often not possible to have conduit crossing over each other.

It is your call.