Prior to the final concrete pouring, the rebar is assembled in-place with the rebar chairs, slab bolsters, or wagon wheels. These rebar supports are then left in-place while the concrete is poured.

When positioned in the upper or top portion of the slab thickness, steel reinforcement limits the widths of random cracks that may occur because of concrete shrinkage and temperature restraints ...

(Downloadable PDF) The dangers of drilling into a concrete slab without verifying what’s hidden inside are endless. Teams that don’t scan might hit utilities, rebar, or post-tension cables ...