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Concrete vibrators are utilized to remove air that can stay when flowing concrete that can decay the unity of the concrete.
Without a concrete vibrator, concrete structures can back down or fail apart from weather, earthquakes, and wear and tear over time.
It is to sort out the concrete securely in the place of formwork.
This is performed to do the best consolidation of concrete and neglect product defects.
These types of vibrators are made with frequencies of vibration limiting from 2800 to 15000 rpm.
2. Types of Vibrators
There are 4 types of vibrators in construction.
a. Internal Vibrators
Internal vibrators are also known as Poker or needle type of vibrators. An internal concrete vibrator is a tiny steel cylinder with an electrical cord at the end of the tool.
The head of the vibrator is placed in the wet concrete. It is a high-frequency vibrator prepared to run at 12, 000 to 17,000 vibrations per minute. Amplitudes limit from 0.015 to 0.08 inches.
The frequency of the vibrator is about 700 cycles per minute. The machine is most productive when the vibrating head advances in contact with the concrete.
Some factors that are to be taken while selecting the type of internal vibrator are:
The Source of Power is Electric, gasoline or pneumatic, and hydraulic. The location of power is inside or outside the vibrating head.
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b. External Vibrators
External Vibrators are also known as shutter-form vibrator types. It comes with a base plate. It is utilized to consolidate the freshly streamed foundation as well as the dense surface of precast concrete.
External Vibrators run on a 3-phase induction motor. It contains a fully closed structure.
Also, it is uneven, dependable, and easy to maintain and its power cord is made of 4 cables containing rubber coating.
Usually, the casing is prepared of aluminum alloy casting.
It has a lightweight motor structure that is highly systematic.
External Vibrators have the construction way as the machine is secure to the form-work horizontally or vertically at best spacing not be over 90 cm in both directions.
They are utilized as the best replacement for an internal vibrator in cases like thin and congested areas, arches and tunnel linings, etc.
c. Surface Vibrators
Surface vibrators are applied directly to the concrete mass. They vibrate concrete from the surface at the time when screeding (cutting off excess wet concrete) is performed.
It is the best choice for compaction of shallow parts and when utilized in combination with concrete containing a low water-to-cement ratio.
It is not chosen to utilize when the depth of concrete that is to be vibrated is larger than 250 mm.
Surface vibrators can be used even in the dry mixes to compact. Pan vibrators and vibrating screeds are the best examples of surface vibrators.
It contains the typical utilization of compacting minor slabs, patching, and mending work of horizontal surfaces like pavement slabs.
It has a working frequency of about 4000 rpm at an acceleration of 4 g to 9 g.
d. Vibrating Tables
It is designed to settle and compact bulk material in various types of containers.
There are 2 types of vibration tables: Electromagnetic and Electro-mechanical.
You can select the right type depending on the use, characteristics of the material, being treated, and maximum weight to be carried along with the type of container.
It consists of a rigidity-built steel platform mounted on a flexible spring and is driven by an electric motor.
They are user-friendly and can support up to 200 lbs.
It involves huge operational efficiency and low power use.
It needs low maintenance and manages a noiseless operation.
The common utilizes contain compaction, detachment, and aeration of bulk materials, testing of welded joints in the automobile and electronic industry, effective packing of powders in the chemical industry, and proper flow of materials in dies to neglect the bubbles in molded parts.
The different advantages of utilizing this machine are the addition of more materials in smaller containers and a decrease in overflow or spillover waste at filling stations.
This was for the Types of Vibrators in Construction.
Read Also: Honeycombing in Concrete
