Evgeniy Stepanovich, Perm asks a question:

Hello! I bought a plot on which I plan to build a house. After looking at how much a brick cost, I just gasped and decided that I would make the blocks myself. Even if I purchase all the components for building walls and a concrete mixer, I will spend less funds than buying bricks. True, I have never been involved in making blocks, although I have general idea about how to make them. Please tell us how. What proportions of components must be observed during their manufacture? What dimensions should the blocks be? How can you make a mold for casting them? Thanks in advance for the advice.

The expert answers:

Hello! Owners of suburban areas who decide to build a house on their own are often interested in how to make concrete blocks with their own hands. Their choice in favor of this building material is easy to understand. Although it is difficult to produce the number of blocks required for construction, in material terms, amateur builders find themselves in a significant gain. It must be said that the construction of the walls of a house with blocks will be much faster, since they are much larger in size than bricks.

You can determine the dimensions of the blocks yourself, but it will be difficult for you to lay out products that are too large. But it is impractical to produce building materials the size of a brick yourself. Optimal sizes products are shown in Fig. 1. From the same diagram you can see how the most simple form for its casting. The box is assembled from steel 2.5-3 mm thick. It has no bottom. When pouring, the mold is placed on a flat surface and filled with solution. To ensure that the concrete block is free of cavities that reduce its strength, the solution is compacted with a special device. Once compacted, the mold can be lifted and placed side by side to make the next block.

It must be said that a solid product will weigh a lot, so it is better to make it hollow. Such a block will be both less heavy and warmer (Fig. 2). To make it, the mold must be equipped with voids made from pipes plugged at both ends. Vertical plates are welded between the pipes in the upper part. In the same way, the voids are connected to the ends of the form. To make it easier to remove the mold after making the block, the seams at the ends of the pipes need to be processed, slightly rounding them. It is no longer possible to compact products in a mold with voids using a manual tamper. You can make the block stronger using a clamping cover and a hammer drill, which, after turning on in jackhammer mode, should be rested against it. The lid should fit freely into the mold. To prevent it from falling through, limiting corners are welded along its edges.

A more productive device for casting blocks is obtained if an electric motor is connected to it (Fig. 3).

In this capacity, you can even use the engine from washing machine. The motor is attached to the corners welded on one of the outer walls of the mold. For it to work as a vibrator, an eccentric must be attached to the shaft. Once the motor is turned on, it will cause the entire structure to vibrate. When pouring a block, it is better to place the mold on thick rubber, like a conveyor rubber. Rubber shock absorbers need to be secured to the bottom of the mold. When compacting, the concrete is covered with a clamping lid.

Blocks can be prepared from various materials. Suitable for this:

• coal slag;
• expanded clay;
• Sand and gravel;
• crushed stone screening;
• crushed bricks, etc.

Coal slag makes the blocks noticeably lighter. The filling solution is prepared:

To make homemade blocks, you only need a few molds for casting them, as well as cement, sand and filler - slag or broken brick. Other types of fillers (gravel or crushed stone) will make the block very heavy, and in addition, a wall made of such material will heat up faster in the summer and cool down in the winter. If you use expanded clay as a filler, then, although it has almost the same thermal insulation properties as broken brick and slag, it will cost several times more.

Molds for the production of building concrete blocks

For self-made building blocks at home, you will need special metal or wooden forms, inner dimensions which are different: 150 X 150 x 300 mm, 175 x 175 X 350 mm or 200 x 200 x 400 mm. With small blocks it is more convenient to carry out masonry, and with large blocks construction is carried out faster.

To make a collapsible metal mold for one block, you will need four rectangular iron plates 3-4 mm thick (the height, width and length of the plates will depend on the selected mold size). Fastening grooves must be cut on the sides of the plates, and handles must be welded to the end parts of the mold. For a four-block mold, you will need to make two rectangular plates and five smaller plates to separate future blocks in the mold.

To make concrete blocks with your own hands, you need to compact and create bubbles in them, for this purpose you need to make special device. It will require one rectangular iron plate (according to the size of the mold), a small piece of rolled wire with a cross-section of 10 mm and three pieces of pipe with a diameter of 50 mm and a length of 150 mm. At one end of each pipe you need to cut four triangular “teeth” to a depth of 50 mm. Then these teeth must be connected to each other to form a cone. The seams between the teeth must be carefully welded. Then you need to weld a wire rod handle to one of the planes of the plate, and to the other - cutting pipes with a blunt end.

Wooden collapsible form
Wooden collapsible form

To make a wooden collapsible form, you will need four cuttings of boards 35-50 mm thick (the dimensions will depend on the size of the chosen form). Of course, wood is a weaker material for forming, so you need high-quality and strong boards. All joints in the wooden form must be secured using tightening screws. Otherwise, the design of the wooden mold is the same as the metal one. Handles for the mold can be made from wire rod with a cross-section of 10 mm, flattening its ends and drilling holes with a diameter of 6-8 mm in them.

To make building blocks with your own hands, you need to make a solution of cement, sand and aggregate (slag or broken brick) in a ratio of 1:4:6. When adding filler to the solution, you need to ensure that it is viscous and sticky, but not liquid or crumbly. Next, the solution is poured into molds in which, in hot weather, it will harden within 2 hours, and will acquire its final strength in 1-1.5 days. In cool weather (+7 ... +18 C) hardening time and completely dry increases by 3-5 times, and at temperatures below +7 ° C and during precipitation, it is not recommended to make blocks at all.

If slag is used for mortar along with cement, you can completely abandon sand, and then the ratio of cement to slag should be 1: 6 or even 1: 8.

Before pouring the solution into the mold, all its parts, regardless of the material of manufacture, must be moistened with water. Should work on flat surface and fill the form with the solution to 2/3 or 3/4 of the volume ( exact amount determined experimentally after using a device for making voids).

After the block has completely hardened, it must be freed from parts of the mold. The raw block must be left until completely dry, and the mold parts must be filled with water.

You can make blocks directly at the construction site, i.e., fill on site. In this case, the dimensions of the pouring mold can be increased to 330 x 300 x 600 mm. This will further speed up the construction process.

Consistency cement mortar and the filling method are the same as in the previous case. You can weld several molds into a working structure (3-4 molds are enough), and then the laying will go even faster.

To cement mixture does not stick to the walls of the mold; before pouring, its internal cavity must be generously moistened with water or lubricated with waste machine oil. After the mixture has set, the mold plates are peeled off from the walls of the block. In the process of erecting walls, it is necessary to verify the horizontality and verticality of the rows. In general, the laying of corners and the band between blocks are fully consistent with the methods brickwork half a brick.

Adobe - a mixture of clay and straw, for making homemade blocks

The cheapest building material for making concrete blocks yourself at home is adobe - a mixture of clay and straw. Cheapness is not the only advantage of adobe - it is a durable material with high thermal insulation properties, easy to “produce”. Collapsible metal or wooden molds are also used to make adobe blocks. It is better to make small blocks, maximum 150 x 150 x 300 mm, since larger blocks are heavy and inconvenient to work with and, moreover, voids cannot be made in them.

On a note!

The disadvantage of adobe is its instability to moisture. Before erecting adobe walls, it is necessary to ensure reliable waterproofing foundation, and finished walls require plastering with cement-sand mortar, coating with any available polymer or metal mesh and finishing work.

Homemade concrete blocks for construction

The order of work in the construction and production of concrete blocks is standard: first you need to choose a place, then make a foundation - here you need to build a slab foundation, you can use foundation slabs, install communications, build walls, build a roof, install windows and doors and perform facing works and interior design summer kitchen.

The walls are laid out in half a brick; for a summer kitchen, the thickness of the wall can be one brick - and that will be enough. As you lay, it is necessary to align the walls vertically and horizontally, using a plumb line and a cord stretched horizontally from one corner of the house to the other.

Home production of building blocks allows you to reduce the cost of laying openings with the subsequent installation of windows and doors. During construction, door and window openings must be made in the building box. The location of windows and doors should be determined at the planning stage. During the process of laying walls, you can leave openings in the places where doors and windows are installed. required width, and also insert wooden plugs, to which the subframe boxes will then be attached. Wooden plugs must be inserted in the second row relative to the bottom of the box and in the penultimate row relative to its top. At the top level of the box, a reinforced lintel with a thickness of 120 mm or a beam with a thickness of 70 mm should be installed. The ends of the lintel must be placed on the walls by 20 cm. If the planes of the next row of masonry and the upper part of the frame are at different levels, it will be necessary to catch them up to required height, using parts of blocks and mortar, or assemble the formwork, tie the reinforcement and fill it with cement mortar.

After the walls are erected, boxes should be installed in the spaces allocated for windows and doors, having previously wedged the corners. Next, you need to align them horizontally and vertically, and only after that you can attach the side parts of the box to wooden plugs using nails or screws. The remaining space between the walls, foundation, lintel and frame must be filled around the perimeter with acrylic foam.

The second method of installing door and window openings- this is when door and window frames are installed in the right places and then covered with blocks. Typically, this method is used for decorative masonry, when further wall decoration is not provided.

In this case, to prevent the door frame from moving during the laying process, you need to clamp it on both sides with blocks while laying the first row, having previously inserted supports into the corners. After the second row, you need to align the box vertically and horizontally, fix it with nails or screws on the sides to the wall. It is also necessary to leave a 10 cm outlet. Then you need to apply a solution to the outlets and clamp them with a block next row, once again making sure that the box is level. The same must be done at the top door frame, as well as on the fourth and sixth rows with a window frame. The jumpers are installed here in the same way as in the first method.

The production of concrete blocks as a mass building material, even with current production volumes, is not able to cover all market needs. Wall block, hollow, block for internal partitions and the lightweight type of material is produced not only for industrial equipment, but even on homemade machines. The attractiveness of this type of business is so great that many choose it to start a business, because for the first step a flat area and a form for pouring concrete are enough.

Production technology

For casting standard concrete blocks from sand- concrete mixture Most often, the most primitive technology is used, which does not require significant capital investments and complex equipment. The technology for the production of concrete blocks is based on the principle of uniform hardening of the concrete mixture in natural conditions at normal air temperature.

Model illustrating the process of preparation and hardening concrete mortar, there will be a description of the process of pouring the shape of a foundation or monolithic slab:

• Preparation of the form;
• Preparation of concrete solution;
• Pouring the solution into the mold;
• Compaction of the solution;
• Shrinkage of the mixture;
• Removing formwork;
• Final drying of the mixture and set of concrete working hardness.

In principle, this scheme is quite suitable for pouring a large volume of concrete, but for a concrete block for building walls it is only partially suitable. The fact is that to form a regular rectangle with clear edges on the sides and a smooth surface on the outer edges, it is necessary to use a concrete solution with a minimum water content. Thus, crumbly concrete is obtained, which, when placed in a mold and subsequently compacted using vibration and press pressure, is knocked down into a dense mass capable of holding its shape.

The use of concrete with a high water content, on the contrary, does not entail the formation of a rigid shape, but the squeezing out of the mass of moisture, which is not able to withstand the rigidity given to it; it simply floats.

When preparing the solution, the order of adding components is observed - filler, cement, water, plasticizer.

Manufacturing technology involves optimizing the production process through the use of equipment for the production of concrete blocks in the form of a vibrating machine or vibrating plate. In the first case, the molded element is left to dry on the platform after removing the vibrating machine mold; in the second case, the silicone mold remains on the element until the drying process is completed.

Using a vibrating press, the following are formed:

• Solid wall block;
• Reinforced wall block with voids;
• Lightweight hollow wall block;
• Half block or half block;

Using a vibrating table and silicone molds, the following are produced:

• Facing block;
• Block imitating stone;
• Decorative tiles or elements for decorating facades, paths, fences.

However, he himself technological process will not be complete without the last stage, in which the remaining moisture evaporates from the concrete and it gradually begins to gain its strength. Drying plays an important role, because in addition to the evaporation of moisture, a second equally important process occurs simultaneously - the gradual hardening of cement.

For production under normal conditions, drying occurs at normal temperature with a minimum daily amplitude of fluctuation, and for extreme conditions For example, for temperatures below +5 degrees Celsius, synthetic additives and additives for concrete at low temperatures must be used.

To control quality and determine the readiness of blocks for transportation and use in construction, a standard scale for concrete strength gain is used - 3,5,7 days the form can be lifted and carried, on days 9-11 it can be stacked, on days 28 it can be used in construction.

Necessary materials

For a building material, strength has always been one of the most significant qualities. But using only cement and sand will make the production of concrete blocks unprofitable; the blocks are expensive.

The way out of this situation is to use also additional types raw materials as filler. Such fillers make it possible to obtain products with additional qualities - lightness and reduced thermal conductivity.

To prepare concrete mortar the following are used:

• Cement grade 400 or 500;
• Natural filler;
• Plasticizers;
• Water.

Cement is preferable to grades 500 and 400; it is not only the most popular, but also the most suitable material for preparing the mortar formulation. All recipes recommended for preparing concrete are based on the proportions of this particular group of cement.

The filler used is:

• River or quarry sand;
• Crushed granite stone of small and medium fraction;
• Granite screening;
• Granular slag;
• Sawdust and shavings;
• Expanded clay;
• Processed products concrete products and brick fight;
• Chemical fillers used for the manufacture of insulation;
• Blast furnace slag.

Preparation of a concrete mixture requires the correct dosage of cement and proportions of filler. For quality concrete wall elements load-bearing walls the proportions are taken:

• Cement - 1 measured part;
• Filler - 7-9 measuring parts;
• Water - 1\2 measured part of cement;

The plasticizer is not used under normal temperature conditions, when the air temperature is stably above +15 degrees. When the temperature drops, when drying in unheated rooms or outdoors, adding a plasticizer is desirable, but if the temperature does not drop below +5, it can not be used. At temperatures below +5, such a plasticizer must be used.

To obtain concrete, the use of a plasticizer must be as precise and dosed as possible. Most additive manufacturers recommend adding 5 grams per conventional block volume.

Industrial equipment

The minimum set of equipment for producing concrete blocks at home is a mold and a press. A construction trough is suitable for preparing concrete, and a shovel is suitable for dosing ingredients and mixing the mixture. True, this set is enough for 20-40 cast blocks per shift; production at this rate will ensure the construction of a house or a good-quality garage only in 6-8 months.

You can intensify production by using small-scale mechanization tools - an electric brick press for 1 mold and a concrete mixer for 120-140 liters will ensure a significant increase in productivity! True, here you will have to look for a large site so that the equipment for the production of concrete blocks can be fully used.

To start successful business In the production of building materials, it is necessary not only to produce large volumes of products, but also to offer the consumer an assortment that differs from the assortment of competitors. To do this, it is necessary to establish the production of materials for load-bearing walls, partitions and partitions, blocks non-standard shape. It is possible to produce such an assortment only by using industrial samples of equipment for the production of concrete blocks. The installation usually includes a container for preparing the solution, a brick press and a control panel. The installation itself is made mobile, so that after making one batch of molds it can be moved to another place so that the blocks begin to dry.

For a mini-factory, equipment with a greater degree of automation and a reduction in the share of manual labor. A concrete block production line requires a mixer for preparing the solution, molding containers and a separate room with climate control equipment to speed up the drying process. The productivity of the line will also require a packaging line and a warehouse for storing products ready for shipment to the consumer.

When planning to produce blocks from cellular concrete, production must be supplemented with an autoclave to dry the material under pressure. The line in this case will allow the production cellular concrete specific shape and purpose, supplying the customer with a ready-made set of blocks for the construction of a house or garage.

Equipment for self-production

Make your own equipment for preparing mortar and molding hollow wall block easy at home. It is enough to have the skills to work with welding machine and a grinder, be able to correctly calculate and cut metal.

The shape for the block is a regular rectangle with dimensions:

• Height 200 mm;
• Width 200 mm;
• Length 400 mm.

The mold is welded from a sheet of iron 4-5 mm thick. And it is reinforced from the outside with a frame made of a corner or profile pipe. For a brick press for the production of concrete hollow blocks, it is better to use replaceable elements to form internal voids:

• For load-bearing structures round with a diameter of 100mm;
• for internal walls, multi-profile elements made of square pipes;
• for piers and semi-blocks, rectangular elements made of several profile pipes, welded into one element.

A standard electric motor with an eccentric mounted on a shaft is used as a vibrator.

A self-assembled vibrating press driven by an electric motor must be safe from damage electric shock- the engine must be attached to the body through rubber gasket, the handles must have rubber protective elements, and the cable used must have double insulation of current-carrying conductors.

Concrete blocks- very popular construction material, necessary for the construction of a house, barn or fence.

The width for a homemade block should be chosen to match the width of the foundation.

In addition, you can make concrete blocks with your own hands without much difficulty, this will significantly save money on construction costs.

Site and formwork preparation

First you need to decide on the sizes. Usually the width for a homemade block is chosen the same as the width of the foundation masonry. However, its deviation downward by 3-5 cm is allowed. The thickness of the bottom of the voids should be at least 2 cm, and the thickness of the walls - 4 cm. If you make a block of dimensions 29x29x44 cm with two vertical voids, then its mass will be about 42 kg.

The optimal size for blocks is 20x20x20 cm or 20x20x40 cm. Thanks to their small dimensions, the process of laying the material, as well as the manufacturing itself, becomes convenient and simple. It should also be taken into account that when special types work may need to be done in half blocks.

To make concrete blocks with voids, a special mold is needed.

Concrete blocks should be made on compacted soil or on a level area (for example, built from boards). The surface must be covered with oilcloth or thick film. The molds in which the blocks are formed are made without a bottom. They are made from boards, chipboard or plywood sheets, and sheathed on top sheet metal. Several liners are made from wooden logs, with the help of which voids will be formed in the blocks, due to which the building material will become lighter and warmer. The edges of the logs are sheathed with metal and handles are mounted to them, which will help in the further process without extra effort pull out the liners from the setting cinder block.

Experts say that it is most convenient to make several forms at the same time. To build them, you need to knock down or fasten with screws a frame with the height of the sides equal to the height of the block, in the middle of which plywood partitions are inserted. By the way, you should first install the longitudinal partitions, and then put the transverse partitions on them.

All elements and parts of the formwork must be coated with drying oil or machine oil, as a result of which the hardened blocks will be much easier to remove from the mold.

Laying the concrete mixture

Necessary materials:

• cement;
• fine gravel;
• sand;
• lime;
• water;
• rigid reinforcing wire.

The size of gravel grains can reach 1 cm.

The amount of materials depends on the required number of finished blocks. Cement, sand and gravel are taken in a ratio of 1:3:5.

The blocks are made of concrete based on a mixture of gravel and sand. Fine gravel, sand, lime (in small portions), and cement are poured into a metal basin. Mix the constituent elements thoroughly and then add water. There should be just enough water so that no problems arise during the process of laying the formwork (the mass should not be liquid).

The strength grade of such a material will be approximately 135 kgf/sq.cm. The size of the filler grains can reach 1 cm. Insert cores to form voids are placed in the mold when a solution 2 cm thick has already been poured and compacted. To fix the distance of the core, it is recommended to install special slats, about 4 cm wide, between the mold wall and the core. These slats can only be removed once the concrete has been loaded and compacted to one-third the height of the form.

The bottom of the form can be covered with old newspapers, which will prevent the block from setting to the previous base. The mixture should be semi-dry during installation. That is, when taken in a fist, compressed into a ball and then placed on a flat surface (for example, on a board), the mass should not spread.

Each formwork compartment is filled with a maximum of half of the solution, after which rigid reinforcing wire is laid.

To prepare the solution at home, you can use a stationary concrete mixer.

Some craftsmen make blocks using cinder blocks as heat-insulating air chambers glass bottles. To do this, plug the bottles with corks and install them in the middle of the block. After this, the forms are filled to the top, the solution is compacted and then smoothed with a trowel.

Homemade blocks harden quite quickly - within 3-4 days, after which they can be safely removed from the formwork. However, this does not mean that they are completely dry. They can be used in construction no earlier than two weeks later.

Block care

The solution sets within 1.5-2 hours. Therefore, if there is a small amount of material for constructing the formwork, after this time it can be disassembled in order to make the next cinder block. In such cases, the concrete mass is prepared in portions for each mold. Using one formwork, you can make about 5-6 blocks per day.

After the building material is ready, it is covered with film. It serves to protect the cinder block from precipitation, as well as protection from excessively rapid drying. If there is no film, it is recommended to water the block daily (starting from the second day after production) for 2-3 weeks. To ensure uniform drying, the material must be turned periodically.

Making cinder blocks with your own hands, of course, is primarily about saving money. Money. But if available necessary materials and time, anyone can cope with this task.