Segregation of Concrete

Segregation of Concrete

Segregation in concrete is the separation of coarse aggregates from cement paste during the mixing and placement process. As a result, heavier aggregates settle down, and the mixture of cement and water forms on top of the concrete.

Factors that Cause Segregation in Concrete

1     1.  High water-cement ratio in concrete

Ø Using a high water-cement ratio in concrete causes concrete segregation, which occurs when concrete is mixed on-site by unskilled workers. Excess water increases the mixture's fluidity. Lighter components, like cement slurry, tend to float towards the surface of concrete causing segregation.

2.    2. Extreme vibration of concrete 

Ø When concrete is subjected to extreme vibration using mechanical needle vibrators (poker), heavier particles settle at the bottom, and lighter cement sand paste forms on top.

3.     3. Leakage in the form work

Ø  Because the column and beam have different widths, leakage mostly happens at the column-beam junction. Only massive particles are present in the concrete because the grouts are seeping from the leakage when we use the vibrator.

4.     4. Handling of concrete mix

Ø If you mix concrete manually, some portions of the mix may contain more or less quantity of ingredients, leading to segregation.

5.     5. Placing of concrete mix

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Ø  Concrete transportation can significantly contribute to the segregation of concrete. The manner the concrete is put is important. If the concrete is poured from a height or transported through long distances, the larger particles may settle and separate from the rest of the mixture.