Needle Vibrator - Nozzle
Product Details:
Manufacturers and Suppliers of Needles and Needle Spares
Concrete vibrators consolidate freshly poured concrete so that trapped air and excess water are released and the concrete settles firmly in place in the formwork. Improper consolidation of concrete can cause product defects, compromise the concrete strength, and produce surface blemishes such as bug holes and honeycombing. An internal concrete vibrator is a steel cylinder about the size of the handle of a baseball bat, with a hose or electrical cord attached to one end. The vibrator head is immersed in the wet concrete.
· A complete range of poker vibrators from 25 to 60 mm.
· Can be driven by either petrol or diesel engines or electric motors.
· High vibration frequency with low shaft speed.

Immersion vibrators should be inserted vertically into concrete, as quickly as possible, and then held stationary until air bubbles cease to rise to the surface, usually in about 15–20 seconds The vibrator should then be slowly withdrawn and reinserted vertically in a fresh position adjacent to the first. These movements should be repeated in a regular pattern until all the concrete has been compacted .Random insertions are likely to leave areas of the concrete uncompacted. The vibrator should not be used to cause concrete to flow horizontally in the forms,
this can lead to segregation. In addition, the vibrator should not be dragged through the concrete as this leads to inadequate compaction and increases the risk of segregation. In deep sections such as walls, footings and large columns, the concrete should be placed in layers about 300 mm thick. The vibrator should penetrate about 150 mm into the previous layer of fresh concrete to meld the two layers together and avoid ‘cold-pour’ lines on the finished surface. In small columns where concreting is continuous, the vibrator may be slowly raised as the concrete is placed. Care should be taken to avoid trapping air at the form face and a means of lighting the interior of the form while the concrete is being placed and vibrated should be considered.The vibrator should not be allowed to touch the forms as this can cause ‘burn’ marks which will be reflected on the finished surface. Generally, the vibrator should be kept about 50 mm clear of the form face. Similarly, the vibrator should not be held against the reinforcement as this may cause its displacement.Stop-ends, joints and, especially, inclined forms are prone to trapping air. To minimise this tendency, the best technique is to place the concrete close to, but away from the side of the form and insert the immersion vibrator close to the leading edge of the concrete, forcing it to properly fill the corner
Frequently referred to as ‘poker’ or ‘needle’ vibrators, immersion vibrators consist essentially
of a tubular housing which contains a rotating eccentric weight or Operates on Pendulum Principle.
The out-of-balance rotating weight causes the casing to vibrate and, when immersed in concrete, the concrete itself.
The effectiveness of an immersion vibrator is dependent on its frequency and amplitude, the
latter being dependent on the size of the head, the eccentric moment and the head weight – the larger