When Concrete Looks Solid but Isn't A freshly cast concrete surface may appear acceptable at first glance. But after formwork removal, some areas may reveal voids, exposed aggregate, cavities, or poorly compacted concrete. This condition is commonly referred to as honeycombing. Honeycombing is not merely a cosmetic defect. Depending on its extent, location, depth, and effect on reinforcement and structural performance, it can require anything from localized remedial treatment