Bleeding Of Concrete | Effects | Prevention

Bleeding is a substance in which free-flowing water rises to the surface and forms a cement slurry in an area known as “laitance”. Bleeding occurs in concrete where study aggregates tend to stabilize and free water rises to the surface.

In some cases, bleeding water does not surface, but bleeding does occur. Bleeding water gets trapped underneath rough aggregates or reinforcements. This is called internal bleeding.

Causes of bleeding of concrete

Bleeding of concrete is caused by the separation of the concrete mixture (separation, paste separation, and water separation of concrete component in the rough total separation firm) as a form of plastic state in which the bulk particles settle in the concrete.

Due to the settling of the particles, the water rises to the top of the fresh concrete surface, and milk is formed on the surface, which plays an important role in the causes of bleeding in the concrete.

Bleeding occurs most frequently on top of new concrete construction and is greatly affected by the strength and life of the concrete when water and cement ratios are high, and by the use of other components such as cement type, fine aggregates, inadequate proportions of concrete components Plays the role.

Effects of bleeding in concrete:

Bleeding is most damaging to the construction of civil engineering concrete, which greatly affects the strength of concrete structures, a large factor in the rate of bleeding water can cause excessive bleeding of water and cement ratio, and cement type and fine aggregates.

While it may play a role in determining the amount of bleeding, we can discuss some of the

Effects of bleeding are as follows:

Bleeding eventually forms lactation on the upper surface.
Internal bleeding is also observed.
Makes a concrete hole
Concrete loses its uniformity.
Reinforcement between the components and layers of concrete is creating a poor bond.
The strength and resistance of concrete decrease.
Delay in finishing surface and curing work due to water structure on the upper surface.
Excessive bleeding breaks the bond between concrete and reinforcement, and the accumulation of water causes water voids and reduces the bond between cement paste and aggregate.
There is a responsibility to cause concrete to enter.
The pumping capacity of concrete is also affected
An increase in the ratio of water-cement on the upper surface is most affected because bleeding is more frequent on the concrete surface.
Lack of sand in the Fine increases the bleeding properties of the concrete

Also read: Properties of fresh concrete

Also, watch this for a better understanding:

How To Reduce Bleeding?

Some factors or methods have been properly used to reduce bleeding :

Bleeding is reduced by adding minimum water content in the concrete mix, and chemical blends are used to reduce the water demand for the required viability. Using a slump mix.
Concrete components are properly incorporated into the design of concrete structures, cement, rough aggregate, fine aggregate.
Adding more cement to the mix.
Used air insertion mixtures are highly effective in reducing bleeding.
Use fly slag or other ancillary cementitious materials such as ad slag cement or silica fume.
Increase the number of fines in the sand.
Free water allows the water to migrate to the surface and evaporate the water-cement ratio of the structures, thus reducing the porosity of the capacity and increasing its density and durability.

Also read: Polymwe impetrated concrete

How to prevent bleeding?

Some of the proper use of concrete in concrete construction is effective, which prevents bleeding as follows:

Controlling the water-cement ratio, using a slump value blend according to the structure of the concrete as it reduces bleeding.
Provide good grading of good aggregates, appropriately used in the design blend formulation associated with blends.
Using more finely ground cement.
Ad-air interacting agents should control bleeding.
Controlling compression.
Concrete that vibrates for a long time.
Completely remove the lactation before pouring the next lift
Uniform, complete mixing, and proper validation.

Also read: Environment impact of concrete