Before assigning concrete, proper planning is required for equipment, layout, projected procedures and methods. Concrete placement remains pending unless formwork is examined and seemed to be appropriate. The equipment required for delivering concrete should be properly sized and designed to maintain incessant discharging of concrete at the time of placing devoid of detachment of any materials based on the project size and placement location.
Concrete is arranged in its finishing position prior to cement is laid primarily as well as concrete is condensed in its final position within 30 minutes of evacuating the mixer.
Once the concrete is placed directly in its final position, it should not be reprocessed or poured in such a manner so that any detachment or loss of materials occur together with dislocation of reinforcement, shuttering or embedded inserts or damaging of its strength.
Concrete is arranged in the shuttering through shovels or other methods and avoid dropping from a height over one metre. Besides, it should be managed properly to avoid detachment.
If concrete is arranged in restricted forms through borrows, buggies, cars, sort chutes or hand shoveling, it should be dependent on the requirement for vertical delivery of limited height to get rid of separation.
As soon as the concrete work starts, it should be continued unless the pour is finished. Concrete must be arranged in sequential horizontal layers with homogenous thickness varying from 150 mm to 900 mm. All these should be arranged quickly as possible to avoid the development of cold joints or planes of weakness amid each subsequent layers inside the pour.
The thickness of each layer must be maintained in such a manner so that it can be placed before the preceding layer that has been hardened. The bucket loads or other units of deposit should be identified gradually by the side of the face of the layer with such overlap so as to allow expanding the layer to homogeneous depth and texture containing least shoveling. If there is any chance for segregation, it must be rectified by shoveling stones into mortar instead of mortar onto stones. Such a condition should be adjusted by redesign of mix or other appropriate methods.
The top surface of each pour and bedding planes must be almost horizontal until conversely stipulated in drawings.