Concrete is often used in the production of building materials. Among the most popular are blocks of:

• concrete;
• aerated concrete;
• foam concrete;
• sawdust concrete.

Concrete

Concrete blocks are made at factories, due to which the price of this building material is quite affordable. In order for the mixture to be dense, a vibrating press is used. During the production process, the blocks are reinforced and steamed in specially designed chambers for 8 hours. During installation, they must be fastened together with mortar.

Concrete blocks have a different purpose: foundations, basements and basements are built from solid ones, and hollow ones are used when erecting the walls of buildings. They are a good alternative to bricks. At the same time, construction proceeds faster, and the monetary costs for the construction of the building are reduced.

Strong concrete blocks are made from expanded clay concrete and heavy reinforced concrete. Such blocks are durable and frost-resistant. They come in a range of sizes and are affordable.

There are parameters 880x400x580 and 2380x600x580 mm, which are used in the construction of multi-storey buildings. Their price will be from 700 to 3500 rubles each. When comparing concrete blocks with other building materials with similar characteristics, it turns out that their cost is quite low.

The use of concrete wall blocks not only speeds up construction work, but also saves mortar. They are characterized by good soundproofing and low thermal conductivity. Due to their small size, they are easy to transport, store and install.

The weight of the blocks depends on their size. with dimensions of 200x200x400 mm (one piece replaces 7 bricks) will weigh 31.7 kg. They are intended for hand-made laying. The lightweight version of the blocks will weigh 28 kg. They cost 50-60 rubles apiece.

Superintendent's advice: When stored outdoors, concrete blocks lose their quality and begin to deteriorate. Therefore, it is recommended to store them only in specially adapted rooms.

Aerated concrete

Gas blocks are made from aerated concrete, the main component of which is a finely dispersed silica component, and in the second and third places - cement and lime. As a blowing agent, an aqueous suspension of aluminum powder is used, which enters into a chemical reaction with lime. The reaction is accompanied by the evolution of hydrogen, due to which a large number of pores are formed in the mass for the manufacture of gas blocks.

After the start of the chemical reaction, the mixture is poured into special forms. When the aerated concrete hardens, it is cut into gas blocks of the required size. Then the resulting semi-finished product is sent to an autoclave, where it is treated with steam for several hours. If an autoclave was not used in the production of gas blocks, then the cost of such a building material will be lower.

Gas blocks are a durable building material that can be used for the construction of 5-storey houses. Due to its cellular structure, it is lightweight, which means that the foundation for aerated concrete buildings requires an appropriate one. In addition, the cellular structure provides low thermal conductivity, and due to the even geometry of the gas blocks, the thickness of the seams is minimized. Due to this, the premises are reliably insulated.

Superintendent's advice: the use of gas blocks will reduce the cost of building a building, since the mass of the entire structure will be significantly less compared to brick.

The cost of gas blocks depends on their size (200x250x625, 375x250x625, 300x250x625 mm and others) and on performance characteristics such as strength, frost resistance, density, and also on the purpose: wall gas blocks will cost more than blocks intended for partitions. Small producers set low prices for aerated concrete. The cost of gas blocks varies from 2,100 to 4,000 rubles per cubic meter.

Foam concrete

It is easier and easier to make foam concrete than aerated concrete. To do this, sand and cement are poured into an industrial mixer, water is poured. Then a foaming agent is added to it, which contains chemicals (therefore, foam concrete cannot be called an environmentally friendly material). Then the mixture is poured into molds and left for 4 hours. At normal air temperature, foam blocks dry for 2-3 weeks, but faster drying methods can also be used - in autoclaves.

The price of foam concrete is lower than the cost of aerated concrete. Foam concrete is characterized by closed porosity. Such wall building material can be used in rooms with high humidity, since it does not absorb moisture as quickly as aerated concrete. When buying foam blocks per piece, you will need to pay 70-180 rubles, depending on their parameters.

Sawdust concrete

Combines the properties of stone and wood (sawdust). At the same time, up to 90% of sawdust is included in it, and their parameters do not affect the final strength of the building material. Despite this, this building material is fire resistant, since the sawdust is concreted, and oxygen does not have access to them.

The huge advantage of sawdust concrete is the simplicity of its production and low cost. You can prepare sawdust concrete, if you wish, even on your own, spending minimal funds. This building material is used for low-rise construction. It can be used to build both residential and non-residential premises.

There are wall and partition blocks made of sawdust concrete of various sizes: 300x200x500, 100x300x500, 100x200x500, 400x400x200 mm and any others. The price can vary from 50 (for a 6-kilogram block) to 160 (for a 24-kilogram) rubles.

The choice of building material depends on the height of the building, the budget allocated for the construction, and the personal preferences of the owner of the house under construction. Aerated concrete is in the greatest demand of the listed building materials.

Concrete has long been used for the production of a wide variety of products and structures, and if earlier from this material mainly reinforced concrete products were made and foundation and monolithic systems were poured, nowadays it is used much more widely. In private buildings, concrete blocks 20x20 × 40 are very popular - it is very convenient to work with them with your own hands, and in industrial construction, FBS blocks are in great demand.

Features of concrete blocks

To understand why the products of this group are so popular, it is necessary to consider their main advantages:

• A wide range of sizes, allowing you to choose the optimal configuration for any width of the foundation... Of course, the most popular option is concrete blocks 20 x 20 x 40, but sometimes they just don't work, so you have to use other configurations.
• High obtained after erection... Solid products can withstand even significant loads, while hollow versions allow you to create strong and durable walls. If you need special reliability, then options with slot fastening are suitable, they are fixed especially securely, and the walls after the end of the work are much stronger.

In the photo - a system of groove-ridge connections, which allows you to create strong longitudinal and corner joints to ensure the greatest strength

• Selection of manufacturing options: you can purchase both solid concrete blocks and hollow products, which are lighter in weight, making them much more convenient to work with. In addition, you can purchase options with filler, most often it is either slag or expanded clay. And finally, the most common option is those characterized by low weight and high thermal insulation characteristics.
• Possibility of self-production of products... The instructions for carrying out the work are very simple, in addition, the size of the finished product can be different - it all depends on which form will be used. It is worth remembering that you should not make too large dimensions, for example, you are unlikely to lift full-bodied concrete blocks 40 by 40 by 40, so it is better to make elements of generally accepted sizes.

• The price of this group of products, regardless of the type, is quite democratic, which makes them affordable for the widest range of developers. But you should not chase after cheapness when buying, since too low a cost most often indicates the appropriate quality.

Important!
When buying, you should ask the seller for the availability of documents certifying the quality of the products.
This is the only way to ensure that the products are manufactured in the factory in compliance with all the necessary technology requirements.

Types of blocks and their features

All products of this type can be divided into two large groups depending on the specifics of the application. Let's take a closer look at each of them.

Elements for foundations

Products of this group must meet several basic requirements:

Strength	All base elements are subjected to a range of unfavorable loads, therefore they must meet the highest quality requirements
Moisture resistant	A very important factor that directly affects reliability. Since concrete itself does not belong to materials with high resistance to moisture, it must be additionally processed or added to the composition of hydrophobic additives
Frost resistance	Since winters are quite cold in most parts of our country, concrete must have high frost resistance
Ease of use	A very important condition, because the more convenient it is to work with products, the higher the quality of work. To work with large elements, it is necessary to involve lifting equipment

The following types of foundation blocks can be distinguished:

• A widely used and well-known demobilizer is concrete blocks 20x20x40, which are most often used due to their ease of use and democratic cost. The products are produced in full-bodied, although, as studies have shown, the presence of several small cuts does not significantly affect the overall strength, but the load on the base decreases and the thermal insulation properties improve, which is also an important factor.
• FBS blocks are large in size, due to which installation can be carried out as soon as possible. The disadvantage is the large mass of products (if you ask how much a concrete block weighs 240 by 40 by 60, you will be surprised - 1,300 kilograms). Naturally, it is simply impossible to carry out work without lifting equipment.

It is worth noting that the dimensions of reinforced concrete blocks vary within a fairly wide range - from 90 to 30 to 60, and up to 240 to 60 to 60. But even the smallest version weighs 350 kilograms, so a lift will be needed in any case.

Wall blocks

This group includes a number of very different products.

Let's consider the most popular and common ones:

• Slag concrete products belong to one of the most budgetary sectors, but at the same time they have rather high operational properties and a solid coefficient of heat retention.
• Similar to the first option - expanded clay concrete blocks, instead of slag, they use more durable expanded clay, which has excellent thermal insulation characteristics. You can build an entire house from such elements, however, it will have to be finished, since the appearance of the building will not be very attractive.

• Gas silicate structures have excellent thermal insulation characteristics. At the same time, the sizes of lightweight concrete blocks can be very different, which allows you to choose the best option for both external walls and partitions.
• Foam concrete products are similar to gas silicate ones, but some of their properties are somewhat lower than those of the above-described option. Concrete blocks 40 by 20 by 40 are perfect for quick erection of partitions, they cost a little, and they do well with their functions.

A separate option is a concrete block B 1 20 50, these elements are not used for walls, they are used to make drainage structures on highways. This option is practically not used in private buildings.

Advice!
Gas silicate blocks must be additionally insulated.
Do not believe the statements that they are enough for high-quality thermal insulation, in fact, this is far from the case.

Conclusion

The selection of the optimal parameters is very important, since the strength of the structure and its performance characteristics depend on it. The video in this article will tell you some points in more detail.

Concrete blocks are used when you need to quickly lay down a reliable and solid foundation. Large-sized solid panels, for example, are actively used in industrial construction and in the construction of multi-storey buildings, but they require lifting equipment. But hollow for manual masonry can only withstand a compact wooden structure.

Advantages of blocks:

• long service life - at least 50-60 years;
• high speed of erection of foundations;
• resistance to aggressive environments;
• a large selection of standard sizes;
• low cost due to serial production.

The disadvantages include the need to attract special equipment during construction. And even if you use light blocks 20x20x40 cm weighing about 30 kg, you will need at least a hand winch to safely unload and stack building materials. At the same time, the foundation of the panels itself has slightly different properties. With a decrease in the time for erection due to ready-made elements, the cost of the structure itself increases. And labor costs during construction will be higher than when pouring a monolith into a formwork. On the other hand, if it is not possible to achieve stable proportions of concrete solution for pouring, or there is simply not enough experience in this matter, it is better not to take risks and buy a concrete block for the foundation.

Main types

Depending on the applications, the blocks are usually divided into several types. They are marked with letter designations:

1. Ф - are used in the construction of support columns of a columnar foundation on soft soils.

2. FL - they form only the base cushion, since they have the shape of a trapezoid with a very wide "heel". This solution allows the solid structure with reinforcement to take on the significant weight of the building and distribute it over a large area of ​​the supporting soil layer.

3. FBS - the most common type of solid blocks, convenient for the construction of a prefabricated strip foundation. For reliable fixation during installation, special cutouts are sometimes made along the edges of such elements. The concrete itself is reinforced with rebars.

4. BF - in tape bases, but only as a support (bottom row).

5. FBP - lightweight hollow products. They are rarely used for the foundation, since they cannot take significant loads. Their limit is a small frame house made of wood, but for reinforcing walls for pouring a monolithic base, their use is quite acceptable.

6. FR - the most powerful foundation blocks made of heavy concrete with steel reinforcement, for capital construction.

7. UDB is a relatively new variety with through square holes.

The letter designation in the marking after indicating the dimensions corresponds to its version: hollow (P), made of heavy concrete (T).

Sometimes special types are distinguished, starting from their main scope:

• For a capital foundation.

These are heavy blocks (FBS, FR, BF) of large size with mounting metal loops for a cable. Thanks to these elements, the products can be hooked up with a crane hook and installed in the designated place in the trench.

• For tape.

The considerable length of the panels during the erection of the strip base allows to reduce the number of butt joints between its parts, but complicates installation, if not a multiple of the size of the side of the foundation. In this case, additional elements will have to be made on site from full-size blocks using diamond cutting.

• With openings for communications.

The products have openings for the installation of engineering systems. It is very difficult to make such samples manually in concrete; the base can seriously suffer from this.

Standard dimensions

Building blocks are mass-produced at the factories of reinforced concrete structures, and their dimensions are regulated by GOST. No one talks about observing the dimensions with an accuracy of a millimeter, and the corners during storage and transportation can crumble. The marking of each product indicates its parameters in decimetres with rounding. This introduces some confusion, since the builders themselves are used to focusing on centimeters. In these units, we give the standard dimensions of concrete blocks:

Features of using FBS

1. Dimensions.

According to SNiP, the block size can have the following values ​​(cm): 88, 138 or 238. In this case, there are only two height options - 28 or 58 cm.

Length matters when it is required to erect a strip prefabricated foundation of concrete panels on soils prone to heaving. At the slightest movement of the ground, long products will work like a lever, increasing the tension in the fastening solution of the joint joints. To prevent the "tape" of the base from breaking up into separate parts, it is necessary to additionally buy blocks of the FL type, which will play the role of a pillow. It is for these reasons that FBS are most often used for columnar types of foundation.

The dimensions are very important, since the uniformity of the transfer of the weight of the building to the base, and from it to the supporting layers of the soil, will depend on their correct choice. Therefore, before buying a batch of reinforced concrete panels, it will be necessary to calculate the loads that the foundation of concrete blocks will have to take. If the dimensions of the prefabricated elements turn out to be less than required, the entire subsequent operation of the building will be reduced to constant repairs of rickety structures.

2. Characteristics and features.

The strength parameters of the FBS can also differ - in the range from B7.5 to B15. The higher the grade of concrete, the stronger the panel itself and the more reliable the foundation made of it. There is one more requirement for the quality of the side surfaces. The finish option that can be used for the basement will depend on the compliance with a particular class:

1. class A3 - high quality, suitable for painting;

2. class A5 - allowed for finishing with ceramic tiles or pasting with composite panels;

3. Classes A6 and A7 - such a surface can only be sheathed using lathing.

The foundation made of FBS concrete panels, due to their solid structure, turns out to be very reliable and has a number of advantages over other types of reinforced concrete products:

• long service life (60-160 years);
• higher moisture resistance and, as a result, frost resistance;
• the best strength indicators, regardless of the type of loads taken.

But do not forget that the price of the foundation will be quite high, and transportation costs will account for a considerable part of it. Therefore, you need to purchase materials from the nearest precast concrete plant or a large supplier.

Price

The price of blocks directly depends on their size and material consumption. Here you need to be tied not so much to the dimensions as to the weight and volume of the concrete used in the production. That is, hollow panels will cost less than solid panels of the same size.

Dimensions, cm	Average cost, rub / unit
40x20x20	52
60x30x58	464
88x40x58	1100
238x50x58	2900

Used blocks are also on sale. Their price is twice, or even three times lower than the new ones, and the characteristics in the absence of visible serious damage and corrosion are no worse.

One of the most common foundation construction options is the use of concrete blocks.

These structures do not need formwork, and their strength is guaranteed by the factory technology of vibrating and steaming concrete.

When building on soft soils, the blocks are supported on foundation cushions - wide prismatic slabs that reduce the pressure on the soil.

In addition to the construction of prefabricated foundations, the blocks are also used for the construction of retaining walls, ramps, fences, platforms and overpasses.

The technical conditions of production, standard dimensions and strength characteristics are regulated by the State Standard No. 13579, issued in 1978. In addition to heavy concrete, this standard allows the use of light silicate mixtures in the production of blocks, provided that their density is at least 1800 kg per 1 m3.

Varieties of foundation blocks

The most common type is a solid concrete foundation block, denoted by the letters FBS. It is used for installation under external and internal load-bearing walls.

GOST clearly indicates the overall dimensions of these structures:

• With a length of 2.38 meters, the thickness of the FBS blocks can be from 30 to 60 cm (the step is 10 cm). The height is the same for all - 58 cm;
• Blocks with a length of 1.18 meters are produced in three thicknesses: 40, 50 and 60 cm. The height is presented in two standard sizes - 58 and 28 cm;
• Short (additional) blocks. Length 0.88 meters. The thickness is 30, 40, 50, 60 cm. The standard height is 58 cm. They are used in order not to chop a full-size block into pieces, thereby breaking its strength.

The weight of a standard FBS block, depending on the size, can range from 380 to 1960 kg (density 2400 kg / m3).

FBV blocks

They are produced to order in small batches, so they are quite rare at construction sites. The main difference from FBS blocks is a longitudinal cut used for laying utility lines. These are short designs with a standard length (L) of 88 cm.The width (B) can be 40.50, 60 cm with a height (H) of 58 cm.

For the production of FBV, as well as for FBS, concrete of a grade of at least 100 kg / cm2 (B7.5) and frost resistance of 50 cycles (class F50) is used. Steel grades A-I and A-III are used for reinforcement.

Blocks of brand FBP

This is a lightweight form of foundation structures with square voids. In width and height, they are completely similar to FBV blocks. They are produced in one length - 238 cm. They are used for the construction of internal walls of basements, as well as foundations for industrial installations.

Produced on the basis of concrete B12.5 (M 150). Frost resistance is 50 freeze-thaw cycles. Reinforcement is performed with steel of construction grades - A-I and A-III.

Marking

A characteristic feature of the marking of all types of foundation blocks is the rounding of the overall dimensions to decimeters. Therefore, for example, the designation adopted by GOST for a solid block with external dimensions: length 238 cm, thickness (width) 40 cm, height 58 cm will look like this: FBS 24.4.6t (t - heavy concrete). The minimum weight of such a structure is 260 kg, and the maximum weight is 2 tons (density 2300 kg / m3).

If the structure is made of lightweight concrete, then after the digital marking they put the letter "L" or "P" (on the porous aggregate - expanded clay). Minimum weight - 230 kg, maximum - 1.47 tons (density 1800 kg / m3).

If after the digital code there is a letter "C", it means that silicate concrete was used during casting. The minimum weight of such a block is 250 kg, and the maximum (with a length of 2.38 meters and a width of 60 cm) is 1.63 tons. Density - 2000 kg / m3.

All foundation blocks are equipped with 2 loops (lugs) made of steel wire with a diameter of 12 mm. They are required for assembly and handling operations.

Benefits of foundation concrete blocks

• Significant reduction in the duration of work ... When erecting a foundation by pouring concrete into the formwork, you have to wait 4 weeks to gain brand strength;
• Standardized sizes ... Allows you to accurately calculate the required number of blocks;
• No need to purchase expensive consumables (boards or OSB board for formwork, anti-freeze additives and to accelerate the setting of concrete);
• Possibility of selection according to the specified characteristics (water resistance, frost resistance, resistance to aggressive liquids);
• Durability (with proper installation and observance of operating conditions, such structures serve for more than 100 years).

Estimated prices

Let's take a quick look at the sizes and prices of foundation blocks used in civil engineering.

The cost of the smallest (additional) block made of heavy concrete FBS-6-3-6t (length 0.6 m, width 0.3 m) averages RUB 500 / piece.

The same block, but 1.2 meters long (FBS-12-3-6t) will cost from 1,000 rubles. Manufacturers offer full-size blocks with a thickness of 30 cm (length 2.4 m) at a price of 2,100 rubles / piece.

Blocks 40 cm thick and 2.4 meters long (FBS 24-4-6) will cost about 2800 rubles / piece, 1.2 meters long (FBS 12-4-6) about 1400 rubles / piece.

The most popular among buyers are FBS blocks 60 cm wide, since this is the thickness of the foundation that is chosen in housing construction.

The price tags for these structures in the Moscow region look like this:

• FBS-6-6-6t - 1,100 rubles / piece;
• FBS-12-6-6t - 2,200 rubles / piece;
• FBS-24-6-6t - 4 100 rubles / piece;

Hollow blocks (FBB) in the prices of suppliers are much less common. Average prices for these structures are 10-15 percent higher than for solid blocks. This is due to the higher labor intensity of filling and reinforcing a mold with voids.

You will not find the price for blocks with a cutout (FBV) in the factory catalogs. For their quotation and manufacture, you will have to contact the precast concrete plant and make an individual order.

Quite often there are offers on the market for the sale of used blocks. Do not rush to rejoice at their low cost, but rather consult an experienced builder. He will competently assess the nature and degree of defects and give practical advice on the justification of such a purchase.

Features of calculation and installation

As you said, calculating the number of blocks is pretty straightforward. To do this, you need to determine the volume of the future foundation and divide it by the volume of one block you have chosen. As a result, you will receive the required number of designs for ordering.

You don't have to worry about the number of storeys in the building. The strength of the factory block is quite sufficient to build a five-story building on it.

The condition of the soil is much more critical for such a structure. Here you need to take into account one feature of block bases - low solidity. Unlike a solid strip foundation, a block foundation has vertical and horizontal seams that weaken it. Therefore, before installing the FBS blocks, a monolithic reinforced concrete belt is poured along the bottom of the trench. It takes over a significant part of the heaving forces that arise in freezing wet soil.

If the foundation of the building is high (there is a basement), then experts recommend making an armored belt every two rows of blocks.

The ideal base for a block foundation is soils composed of coarse sand with a deep aquifer. Since such conditions are very rare, in all other cases the block grillage needs to be strengthened. In addition to using an armored belt, each row of blocks should not be laid dry, but on a concrete M 150 mortar with a thickness of at least 3 cm.

Preparation of the base

For the base under the blocks, it is enough to make a sand bed. It plays the role of a leveling layer and its thickness usually does not exceed 15 cm. If the construction is carried out on dry sandstones, then the blocks can be placed directly on the ground.

For buildings erected on problem soils, reinforced concrete foundation cushions (FL) are placed under the blocks to increase the support area.

Installation of a foundation made of concrete blocks

The norms prohibit the installation of a foundation from FBS blocks if the bottom of the trench is covered with snow or flooded with water. The movement of these structures is performed by a crane.

First, blocks are installed at the corners of the foundation and at the junction points of the inner walls. They act as assembly beacons. After checking with a level the coincidence of the upper planes of all the lighthouse blocks, pull the cord between them and set intermediate structures along it. At the points determined by the project, gaps are left between the blocks for the passage of engineering networks.

Before installation, the blocks are cleaned of dirt and moistened with water. Installation is carried out on a concrete solution with bandaging of vertical seams (due to displacement of rows and the use of additional blocks). Vertical joints are also filled with mortar, sealing it with a bayonet shovel.

Useful advice: when buying foundation blocks, be sure to check with the seller for a certificate of conformity and ask for a copy for yourself. This document guarantees that the quality of the products meets the requirements of the current GOST. It may be needed to substantiate the claims that have arisen and to recover damages.

• Types of foundation blocks
• Solid foundation blocks
• Dimensions of concrete products for the foundation

Construction begins with the construction of the foundation. The use of ready-made concrete blocks is the most economical way, less laborious and quick. A foundation made of in-situ concrete with the same strength costs about 2 times more. Formwork, installation of reinforcement, pouring concrete, waiting for it to dry is a process that requires a lot of time and labor, and is also dependent on weather conditions. The disadvantage of foundation blocks is only that special equipment is needed to lay them - a crane.

The use of concrete blocks in the construction of the foundation is an economical, fast and less labor-intensive construction method.

A combined foundation is often made: the pillow is made of monolithic concrete, and the base is made of blocks. The construction of the foundation from them is relatively quick and easy. It is only necessary to lay them strictly in a straight line, check their levelness in level, reliably tie them to each other. The stability of the future building depends on the correctness of the construction of the foundation. The use of concrete blocks is possible under any climatic and seasonal conditions.

There are three types of concrete blocks. FBP (hollow) are used in the construction of walls and foundations for various equipment. They are not used for the foundation of buildings. They are relatively light, have a high heat capacity, that is, they keep heat better. In addition, the wall of them is stronger due to the cement mortar, which partially fills the vertical voids. Their other type, FBV (solid with a cutout), is used where communications or lintels crossing them are provided in the foundation or basement wall.

Back to the table of contents

Concrete block size chart.

More often used concrete blocks for the foundation solid (FBS). They are also suitable for the construction of basement walls, basements and technical buildings. They are also used as barriers on the roadway. They do not differ in a variety of shapes and are made in the form of a rectangular parallelepiped. In their narrow ends, vertical grooves are left, which, after laying two blocks next to each other, are filled with cement mortar for their strong fastening to each other. On the upper edge, they have 2 mounting loops for easy installation.

In the production of concrete products for the foundation, heavy, frost-resistant, moisture-resistant concrete is used, reinforced with reinforcement rods 8-12 mm thick. To increase their strength, they are steamed in a special chamber for several hours. It can be replaced by drying, which takes several weeks. The production of foundation blocks is a responsible process, strictly adhering to the technology in accordance with GOST 1978, therefore it is better to entrust it to large enterprises with a reliable reputation. Concrete blocks for the foundation must be solid, without internal voids and cracks, have high compressive strength, water resistance, resistance to deformation under loads and temperature drops, to the effects of an aggressive environment.

They also produce blocks with porous fillers (expanded clay) and from silicate concrete. They are lighter, but in any case their density should not be less than 1800 kg / m3. In addition to "rectangular", there are FBS with a trapezoidal end section. Their lower edge has a large area to support the weight of the building under construction and provide it with stability. They are laid in the first row directly on the foundation cushion made of sand, crushed stone or monolithic concrete. FBS with a rectangular section make up the second and subsequent rows of the foundation.

Back to the table of contents

The type and size of concrete blocks.

The sizes of concrete blocks are as follows: length - 900, 1200, 2400 mm, width - 300, 400, 500, 600 mm, height - 300 and 600 mm. True, the actual dimensions are 1-2 cm smaller. Their weight is from 135 kg (the smallest block of heavy concrete) to almost 2 tons. The most acceptable size is chosen based on the following conditions:

• the type of soil on which the building is being erected;
• type of wall and masonry material;
• the weight and dimensions of the building;
• length and thickness of walls;
• design strength of the foundation.

The optimal number of blocks stacked in a row along one wall is 4-5. When constructing the foundation, FBS of different sizes are used to better attach them to each other. Their width may be less than the width of the walls erected on them by 10-12 cm. The more unstable the soil, the larger the area of ​​their base. To protect the foundation from premature destruction, they are waterproofed with bitumen. The service life of a foundation made of concrete blocks is at least 50 years.

Construction of a strip foundation made of concrete blocks.

FBS is modified as follows: the name indicates the length, width and height in decimeters, the type of concrete. For example, marking FBS 24.3.6t denotes a solid foundation block made of heavy concrete 2400 mm long, 300 mm wide and 600 mm high. Most often used in the construction of FBS 24.4.6. FBS from expanded clay concrete is marked with the letter "P", from silicate concrete - with the letter "C".

In addition, they produce concrete blocks with a size of 40x20x20 mm. Their low weight (depending on the type of concrete, only 28-32 kg) allows them to be laid by hand, and their dimensions can be used in the construction of walls. They are suitable for foundations for light buildings: a small garage, a bathhouse, a gazebo, a wooden house, etc. They are irreplaceable on those construction sites where the passage of heavy machinery is impossible.

http://youtu.be/9NwFb7des6M

The use of concrete blocks in the construction of the foundation significantly reduces the cost and speeds up the work in comparison with the method of pouring liquid concrete into the formwork.

At the same time, the highest reliability, strength and durability of the foundation are achieved.

ostroymaterialah.ru

Foundation blocks: reinforced concrete, expanded clay concrete

Prefabricated block foundations appeared many decades ago. And to this day, many buildings stand on strip foundations assembled from concrete blocks. But not all builders consider them reliable: after all, they are not monolithic, and therefore they are less resistant to soil movements.

Monolithic foundations have a very high degree of reliability. But their creation is a very long and difficult process, it is required to install the formwork, make a reinforcing belt for several hundred tying points, knead a large amount of mortar, pour it over. After waiting for several weeks for the solution to ripen, and only then continue construction work. Everything takes at least a month, and more often more - if everything is done by hand, without the involvement of outside workers.

Block foundation assembly technology and scope

To speed up the process and use ready-made foundation blocks. They are produced by many factories, they are of different types, geometries and dimensions. With some you can work only with the help of construction equipment, with others - the smallest - you can work manually.

With foundation blocks, the construction of the foundation takes a little time

When assembling, they are installed in a dug pit on a prepared pillow. Rows and elements in a row are connected using cement mortar, sometimes using reinforcing belts to increase reliability. You can even assemble a small base for a bathhouse, a small house or a garage in one day. After that, it remains to carry out waterproofing and insulation work.

But due to the fact that the structure is not a monolith, it can only be installed on reliable, non-powdery soils. If there is at least a minimal tendency to heaving, it is better not to put a prefabricated block foundation: when exposed to significant forces, it will begin to "walk" and the building may collapse. However, on dry and rocky soils, it is one of the most affordable and quickest foundations to be erected. Now you know where you can put prefabricated block foundations.

What are the foundation blocks

First of all, let's talk about the materials from which the foundation blocks are made. This:

• reinforced concrete;
• expanded clay concrete;
• high strength silicate concrete.

In the manufacture of reinforced concrete blocks, the mortar is most often used grades M-150, M-100, M-200. Depending on this, the characteristics change, the price rises. If a building is supposed to be massive, large and heavy, blocks of the highest quality are needed, with high strength; for low-rise construction and the foundation for a bath, blocks of M-100 solution are sufficient.

Reinforced concrete foundation blocks are classified as heavy

Reinforced concrete blocks are and are called heavy: their mass is large due to the high density of the solution. Their weight, depending on the dimensions, can be from 300 kg to 2 tons. To be able to distinguish the type of block, when marking put at the end of the letter "T".

In the manufacture of expanded clay concrete, expanded clay is used as a filler. This composition is lighter, the weight of the blocks is from 260 kg to 1.5 tons. When marking these products at the end add the letter "L" - lungs. They have better thermal insulation characteristics, the price is lower.

But unpleasant properties and features also appear: high hygroscopicity, as well as lower strength. To neutralize hygroscopicity, careful waterproofing and measures to drain water from the foundation will be required. But nothing can be done about strength: expanded clay concrete blocks can only be used on foundations for light buildings, for example, wooden baths or single garages.

Expanded clay concrete has a characteristic uneven surface

In the manufacture of silicate concrete blocks, lime is used as the main binder. The solution turns out to be of medium weight, because these blocks are called light and are designated at the end by the letter "C". The mass of products manufactured according to the standards (minimum density 1800 kg / m3) can be from 300 kg (the smallest) to 1.63 tons (the largest).

According to GOST, silicate concrete blocks are not used in conditions of high humidity. This means that they will not work for the foundation.

Specifications

In addition to material, density, weight and price, there are many characteristics that you need to pay attention to. There are many more parameters by which you will have to choose them.

Types and sizes

Foundation blocks have different shapes and profiles, in addition, different overall dimensions. Products of different shapes have different purposes and markings:

After the letters that indicate the type of product, there is a set of numbers. They represent the dimensions of the blocks, indicated in decimetres. The first number is the length, the second is the width, and the last is the height. For example, FBS-24-6-6 is a rectangular block, 240 cm long, 60 cm high and 60 cm wide.The designation FL-6-12-3 stands for trapezoidal block (pillow), 60 cm long, 120 cm wide and a height of 30 cm.

There are block-beams. They are also sometimes needed in construction.

The use of all these units involves the use of cranes or at least a winch. But there are very small blocks, measuring 20 * 20 * 40 cm. They are poured into standard forms at the same factories. When pouring, vibropressing machines work, which increase the density of the solution. A mixture of Portland cement, sand and a larger aggregate is used. The aggregate can be gravel, and then the block is concrete, or expanded clay, and then it is, accordingly, expanded clay.

Small-sized concrete blocks are solid and hollow. Corpulent ones are used for laying foundations of light buildings on reliable soils, hollow ones - for erecting walls. You can work with them without equipment: the mass does not exceed 40 kg. But when constructing such a foundation, additional reinforcing belts must be created. In some cases, a metal mesh is placed in each horizontal seam. And to increase the strength, you can also make a reinforcing belt of greater height. It all depends on the conditions on the site and the structure of the building.

Frost resistance

This characteristic is important for most of the territories of our country. Any of the materials can withstand a certain number of freeze and thaw cycles. To increase this indicator, various additives are added to the solution. It is clear that the more cycles the concrete block transfers without destruction, the longer the foundation will serve.

FBS block size table

Resistance to environments

If there are acidic or alkaline soils on the site, it is necessary to choose the type of concrete accordingly. If we talk about the Moscow region, then most of the soils are acidic, therefore here it is necessary to use blocks with crushed stone as a filler: it makes products resistant to acid influences.

The acidity of the soil is determined using tests that can be purchased at a store that sells agricultural equipment. They cost a penny, the method of application is described on the packaging, as well as the scale by which the state of the soil is determined.

Cost and quality

It is possible to say exactly how much a particular foundation block costs only after calling several factories in your region. Prices vary considerably. Moreover, even manufacturers in the same region may have a substantial difference. It could be the concrete grade. Here you need to ask and compare. Do not be lazy to get into each production and inspect, evaluate the blocks presented there, according to the following parameters:

The quality of hand-made foundation blocks must be checked

• Geometry. All blocks must be the same, the edges must be even and clear. It is also desirable that the surfaces also have a minimum of flaws or have none at all.
• The declared density can be compared at home (we are talking about small blocks 20 * 20 * 40 cm). They need to be weighed, their dimensions and weight must be compared. Calculate the density. For expanded clay concrete, it should not be less than 1800 kg / m3, for concrete - not less than 2000 kg / m3. Only these can be used for foundations.
• Then do a crash test: throw blocks from the same height onto a hard surface. In no case should they crumble, chips should be minimal.

These simple manipulations allow you to determine the quality of concrete blocks. Just don't forget which one belongs to which company (sign or number).

Block foundation device

There are several types of foundations that can be built using concrete blocks. These are tape, pile and columnar. The technologies are not much different, but there are still some features.

Strip foundation from blocks

There can be several options for arranging a strip foundation from blocks:

Is it possible to make such foundations from blocks 20 * 20 * 40 cm. If this is a structure that is light in weight and the soils are suitable, then the answer is "yes". In this case, a frame made of a log or a bar will feel especially good. Due to the elasticity of the wood, possible movements will be compensated. In addition, this material is lightweight, and the strength of small-sized blocks will be sufficient to support this weight.

If the soils have even the slightest hint of heaving, or the house is heavy, only experts can say after examining the site and calculating whether it is possible to make a foundation from small-sized blocks.

Using blocks for pile and columnar foundations

For pile foundations, reinforced concrete products of different sections are used: round, square, polygonal. They go deep into layers of solid soil that can support the weight of the house. The upper part of the piles is united by a strip base on which the walls will rest. This type of foundation is good for difficult loose or highly heaving soils.

Pile foundation made of concrete blocks

Columnar foundations have a similar geometry. Only their depth is much shallower. There are shallow (above the freezing level) species and those with the laying below the freezing level. The shallower depth is compensated for by a larger base area: the pillars are usually wider. Here, as in the construction of a prefabricated strip foundation, options are possible:

Outcomes

Correct use of concrete blocks for foundation construction speeds up the process a lot. It is problematic to say whether it will be cheaper or more expensive. In some cases, it is cheaper, sometimes, due to the need for a long lease of a crane, it is more expensive. What is indisputable is that it is being built much faster, and this is sometimes no less important than cost.

baniwood.ru

Concrete blocks for foundation

Foundation blocks are concrete products of strength grades M100, M150, M200, intended for the construction of tape and columnar bases in any climatic zone. They are also suitable for the construction of walls in basements, basements, technical rooms. Almost always have a rectangular shape, on the upper edge there are one or two metal eyelet loops, for which the element is picked up by a crane, and then moved to the installation site. It is possible to combine a monolithic base with a block base, in this case the pillow is poured with an ordinary solution, ready-made panels of factory production are placed on top of it.

1. Pros and cons
2. Varieties and labeling
3. Block sizes
4. average cost

Features of the block foundation

Advantages:

• high construction speed;
• small costs of manual labor;
• minimum amount of work with cement mortar, there is no need to put formwork;
• the possibility of installing the base of the building in adverse weather conditions;
• versatility - the panels are suitable for the construction of buildings of any type;
• on sandy soil, no preliminary cushion is required;
• resistance to the effects of groundwater, temperature drops, and other unfavorable conditions;
• frost resistance (up to -55 ° C, from 50 freeze-thaw cycles);
• uniformity of quality of individual elements;
• compliance with GOST requirements;
• immediately after the completion of the work, you can start building the walls, without waiting for the solution to dry and gain strength;
• service life - from 100 years.

Disadvantages of a concrete panel foundation:

• the need to use special equipment during the installation;
• unsuitability for heaving soil;
• requires reliable additional waterproofing;
• the final price (taking into account the cost of work, energy costs) is higher than that of a cast one.

Types of foundation panels

The classification of blocks is carried out on the basis of the shape, the presence of reinforcement, the type of concrete. The quality depends on the grade of mortar strength, manufacturing technology. The main characteristics are determined by marking:

• FBS - solid unreinforced, suitable for supporting structures, foundations of high-rise buildings, erection of walls in basement rooms;
• FBP - hollow (hollow), used as a permanent formwork, when installing basements, industrial buildings, the voids are reinforced and then poured with mortar;
• F - reinforced concrete (with reinforcement);
• FL - for strip foundations;
• BF - made of heavy concrete;
• FBV - solid with a longitudinal recess (for communications, jumpers).

A variety of foundation panels are pillow ones. They are trapezoidal, which increases the footprint. Such products are used when creating the first row of blocks from blocks, primarily on soil with high humidity.

Marking

Dimensions are in decimetres rounded up:

• FBS -9-3-6t - 880 x 300 x 580 mm;
• FBS -9-4-6s - 880 x 400 x 580 mm;
• FBS -12-3-6p - 1180 x 300 x 580 mm.

Sometimes manufacturers or sellers indicate dimensions in a different order: height x width x length.

The next parameter, which can be determined by the marking, is the type of concrete:

• T - heavy;
• C - silicate;
• P - porous (expanded clay).

Different aggregates are used in the production of each type. The difference lies in the density of the resulting concrete. The lightest - expanded clay concrete, silicate has an average density, the name "heavy" speaks for itself. There is a direct relationship between density and compressive strength.

Most often, heavy concrete blocks are used - they are the most durable, frost-resistant. But other species have their merits. Silicate and porous expanded clay concrete is lighter, which facilitates transportation, is cheaper, and requires less installation costs.

Dimensions of foundation block elements

Most often, when installing the base of a building, products with a height of 58 or 28 cm (in marking 6 or 3) are used. Their width can be 30 (3), 40 (4), 50 (5) or 60 (6) cm.There are three types of panels in length:

• 8 or 9: short (additional), used to avoid the need to crush a whole, their length is 78 or 88 cm, respectively, the weight, depending on the width and height, is from 180 to 700 kg.
• 12: length - 118 cm, weight - from 264 to 960 kg.
• 24: length - 238 cm, weight - from 490 to 1960 kg.

There is one more standard - FBS-4. They have a single size 40x20x20 cm, weight - 310 kg.

If necessary, you can purchase products for the installation of a concrete base of lengths, widths, heights that differ from those listed. You need to navigate by marking. Less popular options include options with a length of 28 (3), 38 (4), 48 (5), 58 (6), 178 (18) cm and a height of 38 (4) or 48 (5) cm. Panels of the FL brand have additional standard sizes that are not included in the grid of blocks of the FBS type.

Cost and size are directly related. Below are the minimum prices for foundation elements made of concrete panels of popular standard dimensions.

FBS-9 price, rubles:

Prices for FBS-24, rubles:

24-3-3	24-4-3	24-5-3	24-6-3	24-3-6	24-4-6	24-5-6	24-6-6
1310	1110	1550	1650	1350	1800	2250	2700

You can buy a concrete block 20x20x40 (FBS-4) at a price of 54 rubles.

The technology and quality of materials are important, so the discrepancy in the cost of blocks produced by different manufacturers can be very significant. It is wiser to purchase products directly from factories located a short distance from the construction site. This will save on transport costs and the intermediary's trade margin.

The use of prefabricated prefabricated block products for the construction of the foundation significantly reduces the time spent, labor intensity, and ensures uniformity of quality. This type of building material is universal, it can be used for the construction of walls in non-residential premises, it is suitable for the installation of the base of a building under the most unfavorable conditions. A large selection of standard sizes allows you to choose concrete blocks for the foundation of structures of any complexity.

stroitel-lab.ru

Features of concrete blocks for the foundation

Concrete blocks are used when you need to quickly lay down a reliable and solid foundation. Large-sized solid panels, for example, are actively used in industrial construction and in the construction of multi-storey buildings, but they require lifting equipment. But hollow for manual masonry can only withstand a compact wooden structure.

Peculiarities

Advantages of blocks:

• long service life - at least 50-60 years;
• high speed of erection of foundations;
• resistance to aggressive environments;
• a large selection of standard sizes;
• low cost due to serial production.

The disadvantages include the need to attract special equipment during construction. And even if you use light blocks 20x20x40 cm weighing about 30 kg, you will need at least a hand winch to safely unload and stack building materials. At the same time, the foundation of the panels itself has slightly different properties. With a decrease in the time for erection due to ready-made elements, the cost of the structure itself increases. And labor costs during construction will be higher than when pouring a monolith into a formwork. On the other hand, if it is not possible to achieve stable proportions of concrete solution for pouring, or there is simply not enough experience in this matter, it is better not to take risks and buy a concrete block for the foundation.

Main types

Depending on the applications, the blocks are usually divided into several types. They are marked with letter designations:

1. Ф - are used in the construction of support columns of a columnar foundation on soft soils.

2. FL - they form only the base cushion, since they have the shape of a trapezoid with a very wide "heel". This solution allows the solid structure with reinforcement to take on the significant weight of the building and distribute it over a large area of ​​the supporting soil layer.

3. FBS - the most common type of solid blocks, convenient for the construction of a prefabricated strip foundation. For reliable fixation during installation, special cutouts are sometimes made along the edges of such elements. The concrete itself is reinforced with rebars.

4. BF - in tape bases, but only as a support (bottom row).

5. FBP - lightweight hollow products. They are rarely used for the foundation, since they cannot take significant loads. Their limit is a small frame house made of wood, but for reinforcing walls for pouring a monolithic base, their use is quite acceptable.

6. FR - the most powerful foundation blocks made of heavy concrete with steel reinforcement, for capital construction.

7. UDB is a relatively new variety with through square holes.

The letter designation in the marking after indicating the dimensions corresponds to its version: hollow (P), made of heavy concrete (T).

Sometimes special types are distinguished, starting from their main scope:

• For a capital foundation.

These are heavy blocks (FBS, FR, BF) of large size with mounting metal loops for a cable. Thanks to these elements, the products can be hooked up with a crane hook and installed in the designated place in the trench.

The considerable length of the panels during the erection of the strip base allows to reduce the number of butt joints between its parts, but complicates installation, if not a multiple of the size of the side of the foundation. In this case, additional elements will have to be made on site from full-size blocks using diamond cutting.

• With openings for communications.

The products have openings for the installation of engineering systems. It is very difficult to make such samples manually in concrete; the base can seriously suffer from this.

Standard dimensions

Building blocks are mass-produced at the factories of reinforced concrete structures, and their dimensions are regulated by GOST. No one talks about observing the dimensions with an accuracy of a millimeter, and the corners during storage and transportation can crumble. The marking of each product indicates its parameters in decimetres with rounding. This introduces some confusion, since the builders themselves are used to focusing on centimeters. In these units, we give the standard dimensions of concrete blocks:

Features of using FBS

1. Dimensions.

According to SNiP, the block size can have the following values ​​(cm): 88, 138 or 238. In this case, there are only two height options - 28 or 58 cm.

Length matters when it is required to erect a strip prefabricated foundation of concrete panels on soils prone to heaving. At the slightest movement of the ground, long products will work like a lever, increasing the tension in the fastening solution of the joint joints. To prevent the "tape" of the base from breaking up into separate parts, it is necessary to additionally buy blocks of the FL type, which will play the role of a pillow. It is for these reasons that FBS are most often used for columnar types of foundation.

The dimensions are very important, since the uniformity of the transfer of the weight of the building to the base, and from it to the supporting layers of the soil, will depend on their correct choice. Therefore, before buying a batch of reinforced concrete panels, it will be necessary to calculate the loads that the foundation of concrete blocks will have to take. If the dimensions of the prefabricated elements turn out to be less than required, the entire subsequent operation of the building will be reduced to constant repairs of rickety structures.

2. Characteristics and features.

The strength parameters of the FBS can also differ - in the range from B7.5 to B15. The higher the grade of concrete, the stronger the panel itself and the more reliable the foundation made of it. There is one more requirement for the quality of the side surfaces. The finish option that can be used for the basement will depend on the compliance with a particular class:

1. class A3 - high quality, suitable for painting;

2. class A5 - allowed for finishing with ceramic tiles or pasting with composite panels;

3. Classes A6 and A7 - such a surface can only be sheathed using lathing.

The foundation made of FBS concrete panels, due to their solid structure, turns out to be very reliable and has a number of advantages over other types of reinforced concrete products:

• long service life (60-160 years);
• higher moisture resistance and, as a result, frost resistance;
• the best strength indicators, regardless of the type of loads taken.

But do not forget that the price of the foundation will be quite high, and transportation costs will account for a considerable part of it. Therefore, you need to purchase materials from the nearest precast concrete plant or a large supplier.

Price

The price of blocks directly depends on their size and material consumption. Here you need to be tied not so much to the dimensions as to the weight and volume of the concrete used in the production. That is, hollow panels will cost less than solid panels of the same size.

Dimensions, cm	Average cost, rub / unit
40x20x20	52
60x30x58	464
88x40x58	1100
238x50x58	2900

Used blocks are also on sale. Their price is twice, or even three times lower than the new ones, and the characteristics in the absence of visible serious damage and corrosion are no worse.