Product knowledge popularization
A construction equipment supplier of construction machinery solutions for 25 years.
Language
A construction equipment supplier of construction machinery solutions for 25 years.
Usually buyers have many questions after purchasing concrete vibrators from abroad. Today I'll be answering your frequently asked questions and I hope you'll ask more questions or contact us.
Use a small head vibrator to compact concrete using shallow formwork or widely spaced steel bars, and use a large head vibrator to compact concrete using full formwork and widely spaced steel bars.
The radius of action of the vibrating head is equal to four times its diameter. Therefore, small-head vibrators must be inserted into the concrete at shorter intervals than large-head vibrators.
The sphere radius is determined by observing how far the bubbles in the concrete extend from the vibrating head. Instead, use a design distance that is 1 to 1.5 times the radius of influence.
Use square or offset modes to drive the vibrator into the concrete. However, vibration patterns are used throughout the process.
In the first case, insert the vibrator into a rectangular grid, making sure to overlap by one-third of the impact radius.
For the offset pattern, use a grid pattern but place the vibrating head in a zigzag pattern.
Do not use the vibrator in air and be sure to turn it on when the tip enters the concrete to avoid overheating the tool and causing subsequent damage.
Insert the vibrator head vertically or nearly vertically into the concrete. Do not tilt the vibrator too much, otherwise it may be damaged. A stand shaker helps release air bubbles and reduce voids.
Do not press the vibrator into concrete as steel bars may obstruct the vibrator. Instead, let the vibrator penetrate the concrete under its own weight.
Avoid hitting the rebar with the vibrating head as this will break the bond between the rebar and the previous layer of reinforced concrete.
Hold the vibrating head in the concrete for 15-20 seconds. However, workers with sufficient experience with vibrators, concrete mixes, and molds can adequately strengthen concrete regardless of the duration of vibration. Exit the vibrator slowly, at a speed of about 2.5-7.5 cm/sec; smaller ranges usually provide the best results.
Concrete must fill the hole created when the vibrator was removed. However, these voids were not filled with dry concrete. Reinstalling the vibrator in the concrete at half the impact radius solved the problem. If the problem persists, replace the concrete mix or vibrator.
Keep a distance of 7-10cm between the edge of the mold and the vibrating head to avoid damaging the mold.
Do not use a vibrator to move concrete.
Avoid excessive vibration to prevent delamination and check the mold for tightness throughout the job.
Pour the concrete evenly and widely to a thickness equal to the length of the vibrating head plus 15 cm. The thickness of the concrete should not exceed 45-50 cm, as is the case with slabs and large foundations. Otherwise, the weight of the concrete will prevent trapped air from escaping to the surface. When pouring concrete in layers, push the vibrator 10 to 15 centimeters into the top layer and move the vibrator up and down for 5 to 15 seconds to improve the bonding strength between layers.
Use a sufficient number of vibrators to control the speed at which concrete is poured.
Continue shaking until the concrete in the mold is smooth, no large particles of aggregate enter, a layer of slurry forms on the top and surface of the mold, and the concrete stops bubbling.
The vibrator operator must be able to see the concrete surface. So use lighting if necessary.
When immersed in concrete, the vibration frequency first decreases, then increases, and finally becomes constant as air bubbles escape.
Keep a spare vibrator on hand. Use this when a vibrator fails completely.
Workers should be instructed to avoid vibrations caused by vibrating concrete.
Clean all parts of the vibrator after each use.
External concrete vibrating screens are suitable for precast and thin-walled concrete products. Maximum effective depth is 75 cm (18 inches).
Concrete scratches and additional internal vibrators require mold vents or vibrators.
Provides correctly shaped supports to prevent damage from external vibrations.
The formwork must be able to withstand liquid concrete and vibration pressure. It must also be able to transmit vibrational forces over long distances.
Low-frequency, high-amplitude vibrations have a greater impact on shape than high-frequency, high-amplitude vibrators. Therefore, when using low-frequency, high-amplitude vibration, such as with steel molds, the mold must be strong.
Distributed shutter vibrators distribute vibration forces evenly. Place your hand or vibrator on the mold to determine the operating range of the vibration and the distance required to evenly distribute the vibration force. Avoid components that vibrate too much or too low.
Do not connect the vibrator directly to the mold, otherwise the mold may be damaged.
Do not use external vibrators until the form concrete depth reaches 15 cm.
Typically the external vibrator is run for two minutes. You can then increase or decrease the time as needed.
As the concrete hardens in the form, the vibrations stop, the large aggregate particles fuse, a layer of sludge forms on the top surface, and the air bubbles between the form surface and the concrete disappear.
Operating the poker or internal vibrator in the air may cause the device to overheat and become damaged.
The concrete vibration process usually takes from 5 to 15 seconds. If there are still air bubbles in the concrete after removing the vibrator, simply repeat the process until the air bubbles disappear.
Most concrete vibrates poorly or inadequately. The best method for using an internal vibrator is to withdraw it very slowly, about an inch per second.
Contractors sometimes encourage workers to perform this labor-intensive task “efficiently,” meaning it is done quickly, but the result may be structural failure once the concrete has cured. At the same time, if the vibrator is left in the concrete for a long time, water and aggregates will separate, causing problems with the strength and aesthetics of the concrete.
3. What happens if concrete vibrates excessively?
If concrete vibrates too much, it may lose consistency and separate. The total will be below the template and the groove will rise to the top of the element. As a result, the concrete loses strength and becomes brittle.
When concrete is poured, hundreds or even thousands of air pockets are created that can damage the concrete structure. Concrete vibrators remove air bubbles by vigorously vibrating freshly poured concrete. The use of concrete vibrators during the pouring process is not only recommended, but in many cases required by building codes.
Before shaking, make sure that other participants are not shaking in some concrete areas. Insert the vibrator head completely into the concrete and hold for at least 10 seconds. Do not turn on the vibrator until the tip is completely submerged.
Raise the vibrator at an average speed of not more than 3 inches per second; In general, 1 inch per second will give the best results. Each vibration input superimposes the path of the previous vibration. A good rule of thumb is that the radius of action is four times the diameter of the tip of the vibrator. Shaking stops when air is released from the concrete and the surface of the concrete appears shiny.
We are a Chinese manufacturer specializing in concrete vibrators. We have 29 years of business experience, 7 professional engineers and 3 local factories. Our many years of experience have enabled us to have more than 1,000 customers around the world and 128 different countries.
if you have any questions about concrete vibrators and need our help, you can contact us at any time, we look forward to hearing from you and establishing a good business partnership with you.
