properties of fresh concrete

Concrete remains in its fresh state from the time it is mixed to solidify. During this time the concrete is handled, transported, placed and compacted. The properties of concrete in its fresh state are very important as impact affects the quality of hardened concrete.

properties of fresh concrete

Fresh concrete has the following process.

  • compatibility
  • feasibility
  • settlement and bleeding
  • plastic shrinkage
  • loss of continuity

1. Consistency

The consistency of a concrete mix is ​​a measure of the hardness or slope or fluidity of the mix. In order to effectively handle, hold and compact the concrete, the consistency must be the same for each batch. Hence it is necessary to measure the consistency of concrete at regular intervals. The slump test is commonly used to measure the consistency of concrete.

2. Practicality

The workability of a concrete mix is ​​the relative ease with which concrete can be laid, compacted and finished without separating or separating the individual materials.

Functionality is not the same as continuity. Mixtures of the same consistency may have different work efficiencies if they are made of stone of different sizes – the smaller the stone, the more workable the concrete.

It is not possible to measure workability, but the slump test gives a useful indication, with assessments of properties such as stone material, cohesiveness and plasticity.

3. Settlement and Bleeding

The density of cement and aggregate particles is about three times that of water. In fresh concrete they settle and displace the resulting mixed water which migrates upwards and may accumulate on the top surface of the concrete. This upward movement of mixing water is known as bleeding; The water that separates from the rest of the concrete is called bleed water.

4. Plastic Shrinkage

If water is removed from the concrete before it solidifies, the volume of the concrete becomes less than the amount of water removed. The reduction in this quantity is called plastic shrinkage.

Water can be removed from plastic concrete by evaporation or by absorption from dry surfaces such as clay or old concrete or dried wooden form work.

5. Bearish Loss

From the time of mixing, fresh concrete gradually loses consistency. This gives rise to problems only when the concrete becomes too hard to handle, hold and compact properly.

Recession loss in concrete occurs due to the following reasons.

  • Hydration of cement (generating more heat)
  • water loss by evaporation
  • absorption of water by dry aggregate
  • Absorption of water by surfaces in contact with concrete.

Er. Mukesh Kumar

Photo of author
Er. Mukesh Kumar is Editor in Chief and Co-Funder at ProCivilEngineer.com Civil Engineering Website. Mukesh Kumar is a Bachelor in Civil Engineering From MIT. He has work experience in Highway Construction, Bridge Construction, Railway Steel Girder work, Under box culvert construction, Retaining wall construction. He was a lecturer in a Engineering college for more than 6 years.