While estimating quantity of concrete for particular structural work, we normally consider 3-5% as wastage. But concrete waste more than that can increase the cost of project and may impact project progress. So, it is necessary to control the concrete wastage at site.
Concrete wastage can be prevented by proper planning of pour. Concrete pour cards shall be prepared for pre-concreting checks. In that way, the quantity of concrete to be poured can be known before mixing of concrete starts.
The concrete production speed should be matched with pouring speed to avoid the waiting time, to avoid the setting of concrete before placement and wastage. Near the completing of concrete pour, the approximate quantity shall be estimated and batching plant operator shall be informed of the same to avoid extra concrete supply, to avoid the wastage of concrete.
During placement of concrete, there can be some issues at site, due to which the concrete pouring is stopped for some time. So, the supervisor should take care in such situations to inform the batching plant operator and hold or control the concrete supply.
In case of excess production of concrete mix, the excess quantity of concrete shall be used elsewhere where it can be used to avoid wastage.
Thus, proper planning is needed to avoid wastage of concrete, not only before placement of concrete, but also during placement, and site supervisor should be properly trained to do such planning at site.