How to cut concrete
Determining the type of concrete
Before you saw with an angle grinder on concrete, you need to determine what type of concrete you are dealing with. This is because different types of diamond blades are used for each type of material. For example, it may be reinforced with metal bars (reinforced concrete).
If the depth of cut is about 10 centimeters and deeper, you may run into a metal lattice (reinforcing frame) on “your way”. As mentioned above, there are special discs for this purpose.
In addition, it should be taken into account that over time the structure of the material changes. Fresh concrete is more abrasive, while old concrete is harder. For this reason diamond discs for old and fresh material must be different.
4 Ways to Cut & Remove Concrete for French Drain. Level 2. EASY DIY
If you have time, you can study the structure of the material in more detail, which will allow you to choose the most appropriate tool for it. For example, if you have basalt or quartz in the mix, it will dull the wheel quickly. Diamond segments should therefore be bonded with a soft material so that the new diamonds “break in” more quickly.
You should also keep in mind that the size of the filler affects the cutting speed. the coarser it is, the slower the procedure is.
Tip! Diamond tools are used not only for cutting, but also for other concrete work. In particular, diamond drilling holes in concrete or grinding with diamond cup discs are often used.
Pictured is a diamond wheel with laser brazing
Choosing the disc
When choosing a disc, keep in mind that the segments can be attached to the blade in two ways:
- Silver brazing. These discs are commonly used for wet cutting.
- Laser welded. Such nozzles are characterized by high productivity, and are usually used for dry cutting.
Also, when selecting a disc, make sure that the diameter and the fixing hole are within the capabilities of the angle grinder. The maximum rotation speed is also important. It is desirable for the disc to be higher than the maximum RPM that the angle grinder is capable of providing.
Once all of the above parameters have been determined, you can choose the best type of tool for maximum efficiency.
Choice of cutting type
However, there is not always source of water near the work area. In that case, you should dry cut it.The dry cutting process must be intermittent, i.e.е. consisting of several cuts.
After the angle grinder for cutting concrete will be prepared, you can start working:
- The first thing to do is to outline the fishing line along which the cut will be made. It is desirable to fasten wooden bars along the mowing line, which will make the mowing line cut even.
- Then you need to turn on your own hands the angle grinder and make a cut with a depth of about 0.5. 1 cm.
- Next, it is necessary to remove the bars and make the cut to the desired depth. While working it is necessary to spray water on the blade. If cutting is performed dry, the procedure, as mentioned above, should be periodically stopped to allow the tool to cool down.
Pay attention! Before you begin, you must protect your respiratory system with a respirator. In addition, other personal protective equipment such as goggles and gloves should be used.
Here, perhaps, is all the instructions for doing this work.
Choice of diamond discs
In order to cut concrete it is necessary to choose the right cutting blade.
There are currently two types of segment clamping on the saw blade. Diamond discs with brazed segments, using silver brazing, are widely used in cases where it is possible to cut wet. When dry cutting, laser welded diamond segments are used more frequently, and are characterised by higher productivity.
The power of the saw also influences the choice of tool. Diamond blades for power tools need a higher diamond concentration and a stronger bonding of the segments. Otherwise the segments (blades) can fail very quickly.
If the amount of work to be done is not very large and you will not use diamond discs often, it is more rational to choose budget class discs, which will save on the purchase of tools. But if you use diamond blades often or the amount of work is rather large, it makes sense to buy professional diamond blades of a high class with a long cutting life.
Dust-free cutting, how to saw
In the text above we have already mentioned the two main ways of cutting concrete. wet and dry.
The wet method, features. Wet or wet method is recommended for high-quality and productive concrete cutting. Cooling with water of the working nozzle and the surface of the cutting zone, will allow you to work without stopping for additional time to cool down the equipment. In addition, the water will knock down the dust, and the technological process itself will be carried out without the presence of large amounts of dust.
If you use an angle grinder as a tool, you should moisten the diamond disc and the cutting surface with water to reduce dust. The help of a colleague at work, who will water the cutting area from a plastic bottle, will come in handy.
The wet method can be used without problems in buildings under construction, where there is no risk of flooding the neighboring premises. In the manufacture of repair construction work in residential areas, such as the organization of additional doorway, wet cutting method fraught with water-soaked walls and short circuits electricity.
Makita GA 5030 angle grinder for cutting concrete. Photo 220Volt
Dry method, features. To avoid the bad consequences of the wet method of cutting will allow dry technology. Here the discs are not water-cooled, so perform an additional hole in a small thick wall in an apartment with this method is quite realistic. In this case, the angle grinder will have to turn off very often to cool down, and the process will take quite a long time. The use of a special construction vacuum cleaner is mandatory for dry cutting. Waiting until the dust settles is to initially condemn the work to fiasco. You will also have to put up with frequent replacement of discs. they will quickly wear out.
When carrying out work in the apartment for the device of the opening in the wall by dry cutting method, the following stages of work should be adhered to:
- redevelopment project must be coordinated with the relevant authorities;
- Make a thorough marking of the boundaries of the opening, taking into account the presence of utilities, provide for the presence of the armature;
- cut the perimeter of the borders on one side;
- drill the corners of the opening;
- taking into account the drilled holes, cut the perimeter of the opening from the back side.
- Dismantling of cut concrete with cutting into pieces of weight allowing them to be transported;
- reinforce the opening (this step must be stipulated in the coordinated project) with metal angles or channel bars.
How and what to cut concrete with?
Cutting concrete. an operation that is widely used at any stage of construction, repair work. Different equipment for concrete cutting is used depending on the features of constructions, material age and working conditions. A variety of tools allows you to quickly solve any problems of cutting concrete, including when you need accurate accurate shaped cutouts and need to minimize the amount of dust, debris.
How to reinforce a concrete opening
After you have cut the opening or expanded it, you need to strengthen the walls with additional metal structures.
Reinforcing openings can be as follows:
- Single row. For the arrangement of this type of reinforcement, a channel is used. Need to make a U-shaped frame around an opening. In such a design uses a variety of channels, and attachment to the walls can be made in different ways. The places where the channel is not adjacent to the wall, you need to fill with mortar.
- Corner. The bezels are made with the corners on both sides of the wall. To fasten the angles to each other, studs, metal plates are used. These are the most common designs.
- Combination. Openings are reinforced by means of channels and angles.
Methods of cutting concrete
Any cutting of concrete is inextricably linked to operations such as:
All of them can act as a supplement or as part of the main technological process. I distinguish between two basic cutting methods: a) dry cutting; b) wet cutting.
The last method is the most technologically correct. When it is used, a jet of water is delivered to the place of tool and material friction, the goals of which are: a) to cool the cutting component; b) to settle the dust; c) to increase cutting efficiency; d) to allow continuous work and increase safety of the work.
However, it is not always possible to supply water due to lack of it. It is not uncommon that water can cause damage to the tool. For these reasons, “dry cutting” can be used. It is slightly different in that the work must be carried out intermittently, allowing the cutting elements to cool down. High dustiness of works forces to use either dust suction devices, or to interrupt the process for a longer period than necessary to cool down tools. Because in closed rooms because of dust there is no visible place for cutting, and there is a risk of mistakes in the work.
When dry cutting, the blade tip should only be plunged very deeply into the concrete because excessive side friction heats the tool and can cause damage. For deep cuts, several side indentations must be made and gradually enlarged to create a clear path for access to the point of impact on the concrete.
What is better to cut the concrete and what tool to choose
In the process of repairing of apartments or private houses the following question often arises: what to cut the concrete with?? This is necessary when the owners are planning to lay new electrical wiring, make an opening for a door and in many other cases.
There are now several options for coping with concrete:
But most often this is done with an angle grinder equipped with a diamond disc. The advantages of this method are considered:
Where to use?
The tool is often used when it is necessary to make a hole in the material. A concrete saw is used when the use of diamond wall saws is not possible:
Such a tool can overcome and aerated concrete.
Any reinforcement can be an obstacle for the concrete saw.
Turbo-diamond discs with a wave housing will allow you to cut with the highest load, for example, when you need to cut reinforced concrete. Of course, this type of nozzle is the most expensive. Tip! Cutting reinforced concrete with diamond wheels is performed first to a depth of about one centimeter.
To remove a weak screed layer, you can use high-pressure water or the hydro-breaking method. This waterjet exposure can be made selective. If properly adjusted, the concrete screed, which is made in good quality, will be intact, while the defective one will be washed away by water.