Segregation in concrete means partition of concrete ingredients as concrete mix isn’t homogeneous. A decent picture of cohesion of the concrete mix is acquired by flow test. On the off chance that the concrete is not cohesive the larger particles of aggregate will separate out and will move towards the edge. Another form of segregation happen if concrete mix carried out on a sloppy surface. A cement particle tends to run away from the center of the concrete mix and leaving the coarser material behind. Segregation cannot be measured in qualitative terms but can be detected by an expert eye.
Segregated cement is a concrete of a variable strength and is generally inclined to breaking and spillages from the concrete. Therefore, it is very important to avoid segregation in concrete to make your structure long lasting.
Here are some tips that are useful to avoid/reduce segregation:
- The concrete mix should be appropriately planned with ideal amount of water i.e. not too wet nor too dry.
- Make sure the concrete is properly mixed at the right speed in a transit mixture for no less than two minutes. Consistently check the performance of mixer with respect to adequate uniformity of circulation of constituents in each batch.
- Transport the concrete mix effectively. Choose the shortest route for transportation of concrete mix.
- Place the concrete in its last position as soon as possible. Never place a concrete from large heights.
- Formwork should be water tight so that paste should leakage from the forms. Try not to vibrate formwork.
- Do not allow concrete to flow.
- Utilize the vibrator effectively and never use the vibrator to spread a heap of concrete over a large area.
- Vibrate the concrete for just the right time-not too long, not too less.
- Use chemical admixtures such as air entraining agent in the mix. Entrained air reduces the danger of segregation.
- If any segregation is observed in concrete, remixing should be done so to make it homogeneous again.
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