CONCRETE VIBRATOR
Concrete Vibrator
So far, the term concrete vibrator may be quite familiar to those who are used to working in the construction field. However, for the layman this term is still rarely found. For this reason, this time we will first discuss what a vibrator for concrete is. So a vibrator for concrete is a tool used when the casting process takes place. This tool has a function to make concrete which automatically produces a sturdy building construction. In general, this vibrator has three central parts. Here are the parts.
- Machine parts used to generate vibrations.
- The hose that will be used to transmit the vibrations that come from the engine.
- The vibrator head is inserted into the concrete. Usually the vibrator head is made of steel cylinders. For its size itself resembles the hilt of a baseball bat.
Why Is Vibrator Important Used In Concrete Casting?
Previously we have briefly known about vibrators, now it's time to understand why vibrators are important to use in foundries. There are many reasons underlying this. The following are some of them.
1. Make Concrete More Dense
One of the reasons for using this vibrator machine is to ensure that the concrete becomes denser. Dense concrete is stronger than less dense concrete. Density of concrete becomes an important thing in the construction process. Concrete density requirements usually vary depending on the type of building. This also affects the size of the vibrator used. In addition to the size of the vibrator, the number of tools also affects the vibrator's ability to reach a certain density in a predetermined time. For example, to achieve this density in a few hours it takes as many as 4 vibrators.
2. Removing Air Trapped in the Concrete Mix
Often in the concrete mix before being poured there are trapped air bubbles. This should be watched out for because it causes the concrete to become weak. For this reason, a vibrator is needed whose vibration can help remove air bubbles in the concrete mixture. The release of these bubbles can help make the strength of the concrete more even.
3. Prevents Concrete from becoming porous
If air bubbles (as discussed in point 2) are left in the concrete, then porous concrete is likely to form. This porous concrete means that there are holes in the concrete that initially contained the air bubbles. This has a big effect on the level of concrete strength. Even the strength of the concrete becomes uneven because there are parts that are porous and there are parts that are not porous.
Concrete Compaction Method and Type of Vibrator
Concrete compaction is also known as concrete consolidation which is used to get the highest density of concrete. Currently, Concrete Compaction Methods and Types of Vibrators are very diverse, but in the past, concrete compaction was carried out by crushing the concrete mix or by stabbing it, but nowadays compaction is mostly carried out by vibration. Air bubbles form when fresh concrete is poured into the formwork or mold. If we do not remove air bubbles from the concrete mix then the concrete becomes porous or permeable. Porous or permeable concrete causes problems such as leakage, corrosion, etc., in houses or buildings.
Compaction or consolidation is a technique, which has the effect of softening the mortar component of the concrete mixture thereby reducing the internal friction and shearing of the coarse aggregate occurs. This technique removes most of the trapped air bubbles from the fresh concrete. This technique helps to achieve the pre-designed strength of the concrete and ultimately increases the service life of the house or building. The main purpose of compaction of concrete is to obtain a dense mass of concrete without holes or pores.
Compaction also helps to get the concrete to surround all the reinforcing steel and to fill all corners of the shape, however small. Compaction should be applied evenly over the entire mass of concrete. If the concrete is well compacted, a durable concrete will be achieved, but over-compacting also causes concrete separation or Concrete Segregation.
Various Concrete Compaction Methods
Following are various methods of compaction of concrete, which are given below.
1. Manual Compaction (Hand Compaction)
Manual compaction is also known as hand compaction, which is done by knocking or stabbing concrete, with bamboo or steel rods.
- Sticks or rods for Concrete Compaction: Compactor sticks or rods are used in small casting or non-essential concrete work. The rods or rods that are commonly used for compacting are steel rods when compacting concrete. We can also use a flat-nosed trowel for compaction of concrete. This method is effective for thinner concrete (high slump). It is not recommended to pierce or pierce concrete for compacting RCC wall concrete or RCC columns. Rodding or punching concrete is good for compacting the corners and edges of a concrete cube. This method is also used to compact precast concrete blocks
- Ramming for Concrete Compaction: Ramming can be carried out in unreinforced concrete foundations or in minor works (basement construction). The concrete must be punctured or perforated to force out any air bubbles trapped during the pouring of the concrete. The compaction of concrete depends on the slump of the concrete. If the concrete slump (water-cement ratio) is high, coarse aggregate (gravel) will settle at the bottom and cement slurry (mortar) may appear in the top layer. This can result in poor concrete strength which can reduce the life of the house or building.
- Tamping for Concrete Compaction: Tamping is done to compact the top layer of concrete floor slabs or RCC road pavements where the concrete thickness is relatively less and the surface must be smooth and flat. This is done with wooden blocks (usually the size of the blocks is about 10 x 10 cm).
2. Compaction of Concrete by Pressure and Jolting
This compaction method is used in the manufacture of paving blocks, grass blocks or bricks. In this method, a dry mixture of sand, cement and gravel is vibrated, pressed, and also given a jolt. Watch the following video: Compaction of Concrete by Pressure and Jolting.
3. Compaction of Concrete by Round
This method is used to compact concrete pipes (culverts). In this method, the fresh concrete is well compacted by the centrifugal force generated during the turning process. Watch the following video: Compaction of Concrete by Round.
4. Mechanical Compaction by Vibration
Types of Vibrators for Compaction of Concrete
The following are the types of vibrators used to compact concrete by mechanical means. Types of Vibrators for Compaction of Concrete:
Internal Vibrator for Compaction of Concrete
Internal Vibrator is also known as Needle Vibrator or Immersion Vibrator. They are generally used for large work with flat surfaces i.e., floors, roof slabs of buildings, foundations, columns, etc. The vibrator is inserted or immersed in one location until the surrounding concrete mix is completely compacted. Compaction can be assessed visually by the formation of a circular laitance around the niddle. Depending on the consistency of the concrete mix, a niddle (poker) is applied to the center of the mortar 0.5 to 1m (2 to 3 feet) to the center for 5 to 30 seconds. It is advisable to have a rigid concrete mix. The vibration time in one location should not be less than 90 seconds. There are two types of internal vibrators available in the market, including:
- Flexible shaft type internal vibrator
Type of flexible shaft (axle) operated by compressed air or gasoline engine motor. This type of vibrator engine or propulsion is behind the vibrating shaft and is not in a position carried (carried) by the operator. - Motor-in-hand type internal vibrator
The hand type motor can be operated electrically or pneumatically. This type of vibrator engine or propulsion is behind the vibrating shaft and in a position carried (carried) by the operator. That's why it's called "in hand". The internal vibrator is well known and it is the most common type of vibrator. The internal vibrator consists essentially of a poker (a metal rod type vibrating rod), which has an eccentric shaft driven through a flexible drive of mortar.
Formwork Vibrator (External Vibrator) for Compaction of Concrete
Formwork Vibrators are also known as External Vibrators. The external vibrator is attached to the concrete formwork and the vibrating force for compaction is transmitted to the concrete through the formwork. External vibrators are mostly used for precast and thin concretes (which are up to 600mm in thickness) or in situations where the internal vibrator cannot be used easily. Compaction of concrete should be carried out in layers of appropriate depth. The height of pouring concrete should not be more than 750mm and if it is greater than 750mm, the position of the vibrator must be changed or a series of vibrators must be used. Roller vibrators, turbine vibrators and electric hammers are also other types of external vibrators. Electric hammer is one of the vibrators used for compaction of concrete test objects.
Vibrator Table for Concrete Compaction
In the case of the table vibrator, the formwork is clamped to a steel platform mounted on flexible springs. Generally, the rapidly rotating eccentric mass makes the table vibrate in a circular motion. With the two shafts rotating in opposite directions, the horizontal component of the vibration can be neutralized so that the table is subjected to simple harmonic motion only in the vertical direction. Some table vibrators are operated by electro-magnets fed with alternating current.
The frequency range used varies between 50 and about 120 Hz. Acceleration of about 4g to 7g is desirable for compaction of concrete. Variable vibration frequency is a plus in this tool. The vibrating table provides a reliable means of compaction for precast concrete and has the advantage of offering uniform compaction. Following are the advantages of table vibrator:
- Low-cement concrete mixes can be used to achieve the same strength. Hence resulting in cement savings of up to 10 to 15% and better strength.
- This allows compaction of narrow or thin sections where hand compaction may be difficult.
- The resulting concrete is more impermeable to water, denser, and free from conditions in the form of a “honeycomb” concrete.
- Faster compaction which results in economy in time and effort.
Sometimes shock tables are used for the manufacture of precast concrete. Vibration with a shock table gives excellent results but the process is rather specialized and is not widely used.
Vibrator Platform for Concrete Compaction
Platform vibrator is one type of table vibrator which is relatively large in size. Platform vibrators are used in the manufacture of large precast parts e.g. Power poles, rail bearings, etc.
Surface Vibrator (Screed Vibrator) for Compaction of Concrete
Surface vibrators are also known as screed vibrators. Surface vibrators are mounted on concrete platforms or screeds and are generally used to compact and finish bridge floors, walkways, etc.
Vibrating Roller for Concrete Compaction
Currently dry concrete and lean concrete are compacted using vibrating rollers. Therefore, this type of concrete is also known as Roller Compacted Concrete or Rolled Concrete. Repair and maintenance problems can occur in house buildings or high rise buildings due to bad practices in concrete construction. Therefore, always follow good construction practice i.e. use proper concrete compaction method to make the concrete durable. This helps you reduce your home or building repair maintenance costs. It is recommended to use an internal vibrator or a needle vibrator for compaction of concrete when you are building a house. This helps you to achieve good quality concrete throughout the construction work.
Tips & Trik Menggunakan Beton Vibrator
The process of compaction of concrete is one of the processes that determine whether the quality of the concrete produced is of good quality or not. The concrete compaction process aims to reduce bubbles and voids in the casting process. The process can be done manually or using a machine called a vibrator machine. Usually the concrete mixture to be poured and molded still has air content that forms cavities. With this vibrator, the air that is still in the concrete mixture will be expelled until the air content is low and solid and sturdy concrete is produced.
Tricks to Use the Vibrator Well
With the help of a vibrator, the work of making concrete will be easier and quality concrete will be obtained, because the air content in the concrete can reduce the strength of the concrete and its quality. For that we need a tool in the form of this vibrator. Unfortunately, many do not know how to use a vibrator properly.
- Insert the vibrator rod as much as possible in a vertical position
- Let the vibrator rod sink itself under its own weight
- What is a good compaction time? This depends on the slump value of the concrete being worked on. Make sure the concrete surface is glossy. Shiny is a sign that the cement paste is slowly starting to rise.
- Know the tools to be used, because each vibration will be different. For devices with 4000 vpm/250 Hz it takes 90 seconds, 5000vpm/80 Hz takes 45 seconds.
- Gently pull the vibrator rod after the vibration process is complete at one point
- Do compaction evenly
- Insert the vibrator rod into the concrete layer until about 10 cm from the top of the concrete
- If the casting is thick enough and is carried out in several layers, then insert the vibrator hose deeper, which is 15 cm in the previous layer
Caring for the Vibrator Concrete Machine to Stay Prime
In construction, construction equipment is one of the main aspects. With the help of tools, the development process will be faster because each tool has its own function and role. In addition to the construction of housing or buildings, the use of these sophisticated tools can also be done for road construction, flyovers, and so on. Construction and construction work will be greatly helped by the presence of advanced tools.
No wonder these tools are priced quite high. Moreover, usually construction equipment requires complementary tools. For example, a vibrator for making concrete which consists of a core machine equipped with a vibrator is sold at a separate price. For this reason, the contractor will usually rent construction equipment. Then, how to take care of it?
1. Service and Check Tools Periodically
To keep the tool in prime condition, check and service it regularly. Make a special schedule for checking and servicing tools. Do a thorough check from the hose to the vibrator. To ensure the machine is in top condition without any damage, so that the machine can function optimally. If there is damage, immediately take it to a construction equipment service center for immediate treatment.
2. Make sure the machine head is always closed
The engine head is a core part that is vulnerable to damage. To prevent damage, provide a cover (casing) on the head of the machine as protection and make sure it is always tightly closed.
3. Caring for the Hose Bagian
The hose is useful as a channel for vibration from the tool to the concrete. Its important role makes the hose section also susceptible to damage. To prevent damage, clean up immediately after the tool is finished. Apply lubricant to maintain the elasticity of the hose and keep it clean. Avoid bending the hose because there is a risk of damaging the hose shaft.
4. Save and Put in a Clean Place
Leave the appliance in a clean place with a normal temperature. Avoid placing the tool in a dirty and damp place, because it will cause dust or dirt to clog the machine, thus making the machine unable to work and function optimally.
5. Use a wrapping cloth to cover the tool when not in use
In addition to being stored in a clean room, you must ensure that the tool is wrapped in a cloth cover when not in use. By covering the machine, the dirt and dust that sticks can be minimized.
