Concrete Vibrator Electric

On other occasions we have talked about concrete and some tools, such as concrete cutters or trowels. Today we are going to talk about the importance of vibrating concrete. With vibrating we achieve compaction of the concrete.

It is essential to treat the concrete as indicated so that it always fulfills its function for a long time.

Although concrete may seem to be the opposite, it is a very delicate material that needs to be executed with certain care in order to really fulfill its function and to continue doing so over time.

Although at first glance we see the hard concrete shortly after pouring it, it does not mean that it is 100% ready. Of course, at first glance it is hard, but it is time to ask ourselves the following: is this hardness enough? It may not break, but are the trusses well integrated to prevent it from flying? How long will you keep your properties?

When the trucks come in with the concrete and pour it into the formwork, it's not just concrete coming in. With the concrete, a large amount of air enters and is trapped inside the mass. As you can imagine this air is not as resistant as concrete, therefore it does not seem a good idea to keep the air inside the mass. Where there is air there is less resistance.

This is when vibrating comes into play. With this method we will ensure that the air that is trapped in the concrete mass rises to the surface and is eliminated, causing the air to remain in the mass, but only concrete.

In the following image we can see the difference between the concrete before and after vibrating.

Concrete vibrating targets

The main objective of vibrating concrete is to eliminate air, but we also achieve other things just as important:

-  Improved resistance . The air is not resistant, so the areas of the mass where instead of concrete there is air, will not resist anything. Important especially in the meetings between different elements (beam with column)

-  Improves the durability of concrete . The air remaining in the concrete mass will end up favoring oxidation in the reinforcing reinforcements, since it creates a network of pores that will facilitate the entry of aggressive external agents into the interior of the mass, such as CO2, water, pollution , etc.

-  Improves the anchorage of the armor . The air that, in addition to being trapped in the concrete mass, is in contact with the reinforcing bars, represents a metal surface that is not in contact with the concrete. The smaller the surface in contact with the concrete, the less its anchorage capacity will be and therefore it loses the ability to help the concrete resist traction, so with vibrating we can eliminate that air, increase the concrete / steel contact surface and Thus improving the anchoring of reinforcements.

-  Rearrange the components of the concrete . Sands, gravels, cement ... different materials with different grain sizes. When applying the vibrate, the smallest particles are repositioned between the gaps that leave the thickest particles, favoring the homogeneity of the mixture, helping to fill small gaps (such as space between bars very close together), correctly filling corners and complicated shapes formwork and ultimately improve the quality of the concrete.

-  Avoid holes  and the consequent touch-ups on the finished concrete. If holes appear on the surface of the concrete when stripping, it is due to the fact that it has not been vibrated correctly, the air has not been removed and therefore, when the mass hardened, the one that was in contact with the formwork has remained there leaving the typical coquettes , which in the end ends up being an additional cost because it is necessary to repair.

-  Improves the aesthetics of the finish . Directly related to the previous one, in exposed concretes it is the worst that can happen, since the repairs in the seen concretes are going to be difficult to hide, they are going to be noticed, so the vibrating, in addition to the importance of the previous points is essential to achieve a perfect finish.

Tools to get vibrated

The tool used for this work is the Concrete Vibrator like the ones shown below:

Keys to keep in mind for a correct vibration of the concrete

There are a number of points that must be considered to perform the vibrate of the concrete:

1. We must introduce the vibrator vertically and with speed up to the vibrating depth. If we introduce it slowly, the upper layers will compact and it will make it difficult for the air from the lower layers to rise to the outside.

2. The vibrator must be removed slowly and inclined to ensure that the entire depth is well compacted and when removing it inclined, we will avoid marking the exit point.

3. Keep the vibrator within the mass for 10-15 seconds maximum.

4. Do several short dives.

5. The distance between the vibrating points will depend on the radius of action of each machine. This is usually stated in the manual.

6. It is important to bring the vibrator closer to corners and recesses to ensure that the finest particles are placed, achieving these shapes.

7. Avoid using the vibrator to remove the concrete since that is not its function.

8. To lower concrete clusters, you should not enter the top of the cluster, but click around until it is distributed by its weight.

9. It is advisable to have a reserve vibrator on site, it would be very expensive, if the vibrator were to break down just with a recently dumped truck, because all that mass would have to be chopped.

As you can see it is a very simple but essential task to achieve a good result from the structure.