Concrete vibrators are used for construction based applications. They come in several different shapes and sizes. It is used for concrete compaction mainly in constructing roads, railways, and buildings. It consolidates freshly poured concrete to remove the trapped air and excess water. It is to settle the concrete firmly in the place of form-work. This is done to do the proper consolidation of concrete and avoid product defects. These vibrators are designed with the frequencies of vibration ranging from 2800 to 15000 rpm. There are 4 different types of concrete vibrators. Let us see each one of them in detail.
- Internal Vibrators:
It is also known as a Poker or needle type of vibrator. An internal concrete vibrator is a small steel cylinder with an electrical cord at the end of the tool. The head of the vibrator is dipped in the wet concrete. It is a high-frequency vibrator designed to operate at 12, 000 to 17,000 vibrations per minute. Amplitudes range from 0.015 to 0.08 inches. The frequency of vibrator is about 700 cycles per minute. The machine is most effective when the vibrating head comes in contact with the concrete. Certain factors that are to be considered while choosing the type of internal vibrator are
Power source - Electric, gasoline or pneumatic and hydraulic.
Power unit location - Inside or outside the vibrating head.
Shaft length and type & head characteristics like diameter, length, and shape.
2. External Vibrators:
It is also known as shutter form vibrator type. It comes with a base plate. It is used to consolidate the freshly poured foundation as well as the compact surface of precast concrete. It is operated on a 3 phase induction motor. It has a fully closed structure. Also, it is rugged, dependable, easy to maintain and its power cord consists of 4 cables having rubber coating. Usually, the casing is made up of aluminum alloy casting. It has a lightweight motor structure which is highly efficient. It has the construction pattern as- the machine is clamped to the form-work in a horizontal or vertical manner at suitable spacing not exceeding 90 cm in both directions. They are used as a replacement of an internal vibrator in cases like thin and congested areas, arches and tunnel linings, etc.
3. Surface Vibrators:
They are placed directly on the concrete mass. They vibrate concrete from the surface at the time when screeding is carried out. It is an ideal option for compaction of shallow elements and when used in combination with concrete having low water to cement ratio. It is not recommended to use when the depth of concrete that is to be vibrated is more than 250 mm. Even the dry mixes can be effectively compacted with the help of this machine. Pan vibrators and vibrating screed are common examples of surface vibrators. It has the typical application of compacting small slabs, patching and repairing work of horizontal surfaces like pavement slabs. It has an operating frequency of about 4000 rpm at an acceleration of 4 g to 9 g.
4. Vibrating Tables:
It is designed to settle and compact bulk material in various types of containers. They come in 2 types namely Electromagnetic and electro-mechanical. You can choose the right type based on the application, characteristics of the material, being treated and maximum weight to be handled 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 hold up to 200 lbs. It has high operational efficiency and low power consumption. It requires low maintenance and conducts a noiseless operation. Some of its common applications include 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 avoid the bubbles in molded parts. Various benefits of using this machine are the addition of more materials in smaller containers and reduction in overflow or spillover waste at filling stations.
Depending upon the form of concrete compaction for different construction and structural requirements there are various types of concrete vibrators. As the concrete comprises different sizes of particles, the best compaction of concrete is possible with the help of vibrators having different speeds of vibration. So, start looking for your best suited concrete vibrator type by comparing the brief details of each type shared above in this article.This will help you in achieving the most efficient results for your project with the right choice of a vibrator.