There are hard effects of segregation and bleeding on the workability and strength of concrete. So before the job frequently we are asked in the interview or on site that how to avoid segregation or how to avoid bleeding in concrete.
At that time can only answer it, if you really know the definition or difference between segregation and bleeding. So, a friend here I have described them in detail.
Difference between Segregation and Bleeding
It can be defined as separating out of the ingredients of the concrete mix so that the mix is no longer in homogeneous condition. It Separating out of coarser particles from the rest of the matrix Like Cement (cement slurry), Sand, etc.
Cause of Segregation
1) Segregation depends upon handling, transportation and placing
2) More workability i.e. slump value means susceptible to segregation.
3) Dropping of concrete from heights will result in segregation
4) Insufficient mixed concrete with excess water is prone to segregation.
5) Excess vibration i.e. vibration for long time result ins in segregation.
6) Segregation may also occur when we use vibration needle to spread a heap of concrete.
How to avoid segregation?
Avoid excessive compaction in concrete.
Use suitable size of aggregate in concrete.
The dropping of aggregate in form-work should not be greater than 1.5 meter.
There should be excess gap between steel bars to enter concrete slurry in it.
What is Bleeding ?
It is a form of segregation in which some of the water in mix tends to rise to the surface of freshly placed concrete. This is caused by the inability of a solid constituent of mix to hold all the mixing water when they settle down during compaction.
Effect and remedies of Bleeding
1) It causes the formation of the porous, weak &nondurable concrete layer at the top of placed concrete.
2) Bleeding may be reduced by proper proportioning, uniform & complete controlled compaction.
3) It also can be reduced by the use of pozzolanic materials and air entraining agents.
4) According to ASTM code 232, Bleeding is expressed in terms of the amount of accumulated water as % of the net mixing water sample.
I Hope friends, you liked my written article on “Different between Segregation and Bleeding in Concrete and it’s Cause” and remains helpful.