When I'm finished installing the plumbing, what should I do with the rebar?

When you get done with the plunbing,do your backfill, just make sure that the backfill is packed down really good, then repour the concrete, throw the old rebar into the new concrete, smooth finish top of concrete.;;

I would use Hammer drill with a masonry bit and drill holes into the side of the existing concrete. Then put the re-bar in the holes. Make the holes somewhat across from each other so you can tie wire the re-bar together.

Nutter nutter;;- YOu can do as you are saying with the rebar, but I well tell you it will not be as easy as you may think. I don't know how much room you have between each edge ,also you will start drilling and hin a rock ,and there goes the bit , broke or burned up . ULessyou have enough room to be able to use a hammer drill that can do the job . If you pour fiber mesh concrete , if you want put the pieces of rebar in it . ( ARE you doing this in a basement?? How wide is the cut out?? HOw long is it?? ) Using fibermesh concrete , they don't even put wire mesh or rebar ion the concrete any more . Except on some slabs ,walls etc. Let me know ,Thanks F.B.E.