Question
What are the key problems if use pumping for concreting works?

Answer
In pumping operation, force exerted by pumps have to overcome friction involving concrete and pumping pipes, weight of concrete and pressure head when placing concrete above pumps. In actuality, as only water is pump able, it is water in concrete that transfers force.

Major problems associated with pumping are effect of isolation and bleeding. To rectify these adverse effects proportion of cement is increased to improve cohesion sequentially to decrease segregation and bleeding. On other hand, the proper selection of aggregate grading helps to get better pump capability of concrete.