Site Technical Guide
"Honeycombs" happen. Maybe the vibrator wasn't used enough, or the rebar was too dense. The result is exposed aggregate and a weak spot in your column.
The Mistake: Plastering over it with a mix of sand and cement. This will crack and fall off within a year because it doesn't bond chemically with the old concrete.
To restore structural integrity, you must use a Thixotropic Fiber-Reinforced Mortar (Class R4).
Step 1: PrepRemove all loose gravel until you hit solid concrete. Wet the surface thoroughly.
Step 2: The Structural PatchApply ZNR Structural Repair Mortar R4. Unlike cement, this contains polymers that bond aggressively to the substrate and fibers that prevent shrinking cracks.
Recommended: ZNR Repair C30 (Structural Coarse Mortar) > Step 3: Cosmetic FinishOnce the structural hole is filled, use a fine-grain cosmetic mortar to match the smoothness of the surrounding column.
Recommended: ZNR Repair C5 (Fine Finishing Mortar) >Need technical advice? Cartel 72 provides site visits to recommend the correct ZNR repair system.