During new house construction using post-tension slab, a problem has required a hole to be made in the slab.?

The hole is about 2x2 feet and about a foot into the subsoil in order to expose a pipe that needs to be repaired. In the middle of the hole are two intersecting cables (not damaged). After the plumbing repair is completed, how reliable of a concrete repair can be made so as not to effect the integrity of the slab? What questions should I be asking the builder? Should I not be concerned with this situation?