I wouldn't allow it. What he has done is just lazy. Tell him to either place the conduit inside the beam cage, or in the slab between the top and bottom layer.
Agree - I think the concern here is that, with flexing of the beam, the conduit might produce spalling in the side concrete cover and this could fall below and pose a safety issue if there are occupied spaces below. If not occupied below, you still would have reduced cover protection for fire and possibly exposure to water/air and rusting rebar.
Check out Eng-Tips Forum's Policies here:
faq731-376
