Placing:

It is not sufficient that a concrete mix is correctly designed, batched, mixed and transported; it is of utmost importance that the concrete must be placed in a systematic manner to yield optimum results.

Concrete is invariably laid as foundation bed below the walls or columns. Before placing the concrete in the foundation all the loose earth must be removed from the bed. Any root of trees passing through the foundation must be cut, tarred or charred effectively to avoid its additional growth and piercing the concrete at a later date. A surface of the earth, if dry, must be only made wet, so in which the earth does not absorb water from concrete. Instead if the foundation bed is too wet and rain-soaked, the water and slush must be erased fully to expose firm bed before placing concrete. If there is any seepage of water taking place within the foundation trench, effectual method for diverting the flow of water must be adopted before concrete is placed in the trench or pit.

The precautions to be taken and techniques adopted although placing concrete in the under-mentioned situations will be elaborate.

(a) Placing concrete inside earth mould.

(Example: Foundation concrete for a wall or column.)

(b) Placing concrete within large earth mould or timber plank formwork.

(Example: Road slab and airfield slab.)

(c) Placing concrete in layers inside timber or steel shutters.

(Example: Mass concrete within dam construction or construction of concrete abutment or pier.)

(d) Placing concrete inside usual formwork.

(Example : Columns, beams and floors.)