What Is Segregation?
Segregation refers to separation of different concrete phases. It happens when concrete mix is not cohesive enough.
Slump Test in Conventional concrete and Flow test in Self Compacting Concrete can give a good picture of segregation of concrete. If concrete is not cohesive larger particles will separate out.
Tips To Avoid Segregation
Here are the tips you can follow to avoid segregation.
- Mix should be properly designed with optimum water content in mind so that mix should be neither too dry nor too wet.
- Sometimes mixing time is responsible for segregation even when mix is properly designed. 2 minutes mixing time is recommended, furthermore standard mixing regime should be followed.
- Never place concrete from larger heights. It should be placed in its final position quickly.
- Improper vibration is another factor causing segregation. Use of vibrator should be carried out with precautions, Standard vibration time should be followed.
- Viscosity enhancing admixtures can be used in Self Compacting concrete to avoid segregation but then again mix design should be checked.
- Form-work should be watertight so that no leakage is observed from mix.
- Reinforcement spacing should be checked so that concrete flows as one mix. If it is less, larger sized aggregates might separate out.