How can Bleeding of Concrete be Reduced?

Bleeding is nothing but a segregation of concrete where some quantity of water is reached to surface creating some channels towards surface. Sometimes some amount of cement also comes out to the surface with the water. This phenomenon is observed in badly proportioned and inadequately mixed concrete or a mix having wetness of higher degree. Normally thin structural member like slabs show extensive bleeding. The bleeding channels described above produce a permeable concrete structure.

More or less every engineer is known about bleeding. In this post we discuss how to reduce bleeding. The ways we can reduce bleeding are:

a. Proper proportioning of concrete mix can reduce bleeding.

b. A complete and uniform mixing of concrete also can reduce bleeding.

c. We have already known about the bleeding channel. If we can increase the traveling length of water to be bleeded, the bleeding can be reduced considerably. For this purpose we can use finely divided pozzolanic materials.

d. An introduction of air-entrainment by using air entraining agent can reduce bleeding phenomenon. 

e. The use of finer cement can reduce bleeding.

f. Application of cement of alkali-content can also reduced.

g. By using of a rich mix rather than lean mix can reduce bleeding.

Controlled vibration can reduce bleeding. When bleeding is appeared in the fresh and plastic concrete, revibration of concrete in controlled way can overcome detrimental impact of bleeding.