Honeycomb, also known as airpocket, is nothing but the air voids in concrete. It is usually formed during concrete casting.
Honeycomb is due to non-reaching of concrete to all places due to which cavities and hallow pockets are created, main reasons are:
- Improper vibration during concrete.
- Less cover to reinforcement bars.
- Use of very stiff concrete (this can be avoided by controlling water as per slump test).
- Places like junction of beam to beam to column and to one or more beams are the typical spots where honey combs are observed. This is due to jumbling of reinforcement of beams and column rods at one place; special attention is required at such place during concreting and vibrating.
- Presence of more percentage of bigger size of aggregate in concrete also prevents concrete to fill narrow spaces between the reinforcement rods.