How to choose a reliable construction vibrator

Concrete is a widely used material in the construction industry. It is utilized for the construction of various buildings and their foundations, as well as columns, bridges, and other structures. The composition of concrete consists of a mixture of sand, cement, crushed stone of different sizes, and water. At the initial stage, the prepared mortar has an uneven structure, containing a significant amount of air. When the concrete hardens, this results in the formation of voids or sinks, which can reduce the overall strength of the structure by at least 20%. To address this issue, a concrete vibrator is employed to enhance the fluidity of the working solution through oscillating motion, thereby compacting the sand and crushed stone. Consequently, the trapped air is able to escape to the surface, while the fillers are uniformly distributed. The use of a vibrator reduces the initial volume of mortar poured into the formwork by approximately one third. This helps to minimize the occurrence of sinks, ultimately maximizing the strength properties of the hardened concrete.

Design and principle of operation of the tool

• actuator;
• unbalance (unbalancer);
• transmission shaft;
• vibrating arm.

Various types of vibrators can have common construction elements, as depicted in the image below.

The drive is the component that enables the execution of useful tasks. It powers the de-balancers and the shaft. The vibrating tip (also known as vibrating head) operates directly on the poured concrete. The shape of the tip varies depending on the type of vibrator. This unit can be classified into the following varieties based on this criterion:

• vibro bayonets;
• vibro shovels;
• vibrating rods.

The shape of the vibrating tip determines the area and volume of concrete work that can be performed. The photo below illustrates the design of two types of vibrobeads.

The utilization of imbalances facilitates the reception of vibrations of various frequencies, which are then transmitted to the vibrocone via the shaft.

Depth (internal) vibrators are outfitted with a flexible shaft. The length of the shaft determines the maximum depth at which the equipment can operate while vibrating and compacting concrete mortar. The flexible shaft, powered by a motor, is a steel cable enclosed within a rubber or plastic casing.

The operating principle of concrete vibrators of different types is based on the application of vibrations to the working solution. This results in the compaction of aggregate (such as crushed stone and sand) and the displacement of air. The structure of the compacted concrete becomes more uniform, leading to increased density and strength properties.

Classification of vibrators for concrete

There is a wide range of models available for the construction vibrator in the market. The industry produces various types of equipment for compacting concrete mortar, which can be categorized based on the following criteria:

• The type of drive installed
• The level or frequency of vibrations generated
• The method used for tamping mortar

Additionally, the tool can be classified into different power groups:

• Low-power and medium-power models (up to 2 kW) that are suitable for household and semi-professional applications
• Powerful models (professional, with a power range of 2 to 4 kW) that are designed for continuous use in the construction of reinforced concrete structures

Professional models are more expensive than low and medium power equipment. In addition, professional models are heavier and larger in size, making them less convenient for transportation. Industrial analogs, on the other hand, can weigh up to 100 kg.

By type of installed drive

The following categories of concrete vibrators can be identified:

• electromechanical vibrators;
• pneumatic vibrators;
• internal combustion engine (motorized) vibrators;
• hydraulic vibrators.

An electric vibrator (electromechanical vibrator) is a vibration device that operates on mains power and is equipped with either a single-phase or three-phase asynchronous electric motor (with a squirrel cage rotor). In this case, the unbalance and eccentric parts are connected to the ends of the electric motor shaft. These models are widely used, but they have lower power and autonomy compared to fuel-powered (diesel, gasoline) units.

Among the different types of electric models, there are battery-operated immersion vibratory rammers. These rammers are just as mobile as their fuel-powered counterparts but are more compact and weigh less.

Another commonly used equipment for compacting concrete mortar is the pneumatic vibrator. It operates by utilizing compressed air provided by a compressor unit. These units are primarily employed in industrial settings. There are two types of rotary vibration generators available for pneumatic vibrators: the pneumatic ball vibrator and the pneumatic roller vibrator. The on-off valve is used to adjust the vibration parameters.

Pneumatic tools are also furnished with attachments for working with wood and metal formwork, as well as a flexible shaft.

Motor units run on either gasoline or diesel fuel. They are known for their impressive autonomy and substantial power.

CHAMPION gasoline deep vibrator

Hydraulic tools are composed of a hydraulic pump, flow control systems, and the working pressure value. Adjustment enables the vibration frequency to be customized to meet specific needs.

Vibration frequency

Based on this standard, vibrators can be classified into the following types:

• low-frequency;
• medium-frequency;
• high-frequency.

Low-frequency models operate at a vibration frequency of up to 3500 vibrations per minute and have a large amplitude. These devices are specifically designed for compacting concrete mixtures with high-density fillers that have a low level of mobility.

ODWERK BVR 350 is a low-frequency depth vibrator that is perfect for various types of concrete mortars, especially those with medium-grained crushed stone. It operates at a frequency range of 3500-10000 vibrations per minute.

For those looking for a universal option, medium-frequency units are the way to go. They can handle different types of concrete mortars and are especially effective with medium-grained crushed stone. The frequency of working vibrations falls in the range of 3500-10000 vibrations per minute.

If you need more power and speed, the high-frequency depth vibrator (and surface vibrator) is the ideal choice. With over 10000 vibrations per minute and small amplitude, this equipment is designed for tamping working mortar with fine aggregate.

The AGP VRN1400 is a high-frequency deep vibrator designed specifically for concrete applications.

By method of interaction with concrete mass

There are various types of equipment for concrete compaction, based on the method used:

• A deep vibrator, which is immersed in the mortar and compacts the mass by vibrating its nacelle. The drive can be connected directly or through a flexible shaft.
• An external vibrator, which does not immerse in the mortar. Instead, it transmits the vibrating effect through the structural elements of the formwork or directly from the upper layers of the pour to the lower layers. The vibration also affects the substrate.

Each type of vibrator serves a specific purpose in compacting concrete effectively.

Important characteristics for selecting a vibrator

When choosing the appropriate concrete vibrator for a specific task, it is essential to consider the following technical characteristics of the tool:

• The vibration frequency and amplitude
• The power of the plant
• The weight
• The shape and dimensions of the vibrating nipples (this criteria is only significant for deep machines)
• The length of the shaft
• The compaction diameter

The last three parameters become particularly crucial when using a depth vibrator.

The frequency of vibrations is directly related to the amplitude: the larger the amplitude, the lower the frequency, and vice versa. If you need to compact concrete mortars with fine fillers, it is recommended to purchase high-frequency units. Medium-frequency units are more suitable for compacting medium-grained compositions, while low-frequency units work best with coarse fractional compositions. Units with a medium frequency of oscillation can also be a good option for home use.

The productivity of the units depends on their power. For home use, a power tool ranging from 750-1500 watts is sufficient. Professional activities require units with a power of at least 2 kW.

When working with reinforced structures, it is important to consider the impact of the size of the vibrating tip on the movement ability within the mortar. To effectively compact concrete pouring without reinforcement bars, it is recommended to use wide tips with a diameter of up to 110 mm. This will result in improved equipment productivity.

The depth of immersion of the vibrating tip into the poured concrete mortar depends on the length of the flexible shaft. A tool with a short shaft is not suitable for constructing large structures as it will not allow for proper concrete tamping. This can lead to a decrease in the quality of the solidified monolith.

The compaction diameter is a measure that determines how far the vibrations spread from the vibrocone. The larger this measure is, the more efficient the technique becomes, as it allows for compacting larger amounts of poured mixture at once.

One crucial consideration in making a choice is the price: generally, higher-priced equipment tends to be of better quality and more durable.

Recommendations on the type of engine installed

When considering purchasing pneumatic tools, there are several factors that need to be taken into account:

• The level of autonomy needed for work performance
• The distance from the power grid
• The potential for explosion in the production environment
• The capability and performance of the equipment
• The expected volume of work that needs to be completed

If there is a significant amount of work to be done, it may be beneficial to invest in pneumatic tools. However, it is important to note that pneumatic tools require a continuous supply of air and the temperature of the air must meet the specifications outlined in the operating instructions.

To utilize power tools, having access to either a single-phase or three-phase network is necessary, depending on the installed electric motor’s type. Unfortunately, this may not always be feasible due to various reasons at construction sites. Nevertheless, when it comes to price and performance, there are options to select optimal equipment that matches the necessary technical specifications, whether it is for personal or professional use.

In terms of portability, fuel-powered units are the ideal option. One has the flexibility to choose a model with the desired power for different types of tasks.

Overview of manufacturers and prices

There are many domestic and international companies that manufacture concrete compactors. In Russia, some of the notable manufacturers include:

• Kalibr;
• Red Mayak;
• Energomash.

These companies are known for producing high-quality concrete compactors at a reasonable price. Their products are comparable to foreign models in terms of performance and specifications. For instance, an electric-powered concrete vibrator with a power range of 0.75 to 1.2 kW and a vibrating tip diameter of 30-50 mm can be purchased for approximately 4000-5000 rubles, such as the Energomash BV-71101.

Vibrator Energomash BV-71101

A high-powered device (ranging from 1.3 to 2 kW), featuring a working tip measuring 38-51 mm in diameter and a flexible shaft that spans 4 meters, is available for purchase. This product can be found at a price range of 13,000-16,000 rubles. For instance, take a look at the Red Lighthouse EPK-1300 model.

EPK-1300 Red Mayak deep vibrator

Foreign manufacturers’ products are highly sought after by consumers, and some of the popular brands include:

• Makita;
• Wacker Neuson;
• DDE;
• Sturm.

Makita, a Japanese company, offers a wide selection of wireless power tools ranging in price from 14,000 to 32,000 rubles. One example is the Makita BVR450Z, a portable vibrator with a battery pack.

The Makita BVR450Z vibrator is a notable tool for concrete compaction. It offers high-frequency vibrations, ensuring professional results. In contrast, the renowned German brand, Wacker Neuson, is also recognized for its top-notch vibrators. One of their popular options, the Wacker Neuson IREN 38, starts at a price of 40000 rubles. With both Makita and Wacker Neuson offering exceptional choices, customers can choose the one that suits their needs and budget.

Wacker Neuson IREN 38 is a deep vibrator equipment.

If you are looking for a more affordable option, Chinese companies Sturm and DDE offer:

• models with a power range of 0.85 to 1 kW. These models are equipped with a vibrating tip and a flexible shaft. You can purchase them at a cost starting from 4000 rubles;
• for those who need more power, there are 2 kW devices available at an average price range of 9000-15000 rubles.