Select core locations and have them approved by the Engineer. Check fabrication sheets so, cores are taken with minimum impact to mild reinforcement. Check design sheets or shop drawings to ensure that cores are not taken through prestressing strands unless specifically approved by the Engineer. For prestressing strands use GPR and other NDE methods to locate the strands.

Take four-inch outside diameter cores when feasible. When approved by the Engineer, take smaller cores in highly congested areas to avoid impact to mild reinforcement or prestressed strands.