Answered Which size Needle is used for compaction of beam, column, wall and slab

amd007

Premium Member
Apr 17, 2018
232
323
mumbai
Needle vibrators are chosen based on the available spacing between the reinforcement.

Columns 6" width: 25 mm dia needle

Columns above 6" width: 40mm dia needle or 60mm dia needle

Beams/Walls: you can go for 40mm dia or 60mm dia based on reinforcement spacing.

Slabs: you can go for 40mm dia or 60mm dia

60mm dia needles RPM is more at considered to 25mm and 40mm so it should be used judiciously as bleeding of concrete may occur due to excessive vibrations.
 
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Dnyan Deshmukh

Eternal Member
Staff member
Sep 7, 2017
2,662
4,642
Pune
The vibrating needles with size of 80 mm, 60 mm, 40 mm and 25 mm available in the market.
For doing compaction, you can use any of the above size needle or bigger than it provided you are able to insert it into section for doing compaction.

When there is reinforcement congestion, using a higher size needle not possible when we cant even move it into rebar, we normally select a lower dia size needle so that it can go freely till bottom of member and can easily removed.

The compaction efforts also get reduced in terms of radius of concrete around the needle, higher size diameter have higher effective compaction area so they are immerse in concrete at great distances compare to smaller dia needle.
 
Sep 5, 2018
9
3
Bhubaneswar
The vibrating needles with size of 80 mm, 60 mm, 40 mm and 25 mm available in the market.
For doing compaction, you can use any of the above size needle or bigger than it provided you are able to insert it into section for doing compaction.

When there is reinforcement congestion, using a higher size needle not possible when we cant even move it into rebar, we normally select a lower dia size needle so that it can go freely till bottom of member and can easily removed.

The compaction efforts also get reduced in terms of radius of concrete around the needle, higher size diameter have higher effective compaction area so they are immerse in concrete at great distances compare to smaller dia needle.
I am supervision the ESR ,which havs 400x400mm size column so what is the dia of vibrater used during casting.