Reinforced concrete columns for arranging frame structures

A huge number of people at the mention of such a word as "column" immediately recall the antique, decorative monuments of architecture and buildings with wide carved columns supporting the ceiling. But in addition to such architectural objects that perform a decorative function, there are reinforced concrete columns of industrial buildings that perform a support function for maintaining the building frame.

Design features

Columns made of reinforced concrete mortar rearrange vertical products with relatively small dimensions of the cross-sectional shape, when compared with their height or length.

Such building elements are mainly used to create frames of the braced or frame type, and they are also used as load-bearing supports for other building elements:

• Beams;
• Rigel;
• Runs.

Basic properties and characteristics

Concrete goods columns are the products possessing the following set of properties:

• High resistance to aggressive environmental influences;
• Full compliance with the stated carrying ability;
• Resistance to a variety of seismic effects;
• Moisture proof;
• Resistance to freezing temperatures.

Instructions for choosing a particular design provides a reference point for compliance with the following parameters:

1. The data obtained as a result of genealogical research;
2. Weather conditions and climatic zone in which the support will be operated;
3. The height of the building under construction or its height;
4. The functional purpose of the building, in the construction of which the columns are involved.

The main and most important technical characteristic of concrete bearings supports is the carrying capacity. The higher the performance of this parameter, the lower the column is located in the building. Products with the highest bearing capacity can be used in the construction of lower floors or basements.

For multi-storey buildings, columns are usually used, the construction of which is endowed with several cantilever protrusions provided at a height of 2.5 and 3 meters. Marks of this type are the designation of the end of the floor, because it is on them that the ceiling beams are fixed for arranging the next level. Thus, the frame of high-rise buildings is formed.

The columns, which are used for erecting buildings on one floor, are higher and do not provide for projections. Such supports can be used for the construction of industrial or agricultural premises.

Normative documents

Concrete products of this type are treated with a high degree of responsibility and impose the strictest requirements. Elements of this type are manufactured in full compliance with standardized documentation. They produce a huge number of different tests and tests for strength, reliability, rigidity and ability to resist cracking.

All the basic requirements and standards for concrete products supports are contained in the following documents:

• GOST 25628 of 1990 regulates the parameters of columns for the construction of single-story buildings;
• GOST 18979 from 1990 regulates the parameters of columns for the construction of multi-storey buildings;

Note! In these State Standards, piles-columns are assigned such designation "SK.40.2.5-1". This designation indicates that the length of such elements is 0.4 m, and their width is 0.2 m.

• Series AI 04-1 regulates the parameters of the products to create a bond frame;
• Series 1.423.1-3 / 88 specifies the parameters of the columns, which are the basis for the construction of single-storey premises for industrial use;
• Series 1.823.1-2 specifies the characteristics of products for the construction of structures for agricultural purposes.

The price of such products belongs to the category of high enough and therefore it is important to follow that the money spent was justified. The parameters of durability and strength of the columns from reinforced concrete have no analogues among the entire range of concrete products. It is these characteristics that cause the columns to become those products around which the building is being built.

What are the columns made of?

By the choice of material for the manufacture of such supporting structures fit with great care, because it depends on it the main indicators of the finished product. Modern elements are made using the solutions of the brand from M300 to M600 with a reinforced frame, performed with the help of rigid rods and wire. Reinforcement from steel can be tense or unstressed.

It is this steel hardening that will allow the column to have the necessary level of strength, durability and ability to undergo enormous loads from floor slabs.

Installation of reinforced concrete columns with their own hands is made in specialized glasses or in monolithic foundations. Column foundations are products that are also made of reinforced concrete. Such elements have simply a huge margin of safety, which allows them to securely hold products of this type, excluding movement and inclination.

Product classification

There are several types of classifications of such concrete structures for various characteristics and characteristics of the finished element.

Kinds

By the form of such structures are divided into two main groups:

1. With consoles - for the construction of buildings erected with the help of bridge cranes:

• Rectangular - for buildings with a height of 9.6m;
• Two-branch - for buildings with a height of more than 9.6 m;

Note! A product of this type consists of the above-crane part, on which the overlap rests, and the crane part, which serves as a support for the beam and takes the load from the overlap.

1. Uncontrolled - for the construction of buildings that are made without the use of bridge cranes.

The unified dimensions of reinforced concrete columns with consoles are also divided depending on the type of cross-section:

• With a rectangular section - 400/400, 400/600, 400/800, 500/500, 500/600, 500/800 (mm);
• With two-branch section - 400/1000, 500/1000, 500/1300, 500/1400, 500/1550, 600/1400, 600/1900, 600/2400 (mm).

By section

According to the type of cross section of the structure can be:

• Round;
• Rectangular;
• Square.

By manufacturing technology

According to the method by which it is made, the support structure can be:

• Monolithic. Manufacturing is made directly on the construction site by pouring concrete solution into the formwork, which is pre-laid reinforcing frame;

• Team. The supports of this type are fully manufactured in industrial conditions at the manufacturers. Transportation of such products to the building site is carried out using specialized equipment.

By position

Depending on the position of the column in the reinforced concrete structure being created, the products are divided into:

• Middle columns;
• Columns of the last row;
• Facade products.

Facade elements have an enlarged console, which provides the possibility of supporting facade coatings on it. The holes in this console are intended for communication risers.

There are also facade products with long consoles for arranging balconies and loggias.

Some features of the calculation

Parameters such as length, availability of embedded elements, cross-section, and bearing capacity of the column are determined by the calculation method at the design design stage. In a huge number of cases, prefabricated concrete products are used, which have a long, equal to two floors of the constructed structure.

Professionals recommend the use of concrete solutions brand from B-15 to B-25. Well, for the products to be used in the construction of the first floors apply solutions from B-25 to B-30, but no more.

The first thing that needs to be determined with the help of the calculation is the cross-sectional area of ​​the concrete product, which will preserve the uniformity of compression. This value is determined by the following formula:

A = F / Rb, where:

• A is the sectional area of ​​the product;
• F - compressive force;
• Rb is the compressive strength of a concrete solution.

Example calculation of reinforced concrete columns:

F = 50 tons. Concrete brand B15 with a compressive strength of 200 kgf / cm2.

A = 50000/200 = 250 cm2

The side of the section square will be equal to:

A = v250 = 16 cm.

After the cross-sectional area is known, a calculation follows, taking into account coefficients denoting working conditions, mounting accuracy and other conditions that can increase the dimensions of the cross section. You should also take into account the eccentric compression, taking into account the random eccentricity and the flexibility of the created structure, which increases in proportion to the height of the product.

These calculations can be so cumbersome and complex that their production is often associated with a high probability of making mistakes. And with the current capabilities of modern computing, it is simply inappropriate to make such calculations manually. Well, if you determine the cross-sectional area of ​​the column is necessary in, so to speak, field conditions then you, of course, will have to be counted manually.

In any case, the calculation must take into account not only the own strength of the column, but also the possibility of its interaction with the foundation and the floor structure. Therefore, the calculated cross section should be increased at least from a constructive look at the reinforcement of the structure.

What to consider before buying

Before you purchase columns for the construction of a building or premises of an industrial or agricultural type, you should find a manufacturer who can purchase products of good quality at a reasonable price.

In order to order and purchase a supporting reinforced concrete structure, you will need to provide the following data:

• A set of working drawings for which the required column was designed;
• Estimated height and height;
• The form;
• Cross section size;
• Availability of embedded parts;
• The location of the building plot in order to correctly calculate the cost of transporting the finished product.

Finally

Columns - an extremely important, durable and reliable product for the construction of tasks. Choosing such supports, you should be guided by the data that GOST indicates on reinforced concrete columns for industrial buildings, agricultural, one-story and multi-storey. In addition to these regulatory documents, you should also rely on the calculation of an eccentrically compressed reinforced concrete column, which must necessarily be present in the project.

Well, assembling reinforced concrete support is not difficult, as long as the product has all the declared characteristics, because the strength and reliability of the structure depends on them. And the video in this article will tell you even more about such an important element for the construction as reinforced concrete columns.