Guide and advice

Vibrating concrete, an essential step

Fresh concrete is a mixture of cement, water, sand, gravel, additives and… air bubbles. Vibrating the concrete as soon as it is poured eliminates the latter. This is an essential step, as without it, air bubbles remain trapped inside the mix, even after it has hardened. As a result, the concrete’s technical properties are degraded, notably its strength and durability.

By expelling air bubbles and encouraging the aggregates to settle, vibration ensures that molds and forms are properly filled, and reinforcement is embedded. Once the voids have been eliminated, the concrete is denser and more resistant.

Vibrating concrete also produces a smoother, more aesthetically pleasing surface!

It all depends on the industry and the application.

In the building and civil engineering sector, and particularly in prefabrication, internal vibration is used to ensure perfect embedding of reinforcement and effective bonding of concrete to it. Internal vibration can be performed using a vibrating needle, a frequency converter and/or a flexible vibration unit.

External vibration of concrete can also be relevant in prefabrication workshops and on construction sites, where the specificity of the structure makes the use of an internal vibrating needle complex, for example. External vibration acts on the concrete via a formwork. This method can also be useful in industry, particularly for testing purposes. External vibration of concrete requires the use of external vibrator(s) and/or solutions such as vibrating table or vibrating rule.