can i change the effective depth for reinforcemen
 

can i change the effective depth for reinforcement
lovely friends
i have a flat plate ,it casted over a concrete plate form can i consider the reinforcement in the lower plate as assistant to the reinforcement or i cant

dose the eurocode accept that
in my opinion, you certainly can but you would have to be certain of a number of things: 1. is the flexural reinf in the bottom plate sufficient to cover the bend mom of the new combined slab. if not, you have to consider the 2 plates seperately as else your crack widths in the bottom plate would be excessive
2. can you connect the 2 plates adequately in shear to force the 2 plates to work compositely