Can diamond discs cut rebar?

What to saw a concrete slab with rebar with

It happens that reinforced concrete structures need to be cut:

  • To create and expand window and door openings;
  • To change the layout, disassembly;
  • For the installation of outlets and built-in switches;
  • For routing wires and cables;
  • In construction, when repairing bridges, overpasses and other complex structures.

How and what to cut reinforced concrete? Today there are different techniques and tools for processing durable stone with an integrated metal frame, which we will talk about next.

General characteristics of the tool

The angle grinder, like many other power tools, has removable parts. This allows the angle grinder to carry out a wider range of work. Diamond disc for angle grinder requires sharpening or just timely replacement. Therefore, from time to time it is simply necessary to purchase new replacement attachments.

It is worth noting that there are simple and diamond discs for angle grinder. On the latter option is stopped more often, because it is a more durable piece of equipment. But depending on the amount of work, you need to choose the characteristics of the discs.

The more load it will be subjected to, the more durable and expensive the tool. It is also important to consider under what conditions diamond discs will be used. For each type of material, the appropriate variety is used.

Can diamond discs cut rebar?

Principles of doing the job

Each type of concrete has its own characteristics, so the work always begins with accurate determination of its characteristics. As a rule, experienced craftsmen choose special discs for simple concrete and reinforced, for fresh and old. Even inclusions in the form of basalt or quartz can tell you which disc is best, if you have enough experience to understand such clues.

If possible, concrete should be cut in wet conditions. A thin layer of water cools the cutting wheel and tool, which prolongs the service life of the latter and ensures continuous work. If there is no water nearby or it is not enough, the cutting is performed dry, but in this case you should not hurry. the work is usually performed in several stages, allowing the unit to cool down a little after each of the approaches. To be sure that the tool and the disk successfully cope with the task, the first cut is limited to a depth of 1 cm, after which the angle grinder and the disk are carefully inspected for possible mechanical damage.

The sawing procedure itself is quite simple. Even with wet cutting care should be taken to protect the respiratory system in case something goes wrong. After that, you should clearly outline the line for the trimmer of the future cut, and supports on both sides, made of wooden bars, at the same time will help not to go deeper into the thickness of the material than it is supposed to at the first cut. The first cut, as already mentioned, is usually made to a depth of not more than a centimeter. When cutting damp, water should be sprinkled on the blade as gently as possible, it should not be too much, otherwise if it gets into the motor of the angle grinder, it could cause a breakdown of the electric unit.

When the first cut is made and the cutting wheel has cooled down a little, remove the wooden spacers. now you can orientate yourself without them, using the existing cut. When you cut into a considerable depth, it is advisable to divide the work into several stages.

Even if you don't know the precise structure of a concrete product, you can be sure that when digging more than 10 cm into the concrete, the chances of finding a metal reinforcement are nearly 100%, so choose an appropriate disc.

How to work with an angle grinder correctly is explained in the following video.

Blades for dry cutting

Their effectiveness is due to the segmentation of the cutting part. Each individual tooth is dusted with diamond. Gaps in the segments allow for cooling of the wheel as it rotates and for dust extraction.

The standard disc dimensions are 230 mm in diameter. Cutting depths of 22 mm or more. Handy for laying wiring.

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Household diamond wheels

For home purposes, it is also often used disc for angle grinder on concrete, which can cut very hard materials, ranging from ordinary bricks, and ending with ceramics, concrete tiles. But they are not suitable for cutting granite, marble or for carving in reinforced concrete. In addition, tools for domestic purposes wear out so quickly that they are not suitable for professional applications.

Such household diamond discs as “Zubr”, “Sparta”, “Tsentroinstrument” have optimal price-quality ratio. Their surface finish meets high standards, so they can be used for quite a long time if not used regularly.

It is very important to use diamond discs according to their intended use, they should not be used to cut metal or concrete without proper cooling. To prevent overheating of the cutting discs and to maintain a reliable service life, limiting the duration of cycles is necessary.

How to choose the right product

When choosing a diamond wheel, you need to consider different reasons in each case. Further we will consider some conditions that affect the choice of one or another option.

The 1st. the material processing. Normal concrete is usually processed by segmented dry cutting disc. But if the concrete is new, it has a high level of abrasion, and the wheels will “eat up” quickly. Therefore, in such cases, it is recommended to take wider discs.

Compared to young, old concrete is more durable and choose discs of moderate width. If it contains quartz sand or basalt, then to process such a material is ideal for the product in which the diamond plates are soldered silver to the base. For cutting granite or reinforced concrete the best choice is the “soft” version, which can be used to make holes in concrete floors, window or doorways.

The method of cutting should also be taken into account. The introduction of wet technology helps to avoid such problems as:

Before buying single-piece blades, find out whether the cutting equipment has a cooling system. If you want to do dry cutting, look for segmented products.

The next factor to consider is the working conditions. So, in the home criteria is best to choose products with good quality-price ratio, through which you can handle concrete and reinforced concrete medium reinforcement. If they are not used very often, they can last a long time, provided that they are not overloaded.

A professional discs are designed for constant implementation, they are durable and have a higher resistance to wear. It is necessary to receive such discs strictly according to their purpose. So, if they are designed for marble, they cannot cut concrete.

Choosing one or the other disc, consider the depth of cut, also what kind of equipment you plan to work with.

The deeper you cut, the bigger should be the disk across. Also, you need to keep in mind that if you attach a very large wheel to the equipment, its linear speed will be very high, this will lead to equipment wear. And if the wheel is very small, it will warm up and slip.

If you are using a massive wall saw, you need to get a special diamond circular saw, the external cross section of which is about 1200 mm. And models with operating cross section up to 400 mm are used for machining foundation blocks or concrete parts.

Handheld electronic tool wheels are not as huge in size. If concrete is to be cut during repair work, you can choose models with a cross section of up to 120 mm. When it comes to the treatment of lintels in the lumen, slopes and other parts, you need to choose a disc for angle grinder on concrete or reinforced concrete with a cross section of up to 230 mm.

Stroborez cutter works by analogy with the angle grinder, but the concrete in this case is processed by means of 2-diamond disks. Cutting width and depth can be adjusted during operation. The cross section ranges from 110 to 365 mm depending on the depth of the groove. Thanks to the discs for reinforced concrete and solid chisel saws you can make grooves for communications quickly and perfectly on dry technology.

Concrete diamond wheel for angle grinder will blunt if it hits reinforcement?

Or it is calculated on the fact that in the concrete there is reinforcement

All depends on the time and effort of contact, if you will be persistent in re-sawing, you will screw up, Adnazhno

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I have a lot of 4's in the walls. Sparks, but passes.

Sawed over a few times a thin (5-6 mm) rebar. Can be sensed by the fall of speed and appearance of sparks. I did not notice any changes in the blade because of the small number of hits.

cut a welded wire mesh a little and rebar in the concrete caught accelerated wear did not notice

ilart wrote : Or calculated on the fact that in concrete there is a rebar

Alex_dr wrote : Depends on the type of wheel.

I often pass reinforcement, even 10-K, with a segmented diamond wheel.No consequences.

DOCA wrote : Often passed rebar, even 10K, with a diamond segmented wheel.No consequences.

Who would object?! Diamond wheels for reinforced concrete. segmented.

Thank you all for the comprehensive information I will not be too afraid of rebar now.

ilart wrote : Or designed for the fact that there is rebar in the concrete

There are special wheels for concrete and rebar cutting at the same time. They are really more expensive. Before the new year I bought a Bosch angle grinder. I was offered such. Like the new model and everything. It really looks more solid than a simple disk on concrete.

Diamond discs are not suitable for cutting metal constructions or steel and aluminum sheets. Nothing is written about the rebar in the concrete.

Reinforcing of strip foundation. the technology of work

The number of reinforcing elements should be calculated on the basis of foundation dimensions. For foundations with a width of 40 cm, 4 longitudinal rods are enough. two from the top and two from the bottom. To install a series of wire cage in strip foundation of 6×6 m, you need, on average, 24 m of reinforcement. If 4 bars are laid, 96 m of longitudinal bars are needed.

For the foundation, which width is 0.3 m and height is 1.9 m, for each anchorage at a step of 5 cm from the surface, according to the concrete calculator we need (30-5-5)x2 (190-5-5)x2 = 400 cm or 4 m of reinforcement elements of smooth shape.

If the spacing of the clamps is 0.5 m, the number of connections will be: 24/0.5 1=49 pcs. So, based on the calculations, we need 4×49=196 m of transverse and vertical bars.

Rebar diameter, mm Calculated area of cross rod, mm2, with the number of rods Theoretical weight of 1m of reinforcement length, kg
1 2 3 4 5 6 7 8 9
6 28,3 57 85 113 141 170 198 226 254 0,222
8 50,3 101 151 201 251 302 352 402 453 0,395
10 78,5 157 236 314 393 471 550 628 707 0,617
12 113,1 226 339 452 565 679 792 905 1018 0,888
14 153,9 308 462 616 769 923 1077 1231 1385 1,208

The minimum area of the foundation's reinforcement is regulated by regulations and the strength of the foundation depends on this

For this, the basis should be a square or rectangle.

Before installing the frame on the bottom of the trench must lay a sand cushion to a depth of 1 m.

  • bricks are placed at the bottom of the trench, the height of which is 5 cm (in order to create a gap between the bottom of the base and the frame);
  • to install the rack rods, it is necessary to make a sample in advance, according to which the rods will be cut;
  • Lay bars longitudinally on the bricks;
  • Longitudinal bars with a step of 50 cm are tied with tying wire horizontal lintels with a length slightly less than the thickness of the foundation (approximately 5 cm on each side);
  • to the corners of the formed cells, fix the bars vertically 10 cm less than the height of the foundation;
  • to the vertical reinforcement, mount the upper longitudinal bars;
  • the upper cross bars are attached to the corners.

When reinforcing the strip foundation it is necessary to follow the requirements of Construction Norms and Regulations 52-01-2003

The main task of the foundation is to transfer the load of the building (construction) on the ground. It is obvious that the concrete in the foundation will experience an internal compression force. the walls are pressed from above, the bottom is repulsed by the ground. The concrete, in contrast to the armature, works very well in compression. So why is reinforcement used in strip foundations??

In the process of operation of the building it is inevitable that there will be some settlement. The soil beneath the base plate under the pressure from above is compacted. The higher the pressure, the stronger the compaction. If it is strictly uniform along the entire strip foundation length, the foundation will not experience the following dangerous internal forces.

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In practice, this situation is very rare. Unsymmetric shape and loads cause uneven pressure. In order to reduce uneven settlement within a single building, foundation strips of different widths are usually used. load. more width. But even in this case it is impossible to equalize the values of pressures under the foundation's underside completely.

In addition, it is impossible to guarantee the absolute perfection of the foundation (soil). Various inclusions in the soil strata also form the unevenness of settlement. Uneven moisture content also has a negative effect. Leakage of water-bearing communications, the lack of a blind area on one side, the probability of different extensions (additional load gives additional settlement). all this forms the unevenness of settlements.

Conditionally, the surface of the ground under the strip foundation tends to become “curved” in the vertical direction. The most dangerous areas are the corners, as well as places with significant differences in loads (e.g., if there are different numbers of storeys, columns, pylons additionally loaded, etc.).д.).

We suggest you read: How to insulate the foundation of the bath from the inside

There are two kinds of reinforcement according to the material. of steel and composite one. The latter appeared comparatively recently and, having a number of disadvantages (as well as advantages), is rarely used in private construction today.

The steel reinforcement is subdivided into bar and wire. The strip foundation reinforcement is reinforced with the bar rebars of periodic profile as the basic (working, also called longitudinal) and smooth as the additional (transverse) rebars.

The working reinforcement must have good adhesion to the concrete to work together. Such reinforcement is made with a periodic profile, dividing it into classes of strength. According to State Standards since the Soviet times, A-III class rebars or its analogue according to modern State Standards. A400 are used for private construction.

In view of a certain unpredictability of the degree of unevenness of the subsidence, it is hardly possible to calculate the exact diameter required for the strip foundation. Therefore over decades of construction and operation of buildings have been developed structural requirements for strip foundation reinforcement.

  • The diameter of working rods is taken as not less than 12 mm.
  • Working (longitudinal) bars are combined into spatial cages by means of transverse reinforcement by welding or tying method.
  • The number of longitudinal rods in the framework is at least four (usually six).
  • Step of transverse reinforcement is between 200 mm and 600 mm. The diameter of the bars is 6-8 mm.
  • The thickness of strip foundation is usually taken equal to 300 mm.
  • Vulnerable points at corners and T-joints are reinforced with rebar or feet. Their diameter is taken equal to the diameter of the longitudinal rods.

Segmented disc.

Ideal for dry cutting (no forced water cooling), because the disc is cooled by the blade design. They are good for cutting concrete, stone (including granite) or brick.

Important note: Continuous operation of the segmented disc should not exceed 1.5 minutes, otherwise the intensity of wear increases sharply.

Note: The smaller the segment size, the slower the heat of the disc. A reduction in the number of segments also reduces vibration.

Solid disc.

This type is excellent for working with ceramic or marble. The shape of the disc ensures a smooth cut so that decorative materials can be handled. On the one hand, a solid blade requires forced cooling (cutting in a puddle is common practice), but on the other hand, if good cooling is assured, there are no limitations on the duration of continuous operation.

For work with particularly hard materials, it is recommended to use special discs with oblique slits (slits). They reduce side friction, reducing the intensity of disc heating and facilitating dust removal.

Combination disc.

Can be used to cut any non-metal material, but ceramic tiles should be cut with water, and concrete can be cut without cooling. The disadvantage of this type of disc is the lower efficiency compared with the above-mentioned alternatives.

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