Needle vibrators for concrete - their size, usage, guidelines & precautions.

Now, let us look into some of the quarries to understand the needle vibrators in a better way.

 1. What are the different sizes of needles in an immersion vibrator?

vibrator needles.

The vibrator needles are available in the size range of 25mm to 90mm.

 The most preferred dimensions that fall in this range are 25mm, 35mm, 40mm, 60mm, 75mm, & 90mm.

2. What should be the vibration timing & specification to run the immersion needle?

The ideal timing per immersion at a particular concrete point should be 5 sec to 10 sec. depending upon the type of structure & w/c ratio. In any case, we should not vibrate the concrete for more than 15 sec at the same position to prevent segregation & concrete bleeding.

The needle covers the concrete area at a radial distance of 10d to 13d from its vibration point, where d is the size of the needle in mm. Or, we can say that the intermittent distance between the two vibration points is between 1ft. to 3ft. depending upon the needle size and type of structural member.

3. What are the ideal needle sizes for different concrete structures?

1.  For the slab, Pardi, chajja, etc.  👉 25mm to 40mm.

2.   For the columns, beams, single mesh footings, etc.  👉 40mm to 60mm.

3.   For the precast girders, panels, double mesh heavy footings, etc. 👉  60mm 90mm.

4. What are the different types of needle vibrators based on power or fuel used?

1. Electric vibrator:

2. Petrol/kerosene vibrator:

3. Diesel vibrator:

4. Pneumatic vibrator:

The type of vibrator is chosen according to the type of construction structure & the availability of power or fuel on the site.

To know the 5 types of concrete vibrators, go through the article 👇

👀  Different types of concrete vibrators for compaction./ 5 types of concrete vibrators used in the construction works.

5. What are the precautions to be taken on the construction site regarding needle vibrators?

1. The vibration period of the needle at the immersion point, in any case, should not exceed 15 sec. The timing of the vibration should be maintained between 5 to 10 sec depending upon the type of concrete structure.

2. We have to select needles of a specific size, according to the type of RCC structures.

3. Vibratory needles should not touch the formwork to maintain the correct structural dimension and to prevent the formation of gaps or openings in the formwork.

4. Standby needle and vibrator machine is a must on the construction site to carry out the ongoing concrete work smoothly.

For you 👇

❤.  Concrete vibration - its necessity, advantages, & different methods.

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