06-09-2022, 11:44 AM
TYPES OF VIBRATORS
Broadly vibrators can be classified into two
Internal Vibrators
External Vibrators
Generally, mechanical compaction is done using internal vibrators i.e. using immersion or poker vibrators. This compaction method is preferred because the poker works directly on the concrete and can be moved from position to position very easily and quickly.
INTERNAL VIBRATORS
The Internal immersion type vibrators are of two types :
The head contains only vibratory mechanism and a flexible Shaft connects it to the drive which is operated by an electric motor or petrol or diesel engine. They are portable and convenient to use along with a separate motor.
The motor and vibratory mechanisms are both in the head. These types of vibrators are operated electrically or by compressed air.
Both these vibrators equally match each other in their performance, the only primary difference between the two is the location of the vibrator's power unit either inside or outside the vibrating head.
Indigenously made vibrators do not have drive inside the head. This may be mainly due to economic reasons. Immersion vibrators with a separate motor are quite commonly used. Generally, electric motor drives are preferred whenever electric power supply is easily available. Petrol or diesel run motors are only used in cases where electric power is not easily available.
The flexible shaft vibrators with separate drive motor have better applicability for different requirements. They are lighter in weight and easier to handle than motor in-head type of vibrators.
For proper compaction it is essential that the operator does not get tired due to heavy weight of the needle and the flexible shaft. It is often essential to change the operators after some time or to have one person handling the needle and another the motor.
The main disadvantage of electric flexible shaft vibrators is their loss of power under load (in concrete). This power loss lowers the frequency and the ability to remove entrapped air from the motor. Power loss problems can be avoided to a certain extent by using correct length of shaft or vibrator head to match the capacity of the motor. However, power loss due to low slump of concrete is unavoidable as concrete workability cannot be altered once it is in the form.
The flexible shaft is also particularly susceptible to strain and damage due to bad and rough handling. The flexible shaft vibrator can be a high maintenance tool specially if it is repeatedly handled roughly or the needle repeatedly hits the reinforcement formwork during compaction.
The motor-in-head vibrators are initially more expensive. However, due to their design features, they are less vulnerable to damage and have fewer maintenance problems. Therefore their life cycle cost may work out to be nearly the same as flexible shaft vibrators. However, the connecting hose between the needle and power supply source protects only the power cable and not the flexible drive shaft and hence it is more delicate and gets damaged more often than the tougher flexible hose housing the flexible shaft.
For more details visit or download
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concrete compaction fd.pdf
Broadly vibrators can be classified into two
Internal Vibrators
External Vibrators
Generally, mechanical compaction is done using internal vibrators i.e. using immersion or poker vibrators. This compaction method is preferred because the poker works directly on the concrete and can be moved from position to position very easily and quickly.
INTERNAL VIBRATORS
The Internal immersion type vibrators are of two types :
The head contains only vibratory mechanism and a flexible Shaft connects it to the drive which is operated by an electric motor or petrol or diesel engine. They are portable and convenient to use along with a separate motor.
The motor and vibratory mechanisms are both in the head. These types of vibrators are operated electrically or by compressed air.
Both these vibrators equally match each other in their performance, the only primary difference between the two is the location of the vibrator's power unit either inside or outside the vibrating head.
Indigenously made vibrators do not have drive inside the head. This may be mainly due to economic reasons. Immersion vibrators with a separate motor are quite commonly used. Generally, electric motor drives are preferred whenever electric power supply is easily available. Petrol or diesel run motors are only used in cases where electric power is not easily available.
The flexible shaft vibrators with separate drive motor have better applicability for different requirements. They are lighter in weight and easier to handle than motor in-head type of vibrators.
For proper compaction it is essential that the operator does not get tired due to heavy weight of the needle and the flexible shaft. It is often essential to change the operators after some time or to have one person handling the needle and another the motor.
The main disadvantage of electric flexible shaft vibrators is their loss of power under load (in concrete). This power loss lowers the frequency and the ability to remove entrapped air from the motor. Power loss problems can be avoided to a certain extent by using correct length of shaft or vibrator head to match the capacity of the motor. However, power loss due to low slump of concrete is unavoidable as concrete workability cannot be altered once it is in the form.
The flexible shaft is also particularly susceptible to strain and damage due to bad and rough handling. The flexible shaft vibrator can be a high maintenance tool specially if it is repeatedly handled roughly or the needle repeatedly hits the reinforcement formwork during compaction.
The motor-in-head vibrators are initially more expensive. However, due to their design features, they are less vulnerable to damage and have fewer maintenance problems. Therefore their life cycle cost may work out to be nearly the same as flexible shaft vibrators. However, the connecting hose between the needle and power supply source protects only the power cable and not the flexible drive shaft and hence it is more delicate and gets damaged more often than the tougher flexible hose housing the flexible shaft.
For more details visit or download
concrete compaction fd.pdf