What Is Segregation?
The tendency of separating coarse aggregate particles from the concrete mix is known as segregation. Generally, it is observed in the plastic stage of concrete. Segregation mostly occurs in very lean and wet concrete. Honeycomb, sand streaks, porous layers, rock pockets etc are the results of segregation in hardened concrete.
Causes of Segregation In Concrete:
Different causes of segregation in concrete are as following:
1. Excessive water content in the mix.
2. Use of poor graded aggregates.
3. Improper design of the mix.
4. Poor compaction of concrete.
5. Over vibration of concrete.
How To Reduce Segregation In concrete:
Segregation can be avoided by taking following precautions.
- The design of the concrete mix should be done properly.
- Water content should not be added more than the desired amount.
- Handling, placing, and compaction of freshly mixed concrete should be done carefully. A proper vibration also reduces the chances of segregation.
- Concrete should not be dropped from more heights.
- Air entraining admixtures can be used to enhance the viscosity of concrete.
- Formwork should be always watertight to prevent leakages.