A bughole (or pinhole) is a small hole in the surface of a

concrete Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...

structure caused by the expansion and eventual

outgassing Outgassing (sometimes called offgassing, particularly when in reference to indoor air quality) is the release of a gas that was dissolved, trapped, frozen, or absorbed in some material. Outgassing can include sublimation and evaporation (whic ...

of trapped pockets of air in setting concrete. Bugholes are undesirable, as they may compromise the structural integrity of concrete emplacements. Bughole-induced outgassing is a phenomenon occurring when applying a protective coating (or lining) to concrete (predominantly vertically cast-in-place) where air becomes trapped within bughole cavities and releases into or through the

protective coating A coating is a covering that is applied to the surface of an object, or substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. powder coatings. Paints and la ...

, thereby causing pinholes and holidays in the coating film.

References

Concrete {{Civil-engineering-stub