Useful Tips

Concrete Cutting Grinder

Concrete, despite its strength, can be cut if desired by yourself, but only if the thickness of its layer is not more than 10 cm. When the layer of concrete mix is ​​larger, difficulties arise that grow in direct proportion to the thickness of the concrete.

It is worth considering that for safety reasons, cutting of concrete with a thickness of more than 15 cm should be carried out exclusively by professionals, there is nothing to be done. From this article you will learn how to cut concrete, the thickness of which does not exceed 15 cm.

Shallow depth

Concrete cutting is always carried out using diamond disks installed in an angle grinder, commonly known as a “grinder”. If it is necessary to cut concrete to a shallow depth (up to 100 mm), the following diamond blades can be used:

  1. Sintered - with a diameter of 10.5 - 12.5 cm.
  2. Turbo diamond.
  3. Turbo-diamond with a silent wave casing.
  4. Segmented.

The latter type of diamond blades is quite inconvenient to work with, but costs much less than others. Wave-shaped turbo-diamond disks are used in work requiring special load, but they also cost much more than other types of disks.

Using diamond discs, you need to observe the operation of the grinder. So, if after passing 10 mm, it continues to work normally, you can cut the concrete further to the required depth, but remember that it should not exceed 15 mm.

To extend the life of the disc, it is necessary to spray water on it periodically, thereby cooling it. If there is no water source, work must be carried out superficially and intermittently.

Great depth

If you need to cut concrete to a depth of more than 10 cm, you will need diamond blades, not less than 35 - 40 cm in diameter. In this case, it is necessary to take into account the following nuances:

  1. At a depth of more than 10 cm, you can stumble on reinforcement, so use in this case is the discs specifically designed for cutting reinforced concrete structures.
  2. Old concrete is much harder than fresh - this should be considered when choosing a diamond blade.

Remember that small particles of dust are formed during operation even when you water the diamond blade with water, so regardless of the method of cutting concrete, you need to protect the airways with a professional respirator.

If you have a large front to do, be sure to wear headphones, glasses, gloves and overalls.

The process of cutting concrete with a diamond disc can be seen in this video:

Instruments

So, to perform this operation, you will first need an angle grinder for concrete, which is popularly called a grinder. As a nozzle, it is necessary to use a special diamond wheel on concrete for the grinder.

I must say that they exist of several types:

  • Segmented
  • Turbo diamond
  • Turbo-diamond with a wave body.

Segmented circles are not the best solution, since cutting them may cause certain problems, which is associated with their segmented edges. But, the advantage is the low price compared to other types of nozzles.

Turbo-diamond discs with a wave body will allow cutting with the greatest load, for example, when it is necessary to cut reinforced concrete. Of course, this type of nozzle is the most expensive.

Segmented diamond wheel

Advice!
Reinforced concrete cutting with diamond wheels is first carried out to a depth of about one centimeter.
If there are no problems with the grinder or disk, the procedure is continued.
Each subsequent cut should be no deeper than one and a half centimeters.

Determination of concrete type

Before you grind concrete with a grinder, you need to determine what type of concrete you are dealing with. This is due to the fact that different types of diamond blades are used for each type of material. For example, it can be reinforced with metal rods (reinforced concrete).

If the depth of cut is about 10 centimeters and deeper, then on “your way” you can stumble on a metal grill (reinforcing cage). As mentioned above, for these purposes there are special discs.

In addition, it should be borne in mind that over time, the structure of the material changes. Fresh concrete is more abrasive, while old concrete is harder. For this reason, diamond blades for old and fresh material must be different.

Reinforced concrete

If you have the time, you can study the structure of the material in more detail, which will allow you to choose the most suitable tool for it. For example, if the composition contains basalt or quartz, then it will quickly dull the circle. Therefore, diamond segments must be bonded with soft material so that new diamonds “open” faster.

It should also be borne in mind that the size of the filler affects the cutting speed - the larger it is, the slower the procedure.

Advice!
Diamond tools are used not only for cutting, but also for other concrete processing.
In particular, diamond drilling of holes in concrete or grinding with diamond cup discs is often used.

In the photo - a diamond wheel with laser soldering

What is necessary for cutting concrete in a domestic environment?

Many might think that a punch and a sledgehammer would be enough to cut reinforced concrete. They are deeply mistaken. We advise you not to try to cut concrete with ordinary cutting wheels.

It will fly into small parts at the first slight skew. Experts strongly recommend using all possible protective measures:

  • protection around the cutting wheel,
  • mask to protect the respiratory organs (an ordinary building respirator is not suitable),
  • headphones.

You still can’t do without a sledgehammer and chisel. Initially, concrete should be sawn on both sides of the reinforcement. This is done using a specialized cutting diamond wheel for concrete.

Then the concrete is knocked out with a chisel and sledgehammer. All that remains is to cut through the reinforcement. However, do not forget that it is under mechanical stress.

Rebar Cutting: Using Plain Cutting Wheels

After the reinforcement is freed from concrete, ordinary cutting wheels for the grinder can be used. This is done to maximize the conservation of expensive concrete disc.

If we are not talking about cutting concrete structures, but about creating strobes in the walls, then today there is a separate tool for this. This is a shtroborez. Its advantage over the grinder is that it is equipped with a vacuum cleaner.

That is, when cutting the shtroba, all concrete chips will be removed immediately. No dust and dirt! You can use a wall chaser even in a room in an apartment building.

If we talk about industrial analogues, then whole installations are used there. The fact is that when cutting concrete, the disk is significantly heated. Cool it with water.

Video instruction that will allow you to cut concrete without dust yourself:

Types of tools and characteristics

The necessary efficiency is achieved by the use of diamond cutting technology. High-quality cutting is also carried out by affordable lasers. Rail, mobile, portable and stationary tools are types of equipment in which diamond is cut. This equipment has electric, gasoline, diesel, pneumatic and hydraulic drives. Its working parts have various designs, diameters and types, however, coatings of various resistance include diamonds. Depth of cut, concrete strength and the presence of reinforcement in a particular design determine whether manual equipment will be used or if a more powerful machine is needed. The resistance of the material heats the cutting (drilling) parts, so they need to be cooled with water and air. A crumb of diamonds is attached to the cutting surface of the discs by brazing (for wet cutting) and welding it with a laser to the surface (for dry cutting).

Seam cutters

A seam cutter is usually used to form horizontal cuts in concrete (roads, runways, etc.). The depth of cut can be up to 60 cm. The design consists of a supporting frame and a drive unit connected via a belt drive to a cutting tool, which has the function of regulating the depth of cut. The wet cutting technology is implemented by supplying water from the tank to the place of work, but there are modifications without it. The electric cutter is manual or self-propelled. The latter (it uses a gasoline drive) is much more powerful, it is used in conditions of high humidity and in the absence of electric mains. Self-propelled diesel equipment is the most overall, and is designed for long-term continuous use. The power of the devices and the rotation speed of the diamond discs allow you to cut both unreinforced and reinforced material.

Wall saws

The wall saw performs precise cutting of concrete walls, blocks in all planes, both in the air and under water. It has a low noise level and high performance. Such a cutter makes a cut to a depth of 0.9 m. Its design is based on a sturdy frame on which a transmission and a segmented cutting disc are mounted. The equipment moves along the guide rail (mounted on the wall) and has a smooth speed controller. The waste material and excess heat are removed from the disk by running water supplied at a speed of 10 l / min. A device can also be installed to suck and discharge used water from the cutting area. Electric models operate from a three-phase network, in powerful equipment they use oil stations connected to hydraulics.

Laser equipment

Laser cutting of concrete has become available not so long ago. Such a tool for cutting concrete allows you to cut, cut, cut an array of partitions and walls up to 70 mm thick. Powerful gas-discharge CO2 lasers in mobile (portable) design are already used, the deployment time is tens of minutes. Power devices - from 0.1 to 45 kW. The seams have a width of 0.05 - 1 mm at a laser head speed of up to 1 meter per minute. Laser technology is advantageous by the possibility of economical formation of complex sections of absolutely any shape with minimal errors, including in hard-to-reach places. The seams have an ideal surface, the laser does not deform the wall structure (local high-temperature effect), does not create noise, has several operating modes.

Hand tools

There is equipment that allows you to cut concrete with your own hands. Grinders help cutting in dry and wet conditions, which involves the use of appropriate types and modifications of discs (turbo-diamond, endless, segmented) with a diameter of 0.2 - 0.8 m. Such a tool requires cooling with water (air). For cutting to a depth of more than 0.1 and up to 0.16 meters, an electric, pneumatic or hydraulic cutter is already necessary - a circular saw. The cutter can have a gasoline drive, which makes it more powerful, but it creates exhaust fumes. The greatest productivity and durability is hydraulic equipment. With a mass of about 8 kg, she makes cuts up to 26 cm deep. Tool hole preparation is carried out with perforators using a diamond crown. With such powerful tools, they drill holes with a diameter of up to 45 cm (carbide bit) with their own hands. Wall fragments can also be cut with a chainsaw on concrete. It will provide a filigree cut of the desired shape. The hand saw has a water-cooled cutter, which is formed by a metal chain with a dusting (diamond). Such a saw is effectively used when working with unreinforced or slightly reinforced material. The drive, providing a depth of cut of joints up to 50 cm, can be with a gasoline engine or powered by an electrical outlet.

Rope cutting

Oversized walls and structures are also cut using equipment, the active element of which is a rope with evenly distributed segments of diamond grains. Such a tool can cover up to 10 m2 of the area of ​​the future cut. The product includes a power plant, a cutting metal cable, a pulley (creates movement) and exhaust rollers (form a cut form). The unit drive is powered by a three-phase network or can be hydraulic. Before starting work, a hole of the desired diameter is drilled in the structure, a rope is pulled into it. The closed loop of the cable is attached to the pulley. The supplied water frees the working area from the waste material and cools the tool.

Drive selection

When choosing a disk, it should be borne in mind that segments can be attached to the canvas in two ways:

  • Silver solder. Such discs are widely used for wet cutting.
  • Laser welding. Such nozzles are characterized by high productivity, and, as a rule, are used for dry cutting.

In addition, when choosing a disk, you must make sure that its diameter and hole for mounting corresponds to the technical characteristics of the grinder. Another important point is the maximum speed. It is desirable that this indicator of the disk was higher than the maximum speed that the grinder can provide.

After all of the above parameters are determined, you can choose the most optimal type of tool, which will ensure maximum efficiency.

Segmented Disc Concrete Grinder

Choice of cutting type

There are two types of cutting:

As a rule, cutting is performed with water, in which case the procedure takes place without dust. In addition, water can increase work efficiency, as well as increase tool life. Due to the fact that the process can be continuous, the speed of work will increase. (See also Stroborez for aerated concrete: features.)

However, there is not always a source of water near the work area. In this case, the cutting is carried out dry. The dry cutting process should be intermittent, i.e. consisting of several cuts.

Cutting concrete along the intended line

After the grinder for cutting concrete is prepared, you can begin to work:

  • First of all, you need to outline the line along which the cut will be made. It is advisable to fix wooden blocks along the line, which will make the cut lines even.
  • Then you need to turn on the grinder with your own hands and make a cut with a depth of about 0.5 - 1 cm.
  • Next, remove the bars and make an incision to the desired depth. In the process, it is necessary to spray water on the blade. If cutting is performed dry, then the procedure, as mentioned above, must be periodically stopped so that the tool cools down.

Note!
Before starting work, it is necessary to protect the respiratory organs with a respirator.
In addition, other personal protective equipment should be used - glasses and gloves.

Here, perhaps, is the entire instruction for performing this work.

The concrete cutting procedure itself is not a big deal. The most important thing is to choose the right diamond blade and adhere to certain rules that are listed above. In addition, safety precautions must be observed, as working with a power tool always requires special care.

From the video in this article, you can get some additional information on this topic.