Compositions and proportions of mixtures for making cinder blocks

A cinder block is a building product that is manufactured industrially or by handicraft. The production uses the method of vibration pressing of concrete in special forms.

Cinder block is one of the most popular building materials due to its low cost composition and low manufacturing cost.

What makes the product popular is the abundance of materials in the working solution—what the cinder block is made of.

Materials for making cinder block

The standard solution for the production of wall stone includes mixtures, materials and substances such as slag, coal ash, combustion waste from blast furnaces and open-hearth furnaces. But in practice, the presence of just such components is not necessary - most often the filler that is most common in the region is used. For example: perlite, gravel, crushed stone, limestone, expanded clay, sawdust, sand and gravel mixture.

If you maintain the correct proportions when adding non-traditional building materials, you can not only increase the strength of the building stone, but also reduce its cost. Reinforced cinder block is produced in accordance with the requirements of GOST 6133-99.

Only a few points are mandatory for compliance with GOST, namely:

1. Compliance with the color of the mixture according to the sample.
2. Compliance with the rectangular shape according to GOST.
3. The amount of voids or fullness.
4. The thickness of the walls and partitions of hollow wall cinder blocks is not less than 20 mm.
5. The symbol of the product must contain the abbreviated designation of the stone - K, the area of ​​use and construction purpose (S - masonry walls or P - partitions, L - front block or R - row block), type of block for laying (PR - row block, UG - corner , PZ - dressing block), with voids (PS - hollow product), length in cm, frost resistance grade, strength grade, average density coefficient and GOST.

An example of designation of a product with a length of 410 mm, strength grade 50, frost resistance grade F75, average density 1800 kg/m3: KRL-PZ-PS-41-50-F75-1800 GOST 6133-99.

The composition of the mortar for the production of cinder blocks according to GOST 6665-91 “Concrete wall stones. Technical specifications":

1. Cement M-400 class D 20.
2. Purified and sifted quartz sand for the mixture.
3. Screening is a material that is obtained by crushing rocks, gravel or crushed stone.
4. Water.

The mixture for preparing blocks is prepared in the following proportion: sand, cement and slag in a ratio of 3:1:5. Adding water is 0.5% of the amount of cement. If the cinder block is pressed without the use of sand, then the following proportions must be observed: 1:9 with the same water consumption.

It is recommended to dry the product until the product is completely hardened for 20–30 days at high air humidity and a temperature of 20 °C (requirements of GOST 6133-99). To speed up the hardening of concrete, plasticizers can be added to the solution.
The blocks can be placed on a pallet 4 days after complete drying. In winter, hollow wall stone should be laid with the voids facing down to avoid cracks. Table of consumption of building materials per unit of building block (recommended proportions)

Note to the table:

• Hollow wall block, size 188x190x390 mm.
• The total volume of one wall stone is 0.0139 m3.
• The volume of solution per block is 0.01 m3.
• The number of blocks in 1 m3 is 72 pcs.
• Strength grade: M75.
• The cost of materials depends on your region and may vary.

Cinder block refers to wall stones, which are made from materials mixed in different proportions according to the standard regulated by OKP 57 4130, which gives an idea of ​​​​the use of materials for the production of wall stone groups that differ in the content of substances.

The dimensions of cinder blocks can vary within +/- 2–10%, since this parameter is not strictly defined by GOST 6133-99 (deviations in size are allowed), but the operational, physical and technical characteristics of the wall block must comply with the standards. Pigmentation of a cinder block is also regulated by GOST 13015.0-83 and GOST 6133-99, which state that the color of the front surface of a cinder block must correspond to duly approved samples.

Proportions of components for the manufacture of screening block grade 75.

Hello, Denis!

Screening block is a building material for the construction of walls. It is a type of wall concrete stones, which, in addition to the screening block, includes cinder blocks and so on. In essence, a screening block and a cinder block are concrete blocks that differ only in the filler. The composition of a cinder block, in addition to cement and sand, includes slag, and the composition of a screening block includes crushed stone screening. The division of concrete stones into varieties is conditional, since the composition of the block may include various impurities. This group of building materials even has its own regulatory document - GOST 6133-99, which defines the requirements for them, including composition.

According to GOST, the brand of a screening block indicates one of its most important characteristics - compressive strength. For grade 75 it is 7.5 MPa. For grades 100 and 50, the compressive strength is 10 and 5 MPa, respectively.

Screening block grade 75 is produced both from heavy and fine-grained concrete, and from lightweight concrete. In this case, the weight of one block should not exceed 31 kg.

When making your own screening block, you should take into account numerous factors related to the composition of the block. To obtain a product of the required brand, you need to correctly select the ratio of all its components. As noted above, the blocks are made of concrete.

Concrete is a mixture of several substances - cement (binder), water, sand and filler. Crushed stone and slag are used as filler. You can also use screenings (stone chips).

The composition for obtaining a block of a certain brand is regulated by GOSTs, which facilitates their industrial production. If you decide to make them at home yourself, and of a certain brand, then the GOST requirements will only confuse you. Yes, and it will be difficult to adhere to factory manufacturing technology at home. Therefore, in this case, it will be better to rely on the experience of your predecessors, who compiled their proportions by trial and error.

First of all, it should be indicated that for the production of screening blocks, cement of a grade of at least 400 should be used. Next, the proportions for this particular grade of cement will be indicated.

As a filler, screenings can replace sand or serve as an additional component. The second option is preferable. In order to obtain a screening block of grade 75, take concrete of grade 75, subtract one part of crushed stone and sand from its composition and add two parts of screening instead. The inclusion of screenings in concrete can increase its strength.

In concrete grade 75, cement, sand and crushed stone (C:P:SC) are in the proportion 1:3.5:6. Thus, to obtain a screening block of grade 75, you should use concrete having the following proportion: 1 part cement, 2.5 sand, 5 crushed stone and 2 parts screenings.

Using this technique, you can easily find the proportions for blocks of other brands. The corresponding proportions for concrete grades can be found on the Internet or construction reference books. To produce concrete grade M50, cement grade M300 should be used. The proportion (C:P:SH) in this case will be 1:3.8:6.5.

I hope this article answered your question.

Composition by type of filler

Cinder block is produced in the form of a solid or hollow parallelepiped with right angles. The following compositions of building stone are distinguished depending on the filler:

1. SCC - with the addition of cement as a binder.
2. SKI - with the addition of lime as a binder.
3. SKSH - with the addition of slags of various origins.
4. SKG - with the addition of gypsum or alabaster.

The cinder block is divided by size into whole (number 1 in the marking), longitudinal half (number 2) and partition wall block (number 3).
For example, SKTs-1 (cement wall stone), SKI-3 (lime wall stone), SKSH-1 (slag wall stone), SKG-2 (gypsum wall stone), etc. Table

1. Depending on the filler introduced, a solid block has an average weight of 25-28 kg, a hollow block - 18-23 kg, and a half-slag block - 10-13 kg. The thermal conductivity coefficient of a cinder block also depends on the composition of the solution and occupies the range of 0.27–0.65 W/m*K.
2. The compressive density is allowed in the range of 750–1455 kg/m3. When the density changes, the thermal conductivity and strength of the wall stone changes. Also, the density characteristics, weight of the blocks and thermal conductivity depend on the composition of the mixture and the number of voids in the product - they can be oval, round, rectangular or square.
3. The percentage of voids to filler is 28–40%.
4. The texture of the blocks is divided into smooth (without visible surface defects), polished (1 grinding cycle), corrugated (repeating irregularities) and chipped (the surface is leveled by chipping off the protrusions). For different slag concrete fillers, their own, most optimal, stone texture is determined.

Table of composition of fillers for wall blocks

Screening block (screening block): features, characteristics, advantages and disadvantages

Screening block, screening block, screening block, screening block - all this is the name of one building material. The screening block is made from screenings of crushed stone, cement, and coarse sand. The screening block is made only from natural materials and is completely harmless to nature and humans.

The finished screening block is formed by vibrocompression with further natural drying and heat treatment, which makes it possible to obtain high-quality building material of the required dimensions and characteristics.

Many people confuse screening block with cinder block and neglect this material. But in vain. Screening block and cinder block are completely different building blocks.

Their fundamental differences:

- Compound. Unlike the environmentally friendly materials of the screening block, the composition of the cinder block includes: gravel, sawdust, slag, combustion waste - these materials can hardly be called environmentally friendly.

— Durability. The strength of the axial block is much higher due to the use of high-quality cement and the quality of raw materials (axial block).

Advantages of the screening block:

Environmental friendliness. The composition of the mixture for the production of screening blocks (screenings) is completely environmentally friendly and safe for humans and the environment

Strength and durability. Thanks to the composition and unique production technology, structures made from screening blocks are durable and retain their properties for many years.

Good thermal insulation and sound insulation. Due to the composition of the material and the location of the voids, optimal thermal and sound insulation values ​​are achieved

Fire resistance. Fire resistance limit 1.5 hours.

Frost resistance. More than 50 freeze-thaw cycles

Economy. One screening block can replace up to 7 conventional bricks, saving mortar is reduced by almost 2 times.

Light weight (the block weighs about 16 kg. Depending on the size). Thanks to the hollowness of the screening blocks, the overall load on the foundation is reduced, which contributes to the durability of the house and savings on the foundation itself.

Construction speed. Thanks to its convenient dimensions and low weight, the speed of building construction increases several times.

Simplicity. Masonry from screening blocks does not require training or high qualifications. The relatively low weight allows you to work without the use of heavy equipment.

Disadvantages of the ejection block:

Unsightly appearance. Despite the wide range of applications, buildings made from screening blocks are inferior in beauty to buildings made from ordinary bricks.

Price. Despite the low cost of the screening block, you can buy building blocks in Krasnodar that are cheaper and made from other materials that are inferior in characteristics, but are nevertheless successfully used in construction.

Thus, if you are planning to cladding a building or the appearance of the building is not fundamentally important, then you can safely buy screening blocks and build a house from environmentally friendly material.

Brick, Abinsk, Krasnodar region