Bubbles of entrapped air and water cling to the form during placement and leave round or irregular voids, usually 1/16 in to about 1 in across, once the forms are stripped. They get worse with sticky, high-fines mixes, impermeable form faces, heavy form release and weak vibration near the face. Architectural specs grade them against reference panels, and the standard repair is a sack rub or skim coat.
Long wall stripped clean, but the stair core's got bugholes everywhere, get the sack rub crew on it.
Also heard as
- bug holes
- surface voids
- blowholes
Related terms
Consolidation
Working fresh concrete, usually by vibration, so it fills the form completely and releases trapped air.
Honeycomb
Patches of bare, loosely bound stone with open gaps, left where paste never worked in around the coarse rock.
Formwork
The temporary molds, supports and bracing that hold fresh concrete in shape until it can carry itself.
SCC
Self-consolidating concrete, a highly fluid mix that fills forms and wraps rebar under its own weight.