It's all about the proportions: what cement is made of so that the foundation stands for a long time. How to prepare a cement mortar with your own hands? How is cement made?

If you decide to build, you will definitely need a cement mortar during the work. It is not enough just to buy cement, because before the start of construction, the gray powder must turn into a real solution. Water, sand and cement - that's all the ingredients, but not everything is as simple as it seems at first glance. Let's figure out how to properly make a cement mortar.

History of cement

Cement is a well-known binder building material, which is classified as a hydraulic binder used to bond different surfaces - bricks or reinforced concrete blocks. Without cement, concrete or foundation cannot be made. In addition to high viscosity, the material has excellent hydraulic properties, which make it possible to create a stable bond with water and other liquids when making a solution in the form of a plastic mass. After hardening of such a mass, a stone-like material is obtained, which has significant strength and rigidity.

Even in ancient times, binders began to be used for construction purposes. The very first binder material was natural unbaked clay. However, over time, it ceased to satisfy builders due to its low resistance to moisture and weak binding properties.

For several millennia, air lime and gypsum remained the only binders, but they had insufficient water resistance. And the rapid development of navigation in the 17-18 centuries required the creation of new water-resistant binders for the construction of port facilities.

In 1796, the Englishman Parker patented a cement called "roman", which could harden in air or in water. However, these qualities have also lost their practical significance in our time. At the beginning of the 19th century, Academician V.M. Severgin described an astringent, which was obtained by firing marl followed by grinding. Since the second half of the 19th century, Portland cement has firmly entered the construction practice of our country.

Industrialization in the USSR and the rapid pace of capital construction predetermined the growth of the development of the cement industry. In 1962 the USSR took first place in the world in the production of cement. Today, about 30 varieties of cements are produced in our country. At the same time, its quality is growing and the prediction of the famous chemist Mendeleev, who claimed that cement is the building material of the future, is coming true.

Cement production process

Natural cement is a mixture of limestone and clay, which forms a high-strength stone-like material when solidified, which is most often odorless, free-flowing and has grey colour. The quality of cement is determined by the presence of various substances in it - granulated slag, magnesium oxide and sulfuric anhydrite. The brand of cement depends on the ratio of these components. Also, the quality of cement, setting time, compressive strength, false setting will depend on the percentage of the listed substances.

As a raw material for the manufacture of Portland cement, a mass of limestone and clay is used, as discussed above. What else is cement made of? In rare cases, a rock called marl is used, which is precisely the natural mixture of clay and limestone in the ratio that is necessary to obtain Portland cement during the production process. Marl was appreciated in the 19th century by the Englishman Aspdin, who collected dust on the road near the city of Portland, made briquettes from it, which were subsequently burned.

Cement plants usually have their own quarries required material- clay and limestone. This allows you to withstand the necessary chemical composition charge with a high accuracy of up to 0.1 percent, which is of great importance. The charge is fired in rotary kilns, which have a diameter of 3.6 - 7 meters and a length of 100 - 150 meters. The temperature in the sintering zone is maintained at plus 1450 degrees Celsius.

The product of sintering is clinker, which is rounded granules, the diameter of which reaches 5 - 100 millimeters. The clinker is ground in ball mills to a specific surface area of ​​3,000 square centimeters per 1 gram. Without fail, when grinding, 5% of gypsum dihydrate is added, which plays the role of a setting time regulator. Without gypsum, the so-called quick cement is formed, which immediately seizes, and from which dough cannot be prepared. All clinker minerals are able to interact with water and form new compounds - hydrates. Hydrates form a spatial structure that creates a cement stone.

The use of cement in construction

Cement is used to build a foundation and make a mortar for laying bricks, pouring a screed when installing a floor, creating paths and blind areas. It is used for prefabricated and monolithic concrete, which serves as a raw material for the production of reinforced concrete, asbestos-cement products, various artificial materials, mortars, fastenings. individual parts buildings, insulation. Large consumers of cement are the gas and oil industries.

Cement and building materials that are obtained on its basis can successfully replace scarce wood, lime, brick and other traditional materials in construction. A little later we will talk about how to make cement with your own hands and a cement mortar. The use of cement in various construction industries is closely related to its technical characteristics. Let's take a closer look at this connection.

Frost resistance is a property that characterizes the ability of a material to repeatedly freeze and thaw over a long period. Pure cement does not have this ability; it receives this characteristic due to various modifying additives. If you live in a cold zone of the country, and high frost resistance of the structure matters to you, then you should choose hydrophobic cement 500.

Corrosion resistance determines the ability of cement to withstand almost any aggressive environmental factor. Increased corrosion resistance is characterized by pozzolanic cement, which is intended for the construction of underwater and underground structures.

Sulfate resistance is a property of the powder, which allows the building mixture to be stable in an aqueous environment that contains sulfate ions. This property is embodied in sulfate-resistant cement, which is used for the construction of hydraulic structures that are exposed to salt water.

Water resistance as a characteristic of cement has found application in waterproof expanding cement. Cement is able to increase in volume during hardening, the setting process takes place quite quickly - in about 10 minutes. Waterproof expanding cement is required for sealing joints and seams in concrete structures that are located in water.

The fineness of grinding refers to the characteristic that affects the setting time, hardening and strength of concrete. The greater the fineness of grinding of the produced clinker, the higher the strength of the hardened cement will be. It should be remembered that too fine grinding provokes, instead of excellent characteristics, excessive water consumption and a decrease in the strength of concrete.

Making cement mortar with your own hands

If you want to minimize the cost of repair work or construction, you should forget about ready mixes, the price of which is much higher than the cost of cement and sand, which are necessary to obtain an equal volume of cement slurry. First of all, you need high-quality cement to prepare the mortar. O right choice We have already discussed this material in a previous article. Let's talk now about how to make cement and its mortar at home.

Cement at home

The production of cement at home allows you to get this material, indispensable in construction, using a minimum amount of resources and endow it with the desired characteristics. Let's take a look at popular methods. self-manufacturing cement.

Putty for sealing cracks and crevices in flooring made in this way: mix lime with coal ash and dilute with water until a consistency of fatty sour cream is formed. For the manufacture of cement intended for puttying iron utensils, wells, steam boilers and holes in metal products, take forty parts of barite white, thirty parts of graphite dust, fifteen parts of lime and knead the resulting mixture to the required density in linseed oil with the addition of varnish.

To fix iron in stone, make cement with your own hands from the following components: sand (20 parts), kaolin (2 parts), ground chalk (4 parts), slaked lime (3 parts), liquid glass (15 parts), mix everything until smooth pasty mass. For ceramics, you will need cement of the following preparation: rub 2 parts of slaked lime with 5 egg whites, dilute the mixture with 2 parts of water, rub with 10 parts of gypsum.

To prepare cement for stone, it is recommended to mix 10 parts of sulfur and bitumen with 1 part of beeswax. Melt the mass, then add 2 parts of brick powder. Immediately before applying the solution, dry the stone and grease with drying oil. For pipes, mix in a heated mortar 15 parts of drying oil or linseed oil and 85 lead oxide to obtain a plastic mixture.

For the production of glycerin cement, you need lead litharge, which should be carefully ground into powder and dried at high temperature. Mix the resulting dust with glycerin. The technological characteristics of cement produced according to this recipe are several times greater than those of Portland cement factory. Such a material is characterized by high density and a level of resistance to negative environmental influences.

Homemade glycerin cement is absolutely not afraid of high temperatures: it is able to withstand temperature increases even up to plus 300 degrees Celsius. Another important practical characteristic of glycerin cement is the ability to firmly glue objects made of porcelain and faience. It is safe to say that this material is a real ideal cement.

Europeans have recently invented new way production of cement, which has unique characteristics. Such Chinese cement is capable of gluing leather, gypsum, marble, porcelain, faience and other materials. For the preparation of cement, the following components are needed: slaked lime (54 parts), quartz (6 parts), fresh blood! (40 parts). The resulting mixture must be thoroughly ground until a homogeneous mixture is formed.

Preparation of materials

The first stage in the manufacture of cement mortar is preparation. Choose a container in which you will dilute the cement. The volume of the container must necessarily correspond to the volume that is planned to be made. If the dishes are smaller than the planned volume, then you will probably pick up the solution from the ground. If the container is too large, then you will not be able to create a uniform mass that will not clump.

In addition, a sufficiently stable capacity is needed. Pay attention to how strong the walls of the container are. It is also not recommended to take a container with low thin walls, because they do not allow mixing a quality solution. The best solution at home will be an old cast-iron bath.

In addition to dishes for the resulting mass, you will need a special tool for the most convenient creation of the solution. It is usually customary to use a special construction mixer, but our skilled compatriots adapt an ordinary drill with nozzles for this purpose.

Preparing the Components

If a bag of cement has been stored in your garage for many years, you should stop using it. To obtain a quality solution, it is also important and specifications sand - uniformity, purity and absence of impurities. The best option is washed quarry sand.

Arrange everything before work necessary tools and materials as close as possible, so as not to be in an uncomfortable situation when you need to "run" for the components of the solution. Next, it is necessary to sift the powder to make a cement mortar in order to avoid the formation of lumps and getting into the mass of debris, which significantly worsens its astringent properties and qualities. When preparing a cement mortar for plastering works you need to use a sieve with cells 5 by 5 millimeters, for stone - with cells 10 by 10 millimeters.

After that, the ratio in the composition of the solution of each element should be determined. At this stage, it must be remembered that the admixture of sand when using high-quality cement should be negligible or nominal. Also remember the classic ratio that builders have been using for a long time: 1 part cement is usually mixed with 3 parts sand. It is customary to measure all incoming components using certain dishes or scales.

During construction, it is often necessary to prepare cement not according to the traditional recipe, which is accepted at all global construction sites in the world. Non-standard mixtures are obtained due to various impurities. They are able to change the properties of the cement mortar, for example, change the rate of solidification of the substance or slow down the speed for long-term work with the mortar, improve the viscosity characteristics of the mass so that it turns out to be plastic and more pliable for working in difficult areas.

There are such types of cement mortars: normal, fatty and lean. A greasy cement slurry is a mixture that contains too much binder. This solution is able to quickly harden, but after use it dries out and forms cracks, therefore it is short-lived.

A normal cement mortar is a mass where the proportions of the elements are observed correctly. Such a solution does not freeze too quickly, but cracks do not form in it, it is strong and durable. Lean cement mortar is a mass in which there was not enough binder component, such a mortar will not be taken if you do not decide how to dilute the cement.

Regardless of the recipe for preparing a cement mortar, a mixture of high quality is considered to be one that does not spread during operation and is characterized by a high or medium level of viscosity. The mixture along with this should not be too dry, as this provokes the loss of the fixing qualities of the cement mortar, laying in this case does not hold.

Solution preparation

So, pour a layer of cement into the container, then a layer of sand, then cement again and then sand again. The number of such layers should be at least six, this will allow you to qualitatively mix the components. Cement and sand are poured in layers in the form of beds to a total height of about 200-300 millimeters.

To begin with, mix the sand with cement correctly. Shovel this bed several times with shovels until smooth. When mixing, do not forget about the concept of "intensity". Without a certain technological mixing procedure, you will not be able to get a quality solution. After that, it is recommended to sift the mixture through a fine sieve, which has cells measuring 3 by 3 millimeters, but not less. The homogeneity of the mixture should be close to absolute.

Do not add water or other liquids when you have mixed the dry ingredients. The addition of liquid to the resulting mixture should be carried out gradually and very carefully. Pour in water slowly so that the mass gets the desired consistency. If you have more water than required, then it is the gradual infusion that will allow you to stop on time.

Remember that the liquid temperature should not be too high or extremely low. Take water of the optimum temperature, what Environment. Masonry requires the preparation of a thicker solution, and the pouring process requires a more liquid one. Do not mix a lot of cement mortar at once, especially if you used wet sand. Now you know how to make a cement mortar at home.

And finally, remember that cement mortar is a material that cannot be stored. This is due to the high viscosity properties of cement, due to which the mortar is able to quickly harden and become unusable for construction works. The composition that you received after proper mixing is available for work for another hour when used wet sand and up to three hours if you dried dry sand.

Every more or less serious construction project never takes place without the use of cement. This popular building material is included in many other complex finishing materials. Cement is not mined in nature, it is made by high-temperature exposure to individual natural compounds, followed by grinding and the introduction of additives.

The cement production technology itself is not a high-tech process, and with certain knowledge, you can make cement with your own hands.

How is cement made in production?

For the preparation of cement, carbonate and clay rocks are used. Also, industrial waste, such as slag, can be used to create cement. The creation of cement itself consists of three consecutive steps:

1. Base manufacturing. As a result of the completion of the first step, we have sludge- the product of a mixture of limestone (three parts) and clay (one part). But the exact proportion of the mixture is adjusted from the properties of the components and changed in order to create a final product with high characteristics;
2. The second step is high-temperature processing of the sludge at temperatures close to 1500 degrees Celsius and further grinding of the resulting substance to a powder state;
3. The third, final step is to add gypsum from 3 to 7% to the resulting substance, as well as other components, to give additional properties to cement, such as frost resistance.

Additional additives give individual properties to cement, so it is possible to distinguish certain types of cement:

• hydrophobic - resistant to moisture contained in the atmosphere. Its use gives concrete increased water resistance and frost resistance up to F1000;

• white - most often used for the preparation of ready-to-eat dry mixes;

• expanding cement. While other types of cements decrease in volume when the concrete mixture hardens, expanding cement allows you to achieve the opposite effect;
• pozzolanic cement - characterized by reduced heat generation. It is most often used for concreting volumetric objects, due to reduced heat release, the risk of uneven settlement (and hence cracking) is significantly reduced;
• colored cement - used for the manufacture of products that do not require further processing. Either white clinker is used, or dyes are introduced into the concrete mixture;

• aluminous cement - distinguishing feature consists in the fact that it gains up to 50% strength already within a day after laying the concrete mixture. Thanks to the selection a large number heat is often used during construction in winter.

Do-it-yourself cement production

The main problem in the preparation of cement with your own hands is the need for firing at a high temperature. Therefore, you will need at least a kiln and a mill in order to grind the prepared clinker. But even in this case, at home it is unlikely that it will be possible to obtain cement for the preparation of concrete of a grade over M200. Although this result is possible only under the strictest observance of the proportions and stages of the process.

Before preparing cement with your own hands, you need to evaluate 2 factors:

• work front. The creation of a home-made production line is justified only under the condition of a relatively large amount of work;
• working conditions. Given the low strength of concrete structures using home-made cement, it is advisable to use it only for structures that do not experience serious loads.

Taking into account these factors, it is necessary to evaluate the economic efficiency of "handicraft" production.

The actual preparation of cement at home takes place in the same order as at a cement plant: raw materials are prepared, fired in a kiln, ground and mixed with additives. Handicraft production also has its advantages - cement can be given any properties by experimenting with raw materials.

To obtain ordinary Portland cement, it is recommended to use crushed chalk and crushed kaolin (75% chalk and 25% kaolin). This raw material must be thoroughly mixed. Then it is fired in a kiln and ground in a mill. In the resulting powder, add 5% gypsum powder.

There are also exotic recipes for making, for example, glycerin cement, Chinese cement, diamond putty. Such options are not considered, since they are used only for solving highly specialized tasks.

Preparation of cement mortar

Any cement mortar consists of water, binder (cement itself) and aggregate (most often sand). The ratio of binder and aggregate depends on the type of work performed. So, for a plaster mixture, the ratio of cement and sand can be taken as 1:6, but, for example, for laying bricks, the ratio of binder and aggregate should be reduced to at least 1:3.

If the mixture is prepared for pouring the foundation, then the content of aggregate can be further reduced, in which case the ratio of binder and filler is 1:1 or 1:2. In addition, crushed stone is often added to the mixture for pouring the foundation.

In construction, mixtures with the addition of lime or clay are often used, but they also use cement to increase the strength of the solution after hardening.

Also, during the preparation of the mixture, you need to pay attention to the water-cement ratio. Of course, the optimal ratio is set for each type of mixture, but it should be remembered that excessive water content degrades the quality of the mortar after hardening.

The process of preparing the solution also has some nuances. It is recommended to mix the binder and aggregate in dry form, and only then add water. It also matters in what order the components are loaded into the container. Layer-by-layer loading of sand and cement and their uniform distribution in the tank are considered optimal. If it is necessary to prepare a large volume of mortar, layers of sand and cement can be alternated several times. These recommendations will make it easier to mix the mixture and make it more homogeneous, eliminating lumpiness.

“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 tamp, 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 ground, then it will stand forever ”and one unpublished comment of my colleague (voiced in a 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 Russian Academy science 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 (that is, 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, anyone else is not 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, Davidovich's recipes open sources no. It got to the point that some individuals with a physical and chemical education argue 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 section of cements and found a recipe for waterproof white cement for BP: 75% chalk + 25% red-burned kaolin. And that's all. 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 with an organic binder to increase strength, if it is introduced in parallel with the inorganic one.

Therefore, after reading everything, I decided to give a damn about the history of cement and try to study the patterns of 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.
Relatively simple production technology
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, 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 various kinds cement to save its consumption and the consumption of other binders in the preparation of the solution and to give solutions waterproofing properties.
Natural active mineral additives include rocks of sedimentary origin.
- diatomites - solid rocks, consisting mainly of accumulations of microscopic shells of diatomite 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; - burnt clay - a product of artificial firing of clay rocks (expanded clay, clay, tartar) and spontaneously combustible in dumps of empty mine rocks (clay and carbonaceous shale); - fuel ash and slag - a solid by-product formed after burning at a certain temperature of certain types of fuel, the mineral part of which is dominated by acid oxides; - blast-furnace granulated slag - 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 of incomprehensible writing here - I won’t 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. AT summer time in view of the tendency to decay, this additive 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 various minerals, so it happens different color. Serves as a binder for the preparation of clay mortars used in laying furnaces, 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 and 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 not difficult to calculate how much can be generated during the 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 is sedimentary rocks that were formed by compaction of the 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 plant for the production of sand-lime bricks in your area, then 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 fill 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 are white and much lighter than 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 used for plastering the walls of houses and stoves.

To increase the water resistance of lime mortars, finely ground burnt clay, broken bricks or volcanic rocks (ash) are introduced into them. 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 assumes the complete absence of voids in the preparation of the concrete mixture.
All we need is a bucket, a liter jar and, in fact, those fillers that the concrete will consist of, as a rule, these 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 the composition of 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;)

Construction is a part of the lives of many citizens, especially those who live in the private sector. It surrounds people everywhere. Today, private construction is developing very actively. It is known that the most commonly used building materials are wood, concrete, brick, cement. Cement occupies an important place in this industry. With its help, roads, foundations for houses and garages, and some other structures are built. To prepare a cement mortar, it is necessary to have all its components on hand. Many do not know how to make cement with their own hands.

To prepare the simplest cement, you will need chalk and kaolin.

The cement mixture consists of three main parts: sand, water and cement powder. This distinguishes it from concrete in many ways. In concrete, in addition to all the listed components, there is one more - coarse-grained material. It can be represented by crushed stone or gravel. It is important that cement is different. The brand of the mixture is determined by the type of work performed and the basic requirements for structural strength. Let us consider in more detail the main stages of work on the preparation of cement mortar at home.

To independently make a cement-sand mixture, you need to decide on its type. Currently, lean, normal and fatty solutions are isolated. All of them have their advantages and disadvantages. If in a normal solution the proportion of cement powder does not exceed the norm, then fatty ones contain a lot of cement. All this contributes to the fact that such a mixture, after hardening, will quickly crack. As for lean mortars, they contain more sand than cement powder. This makes them less durable. In addition, in the construction business there is such a thing as the brand of cement and the mortar itself.

The brand determines the compressive strength of the solution after hardening. The most commonly used in construction are mortar grades 25, 50, 75, 100, 150 and 200. To make cement with your own hands, you need to choose it correctly. This takes into account the nature of the work. For example, for masonry and plastering, a cement mixture of grade 100 or 150 is often used. For the construction of blocks, it is recommended to use a mortar of grade 100. As for the proportions of the main components, they may be different. This largely depends on the quality of the cement powder. Sand-cement mortars can be masonry, building or plaster.

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Stages of preparation of cement mortar

When making a cement mixture, it is necessary to remember the main stages of work. They include:

• correct selection of the brand of the mixture and the brand of cement powder;
• preparation of water, sand and various additives;
• direct cooking.

In some cases, builders need to determine the brand of the resulting solution. This is done quite simply. It is necessary to divide the brand of cement powder by the amount of sand (in buckets). For example, if the main component of grade 400 was used, and there were 4 buckets of sand, then the resulting solution will be grade 100. The first stage includes the selection of cement powder. The brand determines the quality of the material. The higher it is, the stronger the mixture and the whole structure will be.

An interesting fact is that different brands of cement can be used for the same mortar. The difference will be in the amount of cement used. Accordingly, the higher the brand of powder, the less it will be required. Ideally, the brand of the mixture should match the brand of the material (if plastering or masonry work is carried out). This is necessary so that the entire structure has one strength.

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Sand preparation for the mixture

The second very important and crucial stage is the preparation of all other components. First of all, it is sand. To make cement of high quality, you need to use river sand. It must be cleaned and sufficiently dried. Otherwise, excess moisture can change the water-cement ratio. You need to take the choice of sand for facing masonry very seriously. Such sand should not contain clay particles. The thing is that during the operation of the structure, the clay will leave the solution. All this will eventually lead to the formation of defects: cracks, holes, voids.

The quality of sand can be determined with the naked eye. River sand has a somewhat grayish color, while clay gives the sand a yellow tint. Uncleaned sand can also be used in construction, but not for facing masonry. It is suitable for backfill masonry. The amount of sand available should match the scope of work. It is desirable that immediately before use, the sand can lie down for several days. It must be protected from moisture and stored in a dry place.

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Solution water preparation

Before you make cement, you need to stock up on water. Only pure water is used. Most often, groundwater is used. Salt water is not recommended. For greater convenience, you can extend the hose for the water supply. How much water is needed? The volume of water depends on the brand of the required solution and the quality of the cement. The volume of water in the preparation of the mixture is approximately equal to the volume of cement powder. If a bucket of powder is taken, then the same amount of water is required. Much attention is paid to the quality of the sand.

If it is wet and contains a lot of water, then its amount should be reduced. The solution should not be too liquid. Ideally, in consistency, it resembles sour cream. Great importance It also has the fact that water is poured into the concrete mixer first. This ensures optimum mixing. Water is best divided into 2 servings. First one is added, and at the very end the second (if the mixture is thick).

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Other components

Cement is not only made up of cement powder, water and sand. Often other ingredients are added to it. These are various detergents. What are they needed for? Any cement has such characteristics as plasticity and mobility. The simplest solution is to add liquid soap or any other soap to the mixture. detergent. The volume of detergent is 50-100 ml. It will give the solution good plasticity. It must be remembered that this component is added immediately after the water, that is, at the very beginning. Water and detergent must be thoroughly mixed to form a small foam.

If you overdo it with this component, the mixture will lose its strength, and the design will be short-lived. Today, there are special additives on the market that can improve the quality of cement. These include various plasticizers and water repellents.

If liquid cement will be used for brick joints, then it is advisable to use dyes. It must be remembered that with a higher brand of liquid cement, the solution is darker.

Additives also include an elasticizer. It is used to make mortar for tiles. good effect give superplasticizers. With their help, it is possible to reduce the amount of powdered cement used.

In the construction industry, latex and reinforcing additives are successfully used. The latter increase the strength of the cement. At low temperatures, it is recommended to add additives that increase the frost resistance of the solution.

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Mixing the main components

You can prepare liquid cement without the involvement of specialists. This is done manually or with a concrete mixer. A concrete mixer allows you to save energy, as well as get the most homogeneous mass. First of all, water is poured into the concrete mixer. It is not used all, part of it is left for last. Then detergent or other liquid additives are added to the water. In order for the solution to dissolve well and mix with water, you must wait about 3-5 minutes and only then add bulk components. Sand is placed first. It is required to add only 50% of the required volume of sand.

At the next stage of work, all the cement powder is laid. After this, the mixture must be very thoroughly mixed and only then add the rest of the sand. To get high-quality liquid cement, you will need to very accurately calculate the ratio of the main components. If it is planned to prepare a mortar of brand 100 in the presence of cement powder of brand 500, then the ratio of cement to sand should be 1:5. This means that for 1 bucket of cement powder, 5 buckets of sand will be needed. If the grade of cement powder is 400, then the ratio will be 1:4. To prepare a mixture of brand 200, the ratio will be 1: 2 (in the presence of cement 400). Water must be added until a mixture of the desired consistency is obtained.

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, wall plastering, electrical wiring and any other communications require the use of this material. Without cement, it is impossible to prepare concrete or mortar. And even a completely inexperienced person, following enough simple instructions, will be able to prepare cement mortar, high-quality concrete mortar various brands 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 mortar

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 seven parts of sand (1 / 3.5) for one batch. 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 to pre-calculate is to focus on 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. And the required density of the 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. 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 required solution is not too small, it is best to buy them in large five-liter plastic bottles they are cheaper than the smaller 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: preparing a good double-mix mortar in a concrete mixer (approximately eight buckets of ready-made sand-cement mixture) requires 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. In principle, it can 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 undesirable to use too clayey sand for critical concrete (for crossbars of lintels, 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 it is used for critical concretes 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 product of a particular plant.

Production of cement mortars at negative temperatures

Brickwork may well be built at low 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. 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 enough popular question found 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., as:

• 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 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 of dye added to its composition. The minimum value is about two percent of the total volume of the solution. In this case, you can get pastel soft colors. Four percent contributed will provide 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 of the total amount of the solution.

There is another method that cannot be attributed directly to the topic of the article, since it is not applied at the time of preparation of 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.