Conveyance of Concrete

The mixed concrete should be conveyed to the concreting yard as early as possible but within the initial setting time of the cement. The choice of conveyance depends on several factors, viz., nature of work, distance from the mixing place to the construction site, height to be lifted, type of cement, etc.

During the transit from the point of mixing to the point of placement, the following factors have to be borne in mind:

1. Care should be taken not to allow segregation of aggregates.
2. The containers of the drums should be tight such that there is a minimum loss of water.
3. The mixed concrete should be brought to the site before the initial setting time of the cement.

For ordinary simple works, a temporary ladder is erected to convey the concrete using baskets, or it is passed from hand to hand, i.e., by manual labour. For larger and important works, various mechanical devices such as vertical hoists, lift wells for tall structures, wheel barrows, etc., are used.