Bleeding of Concrete

• Bleeding is category of segregation. In case of bleeding water comes out from concrete to the surface of the concrete. Bleeding is observed in a highly wet mix .
• Badly proportioned and in sufficiently mix concrete. In case of comparatively thin member whenever concrete is placed in open sunny weather shows excessive bleeding.
• In case of bleeding certain amount of cement comes up to the surface of water and aggregate goes down this phenomena is known as Laitance.
• Rate of bleeding increases with increase of time after that decreases till the final setting time of cement. Bleeding can be reduced by proper proportioning  and uniform complete mixing.
• Pozzolonic material and air entriaining agent can reduce bleeding. All time bleeding is not harmful if the evaporation ratio is equal to rate of bleeding.