The process of vibrating concrete is a key part of any concrete pour. Concrete vibration removes the air voids or entrapped air in the concrete which increases the density and strength of the structure. A good quality concrete vibrator produces high frequency vibration for the efficient compaction of all types of concrete mixes. Here’s what to look for when you’re shopping for a concrete vibrator.
Concrete vibrators come in a range of different flexible shaft lengths, vibrator head sizes and various engine or electric motor options. Before you choose which concrete vibrator is best for your project, you need to decide if you want a flexshaft concrete vibrator driven by a Drive Unit, a portable option with optimum manoeuvrability or an electric concrete vibrator for noise sensitive environments and zero operating emissions. The key design features of any concrete vibrator are heavy-duty bearings for extended service life, quality oil seals for reduced maintenance frequency and a heat-treated vibrating barrel for reduced wear and tear from abrasive concrete aggregates. It's vital that you choose a product with a high-quality flexible shaft. Look for a flexshaft that provides optimum operator safety and comfort through reduced vibration and heat transfer features.
Lastly you have the option to choose between a steel or rubber tip vibrating head. A steel tip will be suitable for most applications, however a rubber tip is best suited for wall and column applications as it will reduce damage to form work and provide an improved off-the-form finish.
It is essential that a concrete vibrator is used in the correct manner. Concrete vibrators should be inserted into the concrete as quickly as possible. This way it will start compacting the bottom layers first allowing air bubble to dissipate more easily through the top layers. The vibrator head should be kept in the concrete until no more air bubbles come to the surface of the concrete. At this time the vibrator should be withdrawn slowly ensuring that the hole left by the vibrator head closes up. Avoid over-vibration of the concrete as this can cause separation of the mix.