Typically, when composite open web steel joists are used, conduit and other MEP systems are run through the joist webs or under the joists, the same that would be done with using “standard” steel joists in a concrete floor that is not composite with the joists. Embedding conduit in the concrete floor would seem to defeat the purpose of using steel joists. That is not to say conduit cannot be embedded in the floor slab if approved by the Engineer of Record. If access to the conduit were required, it would mean demolition of a portion of the concrete slab. Special care must be taken doing this to avoid damaging the metal deck.