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Making concrete columns with your own hands: preparation, pouring, dismantling. Column concreting Do-it-yourself technology for pouring concrete columns

Concrete columns are durable bearing structures, whose main task is to provide facilities of the proper level vertical stiffness and strength. As a rule, they act as part of a monolithic structure frame, supporting ceilings, terraces, balconies, etc. either being decorative element to decorate the entrance group of the facade and building.

Columns are metal, prefabricated and monolithic, the appropriate type of element is selected depending on the desired characteristics (primarily, bearing capacity). The main task of the element is to become a support for various structural elements, ensure their vertical strength and evenly distribute the load, eliminate the risk of deformation and destruction, and in rare cases, decorate the interior.

You can mount concrete columns for the house with your own hands. Subject to compliance with all standards of production and use quality materials the element will exactly meet the requirements and characteristics, effectively performing the function assigned to it.

Appointment of concrete columns

The element takes over and transfers to the foundation the load from the higher structural parts. become the support of the floors, connecting the structure between the base and the ceiling surface. The pillar supports a variety of terraces, balconies, porches, ceilings, making it possible to realize any design idea and significantly increasing the life of the entire building.

If it's about decorative design, then in this case, the concreting of the columns acts as a means of decorating the facade and interior. Often they are performed with under-columns, consoles, capitals, decorated with stucco molding, original patterns, various types material processing.

Species and types

Concrete column in shape can be: round, square, rectangular, which is determined by the cross section of the support.

According to production technology:

1) Prefabricated concrete columns - produced at the factory, transported to the site, relatively inexpensive, provide quick installation, high drying rate of the solution.

2) Monolithic columns - directly on the object, they are poured into molds. It is possible to control the quality of laying the solution, the flow of the mixture. But the manufacture of such structural elements requires large labor and time costs, and is quite expensive.

When choosing the type of column, it is very important to consider the type of marking of the finished reinforced concrete product of this type.

Column marking:

  • T1 - for fixing concrete consoles installed perpendicular to the main columns.
  • C1 - for the device of lattice connections.
  • L1 - for the installation of flights of stairs with three marches.
  • L - connect stairs with two marches.
  • P - are used in places where it is necessary to create a column for a crossbar (they are installed where there is a turn of the common frame).
  • SS - support with 2-4 edges for high-quality fastening stiffening walls.
  • C - for fixing various panels in contact with the stiffening walls.
  • T - concrete columns at the ends of the buildings of the enclosing panels.

Features of the device of monolithic columns

Before proceeding with the production of reinforced concrete supports, it is necessary to prepare a flat area, take care of tools and materials, mark and calculate everything, then complete all construction work. The requirements for concrete mortar are simple - the mixture must be plastic and strong enough.

The shape and section of concrete columns, the diameter of metal rods, the brand of concrete depend on the volume of the load acting on the element (taking into account the own weight of the support), the climatic features of the region, the number of storeys of the building, and the purpose of the object.

In the construction of a personal building, usually square supports are installed where it is necessary to pick up the load of floors and transfer it to the foundation.

Creation of monolithic columns:

  • Formwork design
  • Installation metal frame
  • , providing normal conditions for its drying
  • Formwork dismantling after concrete mortar completely dry and hardened

Preparation of tools and materials

For the qualitative performance of each of the stages of work on the manufacture of concrete columns, it is necessary to prepare such tools and devices: a concrete pump, a hammer, a building level, a rectangular corner, wooden spacers, a screwdriver, vibrators, a concrete mixer, a tape measure.

Materials: metal wire, reinforced mesh or metal rods, screws and nails, wide boards, steel bar, anchor, cement, water, lime, sand.

The object is delivered dry or prepared according to the recipe: a part of cement, two parts of gravel, crushed stone, sand, water (in sufficient quantity to obtain a homogeneous plastic mixture).

Formwork installation

The formwork is constructed on four sides of the support, with the necessary internal dimensions. Boards, moisture resistant plywood are suitable for work. The shields are aligned vertically in level, fastened with screws or struts and wooden struts. It is desirable to anchor the struts with support blocks in two directions, which will prevent shifting. Corner check the evenness of right angles.

If it is planned to build a high concrete column, the formwork is performed and mounted on three sides, and the fourth is built up during the pouring of the mortar.

Many manufacturers offer to buy ready-made structures made of plastic, wood, metal. Metal ones are usually reusable, quickly and easily assembled / disassembled, guarantee the correct geometry. Wooden ones are made from bars and boards, but only a square, rectangular shape can be made from them. Round shapes are made of plastic. Disposable are made of cardboard, their shape can only be cylindrical.

Reinforcement

To install a concrete column, vertical reinforcement with a diameter of 12 millimeters or more is used. Usually these are four or six rods located at the corners of a square or rectangle. If the height of the reinforcement is more than 3 meters, create flooring steps of 2 meters.

Reinforcement frame is assembled different ways. If a square monolithic concrete column with low weight and volume is created, the frame is assembled into the future formwork manually by tilting. If the weight is large, then the rods are knitted in place, setting the rods separately. The finished structure is mounted using various supports, boards.

The rods in the frame more than 2 meters are fastened together with a metal knitting wire in increments of 20-40 centimeters. Capitals should be reinforced with reinforcing mesh.

concreting

Concrete for pouring is usually done on the spot, from cement grade at least M400, gravel, crushed stone, sand. The solution that is used to fill the foundation is not suitable for work, monolithic walls. good choice concrete with mobility P2 will become (in private construction), but if a heavily reinforced column is poured (construction of pillars for the construction of a plant, for example), concrete P4 is used.

There are different recipes, here is another one: part sand, 4 parts gravel or crushed stone, 1 part cement. In the process of concreting, it is important to monitor the immobility of the frame and finding it in its place. If necessary, the design is adjusted and installed strictly vertically.

Concreting itself is carried out in layers, the thickness of one layer should be equal to 30-50 centimeters, it is poured until the previous layer has set. 5-7 centimeters of mortar are not added to the top of the formwork.

When concreting, be sure to monitor the tamping of the mixture: it can be done with a special vibrator or manually, removing air plugs by tapping the formwork with a hammer or bayoneting with a metal rod into the solution. If the columns are more than 5 meters, technological breaks lasting 40-120 minutes are planned for shrinkage.

Formwork dismantling

The curing time of concrete is 28 days with optimal temperature conditions plus or minus depending on the surrounding conditions - humidity, proper care. On average, the standing period of columns is up to 10 days in summer, when there are already formed side faces and corners. Only then can the formwork be dismantled. During the drying of concrete (28 days), it is forbidden to perform any work related to the load on the column and its base or nearby parts of the structure.

How to make concrete columns with your own hands

Given that correct execution all work and compliance regulatory requirements, taking into account various external factors(type of soil, climatic features, height of the object, etc.) and using quality materials, it is quite possible to create concrete columns yourself. The main thing is to correctly determine the loads, make calculations in advance and strictly follow them.

Useful video on the topic

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Columns are load-bearing engineering structures that provide the structure with vertical strength and rigidity. Depending on the level of bearing capacity formed and the method of manufacture, today several types of columns are being built: metal, prefabricated and monolithic. As one of the main methods of erecting a column structure, pouring concrete columns is considered the most common.

The erection of columns helps to reduce construction time.

Therefore, the most popular, cost-effective and frequently used in self construction are monolithic columns. The advantages of metal racks and monolithic columns are considered to be very fast erection which reduces construction time.

Process Features

Metal columns are installed using special equipment.

At the extreme corners of the house (in places of least load), the columns can be made of steel square pipes with a total cross section within 150 mm, which are connected to the base and the ceiling surface using anchors.

The only disadvantage of using this type of columns is their rather complicated installation (using a crane). This is not always advisable when self installation and concrete columns.

The role of columns can also be small in area brick walls. On the verandas and the porch, you can use columns made of rounded logs or wooden beam. They are fixed on a concrete base by installing them in steel cups pre-fixed with anchors, followed by concreting.

The most important column structures in the house are columns placed in the central part of the building.

Concrete laying in columns: a- up to 5 m; over 5 m high; c - with thick reinforcement; d- formwork scheme with a removable shield; 1 - formwork; 2- collar; 3- tub; 4- vibrator with flexible shaft; 5 - receiving funnel; 6-link trunk; 7- hinged vibrator; 8, 9 - pockets; 10 - removable shield.

In most cases, columns of a certain (calculated) section with a metal reinforced frame, which are cast from concrete using inventory formwork.

Pouring concrete columns is a responsible event that requires certain knowledge and skills of the performer of the work. Ideally, pouring the columns with concrete should be done in one step to avoid the appearance of intermediate cold joints.

In this case, it is important to ensure that the cold seam of the column has a strictly horizontal position. Otherwise, the column will be subject to destruction.

List of tools

To carry out the effective pouring of columns with concrete, you will need the following set of tools and construction equipment:

A concrete pump is necessary for the construction of columns.

  • corner with a right angle;
  • wooden spacers with stakes;
  • level (you can use water);
  • screws (if possible using a screwdriver) and nails;
  • hammer (sledgehammer);
  • metal wire;
  • reinforced rods (or mesh);
  • boards with a maximum width (for creating formwork panels);
  • external or internal vibrators (or concrete pump), which, if necessary, can be replaced with a metal rod;
  • roulette;
  • concrete mixer (or any equipment for mixing concrete);
  • anchor bolts;
  • various types of clamps;
  • metal rod.

Construction stages

Pouring columns with concrete implies the following construction steps

Formwork for columns: shield, anchor, brace.

Reinforcement works

When arranging columns, the installation of vertical reinforcement with an average diameter of 12 mm or more is usually used, consisting of 4 main bayonets (rods) placed in the form of a square (at its main corners). For the convenience of installing the reinforcement of columns with a height of more than 3 m, it is necessary to equip scaffolds with decking more than 1 m wide with fencing with a height of 0.8 m every 2 m in height. The frame bases of the columns can be assembled in different ways.

With small dimensions, volumes and weight, the column frame can be installed in the future formwork box, which is done manually by tilting the finished frame structure. If the diameter of the reinforcement is not more than 16-20 mm and it is heavy enough, then it would be more expedient to pre-assemble the base of the frame, and then knit it in place, installing individual rods. When placing the finished frame of the columns and its further unfastening, all kinds of supports and boards are used.

During the ligament (or welding) work on the installation of vertical frames of columns, it is advisable not to stand on their rods. Between themselves, the reinforcing bars are fastened with special clamps (metal wire) at a certain distance from each other, which is usually 40 cm.

Formwork installation

In normal cases, a formwork box is assembled with the required internal dimensions (for example, 25x25 cm). Attach very carefully. The formwork is mounted on 4 sides of the prepared reinforced column.

Wooden spacers with stakes are installed on all sides of the column. For high column dimensions, the formwork is mounted on 3 sides, and the remaining side is built up during the concreting process. The formwork structure box (from boards, plywood, etc.) must be leveled and fixed with screws to hold the concrete solution inside. With the help of a corner, the correspondence of right angles is checked.

concreting

Has its own nuances. When casting columns, one of the main parameters is considered. For standard monolithic columns, concrete with mobility P2-P3 is used, and when pouring columns of heavily reinforced structures, it is desirable to use concrete with a mobility value of P4 or higher. This type of concrete mixture is also called cast concrete. This type concrete tolerates the process of laying in the formwork quite well, even without the involvement of various vibrators and concrete pumps. When conducting

In the architecture of facades and interiors, columns are increasingly used. This is not only a beautiful decorative element, it is also a practical utilitarian piece of construction.

It allows you to support floors or beams, while not taking much usable area lower floor.

You can buy a ready-made column, but it is more convenient and cheaper to make it yourself. The easiest way is to lay out a brick, but a monolith is much stronger and more reliable, and for its manufacture it will be necessary to make a formwork.

According to the method of use, they are fixed, disposable and reusable. They are made of metal, wood, plastic and even cardboard.

  • Metal. Usually reusable. These are convenient ready-made shields that are easy and quick to assemble, provide the correct geometry, and quickly dismantle.
  • Wooden. Usually homemade, reusable. They are knocked down from boards and bars. Cheaper, but more difficult to provide with their help correct form, especially other than a rectangle.
  • Plastic. usually round shapes are made. You can buy ready-made, or you can make formwork from plastic pipes suitable diameter.
  • Cardboard. are made of thick cardboard impregnated with special adhesives. The form is only cylindrical, such formwork is exclusively disposable.

Ready-made formworks are offered by many manufacturers, however, they can be made independently, given some of the features of this construct.

Peculiarities

The column has a small width and thickness, but often has a significant height. This determines quite specific loads on the form.

The formwork experiences significant pressure at the bottom and very little at the top.

The elongation of the form in height makes the structure very unstable, it can easily collapse, so the formwork requires several props.

Also, the form must be rigid so as not to fold, not to bend under the weight of concrete.

It is assumed that the column will work in compression, so it is extremely important to avoid distortion of the structure. If the form arches, then the support made in it can easily crack under load. The column bears bending loads very poorly.

It is very important to clearly maintain the vertical level. Even a slight deviation from the vertical generates an imbalance of loads that can lead to failure of the entire structure.

Self assembly form

The easiest way to do it yourself wooden formwork for square or rectangular poles. The sequence is:

In order to make the boards easier to remove later, they can be upholstered with oilcloth from the inside. To assemble the form, you need to choose even boards so that the pillars do not have bends or curvature.

Alternatives

You can also make your own mold out of cardboard. But since only ordinary cardboard is available at home, to reinforce it, you will need to use an additional metal reinforcing mesh or a wooden frame.

It is worth remembering that this is a one-time formwork for columns, after the concrete has hardened, the cardboard will have to be torn off from it, like wallpaper from a wall.

The easiest way is to make formwork in a mesh frame. First, a steel mesh with square cells is taken, which is not prone to stretching.

It is folded into a cylinder of the desired diameter, securely fastened in this position by wire or welding.

Then a folded cardboard is placed inside, which, after laying, straightens and rests against the grid. It is not easy to find sheets of cardboard for 2-3 meter poles, so you will have to use several sheets, fastening them between them with an overlap of adhesive tape.

The design turns out to be very unstable, so wooden supports are required.

Such a one-time formwork is suitable for round columns; rectangular or square ones cannot be filled in any way.

You can make a non-removable polystyrene foam formwork with your own hands.

This option is used for facade works, it allows you to get very flat surfaces, monotonous with foam-insulated walls.

However, this fixed formwork low-strength, so it also needs a supporting frame.

Price

Since everything is supposed to be done by hand, the price of molds for pillars is determined by the cost of materials. If you make formwork from wood, then you will need to pay about 6-7 thousand rubles per cubic meter of pine.

Steel mesh will cost 20-25 rubles per square meter, thick cardboard - 200-250 rubles per roll. Styrofoam will cost 1000-1200 rubles per cubic meter.

Column formwork is designed to form a square or rectangular area, which will allow you to properly mount the column. Exist different types formwork, which are intended for certain types construction works. In this article, we will consider the features and parameters of mounting formwork for columns with detailed step-by-step instructions.

Types of columns

The main purpose of creating formwork is to form a certain shape for columns of the desired height and parameters. There are two types of work, the first of which involves the installation of universal columns, and the second is the formation of formwork for columns with a fixed section. When carrying out installation, you need to remember the features of installing additional shields.

Earlier, columns were used as a decorative element of buildings. However, in modern world this type of product is intended as supporting elements for different types of buildings. There are several types of columns that differ in geometric shape:

  • round or cylindrical;
  • square;
  • multifaceted;
  • rectangular.

It should be noted that the universal formwork of columns is carried out for different types of columns and provides for the installation of standard shields with special holes for the kingpin, the pitch for which is 5 cm. For a fixed installation scheme, it is necessary to fasten the column using four corner elements and some formwork locks.

Formwork purpose and product requirements

The formwork of walls and columns is carried out for pouring concrete base under the supporting elements. This is necessary so that the mixture does not spread and, after hardening, has a square or other shape. Without carrying out this stage of work, it is almost impossible to carry out the installation of the column. Experts identify some requirements for formwork:

  • compliance with the dimensions of the structure;
  • stability and strength of the installed product;
  • the formation of a form through which the solution will not flow;
  • smooth inner side;
  • dismantling is not difficult.

Formwork for columns: disposable, reusable, non-removable

The most simple and convenient option work is the construction of a one-time formwork. This design is made up of cardboard, which is wound in a spiral. The formwork product has water repellency that do not allow the solution to soak into the structure of the cardboard. Thicker-walled PVC film can be placed inside the cardboard column formwork.

The approximate diameter of such formwork can be from 20 to 115 cm, and maximum length products can be 12 meters. Depending on the parameters of the column, the height of the formwork may vary, as well as the thickness of the walls. For example, in the lower part of the structure, the wall thickness may be greater, which is determined by the maximum load of the concrete solution. The technology of work is not complicated, with large volumes of installation, you can use lifting mechanisms. Only two people may be required to carry out the installation.

Another option for column formwork is the construction of a reusable structure. As a rule, the formwork can be used several times for the installation of several columns. The following features of the work are distinguished:

  • the need for the construction of formwork on construction site;
  • pouring concrete mortar into the structure;
  • keeping for several days until the concrete dries completely;
  • removal of the formwork structure and its installation in another place.

When performing such work, you must remember to follow the rules for installing the column. When choosing a reusable formwork for columns and ceilings, it is necessary to calculate the height of the product, which should not be higher than the indicated forms. When choosing this form of formwork, the filling will no longer be monolithic. Therefore, you should carefully read the requirements and characteristics of the implementation of this type of formwork in compliance with the height of the column.

Reusable formwork is more expensive than disposable formwork, which is determined by the following parameters:

  • Necessary costs for storage of the structure.
  • Formwork transportation for the installation of other types of columns and maintenance.
  • Additional expenses for the use of lifting equipment services.

There are different types of reusable formwork:

  • shield structure;
  • beam-transom;
  • steel formwork;
  • plastic construction;

Formwork using shields is intended for columns square shape. Shields made of metal must be fastened together using different fixation items. It is important to place laminated plywood in the middle of the boards. Next, a concrete solution is poured after hardening, which the formwork can be removed and moved to another work site.

A similar type of work has a beam-and-beam formwork of columns, for which you need to use the following products:

  • shields;
  • crossbars made of steel;
  • beams.

This type of construction will allow you to form a reliable formwork different heights. As a rule, such a scheme is used to build round walls, columns, bridges, as well as to form large vertical surfaces. Formwork execution technology resembles an assembly scheme children's constructor, and all parts are fixed with struts.

Steel column formwork is designed for square and round products. Main characteristic design lies in the fact that after its use it is necessary to clean and lubricate the sections. This type of formwork is heavy, as well as panel formwork, so it is necessary to use the services of lifting machines to move it.

A more affordable and lighter option is plastic formwork for columns. The main disadvantage of the product is the unreliability of the design, and for the implementation of work it will be necessary to seek the help of specialists. It is advised to work with this type of formwork carefully and with special tools so as not to damage the walls. All elements plastic construction connected to each other using different parts.

There is another type of formwork that is non-removable. The use of this type of construction is rare, however, such a construction scheme is quite popular among builders. All blocks and blanks for formwork assembly are made on special machines. Thus, products with thin walls are created, which are quite strong and reliable.

Formwork elements are made from high-strength concrete. The technology for preparing the solution involves the use of cement, sand and water. A feature of the preparation of concrete is the compaction of pores using rolled products. Thus, all liquid is displaced from the solution, which increases the properties of frost resistance and strength of concrete. Formwork products made in this way have increased resistance to temperature and humidity changes.

Installation of column formwork: features of installation and dismantling

Before considering the installation technology for a particular type of formwork, it is necessary to study standard specifications performance of work. Before installing the formwork on the concrete surface, it is necessary to mark the parameters of the column. As a rule, the column should be installed around a pre-prepared reinforcement frame. All work must be carried out using project documentation. Formwork panels must be assembled in l-shaped, which are fixed with nuts and a kingpin or through a corner, then it is determined by the type of column. The second and other tiers of the structure assembly must be assembled using a mobile tower or scaffolding.

If the height of the formwork of round columns is higher than 4.2, then it is important to mount a special crossbar on the column, which will level the structure. The installed column must be checked for a vertical position, which is carried out using braces or tolpers. The brace consists of the lower and upper areas of the product, as well as a special connector. The latter must be mounted on a concrete surface, then the upper part is attached to highest point fixing the column, and the bottom to the bottom. Using special tools and nuts, the column should be leveled and fixed in a vertical position.

The feature of dismantling the formwork can be done when the concrete is completely dry. First of all, it is necessary to remove the formwork braces, after which the locks are dismantled from the upper part and the shields are removed.

It is important to know! If the height of the mounted column is more than three meters, then the concrete solution must be supplied through a special window. In the next tier, one of the shields must be removed, which forms a window required sizes. Further, the shield is installed in its original place, after which the concrete solution enters through the upper part of the column formwork.

Do-it-yourself step-by-step instructions for installing panel formwork for columns

The installation process must begin with the layout of the workspace. It is important that it coincides with the parameters of the previously erected frame and reinforcement:

2. After that, the formwork is assembled from the panels on one side, and it is important to fix all the details of the structure using locks.

4. Having determined the thickness of the pouring of the concrete wall, it is necessary to install the next formwork wall using the same technology.

5. It is important to mount the running console at the top of the formwork.

6. After leveling all the walls of the structure, you can proceed to further work on installing the column and pouring the base.

It is important to know! To properly install the panels on one side, it is necessary to use crossbars that will allow you to level the formwork.

The dismantling method consists in carrying out the work in the reverse order: first, the running consoles and tolper braces are removed. After that, the locks are dismantled from the upper area of ​​\u200b\u200bthe structure, and the formwork panels are removed.

Instructions for installation of beam-transom formwork

Beam-transom formwork is a structure that consists of beams and crossbars. All parts are fastened with clamps. The main material used in the work is wood, so all work is not labor intensive. This material has a low thermal conductivity, in contrast to the aluminum formwork of the columns.

Such a formwork assembly scheme has many advantages, which is indicated by the reliability, strength and simplicity of the structure used. The work does not require significant costs, while the formwork is considered universal. Using this type of construction construction, it is possible to concrete columns different sizes. Also, using the beam-and-beam formwork scheme, it is possible to erect concrete walls different settings. To strengthen and form the formwork, it is recommended to use only a screwdriver and a hammer.

Formwork advantages:

  • it is used to install columns and walls of different heights and sizes;
  • intended for building formwork different forms, for example, radius, round and inclined without unnecessary waste;
  • allows you to get good quality concrete on the surface of the formwork;
  • using this type of assembly of the structure, it will be possible to reduce the number of gaps and ties;
  • the formwork is able to withstand a large concrete load, up to about 10 t/sq. m.

Detailed instructions for assembling the beam-transom formwork have the following sequence:

1. We prepare the work site for the installation of formwork.

3. Beams for formwork of the required length are laid perpendicularly on the crossbars.

4. These beams must be attached to the ledger using special clamps.

5. The approximate distance between the beams should be from 20 to 40 cm, which is determined by the project documentation.

It is important to know! When laying the beams, make sure that they do not coincide with the fixing points for the tie screws. Laminated plywood sheets should be placed on the installed beams, while the joints should be in the middle of the beam. Plywood is fixed to the beams using self-tapping screws, which are screwed in every 35-40 cm. The length of the fastener should be 50 or 60 mm. The area for the installation of self-tapping screws can be puttied, which will extend the shelf life of plywood for further use.

Exist different variants formwork installation, however, not all work can be done by hand. The installation technology for each type of structure is determined by the height and section of the columns. To better understand the formwork scheme, we recommend watching the video presented at the end of the article.

Monolithic columns - part of the building, vertical load-bearing elements. Resting on columns balconies, terraces, floors. In addition to the main functions, the columns are a decorative element, decorate entrance group buildings and facade.

The columns receive and transfer the load from the upstream elements to the foundation of the structure. Reinforced concrete pillars connect the structure, serve as a support for the floors.

The architectural term "column" refers directly to the middle part, support column. The protrusions in the upper part of the column for supporting floors or crossbars are called capitals or consoles. Sometimes there is a sub-column, a glass for attaching to a columnar foundation.

Species and types

Concrete columns subdivide by section type, production method.

Subdivided according to the type of section square, round or rectangular form.

Classified according to the method of production elements of prefabrication supplied to the facility prefabricated structures or erected at the construction site, monolithic columns.

Features of the device of monolithic columns

Before the work is done, prepare the site, necessary materials, tools, designs. The site is marked.

Then go directly to the construction:

  • collect formwork;
  • mount the reinforcing cage;
  • pour concrete mixture;
  • carry out concrete care procedures;
  • withstand time for the strength of the mixture;
  • demolish structures.

Monolithic reinforced concrete columns calculated at the design stage. The section and shape of the column, the diameter of the reinforcement, the brand used will depend on the amount of the planned load, including the dead weight of the element.

Important! Installation flaws and miscalculations lead to the destruction of the structure. With a lack of section, buckling deformation occurs, the column bends under load.

Preparation of tools and materials

The need for materials and tools is clarified at the stage of preparation for work. Of the tools you will need:

  • metal square, level for checking the verticality and horizontality of surfaces;
  • steel bar, will help to release air;
  • screwdriver for fastening the formwork;
  • vibrator compacts the mixture;
  • prefabricated formwork from shields, props.

The concrete mixture is delivered to the construction site in ready-made or mixed immediately before laying with a concrete mixer. For preparation, take one part of cement, add two parts of sand, mix with two parts of crushed stone and two parts of gravel. By kneading a dry mixture with water, plastic concrete of a uniform consistency is achieved.

Except concrete mix the following materials are required:

  • nails, self-tapping screws for fastening the formwork;
  • reinforcing bars of calculated section and length;
  • steel wire;

Formwork installation

The formwork is installed in the design position. Shields are aligned vertically and reinforced with braces, wooden struts. The struts are anchored with support blocks in two directions to prevent shifting.

When concreting a high column, the formwork installation process is somewhat different from the usual one. Three sides of the form are mounted, and the fourth side is closed as the formwork is filled with concrete.

Reinforcement

By tying the rods together, they get rigid bulk frame to reinforce concrete. The number of longitudinal rods in the frame is 4-6 pcs. For a square section, four rods are sufficient at the corners of the element, for rectangular shape the long side is additionally reinforced. Cross-linking of reinforcement is used when constructing columns up to 2 meters long.

The frame, exceeding the length of 2 m, is tied with short rods across, with a step of 20-50 cm, taken in the calculation according to the planned load.

The capitals are reinforced with reinforcing mesh.

The thickness of the mesh rod is taken from 15 mm, the cell size is 10 x 10 cm.

Reinforcement of the sub-column occurs by laying the mesh in each step, the dimensions and number of meshes are taken from the project.

concreting

After formwork installation and reinforcing cage start concreting, which produce in layers, in layers 0.3-0.5 m thick, preventing the previous layer from setting. Do not add 50-70 mm of solution to the top of the formwork.

For shrinkage of concrete in columns above 5 meters, they arrange technological breaks from 40 minutes to 2 hours.

With mechanized supply of ready-mixed concrete, the feed rate is reduced to avoid delamination. Air is released from the mixture with steel bars, concrete compacted with hand vibrators. In places inaccessible to the vibrator, the concrete is compacted by hand, carefully bayoneted.

Upon completion of work, produce seasonal care behind concrete.

Formwork dismantling

The term for the set of concrete 100% of the working strength is 28 calendar days. The indicator may vary from environmental conditions - temperature, humidity, a set of maintenance work. The average standing period of monolithic columns before stripping is 7-10 days in summer. This period allows the formation of corners and side faces.

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