What is Compaction of Concrete?
To ensure a structure is strong and will last a long time, ideally for life, it’s really key that your structure is either non-porous or impermeable. Concrete that is porous can end up causing issues like corrosion or leaks. These issues can occur if compaction isn’t done properly during the placing of concrete.
Weak concrete could drastically lower the service life of a house or build.
Higher porosity of concrete can lead to leakages within a house or building.
Honeycombing of concrete can lead to leaks in the house or building.
The more reduced the durability of concrete, the more increased odds of needing to repair and maintain the house of building.
Hypothetically, the compaction of the concrete is the processed used for expelling trapped air as quickly as possible from fresh concrete, to ensure the best possible density of the compacted mass. It essentially means there should not be any voids present in the concrete.
The main intention of using compacted concrete is to get as dense a mass as possible with no voids, to get the concrete to comfortably surround all the reinforcement and to fill all the corners.
Compaction of Concrete
During the process of mixing, moving and placing the fresh concrete, air bubbles can get trapped in the concrete. The lower the workability, the more air bubbles will get trapped.
Those air bubbles will occupy between 5-20% volume of the total concrete. If that air isn’t fully removed, it will reduce the bond between reinforcement (and/or any other embedded part) and concrete, and the structure will lose significant strength.
Voids deteriorate the strength of concrete and make the concrete either porous or permeable. So, the experts follow good concrete making best practise to make the most durable concrete. If you’re aiming for durable concrete, it’s vital that 100% compaction of the concrete is achieved. It should be kept in mind that compaction is key not just for strength but also durability.
The various methods to get compaction of concrete are as follows:
- Manual (hand) Compaction
- Mechanical Compaction (using vibration)
- Internal vibrator (Needle vibrator)
- Vibratory roller
- Formwork vibrator (External vibrator)
- Platform vibrator
- Table vibrator
- Surface vibrator (screed vibrator)
Compaction by Pressure and Jolting:
Compaction by Spinning:
Many of the maintenance and repair issues might happen in the building thanks to poor concrete construction practices. For example:
- Use of building materials which are not quality tested
- Inadequate curing of concrete
- Poor batching of concrete
- Poor compaction of concrete
- Bleeding in concrete
- Improper use of concrete admixture
- Segregation in concrete
From the mentioned practices above, concrete compaction generally creates issues which ultimately end up in a need for home repair or home maintenance which might end up costing a fortune. It’s already been discussed in a list of do’s and don’t whilst concreting some tips that can make every concrete job safe and easy.