If you can believe it, this photo shows new construction.  This honeycombing happened while pouring concrete.  Honeycombing is the term used to describe areas of the surface that are coarse and stony.  It may be caused by insufficient fine material in the mix, perhaps due to incorrect aggregate grading or poor mixing.  The contractor will go back and use US SPEC STR Mortar CI to repair the structure.

STR Mortar CI

More Form and Pour Repairs