Anchor hook how to attach. High-quality installation of anchors in concrete. Video: Anchors. The principle of operation of the anchor bolt

Fastenings using various types of anchors are characterized by experts as connections that can provide reliable retention of heavy loads. After deepening into a pre-prepared hole, the worker, depending on the tasks, chooses the best way to fix the anchor bolt. After the assessment, when the selected areas of the surface are suitable for organizing a point that provides fastening of anchor devices, the point is arranged with subsequent fastening of the equipment.

The use of anchor supports is necessary when using a cable movement system during installation and construction work at height, fixing slings for positioning and holding a worker without slipping and jerking. The strength of the connection allows the use of anchor points and lines to ensure the installation of collective and personal protective equipment, which makes it possible to safely perform installation work on products and maintenance of devices located at a height.

With the help of a kit for fastening to anchor supports, it is possible to install a sleeve on power transmission line supports, winding a free length of an optical cable on the frame. This type of connection is used to ensure the safety of work performed at height according to the tolerance. To carry out such activities, a permit is required, issued by a labor protection specialist and endorsed by officials from among the leaders, and the work itself is carried out by a group of workers under the guidance of foremen, link leaders.

The most widely used anchor bolts have a spacer operating principle based on the expansion of the rear section of the sleeve when a cone-shaped sleeve is screwed into it. Among the well-known types of anchors, experts call driven, expanding, chemical, spacer and wedge structures. Each of them provides reliable holding of the fastened part by using the friction force between the contact surfaces of the bolt and the installation zone, the stop force, which provides compensation for the acting stress by the resistance of the metal of the product. Increasing the diameter of the spacer when the bolt is screwed into it ensures a secure connection due to the combined action of stop and friction forces.

Experts emphasize the importance of choosing the right type of anchor, based on the study of the manufacturer's documents that determine the specifics of each type of product. since the reliability of the system also depends to a large extent on the building material used at the point of attachment of the bolt. Proper fastening is necessary to prevent damage during operation of the parts that make up the connection, to ensure comfortable work in the backwater. Such a connection will ensure safety when working at height, fastening heavy static (horizontal bars) and dynamic (rigs for diamond drilling) structures.

Types of fastening anchors

As noted above, the correct choice of the place where the anchor point is made plays an important role in the process of ensuring the safety of the worker. It is possible to assess when the selected sections are suitable for the installation of an anchor device attachment point by the load they can withstand, each of them must withstand a weight of at least 22 kN. To ensure the reliability of the connection, the anchor point used for fixing the equipment can be connected to the load-bearing elements of the building, pre-assembled steel structures. After drilling the hole and installing the anchor, kits are used that provide fastening of the safety structures to the anchor supports. The kit used for the anchor type of fastening, in the standard version, provides for the presence of:

3 anchors;
threaded stud;
center punch for deepening;
nut, involving the use of an open-end wrench.

Additionally, the kit used for fastening to anchor supports may include a washer, a punch to ensure wedging when using an anchor of the appropriate design. In addition, the kit for anchoring may include more bolts, but in this case, the cost of one set increases. The kit that provides fastening of security systems to anchor supports includes an anchor clamp, a small steel cable, wedges and a bracket that allows mounting up to 3 clamps.

Structurally, an anchor bolt with a nut is a stud with a thread on one side, with which the nut is screwed, and the other end is made in the form of a spacer cone. When the nut is tightened, the spacer-type sleeve, on the side surfaces of which slots are made, expands, forming "petals" that provide a reliable connection with the support surface.

Note! Before fixing the anchor bolts, drilling of the concrete surface is carried out, while the drill, with the exception of cases where impact type bolts are used, corresponds to the diameter of the anchor used.

Anchors used for attaching parts of geogrids are mounted around the perimeter of each of the mounted modules. The anchor for anchoring the geogrid is installed according to a pre-approved scheme, so that the provided tension lines resemble a rectangle.

Manufacturers place high demands on the quality of products, checking the strength of the elements necessary to ensure safety, excluding their damage, breakage or failure. When using rope access systems when climbing or descending planes, as well as performing installation work, it is forbidden to use only one rope. To ensure the safe operation of flexible anchor lines, the correct answer when asked by the instructor about the features of use is the need to use end stops to prevent the descent from passing the end of the rope. Permissible impacts are determined by the acting load in the operating structures. In turn, workers receive a work permit, giving the correct answers after a preliminary adventure of the appropriate briefing.

impact method

The use of this method involves the use of driven type anchors and is distinguished by ease of installation and reliability of the resulting connection. However, the method has limitations regarding the possibility of using it exclusively when working with materials with high strength indicators, for example, for concrete, solid brick or stone.

Before fastening the driven anchor bolt, it is necessary to drill a hole, the diameter of which corresponds to the parameters of the bolt used.
After that, it is necessary to clean the prepared hole from debris and dust.
The next step is to mount the driving-type bolt into the hole.
Using a hammer and other tools, such as a barb or a special wedging design, the striker is driven into the conical hole. At the same time, the sliding part of the bolt opens, providing support against the walls of the prepared hole.
At the last stage, parts are fastened using a stud or bolt.

Expanding design

The design of the expansion type bolt has the form of a cylindrical rod, in which 3-4 independent segments are located. In the upper part, the segments are held by a ring, and a spring with high elasticity is located below. Elements of this type are used for fixing massive structures into brick, rock, concrete material. When using fasteners to hold structures whose weight is below average, it is permissible to make a connection into a brick (silicate type) wall, limestone and concrete of a cellular variety.

Before fixing the anchor bolts of the fastening, it is necessary to mark and drill the hole before installing the fixing element. After that, the sleeve of the product is mounted into the wall, when the stud or bolt is screwed into it, the expansion element moves to the rear section of the fixtures, which ensures high pull-out strength of the connection.

An anchor bolt with a ring is a stud, at the end of which there is a ring and a threaded thread. When the pin is rotated during twisting, the spacer element moves, ensuring the divergence of the segments in opposite directions. A product of this type is used when it is necessary to permanently fasten structures with a large or medium weight, for example, to stretch cables.

wedge design

The wedge-shaped anchor is a stud, at one end of which there is a wedging sleeve, which ensures a solid installation of the product in stone, solid brick, reinforced concrete. On the other side there is a thread, when moving along which the nuts, when the structure is tightened, the coupling is wedged. The fixture is used when mounting equipment of a hinged type, pipe and cable communications, bearing consoles and is used when it is necessary to ensure high strength of fastening.

How to install an anchor bolt

Before attaching the anchor bolt with a nut, it is necessary to drill a hole, the diameter of which must be equal to the thread parameter. After cleaning the hole from dust, the anchor is installed in it, while the conical part is directed into the hole, the length of which slightly exceeds the minimum depth for anchoring. Using a hammer, the anchor is inserted until the required installation depth is reached, after which the nut is tightened.

After providing the necessary tightening torque, which is better controlled using a torque wrench, the nut is unscrewed, a suspended structure (for example, a bed for diamond drilling) is installed on the stud and the nut is tightened.

Chemical anchor, adhesive fixing

Fasteners based on filling the inside of a metal rod embedded in the wall are used to provide strong connections in stone, brick, sandstone, shell rock, limestone, and cellular concrete. Such connections involve the use of chemical anchors, such as the popular all-weather type cf900 moment fastener. A metal insert, which is a reinforcement rod, a threaded stud or a sleeve with a thread on the inner surface, is deepened into a prepared hole, the diameter of which exceeds the anchor parameter by 2 mm. After that, a capsule with an adhesive based on polyester, polyurethane or acrylic resins, a hardener and a filler in the form of sand is inserted into the sleeve. Then the glass cylinder is destroyed and a metal rod is inserted into it and the binder is expected to set.

Anchor calculation

Pull-out testing is often done at the installation site. The load capacity will depend on the base material, for example:

When installing massive structures at a height, the required pull-out strength should be about 700 kg, and therefore experts recommend using chemical varieties of anchors for such fasteners.
When used as a base of concrete or brick, the average load is about 350 kg, this value is enough for fixing structures of medium and heavy weight.
When using foamed concrete, the load it can withstand will be about 250 kg.

In addition to calculating the load-bearing capacity of the elements used, the correct tightening torque of the threaded connections must be ensured. In case of insufficient tightening, there may be no friction force in the connection, if the recommended values are exceeded, there will be a possibility of material destruction due to excessive pressure on the base.

Fasteners have entered our lives so firmly that we have not noticed their presence for a long time. But they surround us everywhere, and if we imagine for a moment that they all disappeared at once and at the same time, this would be the worst catastrophe in history. Without the most common nails, screws, bolts and nuts, progress in any field of science and technology would be impossible. But not only industry and production need these indispensable helpers.

It is enough just to look around, remember how many tasks we have to solve in everyday life in order to equip our life, what problems arise when it is necessary to hang a chandelier or a picture in the house, fix kitchen cabinets or a satellite dish on the balcony on the wall, install a hanging sink in the bathroom or a large mirror in the hallway ... All of them are associated with the need to attach various objects to the elements of building structures: walls, columns, ceilings, etc. Usually, there are no big problems with this in a wooden house, but what if it is brick or concrete ?

Fastener - anchor

Once upon a time, however, not so long ago, to solve these and many other problems, wooden chops were used, hammered into pre-drilled holes. This method had many drawbacks: over time, the tree in a dry room decreases in size and the cork begins to hang out, or even falls out altogether; in damp conditions, on the contrary, it swells, which leads to cracking of the hole and, as a result, also to the loss of the cork.

To get rid of these problems, plastic dowels were invented. They have a lot of advantages: they do not change in size, are unified, cheap, reliable. But there are also disadvantages: they do not withstand large and massive loads. Due to the large weight of the structure, the plastic deforms over time and ceases to be securely held in the hole. In addition, the holes in the walls of high-quality in-situ concrete have a smooth inner surface, which increases the likelihood of dowels slipping out of them.

For these purposes - reliable fixation in brick and concrete walls fasteners under heavy weight loads and anchor bolts were invented.

Anker means "anchor" in German. And their action is somewhat similar, because the holding mechanism of the anchor fastener is also located at the bottom of the hole.

By way of action such products are divided into two main types:

. A capsule with a special adhesive is placed into the hole, crushed when installing the fastener, which is securely held after the polymerization of the adhesive. The disadvantage of this method is the need to wait for the glue to harden. The advantage is the possibility of using not only in monolithic wall structures, but also in hollow ones.
Mechanical. They are based on the principle of wedging or collet expansion of a special metal sleeve, which is put on a bolt or threaded stud with the help of an expansion sleeve when it is screwed along the thread.

In its turn, metal anchors are also divided into several types:

wedge. When driving the anchor into the hole, the wedge located at the inner end of the sleeve pushes its edges apart. In some samples, wedging is done with a separate barb, which is then pulled out of the hole, and a threaded stud is screwed in its place. This type of anchor usually requires precise hole tolerances.
clogged. In such designs, there is not even a need for a wedge. They use a special shape of the edges of the sleeve made of soft metal. When hammering it into the hole with a hammer, these edges are deformed, resting against its bottom and, reliably holding the sleeve itself in it. This is the simplest type of device, but it requires precise drilling of a hole in both depth and diameter. Usually such anchors are used for walls made of cast concrete or natural stone.
Expander, or "butterfly". Refers to the through type and can be used for thin-walled and even sheet materials. The sleeve has slots along the length that do not reach the edges. When twisting, it is deformed in its middle part, opening to the sides with petals from the back side.
Spacer is the most common type of device. It does not require strict adherence to tolerances for the depth of the hole, but only for the diameter. It uses the collet principle of expanding the sleeve in its rear part when twisting a cone-shaped sleeve into it. For use on concrete or solid bricks only.

For the manufacture of anchor fasteners are used usually high-quality stainless steels with an additional anti-corrosion coating. As a rule, it is made for metric threads from M6 to M30. For anchor connections, there are standards for the reliability of the connection for pullout force and shear. They depend on the material of the walls and the installation depth.

How to install an anchor bolt?

For example, consider how to fix the anchor of the expansion structure in a concrete wall.

Often concrete walls are covered with plaster. For reliable fastening, the anchor bolt must be in the concrete layer at a certain depth, usually at least 50 mm. Therefore, before fixing the anchor, you should determine the thickness of the plaster and select the appropriate length of the anchor sleeve.
The diameter of the hole for the expansion anchor should be fairly accurate so that the sleeve will go into the wall with little effort. The perpendicularity of the hole must also be observed. Its depth should be slightly more than the length of the sleeve.
Hole markings must be done as accurately as possible. After installing and fixing the anchor, it will no longer be possible to pull it out.
The hole after drilling must be thoroughly cleaned of dust and crumbs of concrete. This can be done with a brush, a vacuum cleaner, a can of compressed air, or simply by blowing with a rubber bulb and a straw.
An anchor is hammered into the prepared hole with light hammer blows. If it does not enter without effort, you should once again go through the hole with a drill with slight wiggles.
When the nut on the outer end of the stud or bolt head has reached the surface of the wall, you can begin to tighten it with a wrench. After one or two revolutions, the force usually increases noticeably. This indicates that the cone-shaped sleeve enters the sleeve. If a maximum torque is indicated on the package for a given anchor, it is best to use a torque wrench.

In any case, it is not necessary to twist "to the stop" in order to avoid destruction of the wall material. This is especially true for light, porous or foam concrete, as well as bricks.

It often happens that the nut or bolt head begins to go deep into the plaster layer when tightening. If this is a nut on a threaded stud, you can continue to tighten it until it goes completely into the wall, and fasten it with another nut from above. The bolt should be unscrewed and a washer of a larger diameter should be selected under it.

This video shows examples of mounting anchor bolts (how to attach different types of anchors).

There are also more exotic designs of anchor fasteners., for example, frame, which wedged simultaneously from two ends, or with a tear-off head for anti-vandal protection.

Specialized anchors with a hook or ring, anchors for suspended ceilings of rack or raster type, and many others are widely used.

Anchors for concrete are special fasteners necessary for reliable fixation of various objects and elements on concrete structures. Fasteners are used where the strength of the walls does not allow the use of screws or nails. Usually, appliances, furniture are attached to the walls in this way, they are also relevant for the installation of doors and windows.

Externally, the concrete anchor looks like a bolt. It is made of galvanized or stainless steel in the form of a cylinder with an extension in the form of a cone at the end of the fastening. After installation, the expansion part opens into concrete and ensures maximum density between the elements, guaranteeing reliability.

Installation of an anchor for concrete is carried out in a hole of the desired size. The high holding capacity of the anchor is ensured by the force of friction, gluing with the help of a special composition, and the interaction of the thrust element with the inner walls of the hole.

Working principle and application

Concrete is a porous non-uniform structure material. And in the places of fastenings, various forces appear - for twisting, bending, shearing, shearing, compression, tearing. Their concrete anchor takes over, distributing together with the supporting structure.

The basic principles of operation of anchors for concrete:

At the moment of interaction of the base material and the anchor, a friction force appears - the expansion is performed by dowels, metal collets.
When, at the depth of anchoring, the material gives resistance to fracture or crushing - due to collet bushings on the fasteners, a bent shape of the rod, and expansion.
Loads at the point of contact between the base and the rod are compensated by tangential stresses during embedding or gluing - this is how embedded smooth, adhesive anchors work.

Anchors for concrete can be of different designs, different types, sizes. They are made of special steel according to GOST, covered with a layer of anti-corrosion agent. The rod can be 6-20 mm in diameter, up to 220 mm long.

Any anchor includes the following parts:

The bolt itself
Cone with thread layer inside
Sleeve with special cutouts

Anchors perform a constructive or load-bearing function. The bearing function is implemented in cases of connecting floor slabs, beams, columns, balcony consoles, landings and marches, finishing and wall panels, engineering equipment, communications, hoods, ceiling lights, etc. Anchors are also used for mounting logs on concrete or hollow floors. They are attached to the walls of electrical equipment, hanging furniture.

Structural fasteners are used to counteract the displacement of parts of the assembly, if their stability is guaranteed by their own weight, and anchors are also relevant for straightening in construction.

Types and types of anchors and methods of their fastening

Anchors for concrete can be very different, they can use one or more acting forces - stop, intermolecular bonding during gluing, friction, bending, compression, etc. According to the purpose, anchors for concrete are frame, ceiling, foundation and universal. In shape - curved and straight, with a prefabricated or one-piece structure.

The surface of the anchor can be corrugated or smooth. There are different types of fasteners depending on the contact area - those used for porous material and for dense. According to the method of installation, anchor fasteners for concrete may involve through connection, gluing, driving, screwing, etc.

Of great importance is the material from which the hardware is made. If it is steel of strength class 6.8 and higher, covered with an anti-corrosion coating, then the fastening will be as strong as possible. But brass will not withstand serious vertical loads.

Spacers

Expansion anchors for concrete are usually used with nuts, here the working force is friction. They are a small threaded stud with a cone-shaped tip and a sleeve. When the fastener is screwed into the base, it wedged and firmly holds the fastener in the monolith.

The main advantages of such anchors are: the ability to perform through installation, ease and simplicity in installation, excellent bearing capacity. Wedge anchors are chosen mainly for dense concretes, they sink deep, they cannot be used a second time.

If a hook (bracket) is installed on the anchor bolt instead of a nut, the mount is suitable for attachments. Wedge anchors are sleeve and sleeve. Such a bolt looks like a sleeve with special cutouts, at the end it can be made with a stud with a conical extension or a wedge nut. Used for medium and high density bases. A small contact area even with a minimum diameter of the product makes it possible to withstand significant loads.

Anchor bolt with nut can be electro-galvanized (KA), hot-dip galvanized (HOD), and acid-resistant (CAN). This also includes screw anchors made of stainless steel (RAR).

driven

Drive-in anchors for concrete are chosen for dense concretes. These are short internal taper bolts with metric threads. The fastener wedges the base when the stud or bolt is screwed into the concrete, the fastener does not protrude to the surface.

Installation of anchors in concrete using this type of bolts is relevant when installing ducts, ceiling ducts, installing engineering equipment. Before hammering the anchor into the concrete wall, a corresponding hole is drilled. Then the hardware is hammered in, it is wedged with a center punch, the threaded rod of the required length is screwed in.

This type of anchor includes a dowel-nail, a ceiling anchor. It is convenient to mount suspensions, rails, Armstrong ceilings on them. Often, fasteners are used as fire or vandal-proof, since the bolt is fixed.

frame

Used to fasten door and window frames. The sleeve is made with a cut along the length, a small wedge nut in the process of tightening well presses the structure against the opening, bringing it to the desired position. To protect against displacement and rotation around its own axis, there are stops at the top of the sleeve.

Self-tapping screws for concrete

Here, the reliability of the connection is ensured by a thread made along the entire length of the bolt. In the process of screwing into a concrete base, a powerful resistance to tearing or shearing of the product is created. Therefore, when using this type of fastener, a very high bearing capacity is observed. The self-tapping screw is able to easily take up to 100 kilograms of load, it is very reliable in operation and easy to install.

expanding

In everyday life, this type of anchor is called a "butterfly" (aka Molly bolt). It is used for mounting cornices, shelves, lamps, paintings and other elements in hollow structures with a small bearing capacity. The collet on a screw or bolt is made in the form of a wedged skirt, which, in the process of screwing the rod into the base, abuts against the inside of the base cavity. On the outer side of the collet, special spikes are deepened into the concrete, which do not allow the bolt to move or rotate during installation.

chemical anchor

Anchor bolt for concrete is made in the format of a semi-liquid mass, which quickly hardens. It is with this mass that the bolt or stud is glued into the monolith. Thanks to the composition, it is possible to ensure a reliable connection between the base and the bolt without local or point stresses, but with a uniform distribution of the load along the entire length of the fastener.

Chemical anchors for concrete do not provoke internal stress at all, significantly reducing the risk of damage and deformation.

Dimensions and characteristics of anchor bolts

Before deciding which anchor is best for concrete in performing specific tasks, it is necessary to consider not only the variety of designs, but also the dimensions, because fasteners can be of various lengths and diameters.

Anchor classification by size:

Small - section up to 8 mm / length up to 55
Medium anchors - up to 12/120 millimeters
Large - with a maximum diameter of 24 and a length of 220 millimeters

An anchor bolt for concrete can have different sizes: the characteristics are determined by three indicators. So, if you decipher the marking M8 10 / 60-115, then it will be: the thread diameter of the anchor M8, the outer diameter is 10 (it is with this diameter that the hole for fasteners is drilled, this is the diameter of the drill), the length of the anchor is 115 millimeters, the approximate thickness of the element that it is planned to strengthen - 60 millimeters.

All technical characteristics of anchors are indicated in the table, it can be weight, maximum torque and permissible bending moment, minimum pull-out force, optimal loads, distance between axes and to the edge, etc. In accordance with all these parameters, suitable products are selected and high-quality fastening to concrete is performed with anchors.

Installation instructions

Before you can fix the anchor bolt in concrete, you need to prepare the tools. To perform the work you will need: a wrench, a construction vacuum cleaner, a drill with a perforator function or a perforator, a concrete drill, a hammer.

drilling

First, the base is carefully marked for future drilling sites. Here you need to do everything as accurately as possible, since after installation it is not possible to pull out the anchor bolt from concrete - the fixation is very strong. Further, according to the marking, holes of the required length are drilled in the concrete (measured by the expansion part of the bolt), setting the limiter on the drill.

The distance from the edge of the wall must be at least 2.5 times the depth of the hole. Next, the holes must be cleaned with a vacuum cleaner, compressed air from a can, a rubber pear. If it was not possible to remove the crumb without a residue, you can deepen the hole by 1-2 centimeters.

Installation of an anchor with a nut

The spacer part of the bolt is inserted into the base, driven in with a hammer until it is completely immersed in concrete (so that the edges are flush with the wall). Then a threaded stud or bolt is inserted, the nut is tightened, twisting as much as necessary so that it is impossible to turn further.

It is desirable to know in advance how to use a particular type of fastener. Manufacturers can set the maximum torque - in such cases, you will need a torque wrench. Tightening to the stop when working with some bases (aerated concrete, foam concrete) can cause deformation and destruction of the material.

Chemical anchor installation

To install chemical fasteners in concrete, you need a slightly modified set of tools: you will need a puncher, a wrench, a construction vacuum cleaner, as well as threaded studs, glue or capsules, and a mounting gun. For a large number of fasteners, glue is chosen, the choice of capsules (ampoules) is relevant where small amounts of work are planned.

First mark the base, drill and clean the holes. Before pouring the adhesive solution into the concrete, it is advisable to screw in a mesh sleeve, due to which the chemical will linger inside. Then you need to fill the holes 2/3 with glue (using a mounting gun) or install the capsules, insert the pin, gradually screwing it in to evenly distribute the adhesive. Now you need to wait until the glue dries and only then tighten the nut with a wrench.

Pros and cons of application

The main advantages of using anchor bolts for concrete are maximum reliability and structural strength. The anchors can withstand enormous loads, guaranteeing quality fastening in concrete with characteristics that cannot be achieved using other types of fasteners.

The main advantages of anchors for concrete:

Resistant to deformation and corrosion
Ease, simplicity and high speed of installation
Resistance to dynamic and static loads of various types
Large selection of anchors by length, diameter, fastening type, load, function, shape, material, etc.

Choosing an anchor bolt for the implementation of a particular task is not difficult. There are no obvious shortcomings in this type of fastener. Unless you need to remember some features: the importance of marking accuracy, the correct selection of a drill for concrete and determining the depth of the hole, the need to use a certain set of tools.

For foam concrete

Foam concrete is used today in many areas due to poor combustibility, low density, excellent thermal insulation properties and resistance to temperature changes of the material. The structure of the foam block is a large number of frozen bubbles. For fixing the material, screws, dowels, self-tapping screws can be used. The highest level of reliability is provided by plastic and chemical anchors.

For aerated concrete

For aerated concrete, wedge anchors with a length of at least 10-15 centimeters are chosen. With this fastening, it is possible to achieve maximum reliability and strength, taking into account the porous structure of the material. Also, a strong fixation is provided by a chemical anchor.

How to install an anchor bolt in concrete

The whole process is quite simple, the main thing is to correctly measure and implement everything as accurately as possible. But there are several nuances that must be taken into account.

Practical tips for installing anchors in concrete:

The fastener strength index is affected not only by the anchor, but also by the quality of the base material (concrete in this case), proper preparation for installation, taking into account the material of the attached structure and the design of the bolt itself.
If a finish layer is applied to the wall, the hole must be deeper, as the finish is usually less durable than concrete.
It is advisable to take a drill 0.5 mm thinner than the diameter of the future hole.
When working with a hammer drill, it is best to use a tip made of a special carbide material.
Carefully read the instructions - the package with anchors must indicate the allowable force and the maximum number of revolutions.
When screwing the anchor in, in no case turn it all the way, as the material may collapse.

Eternal fastener: dowel for concrete

A dowel is an expansion element made of polypropylene or nylon, which is similar in function and features to an anchor. It is not used independently, it is fixed in concrete with special nails or self-tapping screws. To strengthen the fixation, it is often performed with spikes or antennae.

This type of fastening is used where there are no too large loads on concrete - fastening shelves, hooks for TVs, lighting fixtures. Dowels are hammered into the concrete wall with a hammer, self-tapping screws are screwed with a screwdriver or screwdriver. To drive in nails, you also need a regular hammer.

You can also find dowel-nails designed for use with a mechanical gun. Fasteners in concrete are made of metal, outwardly it is somewhat reminiscent of a bullet. It is relevant where you need to hang a large number of objects of small size.

Concrete dowel: fast but strong

Nagels are those that are most often used for arranging fasteners near the edges of a concrete wall. The fastener does not require additional fixation, it is screwed into the hole, where a little epoxy glue is first poured. Drilling holes is not necessary - the dowel can be screwed directly into the concrete wall. If a hole in the concrete still needs to be made, then it is better to choose a drill (a hammer drill can damage the wall).

They are screwed in with a screwdriver - and after that it is no longer possible to unscrew the dowel back. Therefore, preliminary marking must be carried out especially carefully.

Conclusion

The variety of anchors for concrete foundations today is simply huge - a wide range is offered by many manufacturers. Therefore, choosing the right type of anchor in accordance with the type of foundation, expected loads, length, shape, material and other parameters is not difficult. Further, everything depends on the accuracy of measurements and the quality of the work performed by the master.

In order to ensure high reliability of the connection using an anchor bolt, it is important not only to choose the right size and type of construction, but also to know how to properly fasten such a product.

There is a wide variety of anchor bolts that differ in their device and principle of operation, so it is important to know how to fix an anchor of one type or another.

An anchor bolt of a classic design provides a reliable connection not only due to the forces of friction of its outer surface with the walls of the mounting hole, but also due to the fact that its expansion sleeve increases in diameter when the threaded element is screwed into it. The reliability of the installation of such a fastener is also influenced by the strength characteristics of the material of the building structure, which should also be taken into account.

For all considered fasteners, the drill for making the mounting hole is selected according to the diameter of the anchor, with the exception of impact-type anchor bolts.

with nut

The structural elements of this type of anchor bolt are:

threaded stud, one end of which is made in the form of a cone, and a nut is screwed on the other;
a spacer sleeve wound onto a hairpin (its lower end has longitudinal slots on the side surface, which form peculiar petals).

Reliable fixation of such a fastening element is provided due to the fact that the petals of the spacer sleeve are unclenched, which occurs when they are exposed to the conical end of the pin. In order for the tapered end of such a bolt to begin to enter the sleeve and unclench its petals, a nut is used.

An anchor bolt with a nut is fixed in the foundation or any other building structure made of concrete, performing the following steps:

a hole is drilled, the diameter of which must correspond to the size of the cross-section of the spacer sleeve;
thoroughly clean the landing hole;
carefully hammered with a hammer;
by tightening the nut, the anchor is securely fastened.

After the installation of the anchor bolt is completed, you can twist the nut from the top of the stud and proceed with the installation of the required item.

When choosing products of this type, it should be borne in mind that they demonstrate their effectiveness only if they are fixed in durable and full-bodied materials (concrete, brick, natural stone, etc.). Manufacturers, in order to ensure high reliability and corrosion resistance of such products, make them from high-quality zinc-coated steel.

An improved model of an anchor bolt of this type is a two-space anchor, which, due to the design features, can be successfully fixed not only in durable concrete, but also in hollow and porous materials. In such a bolt, there are two bushings at once, which are unclenched in the process of tightening the threaded element, creating a more reliable fastening in the wall or foundation.

Wedge

An anchor of this type, whose expansion or wedge sleeve has a shortened length, is also a modification of a fastener with a nut. The wedge element that expands such a bushing is the reverse end of the threaded part of the bolt, which has a conical shape.

The big advantage of using them is that for their reliable fastening there is no need to maintain the exact diameter of the mounting hole, moreover, it can not be cleaned from construction dust. Such a bolt is fixed in the mounting hole, and its expansion element is unclenched by tightening the nut.

Hex head

The threaded part of such a fastener is a classic bolt, the reverse end of which also has a conical shape. Screwing into the spacer sleeve, such a bolt expands it with its tapered shank, ensuring reliable fastening of the product in the wall or foundation.

Such an anchor should be fixed by inserting and carefully hammering it into a previously prepared and cleaned hole. Then you need to securely fasten the bolt by tightening its hex head.

Bolts of this type, instead of a hexagonal head, which may have a hook or ring, are used to perform installation work on concrete, stone and other building materials with a dense internal structure.

Drums

Anchor bolts of this type consist of:

a hollow metal rod, on the upper part of which there is a thread for the fixing nut, and the lower part is a spacer sleeve with longitudinal slots on the side surface;
a percussion element (nail), which, when hammered into a hollow rod, just ensures the expansion of its lower part;
nuts and washers, which are needed only to fasten the required item with such a bolt.

Thus, in order to correctly and reliably fix such a bolt in a wall or other building structure, it is necessary not only to insert it into the mounting hole, but also to drive a percussion element into it, which will open the petals of the spacer coupling.

Taking into account the fact that significant shock loads occur during the installation of such a bolt, it is not recommended to fasten it in porous and fragile materials.

Four-segment

The design of such an anchor bolt does not provide for a wedge part, and the expansion of the spacer sleeve, divided by longitudinal slots into four segments, occurs when the bolt is screwed in, which moves the tetrahedral element in its internal cavity. Four petals, which are formed by slots on the side surface of the spacer, are initially compressed and form the conical tip of such a bolt. When the bolt is screwed in, which moves the threaded square element inside the spacer, the segments expand, which allows the anchor to be securely fastened in the bore.

The petals of such a product open wide enough and this happens very carefully. That is why it can be fixed in porous and even hollow materials. As a threaded element, which is not usually supplied with such an anchor product, a bolt with a conventional hex head or a bolt, the top of which is crowned with a ring or hook, can be used.

driven

A drive-in anchor is the simplest anchor-type fastener, the design of which consists of a spacer sleeve with an internal conical hole. To install this at the required point of the building structure, it must be hammered into the mounting hole, and then a threaded element is screwed into it, which will ensure the opening of the bushing petals.

The material for the manufacture of such fasteners, the process of proper installation of which can be viewed on the video, can be galvanized steel or brass.

screw

The design of screw fasteners, which is very easy to use, differs from all other anchor-type products. Slots on the expansion sleeve of such an anchor, which ensure its expansion during installation, are made in its middle part and have a weakened design. The lower part of such a bushing is a nut into which the anchor bolt is screwed, compressing it along the length and ensuring the expansion of the petals.

The anchor plays a very important role, regardless of whether it is an element of which structure it is - a machine installed on a concrete floor or a bolt ladder mounted on a wall.

It provides a connection with the foundation, and if this connection turns out to be fragile, the structure is threatened with destruction, no matter how strong it is from the inside. For reliability, the anchor should be installed following a certain technology.

So, what does it take to properly and securely fasten an anchor bolt?

You need to look at the pages of the online magazine about construction and read the following step-by-step instructions

1. The chemical anchor is very durable and reliable. It can be installed in any material: brick, stone, cellular concrete, wood, etc. Since it is fastened with glue, it not only does not weaken the base to which it is attached, but in many cases makes it even stronger.

To install the anchor, we drill a hole of the desired diameter to the required depth. We clean it with a ruff brush, blow it with a pump or a pear.

2.Fill it 2/3 of the hole with an adhesive mixture - epoxy or polymer resin. A container with glue (cartridge) can be designed in different ways - a syringe, a tube, etc. The methods of mixing the glue components also differ. Whatever the version of the adhesive cartridge, you must act strictly according to the instructions attached to the product.

3. With a rotational movement, we install the anchor in the hole to its full depth. We remove the drips of glue from the base. The time the anchor is ready to accept the load depends on the brand of glue, it is indicated in the instructions. After the specified time, any structure can be attached to the anchor.

4.Mechanical anchors are installed without glue. The principle of their operation is based on the wedging of the anchor sleeve inside the hole, due to which its reliable fixation in the base is achieved.

We drill and clean the hole in the same way as described above. Through the part to be mounted, we insert the wedge anchor into the hole and hammer it with a hammer until the nut rests against the part to be fixed. Tighten the nut with the necessary (but not excessive) force. As a result of tightening, the end of the anchor wedges the sleeve and is securely fixed in the hole.

5. Ways of wedging may be different. If for this there is a special rod inserted inside the anchor, then after installing the bolt in the hole, we hammer this rod with hammer blows inward. Thus, we wedge the sleeve and fix the anchor in the hole.

6. To install a wedge anchor with an internal thread, a special tool is required - a rod similar to a center punch or barb.

After the anchor is installed, we place this tool inside and wedge the sleeve with hammer blows. Then, remove the center punch and screw the fixing screw into the threaded hole of the anchor.

7. The so-called frame anchor has two wedged zones - at the base and in the fixed part.

We drive the frame anchor into the base through the part to be fixed. We wrap the screw with the necessary force. In this case, the lower part of the anchor, located at the base, will first wedge, then the upper part, located in the part. As a result, the latter will be firmly attached to the base.

8. Purchased products are very convenient to use - especially if you have to install a large number of anchors. However, if necessary, you can firmly fix in any base and a home-made device - a bolt or rod of any kind.

9. We drill a hole with a diameter of 1-2 mm larger than the diameter of the anchor. We clean the hole well from crumbs and dust. We fill the hole halfway or a little more with epoxy or putty with a hardener. With a rotational movement and light blows of the hammer, we install the anchor in the hole. We remove resin drips. After some time, when the epoxy hardens a little (but not completely), we level it around the anchor flush with the base. You can use this anchor in about a day.