How can Concrete be Made Pumpable?

Are you astonished? Why should concrete be pumped?

Now-a-days ready mix concrete is an essential part of concreting process. This plant or truck mixed concrete is transported to the site to place followed by other operations of concreting. In the project where concrete have to lift long vertical distance, it is the simplest way to pump it. The application suitable pump can lift concrete several hundred feet. To pump concrete mass it is required to make concrete pumpable.

Pumpable concrete has the properties not to be segregated or bleeded with the right selection of constituent materials to bind all material, that consist concrete, under pressure. The requirements of mix are:

1. Under pumping pressure do not get segregated or bleeded.

2. When concrete mix flows through the bends, it should have ability to deform.

3. The concrete mix must assist redial movement of adequate grout to provide and maintain initially provided lubricating film on the pipe line.
 
To reach these properties special cares are taken. These steps are:

a. The size of fines in the proportions should be less than 0.25 mm (approximately less than 300 microns). The fines are cement and other fine particles like sand. 
 

b. In the mix proportions 350-400 kg/cum fine particles are essential.

c. Concrete of slump 75 mm towards collapse range provides pumpability properties in concrete.

d. The pipe line should have diameter of >(3-4)times of the maximum aggregate size.