How to make an adjustable floor

Fasteners - anchor

Once upon a time, however, not so long ago, to solve these and many other problems, wooden chop plugs were used, driven into pre-drilled holes. This method had many drawbacks: over time, in a dry room, the tree decreases in size and the cork begins to dangle, 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 plug.

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 reliably held in the hole. In addition, the holes in the walls made of high-quality monolithic 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 of fasteners under heavy weight loads and anchor bolts were invented.

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

According to the mode of action, such products are divided into two main types:

1. Chemical anchors. A capsule with a special glue placed in the hole is used, crushed when the fastener is installed, which is securely held after the glue has polymerized. The disadvantage of this method is the need to wait for the glue to harden. The advantage is the ability to use not only in monolithic wall structures, but also in hollow ones.
2. Mechanical. They are based on the principle of wedging or collet expansion of a special metal sleeve, put on a bolt or threaded rod using a spacer sleeve when screwing it along the thread.

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

• Klinova. 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 performed with a separate bar-barb, which is then pulled out of the hole, and a threaded pin is twisted in its place. This type of anchor usually requires accurate 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 accurate hole drilling in both depth and diameter. Typically, these anchors are used for in-situ concrete or natural stone walls.
• Expandable, or "butterfly". It belongs 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 twisted, it is deformed in its middle part, opening to the sides with petals from the back.
• Spacer is the most common type of device. It does not require strict adherence to hole depth tolerances, but only in diameter. It uses the collet principle of expanding the sleeve in the back of it when screwing a tapered sleeve into it. Applies only to concrete or solid bricks.

For the manufacture of anchor fasteners, high-quality stainless steels with an additional anti-corrosion coating are usually used. 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 pull-out force and shear. They depend on the wall material and installation depth.

For example, for an M8 anchor installed in heavy concrete at a depth of 80 mm, the recommended pull-out load should not exceed 7.3 kN, and for M10 - 13.0 kN. In lightweight or aerated concrete, it is almost halved.

Heat-block houses. Photo and article about this building material here.

And this article talks about cork wall coverings.

Installation of anchor bolts

The bolts are set clearly in size, before the foundation is poured with concrete. The problem here is that the reinforcing cage or formwork during pouring with concrete can move and, accordingly, the installed anchors will also go away.

My way of exposing foundation bolts. Take a stepped foundation for example. In order to be able to securely fasten the anchor to the reinforcing cage, we fill in the lower part of the foundation. Two days later, when the concrete has risen and the reinforcing cage is fixed, you can start setting the bolts.

The first step is to complete the formwork setting. We fix it so that it stands "dead" does not move and does not fall apart when pouring concrete mixture.

After that, using a level, mark the elevation on the foundation minus 10 centimeters from its top according to the project. One person stands on the level, another holds the rail and the third with a marker marks the marks at the corners of the foundation on the reinforcing cage.

On the anchors, we also set aside minus 10 centimeters from the top of the design level of the foundation. Suppose the anchor protrudes from the foundation by 15 centimeters, then we set aside 25 centimeters from its top. When aligning the marks on the foundation and the anchor, we set them clearly according to the design heights.

Further, one cannot do without a surveyor with his precise instrument, which is called a total station. I have tried more than once to expose myself by pulling the lace along the axes, but did not fit into the dimensions.

There are several reasons the wind blew, the lace was deflected, the tape measure with an error or the human factor got confused in the dimensions. In this case, the more accurate the better.

The surveyor, with an accuracy of a millimeter, takes out the axes to the foundations, to which we tie when installing anchor bolts.

Basically, the bolts are fastened by welding, but at the facility in Kstovo, the technical supervision took a pose if the project does not indicate that they need to be welded, then I forbid. He believed that this weakens the metal and it will not withstand the design load. We fastened them to a knitting wire, and as a result, all anchors were displaced during the pouring of concrete.

How is it fixed by welding? I forgot to say after setting it is necessary to fix the reinforcement cage of the foundation by welding on stoppers. A stopper is a piece of reinforcement that is welded to the frame and rests against the formwork, in this way we do not let it move.

In addition, it is also necessary to weld on the reinforcement, for example an anchor with a diameter of 24 mm. stands strictly on the axis. We weld two reinforcement bars to the frame at a distance of 12mm. from the axis. As a result, the angle of their intersection is the place for the anchor bolt attachment. In the photo below, I showed what it was about.

Consequences of incorrect alignment of the anchor bolts.

If the foundation bolts are out of size, it will be visible after survey by a surveyor and dimensioning on the executive scheme. As a result, the company will have such consequences as cost overruns of money and time, calculated for the construction of the facility.

In Kstovo, when the technical supervision saw on the diagram that the anchors were not within tolerances, it was forbidden to bend them by welding or expand the holes on the heels of the columns.

Kstovo

Incorrectly installed anchor bolts were cut off, chemical ones were installed strictly according to the bindings to the axes and the work continued.

What are high-strength bolts, how to prepare them before installation, what tool to tighten, read here.

Your thanks for my article is a click on any button below. Thanks!

GEOMETRIC DIMENSIONS OF SELF-ANCHORING TAPER BOLTS WITH COLLETS (type II) AND WELL DIAMETERS FOR THEM

* Allowed welding
produce any other seams that ensure the uniform strength of the seam with
the parts to be joined and the depositional amount is not more than 2 mm.

** Manufactured from
spring steel carbon wire according to GOST
9389-75.

table
13.

Geometric dimensions
self-supporting taper bolts with collets (all-metal bolts and bolts
with welded all-metal liner) and borehole diameters for them

Note. Allowed change
of the specified dimensions in accordance with the available drilling (drilling)
tool while maintaining the angles of inclination of the tapered part of the bolt and the inner
collet surfaces. In this case, the design of the bolt should provide maximum
approximation of the size to the borehole diameter.

TAPERED BOLT
NUT

___________________

* Produce from
spring steel carbon wire according to GOST
9389-75.

Table 14.

Geometric dimensions
self-supporting taper bolts with collet (taper nut bolts) and
borehole diameters for them

Note.It is allowed to change the indicated dimensions in
according to the existing drilling (drilling) tool while maintaining
angles of inclination of the conical part of the bolt and the inner surface of the collet. Wherein
the design of the bolt should be as close as possible to the size D_c to the borehole diameter.

BOLT WITH WELDED
NAKED SHANKS

__________________

* Manual welding
arc electric welding with electrodes E-42, E-42A type UONI in accordance with GOST
9467-75.

** Made from spring
steel carbon wire according to GOST
9389-75.

table
15.

Geometrical dimensions of self-anchoring conical bolts with collets (bolts
with a welded hollow liner) and borehole diameters for them

Where is used

Anchor bolts today are one of the most popular types of fasteners, which is associated with their unique technical characteristics and wide versatility, which makes it possible to use such elements for fastening a wide variety of structures and objects of different sizes and weights.

The metal frame anchor got its name because it was originally used for high-quality and reliable installation of window frames and door frames. Today, a metal frame dowel (another name for a frame anchor) is still used in the installation of window and door structures, but the scope of its application has expanded significantly.

Securing a door or window frame - typical examples of using frame anchors

Specialists working in the field of construction and repair paid attention to the versatility of this design, as well as to the high reliability of fixation that it provides, and began to actively use it for the installation of finishing materials, elements of building structures, as well as items for various purposes. In particular, this anchor has gained particular popularity when installing wooden beams on various types of surfaces.

Classifications

Anchors are distinguished according to the service life:

By size, fasteners are divided into:

• Small (up to 5.5 cm long and up to 0.8 mm in diameter).
• Medium (up to 12 cm long and up to 1.2 cm in diameter).
• Large (up to 22 cm long and up to 2.4 cm in diameter).

Anchors are distinguished according to the material of the base:

• For dense concrete, brick or stone materials.
• For hollow brick and concrete substrates.
• For sheet materials - plasterboard, chipboard and fibreboard.

By the method of attachment, the following are distinguished:

Fastening is carried out due to the direct mechanical action of the working part of the anchor on the base (wedging, friction, stop, material resistance, etc.).

Additionally, a gluing mechanism (force) is used; when fastening, glue based on polyester resins is used.

What anchor do you use?

ChemicalMechanical

Mechanical anchors, according to the technique of insertion into the base, are divided into the following types:

• Wedge.
• Spacer.
• Driving.
• Screw.

• Sleeve.
• Expandable.
• Spring loaded.

Spacers

Expansion anchors are a classic version of this type of fastener. They are a rod in the form of a bolt or a stud with a tapered end and an external element in the form of a sleeve, sleeve or spring ring. The conical element under the influence of the translational movement of the rod expands the sleeve and fixes the structure in the base.

Expanding

Expanding anchor consists of a threaded rod, which can be a bolt, stud or screw, and a sleeve consisting of 4 longitudinal petals with a spring washer and a flare nut on one side. When the rod rotates, the flare nut expands the sleeve petals, as a result of which the anchor expands and is fixed in the base due to the frictional force.

Wedge

Wedge fasteners are a long rod, at the end of which there is a deformation sleeve. After screwing the rod into the drilled hole, the sleeve petals expand. This type of fastener is capable of withstanding heavy loads.

Spring loaded

Spring anchors are used when working with thin-walled bases, for example, when decorating an interior. Spring anchors are often used as ceiling anchors and are equipped with a hook. The anchor is secured by unrolling the spring.

Screw

Screw anchors, or Molly bolts, are used when working with hollow structures with a low load-bearing capacity - hollow bricks, drywall, chipboard and fibreboard, etc. material from the back.

Bushings

Sleeve type anchors consist of 3 or more elements, the main of which is a collet - a spring split sleeve. The sleeve anchor also includes a proppant and a threaded rod. When the anchor is screwed in, the proppant enters the collet and expands it, thereby securing the fastener in the base.

Hammered

The base of the drop-in anchor is a metal expansion sleeve with a tapered bore, cuts on the body and an internal thread. A striker is installed at the bottom of the sleeve. The sleeve is installed in the drilled hole manually or with a pneumatic pistol. When struck at the outer end of the sleeve, it is deformed, after which a bolt or stud is screwed into the sleeve, which is necessary for fastening an object.

How to choose the right shrinkage compensator?

When choosing adjusting elevators, it is necessary first of all to take into account the massiveness of the structure. The range of manufactured elevators includes models designed for the load along the axis of the product from one to tens of tons... This value depends on the size of the anchor rod used and the area and thickness of the base plates (ladders). Depending on the predicted load, the size of the anchor-jack is selected for the future structure.

Geometric parameters of adjusting anchors:

• The size of the platforms: 50x50, 100x100, 110x110, 120x120, 150x150, 250x250 mm.
• Platform thickness: 4 - 20 mm.
• Spire diameter: M20, M24, M30, M36, M48.
• Spire height: 150 - 400 mm.

The larger the area of ​​the plates and the thicker the expansion joint stud, the higher its load characteristics. For example, the simplest carbon steel model with an M20 stud and 100x100 mm plates is capable of supporting a weight of 1.6 tons. And the model with M30 hairpin and 150x150 mm platforms can withstand a load of 3 tons.

Recommendations for the selection of the size of the shrinkage compensator

• When choosing a screw support for a log house, it should be borne in mind that the size of its sites must correspond to the diameter of the vertical column and the width of the horizontal support beam.
• For one-story houses, baths and outbuildings, shrinkage elevators with a side of the site 100-120 mm, 4 mm thick are used. The diameter of the threaded rod for such models is usually 20 mm.
• For heavy structures made of large diameter logs, models are used with ladders 150x150 mm made of thick sheet steel 6 or 10 mm with an anchor rod 24-30 mm.
• For higher loads, shrinkage compensators are usually made to order. The thickness of the platforms can be up to 20 mm, and the diameter of the rod is up to 36 mm and higher.
• The length of the shrinkage jack stud is selected taking into account the size and type of wood, since different materials are characterized by different percentages of shrinkage. The greatest shrinkage is observed in a log (30-60 mm / m), the lowest - in glued beams (10-30 mm / m). In practice, adjustable supports with stud lengths of 150 and 200 mm are most often used.
• When installing an elevator under a column on a concrete base, choose models with large holes in the support platform, which are designed for concrete anchors.

Materials and tools

The material for laying the sub-floor is coniferous and deciduous wood. The most popular varieties are spruce and pine.

Fiberboard sheets or cork gaskets are used as the underlying material.

You may also need:

• fastening parts;
• antiseptic;
• waterproofing material (polyethylene, hydro-barrier, etc.);
• floor primer;
• sound and heat insulation products.

Fasteners

To fasten the beams to the base, apply:

• dowel nail;
• anchors;
• self-tapping screws;
• metal corners;
• brackets;
• rack bolts.

The dowel-nail consists of two elements: a nylon plug and a metal rod with a screw thread. The plastic dowel presses the part, and the bolt, when struck with a hammer, secures the connection.

A metal anchor is a device designed for attaching a wooden log to. It consists of a spacer mechanism with an internal thread and a bolt, during the rotation of which the petals of the device abut against the walls of the hole and ensure the fastening of the bar to the concrete base.

Self-tapping screw - a metal screw with a sharp external thread. It is used only in tandem with nylon or wooden plugs. When screwing it into a plastic plug, it cuts the through channel itself. This secures the part to the surface.

Tools for fixing the lag.

Metal corners and brackets are made of steel or aluminum perforated profiles. On one side, they are attached to the floor, on the other to wooden logs.

Stand bolts are studs with threaded couplings, by rotating which you can change the level of the future base.

The choice of fasteners depends on the following factors:

1. Uneven floor in the apartment. Such conditions for the performance of work include the use of an adjustable mount. The use of stud bolts ensures that all the laid joists are in the same horizontal plane.
2. Mechanical stress level.
3. Projected floor height.
4. Humidity of the concrete base (natural ventilation).

Tips for choosing a lag

When choosing wood for the floor, the following material characteristics must be taken into account:

• wood species;
• humidity level;
• conformity of the quality of products to the specified operating conditions;
• thickness and height of the profile.

For timber, you need to use non-planed boards of the second or third grade made of deciduous and coniferous wood, except for poplar and linden.

Defects of lumber, excluding their use in the construction of the base of a wooden floor:

1. Pores with a diameter of 1-2 mm - indicate a defeat by a bark beetle.
2. Knots, chips, cracks or remnants of bark are inferior products.
3. The surface is covered with spots of different colors - a sign of fungal infection, mold.
4. Curvatures are a sign of a violation of the wood drying technology.

Lags on a concrete base.

The choice of the width of the lag depends on the area of ​​the room, the type of topcoat and the expected load on the base. The larger the volume of the room, the wider the profile is needed.

The thickness of the logs, resting with the entire plane on the floor slabs, should be 40 mm, width - 75-100 mm. The width of the timber laid on separate supports is 100-120 mm, the thickness is 40-50 mm.

The height of the lag is selected based on the size of the room and the presence in the project of recommendations for the device of natural ventilation of the floor. An ill-considered choice of profile sizes can reduce the height of the premises by 50-250 mm, taking into account the thickness of the finishing coating.

It is possible to strengthen the bearing capacity of the elements by increasing the number of support posts, which is much cheaper than buying a larger section profile. When calculating the amount of lumber, you must also take into account that the installation on a concrete base of the lag should be carried out at a distance of 20-30 cm from the enclosing structures.

The moisture content of the purchased timber and gaskets should not exceed 18%. All logs and substrates must be treated with an antiseptic.

Instruments

For device wooden floor on lags require a set of specialized equipment and tools:

1. Construction tape.
2. Crayon or marker.
3. Square.
4. Hand or electric saw.
5. Plane.
6. Chisel.
7. Hammer.
8. Mallet.
9. Electric drill for drilling holes for adjustable mountings.
10. Perforator for the installation of anchors and dowels.
11. Water and rack level.
12. Screwdriver with nozzles of the required size.
13. Scissors, including for metal.
14. Knife with a durable blade.
15. A fly brush or floor priming rollers.

Set of tools.

EXAMPLES OF CALCULATION OF SELF-ANCHORING TAPER BOLTS

Example I.
Determine the diameter d self-locking tapered bolt with caulking
(type I) and the required depth of its embedding in the foundation made of concrete of class B12.5,
at design bolt load R = 30 kN, its distance from the edge
foundation l _cr = 12 cm, bolt spacing l _s = 25 cm, with multiple repetitive loading N
= 1012 cycles.

R _{b a} =
145 MPa - design tensile strength of bolts,

R _{b t} =
0.66 MPa - design tensile strength of concrete of class B12.5.

Using the formula (3), we determine the diameter of the bolt

Using the formula (2), we determine the design resistance of the bolt to fatigue
destruction

Checking the bolt
fatigue endurance according to the formula (4)

Because P₃ Q =
0, P ₃ = P₃ p = R(1-χ). V
in accordance with clause 3.15 of these Recommendations, χ =
0.3, then

R _s = 30 (1-0.3) = 21 kN.

According to the table. 8 of these Recommendations at the number of cycles

N = 1012 and determine Krb: Krb =
0,96.

According to the formula (5)
find bolt embedment depth.

Into the calculation we enter
coefficient Kdl = 0.85 (for bolts with caulking), since Kdl = 0.85

Given
distance between anchors l _δ = 25cm = 15.6 d > 10d and, therefore, Kp = 1.0.

Distance
bolts from the edge of the foundation l _cr = 12cm = 5.5 d

According to the table. 7 define
coefficient Вкр = 1.18, then the embedment depth will be: h_{3, kr} = 14.7 × 1.18 = 17.3 cm.

We accept
bolt embedment depth equal to 17 cm.

Example 2. Determine the diameter d
self-supporting conical bolt with collets (type II) and its embedment depth h₃
for fastening equipment to a column with a section of 30 × 30 cm made of class concrete
B30 (R _bt
= 1.3 MPa) under the action of transverse forces Q = 5 kN and longitudinal forces Рпр = 20
kN. The equipment is fixed to the column with four bolts without shims. Distance
from the edge of the column to the axis of the bolt - 8 cm, between the bolts along the height of the column - 25 cm
(see fig. 10).

Rice. 10 for example 2

Condition of clause 3.12 of these Recommendations
is fulfilled since Q = 5 kN ≤ 0.5 Рпр =
0.5 x 20 = 10 kN.

Design effort
per bolt (see clause 3.12 of these Recommendations) is

In accordance with
nn. 3.15 and 3.16 real
Recommendations χ = 0.25 and f = 0,3.

Using formulas 8-10, we determine the required tightening force
bolts

R R _s = (1 -0.25) × 20 = 15 kN;

R _s = 15 + 4.2 = 19.2 kN R
= 0.9 × 28.6 = 25.8 kN

Using the formula (3), we determine the diameter of the bolt

We accept
anchor bolt with a diameter of 16 mm.

Using the formula (5), we find the depth of the bolt embedment.

Meaning
coefficient Kdl in accordance with clause 3.7 of these
0.9 of the recommendations accepted. It is necessary to take into account the influence of the edge and the distance between
bolts for their bearing capacity.

l _cr = 8 cm = 5 d ... By column width l _δ = 30-8.0 × 2 = 14cm = 8.7 d ... By
column height l _δ = 25 cm> 10 d.

In accordance with paragraphs. 3.9 and 3.11, according to table. 6
and 7 of these Recommendations determine the values ​​of the coefficients
Kp and Vkr:

Kp = 1.11; Vcr = 1.30.

Embedment depth
taking into account Кп and Вкр is:

h = Кп × Вкр ×h₃
= 1.11 × 1.30 × 9.5 = 13.7 cm.

We accept
embedment depth of bolts 14 cm.
install the bushings in accordance with clause 3.13 of these
Recommendations.

Application
5

Installation instructions

Before fixing the anchor bolt in the concrete, the tools must be prepared. To carry out the work you will need: a wrench, a construction vacuum cleaner, a drill with the function of a perforator or a perforator, a drill for concrete, 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 the anchor bolt out of the concrete - the fixation is very strong. Further, according to the markings, holes of the required length are drilled in the concrete (measured by the bolt spacer), setting the stop 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, and a rubber pear. If you did not succeed in removing the crumb without a residue, you can deepen the hole by 1-2 centimeters.

Installation of anchor with nut

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

It is advisable to know in advance how to use a specific type of fastener. Manufacturers can set the maximum tightening torque - in such cases, a torque wrench is required. Tightening to the stop when working with some substrates (aerated concrete, foam concrete) can cause deformation and destruction of the material.

Installation of a chemical anchor

To install chemical fasteners in concrete, you need a slightly modified set of tools: you will need a hammer drill, a wrench, a construction vacuum cleaner, as well as threaded rods, glue or capsules, and an assembly 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, thanks to which the chemical is retained 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.

What is Concrete Anchor Bolt

Many have heard that a special fastening element - an anchor bolt - is used to solve issues of fixing to the ceiling, internal and external surfaces of concrete walls. Not everyone knows what it is. Let's try to figure out what an anchor is. This is a metal fixture that allows you to securely fasten furniture, equipment and appliances on brick, stone, concrete and foam block surfaces, as well as on hollow panels and walls made of gas-filled blocks. The fastening element is installed in a hole with a certain size.

An anchor is a fixation device capable of absorbing significant forces due to the following factors:

• friction forces, due to which the collet sleeve is held in the formed cavity;
• efforts of interaction of a special spacer mechanism with the inner surface of the channel;
• the adhesive characteristics of the adhesive ingredients inside the drilled hole.

Among the many varieties of fixing devices, wedge-type anchors, as well as expansion anchors for concrete, are in high demand. Their design features and technical parameters allow the fixing element to increase the diameter of the working surface when expanding inside the cavity. In this case, the magnitude of the friction force increases sharply. The anti-corrosion coating of the surface of such an element prevents the occurrence of corrosion and increases the service life.

Anchor bolt for concrete