We have discussed about the requirements of height of concrete layer in the last post. There we have found a term capacity of vibrator. In this post we will learn about most common vibrator that are frequently used in construction sites for regular concreting work having no special difficulties. Here we will discuss technical features and capacity of this vibrator.
Yes, friends I am talking about poker vibrator. The poker vibrator is also known as immersion vibrator or needle vibrator. This vibrator consists of
a. Power unit
b. Flexible shaft
d. Sometimes blade instead of needle
Power unit can be driven by
2. Patrol engine
3. Air compressor
The eccentric weights that are attached to-
-rotor of a vibrating element cause vibration.
Sometimes pulsating equipment of electromagnet are used. The diameter of needle normally varies from (20-75) mm having a length of (250-900) mm. Longer needle with large diameter is used in mass concreting of greater depth like dam construction.
A vibration frequency up to 12000 cycles/min is generated with this type of vibrator. As stated earlier the needle is sometimes replaced by blade. This is due to facilitate penetration of vibration energy where needle cannot be passed through the closely spaced congested reinforcement. But the requirement is the length of blade should be equal to length of needle.
The main advantage of poker vibration is portable and the movement of vibration in construction site is very easy. In many unfavorable positions and situations, this vibrator can be used.