Compaction of Concrete:

The procedure of consolidating concrete mix after placing it in position is called as compaction of concrete.

The object of compaction is to remove air from the concrete and to give maximum density to the concrete. Presence of additional air voids will reduce the strength. It also ensures an intimate contact between the concrete and the surfaces of reinforcing steel and other embedded parts of the structure. During the process of compaction it is important to note that the reinforcement should not be disturbed and the forms should not be damaged or displaced. If the compaction is not uniform, the concrete becomes porous, non-homogeneous and attains less strength. The mix to be used should have adequate workability for placing without any difficulty and in order to obtain maximum density. The mix should also not be too wet, as it would or else cause segregation, lower density, and excessive laitance at the top.