How to make cement at home. How to prepare a cement mortar with your own hands? Wet production technology

Cement mortar is widely used in construction and repair. It is used for the construction of brickwork, when laying the foundation, internal and external finishing works. Not a single home repair is complete without cement mortar - it is needed for plastering walls, leveling the floor, laying ceramic tiles.

The technique for making the solution is quite simple - any novice repairman can mix the components. In this material, we will figure out how to make cement with our own hands with a small set of tools.

In construction cement mortar used in laying foundations brick walls, used in the process of external and internal finishing works.

Overview of concrete brands

The brand of concrete is the main indicator of its strength. The higher the numerical number of concrete, the more reliable and stronger the finished composition will be.

  • M50–75- a light version of cement mortar, used in interior finishing work, for floor screed and as a grout for brickwork;
  • М100–150- the so-called "lean concrete", used as a screed for the floor, in the manufacture of paths and curbs and in auxiliary work during construction;
  • M200- mortar for brickwork, screeds and plasters for interior and exterior work;
  • M300- durable composition, used mainly in street construction.

To make a cement mortar of the required strength, it is not necessary to buy concrete of the appropriate brand. In the process of preparing the mixture, concrete is mixed with sand, changing the proportion. Thus, from raw materials of the M400 brand, it is easy to obtain a cement mixture M100 or M200.

A high-grade cement mortar is used for outdoor work, as well as for finishing especially protected buildings. You should not use it at home, since such cement weighs a lot and has a pronounced texture.

The most common brands of concrete for mortar preparation are M400 and M500. From them you can get a cement mixture for both finishing and small construction works.

Necessary materials and tools for work

Its strength, technical and visual characteristics depend on the composition of the cement mortar. The standard composition of the mixture consists of three elements:

  1. dry cement;
  2. sand;
  3. water.

In order to change the qualities of the composition, the following additives are used:

They affect the color of the coating, help make it more plastic and sticky.

In order to mix and lay the cement mortar, you will need the following tools:

  1. a bucket or a deep basin for stirring, corresponding in size to the volume of the mixture;
  2. construction mixer or drill with a nozzle;
  3. spatula or spatula to distribute the mixture over the surface;
  4. gloves and goggles for safety.

All these tools are likely to be found in the household of people who have ever done repairs. Otherwise, they should be purchased or borrowed from friends.

A construction mixer or a drill attachment will help to mix the mixture without lumps. The composition will turn out to be homogeneous and there will be no voids in it after solidification.

Mortar types

The type of cement mortar varies depending on the brand of cement, the composition of the components and the presence of plasticizer additives. According to the composition, two types of mortar can be distinguished - using lime and sand. Let's consider the properties of each of them.

cement-lime

Cement mortar with the addition of lime is characterized by plasticity and adhesion, therefore it is most often used in plaster or when laying tiles.

The composition of the mixture includes cement, lime and sand in proportions of 1:1:6 and 1:2:9 parts, respectively. To improve the plasticity and stickiness of the solution, PVA glue, detergents, clay sand are added to it.

If quicklime is used, it should be extinguished by mixing with water. In progress chemical reaction a lot of heat is generated, so you need to protect your hands and face when working with lime.

Lime in the composition allows you to brighten the cement mortar and make it more plastic. Therefore, it is often added when decorating walls indoors.

Cement-sand

Cement-sand mortar is the easiest coating option to manufacture. To mix it, take one part of cement to 6 or more parts of sand. The composition is suitable for outdoor and rough work indoors. Since it does not have additional additives, its plasticity and adhesion do not allow the mortar to be used for small plaster and tile work.

As plasticizers that improve the stickiness and elasticity of the material, it is used liquid soap and PVA glue. Clay or quarry sand helps to make the composition more plastic. To clarify and improve adhesion, builders add slaked lime to the mixture, obtaining a cement-lime mortar.

Sand is the main component in any cement mortar. Its share in the composition is several times higher than the content of concrete, water and plasticizer additives.

Color seam additives

Color additives in the cement mix serve purely decorative purposes. They are most often used when laying bricks to make the seams more expressive and aesthetic.

Carbon black was previously used to impart a dark color, but experience has shown that this component worsens specifications cement. Today, salts and metal oxides are used for this purpose. Color additives can be purchased at hardware stores.

How to make seams white?

The white color of the joints is most easily achieved by increasing the amount of lime in the solution. However, you can purchase a special tinting mixture with titanium oxide or other metals.

It is customary to make masonry seams contrasting with the shade of the brick. For buildings made of red brick, white grout is used, for light material - gray or black.

Dyes for cement are produced in the form of powder or liquid paint. They are added to the composition of the mixture during its preparation and thoroughly mixed with other ingredients.

Mixing ratio

The ratio of elements in the cement mortar depends on the area of ​​​​application of the mixture and the brand of concrete. For example, if you need to get a cement mortar M100 from concrete M400, the ratio of cement to sand will be 1:4. Thus, it is easy to calculate what ratio is needed to obtain the desired grade from any concrete.

How to make cement mortar for different types works (cement: sand):

  1. Plaster: 1:5 with the addition of one part of lime;
  2. Floor screed: 1:4 for M500 brand, 1:3 for M400 brand;
  3. Brickwork: 1:5 - M3, 1:4 - M5, 1:3 - M8. In this case, the brand of the finished solution must correspond to the brand of brick.

The volume of water for the preparation of the slurry must not exceed 60% of the total volume. Usually it is 1-2 parts in proportion.

During the mixing process, the cement slurry sometimes turns out to be too liquid. Set aside some of the dry mix so you can add more if needed.

Drying time

The curing time of the cement slurry is directly dependent on temperature. environment and coating thickness. The thicker the screed layer and the lower the thermometer, the longer the mixture will dry.

Consider the solidification time under favorable conditions:

  • 2-4 hours - setting of the solution;
  • 12-24 hours - incomplete hardening of the cement, you can walk on it, but finishing work is not recommended;
  • 10-14 days - complete drying of the coating, after which you can proceed to finish the surface with tiles or other material.

The conditions for solidification are easiest to observe indoors - when floor screeding, plastering and other finishing work. There are no temperature fluctuations in the apartment, so the solution hardens evenly and quickly.

How to prepare cement at low temperature

The ideal temperature for pouring cement mortar is + 200C and above. But such conditions are not always possible to create during construction and exterior finish building. At sub-zero temperatures, the concrete solution falls in lumps, and the water in the composition turns into ice. This directly affects the quality of the coating.

In construction, there are several techniques that help to avoid damage to the cement mixture at sub-zero temperatures:

  • Special antifreeze additives in the composition;
  • Heating water and sand when mixing concrete;
  • Electrical heating of the coating;
  • Shelter filling with awning and formwork insulation.

For masonry at sub-zero temperatures (up to -7 ° C), you need to use a cement mortar (in the ratio of cement to sand - 1: 4) or cement-calcium (1: 1: 6 - cement, calcium, sand). The solution should be densely plastic, that is, contain a small amount of water.

It is very difficult to make electric heating of concrete with your own hands. To do this, heated electrical cables are brought to the surface, which transfer heat to the concrete pavement.

The easiest way to insulate the surface of the cement in the open air is with a stretched awning. This design will retain heat in light frosts.

The use of concrete in home decoration

In interior decoration apartments and houses, concrete is used in three types of work:

  • wall plastering;
  • pouring floor screed;
  • installation of ceramic tiles in the bathroom.

The home finishing mortar must be sufficiently plastic and have good adhesion to the rough coating. Therefore, plasticizers and adhesive additives are necessarily added to it.

For laying tiles in the bathroom, ready-made glue is often used, but cement mortar is also well suited for this purpose. It is important to take care of the waterproofing of the floor and the presence of antifungal compounds in the finished mixture.

  1. Choose a deep container for the solution so that when stirred, it does not splash out over the walls;
  2. Instead of a mortar for treating brick or tile joints, special grouts can be used, in which case cement dyes are not required;
  3. A day after the floor screed, cover it with a film so that the coating is not damaged during the repair process.

Cement production today is a fairly profitable business. And even despite the fact that there is high competition in this area, every novice entrepreneur has the opportunity to create his own successful business. However, before purchasing equipment and starting production, it is necessary to carefully consider all the details of the business plan, taking into account the specifics of your region, the current economic situation and the activity of direct competitors.

What is cement?

We all know that construction is impossible without this material. How to make cement? To create it, limestone, gypsum, clay, mineral additives and other components are combined. There are various types of this material, as well as technologies for its production. We offer a closer look at the main stages of opening such a business.

Cement production technology

The manufacturing process of this material consists of two main stages. At the first of them, clinker is obtained, which is a specific intermediate product in the form of mechanically mixed and heated to one and a half thousand degrees granules of lime and clay (or other materials of a similar composition). The resulting clinker granules are the basis of any cement. The process of their production is very complicated and the most expensive. The next step is the manufacture of Portland cement, which is obtained by grinding clinker with gypsum or other additives.

Important Factors

The production of cement is complicated due to the fact that the mineralogical and chemical composition of raw materials (homogeneity, hardness, moisture content) varies quite widely. Enterprises that manufacture this material on the basis of imported raw materials know this firsthand.

Also taken into account are technical and natural varieties raw materials, which may differ, for example, in moisture and purity. For each of them, the production of cement is carried out in a special way, ensuring uniform mixing and fine grinding of the components, while using the minimum possible amount of energy.

A very important role is played by the conditions for the extraction of raw materials, their storage and transportation, as well as the human factor.

Methods for the production of cement

There are three main options for creating this material:

1. Wet process: the grinding of raw materials and production takes place in water, resulting in mixed ingredients (or batches) in the form of a suspension.

2. Dry way. The production technology does not require water, and the mixture is a crushed powder, the components of which are dried before mixing.

3. Combined method based on one of the first two options. This results in a mixture with a moisture content of up to 20%.

Equipment

This item is the main cost item when starting a business. Equipment for the production of cement, first of all, includes industrial crushers (if limestone is used as a raw material), or mill-mixers, or, as they are also called, mashers (if the material is made on the basis of clay). The cost of this equipment can reach 200 thousand rubles.

Also, for the production of cement, pipe ball mills will be required, in which limestone or clay slurry with various additives are mixed and finely ground. This equipment will cost about 3.3 million rubles.

After the composition is corrected, the sludge is sent to a rotary kiln for firing, where it turns into hot clinker, which is then cooled using an industrial refrigerator. The cost of this equipment is about 170 thousand rubles.

The cement production line includes additional equipment for packing the finished product into bags and shipping it.

In general, the amount of equipment, as well as personnel, is directly dependent on the planned production volumes. Not the last role is played by the financial capabilities of a businessman. Purchasing costs necessary equipment will average 2 million rubles. The amount is considerable, but these investments will definitely pay off in the course of work.

Production room

To create a workshop for the production of cement, it is necessary to choose a suitable room. Its area must be at least 500 square meters. meters, and the height of the ceilings - not less than four meters. The ideal option for the organization of the workshop is its placement in the immediate vicinity of a clay or limestone quarry. In this case, the cost of raw materials will be minimal, and all your costs will consist of the purchase of equipment, utilities and wages employees.

Payback period and demand for a cement production enterprise

Despite the fact that competitive activity is quite high in this area, it is quite possible to build a profitable cement business today. As for the financial side of the issue, the start of such an enterprise will require an amount of at least 30-50 thousand dollars. This is due to the high cost of the equipment. However, you should not be afraid of quite significant investments, since the invested funds will pay off after 6-12 months of active work. After all modern market construction is developing rapidly, which, accordingly, leads to the consumption of more building materials, including cement.

Making cement at home

Despite the fact that the production process of this building material is very complex and requires special equipment, there are people who manage to make it in artisanal conditions. However, the way home production cement is also quite costly and energy intensive. In addition, at first you will have to spoil more than a dozen kilograms of raw materials until you learn how to produce high-quality building material.

Keep in mind that for the manufacture of cement in artisanal conditions, you also cannot do without special equipment. You will need at least a mill and a high-temperature furnace. We bring to your attention one of the recipes for the preparation of cement at home. This material is perfect for cementing slabs and stones. It can also be used on objects exposed to regular temperature changes and moisture.

So, to prepare cement, we take one part of the resin and melt it in a stable iron container. At the same time, in another container, melt one part of the sulfur. After both components are melted, we connect them. Two parts of sifted sand and three parts of lead litharge must be added to the liquid mixture. After prolonged stirring finished material must be allowed to stand. Such home cement should never be used on a wet surface. It is also desirable to pre-treat it with drying oil.

Prospects for the cement business - production of concrete fences

If you have successfully mastered the production of cement, then as an expansion of your business, you can move on to the manufacture of concrete fences. These products are durable, beautiful, diverse, and blocks can be used to make a fence of any length. Such fences surround the territory of both houses and cottages, as well as offices and industrial facilities. They look much more presentable than chain-link fences, and are cheaper than fences made of forged metal rods.

The main advantage of this business is the relative freedom in the market, since today few enterprises are engaged in the manufacture of such fences. The main direction of your activity may be the production of fences based on individual orders. In order for the product to best match the size, color and pattern of the facade of the house, paving slabs and the general appearance of the site, it is advisable to hire a professional designer.

To start such a business, it is necessary to purchase special equipment for molding and the forms themselves of various variations. As raw materials, you will need cement, crushed stone, river sand and additives that improve the quality of the product. And be sure to keep in mind that the better the raw materials and equipment will be, the more presentable hedges you will produce. So it is not worth saving on these components.

Cement is an artificial powdered substance that acts as a binder when mixing concrete. In combination with water, it forms a plastic mass, which subsequently hardens and becomes stone-like. What cement consists of primarily depends on the method of production. In the general case, the basis is clinker in combination with mineral additives and gypsum.

History of cement

The word "cement" comes from the Latin caementum, which translates as "crushed, broken stone." This substance was the result of a search for ways to cope with the low water resistance of gypsum and limestone rocks. For this purpose, water-resistant mineral substances were introduced into their composition. At the very beginning, they were the remains of baked clay bricks and volcanic rocks. The ancient Romans used the ash deposits of the famous volcano Vesuvius - pozzolana.

The optimal cement production technology was developed many years later, when the need for in large numbers inexpensive and durable binder has not become the most pungent. The greatest contribution to the research was made by:

  1. Mason John Aspind, who in 1824 received a patent for Portland cement.
  2. Russian builder Yegor Cheliev, who wrote a book in 1825 on cement for underwater work.

The name Portland cement comes from the English island of Portland, consisting of limestone rocks. In England, stones from this island were considered the most prestigious building material. Aspind managed to obtain an artificial stone, which was very similar in strength and color to the specified material.

But it was made without firing the raw materials. Greater compliance of technology with what is today Portland cement is noted precisely in the production process of Cheliev.

What is cement made of: composition and main raw materials

The composition of cement includes the following components:

  1. Lime (calcium oxide, CaO) - 60%.
  2. Silicon dioxide (SiO2) - 20%.
  3. Aluminum (alumina, Al2O3) - 4%.
  4. Gypsum and iron oxides (Fe2O3) - 2%.
  5. Magnesium oxide (MgO) - 1%.

The indicated percentage ratio of the listed components is typical for the most popular type of cement - Portland cement. It may change somewhat. It all depends on the production technology and class of cement products.

Important! existence various kinds and brands due to the lack of an exact chemical formula of cement. All important information is provided by indicators of mineralogical composition.

The main material from which cement is made is clinker. This is the name of the product of firing the raw materials - limestone and clay, which are taken in a ratio of 3: 1. Clinker is a semi-finished product for cement production. After firing at temperatures up to 1500 ° C, the clinker is crushed, as a result of which it is presented in the form of granules with a diameter of up to 60 mm.

When grinding, the following additives are introduced into the composition of clinker:

  1. Gypsum (CaSO42H2O), which regulates the setting time.
  2. Corrective additives (up to 15-20%) that improve certain properties cement: plasticizers, additives, etc.).

Various rocks are used as the main raw materials for the production of cement:

  1. Fossils of the carbonate type. They can have an amorphous or crystalline structure, which determines how effectively the material will interact with other components in the composition when fired.
  2. Sedimentary origin. This is a clay raw material with a mineral base, which, with excessive moisture, becomes plastic and swells, i.e., increases in volume. The main feature of the material is its viscosity, which determines its use in a dry production process.

Among the carbonate rocks for the production of cement are used:

  1. Marl limestone, or marl. It contains impurities of clay, therefore it is considered a transitional material between carbonate and clayey rocks.
  2. Chalk is a kind of smearing limestone, which is characterized by ease of grinding.
  3. Shell rock. It is typical for him porous structure, which is not very resistant to compressive loads.
  4. Dolomitic rocks. Of all the types of carbonate rocks, they are distinguished by the most valuable physical properties.

Clay rocks used in the manufacture of cement include:

  1. Clay. The main variety of clay rocks with mineral inclusions in the composition.
  2. Loam. Differs from clay in the increased concentration of dusty particles and sandy fraction.
  3. Loess. Less plastic rock. It is more characterized by porosity, friability and fine grain. The loess may contain inclusions of quartz or silicate.
  4. Shale. Of all the types of such rocks, it has the highest strength. When crushed, shale is converted into lamellar particles. There is little moisture in the material, it is characterized by a stable granulometric composition.

Corrective additives

In order to adjust the composition of cement, special mineral additives are introduced. First of all, these are fossil-based modifiers containing:

  1. iron,
  2. flint-belite
  3. fluorspar,
  4. apatite,
  5. alumina.

Even corrective additives can be represented by industrial waste from other industries. They are used as:

  1. pyrite cinders;
  2. dust from blast furnaces;
  3. belite sludge;
  4. mineralizers.

The use of additives improves the characteristics of cement and concrete mortar, which is prepared on its basis. Each of the modifiers gives the mixture special properties, for example:

  1. - has antifreeze, plasticizing and accelerating action.
  2. - allows you to get a highly mobile concrete mix with increased workability, as well as increase the activity of the binder, i.e. cement, and ensure the completeness of hydration.
  3. and - a waterproofing, water-reducing, water-repellent surface treatment.
  4. - increases the strength, frost resistance, water resistance and durability of concrete products.
  5. - a multifunctional water-reducing and plasticizing additive that increases the branded strength of concrete products.
  6. - additive-accelerator used for concrete mixtures, which require high early strength.

How cement is made: 3 main ways

Cement production in modern conditions is carried out in one of three ways:

  1. Wet. Her main feature- replacing lime with chalk, as well as the production process with the addition of water. The raw material for manufacturing here is a charge (a mixture of raw materials) with a moisture content of up to 50%.
  2. Dry. This is a technology with minimal energy consumption and cost, since here several technological operations are combined into one process. Entering the ball mill, all components are simultaneously ground and dried.
  3. Combined. This production method combines the features of dry and wet technology processes. Here, according to the results of firing, a semi-dry composition with a moisture content of 18% is obtained.

Dry method of production

How dry technology cement is made:

  1. The feedstock is subjected to crushing.
  2. Dry it to a certain level of humidity.
  3. The dried mixture is ground to a state of flour.
  4. It is fired inside a rotary kiln, after which it is cooled and sent to a warehouse.

Wet production technology

In contrast to the dry manufacturing method, here, after grinding the components, water is additionally added to them. The result is not flour, but raw sludge, which enters the kiln for roasting, and then into the refrigerator for cooling. Already cooled clinker is crushed and supplemented with additives.

Combined manufacturing technology

The combined method of cement production combines the stages of dry and wet:

  1. First, raw sludge is obtained using wet technology.
  2. The sludge is subjected to dehydration and granulation.
  3. The granules are fired in a kiln, which is used for dry technology.

Clinker-free production method

In the clinker-free production technology, hydraulic or blast-furnace slag is used as a feedstock for the manufacture of cement. It is also supplemented with various additives and activators. The resulting slag-alkaline mixture is subjected to crushing and grinding to a powder state. This production technology has several advantages:

  1. Improving the cleanliness of the environment through the processing of waste from the metallurgical industry.
  2. Obtaining a product with high resistance to negative influence environment.
  3. Ability to produce cement with different properties and in a wide range of shades.
  4. Lower costs for electricity and heat.

Types of cement by composition and scope

Video: what is portland slag cement

Production of cement in factories

The production of cement by the wet method is traditionally carried out by domestic cement plants. Abroad, dry technology is more often used. It is used by cement plants in China, Turkey and Egypt. White cement is produced by only one Russian enterprise- Holsim (Rus) SM LLC. Much of this binder is often supplied by foreign companies, such as:

  1. AalborgWhite (Denmark).
  2. Cimsa/Adana (Türkiye).
  3. Holsim (Slovakia).

IN general view cement production technology includes several stages:

  1. Mixing of all components for the manufacture of clinker (75% limestone and 25% clay).
  2. Roasting raw materials at high temperature. At this stage, clinker is obtained, which is the basis for cement.
  3. Grinding of clinker in ball mills. The result should be a substance of a powdery consistency. Ball mill is horizontal drums with steel balls inside.

Please note: the smaller the clinker grinding fraction, the higher performance characteristics and brand of cement composition.

Equipment for the production of cement

Cement production at each stage requires the use of special equipment. It is divided into the following categories:

  1. for the extraction of raw materials;
  2. for the transportation of raw materials to the place of production;
  3. kiln for roasting;
  4. ball mills for grinding and mixing clinker;
  5. machines for packing finished cement.

How to make cement at home

You can get cement at home, but only if you have all the raw materials and necessary equipment:

  1. blast furnace for roasting at a temperature of 1500 °C;
  2. crusher for grinding clinker into flour.

In one of the ways homemade cement used resin and sulfur. The resulting cement can be used for laying tiles and bricks, creating cement screed. Manufacturing technology is as follows:

  1. Melt 1 kg of resin in a metal container, 1 kg of sulfur in a refractory container.
  2. Combine liquid ingredients, mix until smooth.
  3. Enter 2 kg of sifted homogeneous sand and 3 kg of lead oxide (lead litharge).
  4. Constantly heating the mixture, stir it until a homogeneous mass is obtained.
  5. Fire in a blast furnace and allow the product to settle.

In reality, there are certain difficulties with the manufacture of cement at home, since the production requires a kiln and a grinding mill. In this regard, at home, it is necessary to slightly change the recipe of cement, using water, water lime and stone ash for its manufacture. The resulting solution is suitable for sealing small cracks, and it must be used immediately after manufacture.

Video: how to make refractory cement from ash

How white cement is made

The difference between white cement also lies in the composition. It contains less iron than gray, and there are also additives:

  1. mineral,
  2. gypsum,
  3. salt,
  4. limestone, etc.

The raw material for the manufacture of white cement are clay or carbonate rocks. The main advantage of the binder is its snow-white color, which enhances the decorative properties of the cement mixture. Because of this, white cement is often called decorative. At the same time, due to more sophisticated technology production material has a higher cost.

Video: Loft-style white concrete table

Video: how to prepare a mortar on white cement

Video: how and what cement is made of

To mix the cement mortar, it is necessary to observe the proportions of its components. 1 part of cement is 3 parts of sand. Water is added depending on how plastic or viscous the solution needs to be. Also, the proportions are selected taking into account the type of work and the brand of cement. For example, to prepare a solution for a floor screed, use the proportions from the table:

First, dry fractions are mixed together, i.e. cement and sand. Only then do they begin to add water in small portions, gradually bringing the composition to the desired consistency. As a filler, you can use not only sand, but also gravel or crushed stone.

Please note: it is better to use sedimentary water for mixing the solution, and not tap water.

Solution classes for different types of work:

  1. M50 or M100 - for plastering;
  2. M50 or M100 - for the construction of brickwork;
  3. M100 or M200 - for floor screed;
  4. M200 or M300 - for foundations and foundations.

To mix the solution, you must use a special pallet or concrete mixer. The latter allows you to get a mixture of the most homogeneous consistency.

Video: cement mortar, tool-free preparation

Video: how to mix cement mortar

Finally

IN modern world cement is produced in a large number of different types, which allows you to choose a binder for any construction work. Through the use of various additives, cement can be given certain properties and used in various difficult conditions, for example, for structures operated under water or at low temperatures. Cement is very easy to use, and can also be prepared at home if you know its composition and common technology manufacturing.

“And they said to one another, Let us make bricks and burn them with fire. And they became bricks instead of stones ”(Old Testament, Genesis, 11-3)

This material is a logical continuation of the article about Saman and is published as a continuation to with his permission;).

We are not talking about houses and shelters, but about the use of "nanotechnology" in construction - about building mixtures and concrete. Basically, of course, about building mixtures, because. Concrete is a building mix with filler.

To begin with, about a couple of things that few people paid attention to in the daMIR article. Namely, “they ram, fill it with a 6 mm layer of lime mortar of normal fat content and lay the next layer of soil”, “if you add 1-2 bags of cement to the earth beater, then it will stand forever ”and one unpublished comment of my colleague (voiced in the conversation) who advised adding a little rotted manure to the adobe.

The fact is that in all these cases, an additive of a binder (inorganic or organic) was used, which significantly increased the moisture resistance and strength of the adobe walls. And you can judge the strength of building mixtures based on lime for yourself using the example of the Roman Colosseum - there the stones are connected by a similar solution.

Well, now to the point.

To be honest, I wanted to start the presentation with the OFFICIAL history of cement and suggest using the intermediate result of this evolution after BP. But the day before yesterday I watched episode 4 of the cycle “History. Science or Fiction" called "Alchemy of the Pyramids" and it turned all my thoughts.
This film tells about the hypothesis of the French chemist Joseph Davidovich, confirmed by a group of researchers from the Russian Academy of Sciences that the pyramids were built of concrete ( artificial stone– i.e. cement with filler, please do not confuse with Portland cement). If you cannot watch this film, you can familiarize yourself with the hypothesis, for example, or. The film and articles detail the evidence for this.

All cheese is boron due to the fact that modern technology the production of cement (Portland cement) requires quite complex intermediate technologies to create firing temperatures of about 1450 degrees, which was not possible in ancient Egypt. Davidovich suggested that the Egyptians used COLD cement technology (i.e. a mixture of natural materials was not burned, but also turned into stone under the influence of water) and called it geopolymer (indicating that both mineral and organic substances are included) cement, he even demonstrated it.

THAT'S IT, I think. I'll find the recipe and everything will be good.

But not everything is so simple - Davidovich does not disclose his recipe, no one else is particularly looking for this recipe - due to the fact that it is unlikely that anything will be cheaper than Portland cement, and research requires money. Only historians are interested in this. And the materials for the manufacture of geopolymer cement will be much more expensive than for modern cements.

In short, there is no recipe for Davidovich in open sources. It got to the point that some individuals with a physical and chemical education claim that the very idea of ​​\u200b\u200bcement with the main binder not subjected to heat treatment is absurd. Let's leave it on their conscience - this is not my goal. My goal is to find an easily accessible analogue of Portland cement.

And a couple of simple BP recipes:
There is such a book "Encyclopedia of Forgotten Recipes" of 1994, and although it contains recipes for handicraftsmen and artisans of the late 19th and early 20th centuries, some things can be used after BP. I climbed into the cement section and found a recipe for waterproof white cement for BP: 75% chalk + 25% kaolin burned to red heat. And that's it. For me, it’s not very costly - chalk mountains exist in nature, and kaolin (white clay) can be replaced with another baked clay.
Pliny (Ancient Rome) gives the composition of hydraulic concrete made of lime, pozzolans (rocks consisting of loose products of volcanic eruptions of ash, pumice, etc. in the USSR, there are deposits of P. and a route in the North Caucasus (Nalchik), in the Crimea (Mount Karadag) and the Armenian SSR) and broken tuff in a ratio of 1:2:1

And what should we do if there is neither the Nile nor the chalk mountains nearby. Our ancestors, for example, added crushed garlic or egg white to cement. At first I thought it was very expensive, but as it turned out, it is possible to add only about 0.1 to 1 percent of the total cement mass to increase the strength of the organic binder if it is introduced in parallel with the inorganic one.

Therefore, after everything I read, I decided to give a damn about the history of cement and try to study the patterns of composition cement mixtures. What came out of it is up to you to judge.

To begin with, I decided on the requirements - the building mixture after the BP must meet the following requirements:
Affordable raw materials, no expensive / rare or difficult to obtain components.
Enough simple technology production
I don't need the strength of modern Portland cement. And although even now there are buildings "on the egg", picking a piece of cement from the wall of which is not entirely easy. Such a fortress without observing a complex recipe is not achievable. And is it necessary? Look at the real stones of the Egyptian pyramids - let's be honest - crumble. And by the way, if you open any textbook on concrete, then it says that concrete parameters such as strength, water resistance, etc. MUCH depends on the filler (gravel, expanded clay, etc.), and not just on cement.

Let's define what exactly we call cement - a powdered building binder material, which - has hydraulic properties. That is, when interacting with water or other liquids, cement forms a plastic mass (cement paste), which, when hardened, turns into a stone-like body.

To start some theoretical part, naturally not mine, and by the way, more than half concerned the plaster. But you yourself know "husband and wife - one Satan."

Binder materials, depending on the origin, are divided into inorganic - lime, gypsum, cements, soluble glass and organic - bitumen, tar and resins.
Binder additives - materials added to mortars to speed up or slow down the hardening of binders, as well as special additives.

Inorganic hydraulic binders that we may be interested in are lime-slag, lime-pozzolanic (volcanic), lime-ash binders and hydraulic lime.

Depending on the properties of additives, they can be divided into the following groups: active mineral additives; surface-active additives; additives for accelerating and retarding the setting of binders.

Active mineral waterproofing additives are called natural or artificial substances, which, when mixed in finely divided form with fluffy lime and mixed with water, form a dough that, after hardening in air, continues to harden under water.
Active mineral additives are used in the production of various types of cement to save its consumption and the consumption of other binders in the preparation of the mortar and to impart waterproofing properties to the mortars.
Natural active mineral additives include rocks of sedimentary origin
- diatomites - hard rocks, consisting mainly of accumulations of microscopic shells of diatomaceous algae and containing mainly silica in an amorphous state; - tripoli - rocks consisting of microscopic, mostly round grains and containing mainly silica in an amorphous state; - flasks - compacted diatomites and tripoli; - rocks of volcanic origin; - ashes - rocks containing aluminosilicates and found in nature in the form of loose , partially compacted deposits; - tuffs - compacted and cemented volcanic ash; - pumice - stone-like rocks characterized by a porous spongy structure - silt (and although it is organic, I myself stuck it here, because this is the only thing I can imagine how it looks and where search;))

Artificial active mineral additives include: - silica waste - substances rich in silicic acid, obtained by extracting alumina from clay; shale); - fuel ash and slag - a solid by-product formed after combustion at a certain temperature of certain types of fuel, the mineral part of which is dominated by acid oxides; - blast-furnace granulated slags - acidic and basic, obtained during the smelting of iron and converted into a fine-grained state by rapidly cooling
(Note: for me, after BP, the easiest way is crushed brick, the more it is clear where to get it or burnt clay)

Surfactants are predominantly organic substances capable of changing the bond between water and the surface of the binder particles. There was a lot written that was not clear - I will not give it, I just say that you can experiment with soap or alcohol - theoretically, their small increase can VERY change the properties of cement.

Finally, additives to accelerate and retard the setting of binders
To slow down the setting of gypsum, the following retarders are used: an aqueous solution of animal glue (mezdrovy, bone) of 10% concentration, slaked lime, lye.
An aqueous solution of glue is injected at the rate of 0.2-0.5% (on dry matter) by weight of gypsum; this lengthens the setting time by 20-30 minutes. In the summer, due to the tendency to rot, this supplement is prepared at the rate of no more than a three-day requirement.
Slaked lime is introduced in an amount of 5-20% by weight of gypsum - the setting time of gypsum slows down by 15-20 minutes.
Lye is introduced into solutions in the amount of 1-2% of the gypsum mass.

It is also possible to add organic binders - substances org. origin, able to move from plastic. state into a solid or low-plasticity as a result of polymerization or polycondensation. Compared to miner. binder materials, they are less brittle, have greater tensile strength. These include products formed during oil refining (asphalt, bitumen - it will be difficult to do), thermal product. decomposition of wood (tar - much more interesting). (I moved the silt to the top, although not scientifically - but more realistically). And the same notorious ones: crushed garlic, egg white, manure, etc.

And finally - Practical Tips or a few particulars about binders:

Clay. - This is a soft, finely dispersed variety of rocks. When diluted with water, it forms a plastic mass, which is easily subjected to any shaping. During firing, the clay sinters, hardens and turns into a stone-like body, and at higher firing temperatures it melts and can reach a vitreous state.
Clay is made up of different minerals, so it comes in different colors. Serves as a binder for the preparation of clay mortars used in laying stoves, plastering, making bricks, adobe walls, adobe-straw roofing and other works.
Clay has the ability to absorb water up to a certain limit, after which it is no longer able to absorb or pass through itself. This property of clay is used to create bulk waterproofing layers.

Gypsum. The raw material for producing building gypsum is natural gypsum, or, as it is often called, alabaster stone. Gypsum stone deposits are found in many parts of the country. It is made by firing and grinding or grinding and firing.
Depending on thermal conditions processing, setting speed and hardening gypsum binders can be:
1) fast-setting, fast-hardening and low-firing (firing temperature 110-190 ° C). Low-firing ones include building, molding, high-strength gypsum and gypsum-cement-pozzolanic (volcanic) binders.
2) slow-setting and slow-hardening high-firing (firing temperature 600-900 ° C). Anhydrite binders are used after joint grinding with hardening catalysts - lime, burnt dolomite, etc. Gypsum-anhydrite binders are used for the manufacture of panels, partitions, slabs, wall stones, architectural and decorative products, models and forms in porcelain, faience and ceramics. . prom-sti, orthopedic. corsets, etc.

Lime. Lime kills microbes, and cleans the air from harmful aerosols better than any air conditioners with filters.
The lime production process is not difficult, but it requires a stove and coal. The burning process takes place at a temperature of 800 and above. On wood, such a regime is difficult to create. In an ordinary home stove, one firebox can burn a kilogram and a half of raw materials. It will turn out after extinguishing about half a bucket of lime sour cream or a bucket of lime for whitewashing.
On average, the stove is heated five to six months a year. It is easy to calculate how much you can work out for heating season. Enough for a good building.
The raw material for the production of lime is limestone. They are distinguished from ordinary stones by the fact that they are lighter than rubble stones and granite and are gray-blue in appearance. Easily scratched by metal objects. And most importantly, if you drop acid on them, then they begin to hiss and foam, but this is concentrated acid - you will agree that it is difficult to get it after BP. Therefore, I can tell you something else for the search: limestone sedimentary rocks, which were formed by the compaction of sediments of the world's oceans. Therefore, when struck with a hammer, they split in layers. And railway embankments are very often made with such stones. Sometimes surface treatment of roads is made with such gravel. If there is a factory in your area silicate brick, it's generally excellent. This production uses the raw materials you are looking for. I think that you will find a way to "purchase" stones from the factory.
The burning process is as follows: the coal must be sieved on a sieve with a cell of 10 by 10 mm. Lime stones are not thicker than 20 mm, 10-15 mm is even better. Large stones are easily hollowed out with a hammer, in layers.
You fire up the oven. Pour in a bucket of coal, when it is well lit, level the firebox with a poker, pour in another half a bucket of coal. After that, you begin to lay the raw materials on the coal, lay them out evenly in one layer, then let the stove flare up again, then pour in half a bucket of coal so that the raw material is covered. After that, take a couple of scoops of the coal that was sifted out (dust) and pour it on top so that the heat lasts until the morning. You can start taking out in the morning.
The recess is best done with special pliers. After the stones are pulled out, inspect them. Well annealed stones white color and much lighter raw materials.
Then the lime should be extinguished. The extinguishing process is carried out on the street. It is necessary to pour water into metal dishes, and then the resulting products are gradually dumped there. The decomposition of lime is very rapid, so you should be very careful.
After a couple of days, the lime is ready for use. The slaked lime turns into a dough that can be stored for many years. From prolonged storage, the properties of lime can even improve. To obtain a binder solution, lime paste is mixed with sand. Such a solution is used when laying foundations for furnaces, chimneys up to 4-5 m high and is used for plastering the walls of houses and furnaces.

To improve water resistance lime mortars, they are injected with finely ground burnt clay, broken bricks or volcanic rocks (ash). With a fine selection of the recipe, you can get the hydraulic lime invented in 1756 by the Englishman D. Smith. Obtained by roasting limestone with clay impurities - a product of moderate firing (not before sintering) marl limestone (unfortunately this does not tell me anything), containing from 6 to 20% clay impurities. Hydraulic lime tends to harden not only in air, but also in water.

At the end of the article I want to give a method for determining the optimal proportion of concrete components.
It is based on the method of selecting the composition of concrete by absolute volumes, which involves complete absence voids in the preparation of concrete mix.
All we need is a bucket liter jar and, in fact, those fillers that the concrete will consist of, as a rule, are crushed stone, cement, sand, and water.
To begin with, let's count how many cans of water fit in the bucket, pouring them there one by one. We get, for example, 10 pieces. Let's write down.
Then, we will fill the bucket with rubble to the brim and we will pour water into it with a jar filled with a glass too, in order to know how much water we filled the bucket with. When the water reaches the edges, remember the amount of water poured. This will be the volume of voids after loading the rubble. Let's say we got 5 cans.
Now let's dump everything out of the bucket, wipe the jar dry and put as many cans of sand into the bucket as we poured into the bucket filled with rubble, in our case 5 pieces.
Pour water again and count the cans until the water reaches the surface of the sand. Let's say we got 3. This figure will show us the volume of cement that will be required to fill all the remaining voids, after loading crushed stone and sand.
That's actually all. In our case (for our crushed stone and sand), the proportions of aggregates and cement for our concrete will be as follows: crushed stone - 10 parts, sand - 5 parts, cement - 3 parts.
Note that crushed stone is mainly responsible for the compressive strength of concrete, therefore the strength of concrete will also depend on the quality of crushed stone. As a result of the use of crushed stone, we will improve such characteristics as: strength, durability, reduce shrinkage and creep of concrete, as well as save cement - the most expensive component in concrete.
Fine aggregates are responsible for the shear strength of concrete; for this, they must evenly and densely fill the voids between the crushed stone grains.
With regards to the mortar for laying brick or stone, the technique is similar, but we measure only sand, cement and water.

And finally, all this is THOROUGHLY mixed - this is the secret of successful builders.

At the very end, I’ll say that, as you yourself already guessed, I didn’t come up with all this myself - there were VERY many sources, so there may be errors. But my main goal was to show that, if necessary, a replacement for cement can be invented and show possible search directions, as one of my colleagues said, when everything gets better;)

Almost any repair, and certainly not a single construction site, can do without the use of cement. The creation of a foundation, the formation of block or brickwork, plastering of walls, electrical wiring and any other communications require the use of this material. Without cement it is impossible to prepare concrete or building mixture. And even a completely inexperienced person, following enough simple instructions, will be able to prepare a cement mortar, a high-quality mortar of concrete of various grades from M100 to M500.

How to identify a brand?

It's very simple: the brand of cement is divided by the amount of sand. Let's take a few examples as an example.

  • If cement is used stamps 400, then the ratio between cement and sand is one to four, four buckets of sand are taken per bucket of cement.
  • When using cement stamps 500 the ratio changes to one to five, five buckets of sand are added to one bucket of cement.
  • If a solution is needed stamps 200, the ratio between cement and sand will be one to two. So two buckets of sand are added to one bucket of cement 400.

It will be necessary to add water and detergent to the resulting mixture in a certain order (few people know about this constituent component, we will talk about its value a little lower) and get the required brand of solution.

Determining the required brand of solution

Theoretically, the brand of mortar used should match the brand of material used (blocks, bricks, etc.). So, for example, if brickwork, and the brand of brick used is 100, then, ideally, the brand of mortar should match this figure. The result is an almost homogeneous solid brick structure.

However, it is far from necessary to go too far and strive for an absolute match. If a face brick corresponding to grade 350 is used in the construction of a house, the solution is far from necessary to be made according to the above formula.

Usually, a mortar with a brand corresponding to approximately 115 is used for facing brickwork. For its manufacture, two parts of cement are laid for one batch for seven parts of sand (1 / 3.5). About three weeks later, after the final drying, it is very difficult to hammer a nail into the seams of such a solution.

Do not think that an increase in the brand number of the solution also leads to a mandatory increase in its quality. When kneading one to three, the solution will set too quickly and therefore it will not be very convenient to work with it. If the batch is done one to four, the seams of the front brick will begin to crumble over time.

When building partitions from backing bricks, the grade of which corresponds to 75, the mortar used can also correspond to 75 (5.3 parts of sand are taken for one part of cement). And during the construction of blocks (cinder blocks, shell rock, etc.), mortar grade 100 is usually suitable.

Step-by-step process for preparing cement mortar

There are many ways to prepare solutions. We will describe the highest quality, fastest and optimal of them.

Water

If it is not a dry mix that is being prepared, but a classic ordinary mortar in a concrete mixer, first of all it is necessary to pour water into it. At the same time, its exact amount cannot be determined in advance and one should not rely on any formulas. So, for example, the amount of water will decrease if wet sand is used. The easiest way preliminary calculation- Orientation to the amount of cement. For example, if a batch requires one bucket of cement, it will take about the same amount of water - about one bucket. In order not to get an excessively liquid solution, it is better not to overdo it with the amount of water and fill it a little less than the required rate.

At the same time, if there is too little liquid, you will have to constantly add water, then add cement or sand. This will lead to a significant lengthening of the solution preparation process. If the species is flooded quite a bit less than the norm, mixing sand with cement in a liquid state will occur much faster than in the case of a thick solution.

When the last components of cement and sand are added to the concrete mixer, the rest of the water is added by eye. In order for sand and cement to be mixed better and faster, they must be in a liquid state. A required density solution is adjusted at the end of the batch.

When more water was added than required, and the solution turned out to be too liquid, nothing terrible will happen. You just need to add some cement and sand in the same proportions required for this brand (1:4, 1:3, etc.).

Detergent

Not a very common additive, which is nevertheless very useful and significantly improves the quality of the resulting solution and makes it elastic. It is best to add liquid soap or dishwashing detergent. Of particular importance is the quality (and even more so the brand's fame) does not matter, the main thing is that the product foams. If the amount of the required solution is not too small, it is best to buy them in large five-liter plastic bottles, they are cheaper than small ones.

During the preparation of the solution, approximately 50-100 grams of detergent is added to the mixer. Its exact amount cannot be determined, since it depends on various factors.

This component is added after water is poured, then good dissolution and foaming will occur. For the final dissolution and foaming in a working concrete mixer, three to five minutes are enough. If you add detergent at the end of the batch, the dissolution will be poor and the elasticity will hardly improve.

Sand

Sand should be added next to the detergent (after it has been well dissolved). However, it is not filled up all at once, but half of the total amount needed for the entire batch. So, if a mortar of grade 100 is prepared and cement 400 is used, two of the required four parts are poured into the first tab.

Cement

After half of the added sand, cement is poured into the concrete mixer - the entire rate required for kneading. After that, you need to wait a couple of minutes for it to completely mix with water and sand.

Sand

When all the cement in the concrete mixer is completely mixed with other ingredients, the rest of the sand is added to the resulting mass. If necessary, the missing part of the water is added and at the end of the process the density of the solution is adjusted. After that, the solution is finally mixed for three to five minutes.

As a result, the resulting solution should not be too thick and not too liquid. Its consistency should be similar to non-store sour cream. The form of the solution should hold well enough. To check on its surface, you can try to write or draw something. The written letter should not blur.

Summary: preparation of a good double-mix solution in a concrete mixer (approximately eight buckets of finished sand-cement mixture) takes only about fifteen minutes.

The quality of the materials needed for a good mortar

Pure water

Theoretically, for the preparation of the solution should not be used dirty water, such as water with impurities of oils or rainwater. But in reality, such strict rules are applied in the construction of critical structures and buildings (bridges, nuclear power plants and the like). If the construction of civil buildings (residential buildings, dachas, etc.) is underway, then the requirements for purity and quality of water are not so strict. Usually, water from a water supply system, from wells or wells, sometimes from rivers or lakes is used to prepare the solution.

Detergent

The addition of detergents improves the elasticity of the solution and prevents it from settling. Any detergent can be used, but not cleaning products. Basically, it could be washing powder, white clay, laundry soap or even shampoo. There is a certain nuance: if too much detergent is poured into the batch, then the solution may lose strength. The fact is that exceeding the amount of detergent will make it airy and foamy. The solution will contain too many air bubbles and it will become like cotton wool. Therefore, when adding detergent, one should not overdo it, so as not to reduce the strength of the solution.

Sand

It is very important, especially for facing masonry, that the mortar sand is of normal quality and does not contain clay. If you use clay sand, then after a while the seams of the front masonry will be covered with holes. Clay that has entered the solution along with sand comes out, where it is washed out by rain and forms voids. Good (no clay) sand or not is easily determined visually. So, if the color of the sand is too yellow, then it is not washed, quarry, and contains too much clay. Such material is suitable for backfilling or for dirty, backfill masonry. But for the front it should not be used. It is also not desirable to use too clayey sand for responsible concrete (for lintel crossbars, reinforced concrete belts etc.)

If the sand is washed, then it contains a very small (or completely absent) amount of stones and clay. The color of this material is much closer to white. Alluvial sand is used for responsible concrete and for facing masonry.

Cement

Naturally, for the manufacture of a normal solution, it is necessary to pay attention to the quality of the cement used. If it is weak, then you need to add more to each batch. In some cases, the amount of cement produced by an unscrupulous manufacturer has to be almost doubled. It is quite difficult to give recommendations on the choice of material, so you have to focus on the reviews of those who have already used the goods of a particular plant.

Production of cement mortars at negative temperatures

Brickwork may well be erected with negative temperatures.

If front brickwork is made at temperatures up to minus five degrees, then it is quite possible not to use any additives. When the temperature drops below, mortar prepared without such additives may later crumble, especially if the seam has been embroidered with a semi-circular joint. Potash has proven itself as such an additive, especially since its cost is very low.

If, however, at a temperature of up to ten degrees, backing masonry is erected, the use of special chemical additives is not required, while the strength of such a solution does not decrease. If the temperature is even lower, potash is applied again.

Solution preparation

  • Sand

Frozen sand becomes a major problem for mortar preparation in winter time. It is best if it is prepared in advance. For example, before that, sand is brought into a heated room. At the northern construction sites, the sand is specially heated.

  • Water

In order for the mortar to cool longer, it is best to pour heated or hot water. In addition, detergent will dissolve better in such water and the solution will become more elastic. Various antifreezes can also be used, but only with proven quality.

Solution color change

The standard color of cement mortar, as you know, is gray. It can, depending on the manufacturer and brand, change shades or saturation, but this is weakly reflected in the appearance. But the desire to change its color arises very often - this is a fairly popular question that occurs on specialized forums. To solve this problem, two different methods can be applied.

In the first case, special, called pigments, types of color additives are used, which become part of the solution. The use of such colored concrete allows you to greatly diversify the appearance of buildings. Actively colored concretes are also used in various areas of construction.

Pigments must be added at the stage of preparation of mixtures, the period of their introduction does not matter much. It should be borne in mind that the cost of such substances is not too small, but they do not lose their color qualities for many years.

colored concrete resistant to these factors., How:

  • Moisture– even when atmospheric moisture enters the structure of the structure, the pigments do not lose appearance and quality. The saturation of the surfaces will remain the same everywhere, and this allows them to be used for any surfaces and any conditions.
  • sunlight- usually direct sunlight leads to fading of ordinary colors and loss of their saturation. In this case, the color becomes faded, and the exterior of the building changes for the worse. Modern pigments have a high degree of resistance to ultraviolet radiation.
  • Mechanical damage- ordinary paint, as a rule, simply crumbles due to physical damage. And the pigment becomes part of the entire structure of the material, present not only outside, but also inside. And this leads to the impossibility of its removal.

The degree of saturation of colored concrete may vary. This factor depends on the amount added to its composition. coloring matter. The minimum value is about two percent of the total volume of the solution. In this case, you can get pastel soft tones. Four percent contributed will provide a more effective result. The structure will have the usual dye color, but will not differ in brightness. A truly saturated shade is obtained only if the pigment is applied in an amount of at least six percent. total solution.

There is another method that cannot be attributed directly to the topic of the article, since it is used not at the time of preparing the solution, but after its final solidification, and at any time after construction. In this case, the concrete is painted in the desired color with the help of special impregnations. Ordinary concrete turns into colored after the application of special substances to its surface, which are absorbed to a depth of at least two centimeters. As a result, the advantage of the previous method is provided, but at a lower cost. But it is worth considering that only areas with a large surface can be painted in this way, and in the case when you want to get colored masonry seams, it will not be possible to effectively apply impregnations.