Cement is a binding powder that is used to make masonry and plaster mortars, as well as to create concrete structures(foundations, screeds). To properly mix the composition with sand and water, you need to accurately calculate their proportions. If you violate the cooking technology, it will turn out too skinny or greasy, it will crack or crumble.

Depends on the destination. For bricklaying and plaster, compositions with different ratios of sand and cement are required. Only clean water is used - drinking water, rain water, but in no case lake or sea water. If it is clogged, mold will appear on the masonry or plaster over time. Crushed stone, sawdust or slag can also be used as a filler.

To increase plasticity, special plasticizers are added or liquid soap. Their quantity should not exceed 5% -10% of the volume of cement. If it is more, the adhesive characteristics of the composition will decrease. To increase resistance to low temperatures or moisture, special additives are also introduced (according to the instructions specified by their manufacturer).

It is necessary to prepare all tools and components, since the mixtures begin to set after 45 minutes if additives or fast-hardening Portland cement were not used. If you pour water into the solution after it has hardened, all of it specifications will get much worse.

Cement powder and sand are sifted through a sieve to remove debris and lumps. If the sand is damp, it is better to dry it in advance. If dirty, rinse and leave until completely dry. Otherwise, due to excess moisture, it will disrupt the water-cement ratio, and the composition will turn out liquid.

The main rule that must always be observed when kneading is homogeneity. All components must be thoroughly mixed. The presence of lumps will reduce the characteristics, including strength.

The solution can be diluted in any container. The main thing is that there is more than the amount of mixture being prepared, then during mixing it will not splash out. For this purpose, you can use a bathtub, basin or bucket. For mixing, use a shovel, trowel, drill with a special mixer attachment or concrete mixer.

The mixing sequence depends on the preparation method - manually or using a concrete mixer. If they dilute using the first method, then the measured proportions of the components are poured one at a time, first sand, then cement and water. If a concrete mixer is used, then water is poured in, and then the remaining elements are added.

Mixing time is 5 minutes. It is necessary to ensure that the mixture is homogeneous, without lumps. Density depends on the purpose of use. If you plan to use additives, then they are diluted in advance (if allowed by their manufacturer).

Component proportions

The ratio of sand, cement and water depends on the purpose of use. The following species may be involved:

1. For plaster. The preparation proportion is as follows: 1 part cement, 3 parts sand. The same amount of water is added as powder. If the solution will be used indoors, then the minimum grade of binder is M150-M200. For facade works M300 is used. To make the mixture more plastic and to be able to apply it in a thin layer, add lime, but not more than half the volume of sand.

2. For laying bricks. Proportion of components: 1 part powder, 4 parts sand. Water is taken half of the volume of binder, grade - M300-M400. Additionally, you can add lime (slaked) - 30% of the amount of powder, as well as 50 g of liquid soap to make the composition more plastic. The sequence of preparation is to pour in water, then cement without mixing with sand, then the rest of the fillers. The mixture is considered correctly mixed if it does not flow off a plane inclined at an angle of 40°.

3. For foundations. The components must be diluted in the following ratio: 1 part cement, 2 hours sand and 4 hours crushed stone or other coarse filler. Take half of the water from the binder M500, the minimum grade is M400. It is best to dilute such a composition in a concrete mixer, since it will be difficult to manually achieve a homogeneous and uniform consistency, especially if the volumes are large.

4. Concrete screed. In this case, only high grades are used - from M400, the proportion is 1 to 3. Half of the volume of binder is taken of water.

5. Ironing. The ratio of sand and cement is the same. Lime is added in a volume of 10% of the amount of binder.

The grade of cement should be 2 or 3 times greater than the grade of mortar. If it is necessary to mix the M300 composition, then M150-M200 powder is used, but no less. For bricklaying you will need M50-M100, plaster - M50-M100, concrete screed– M100-M200, foundation – M200-M300.

You should not take cement that has been stored for a long time in open form. Even packaged powder loses some of its strength after 2 months from the date of manufacture. Old cement can be used only for those jobs where it will not be subjected to loads or be in aggressive conditions. In order to increase the grade of the solution in this case, it is necessary to increase the proportion of the powder.

When mixing the mixture, it is not recommended to pour in the entire volume of water at once, but only a large part of it, approximately 85%, then add the rest. To properly pour in liquid soap without forming foam, dilute it in advance and let it sit for several minutes, during which time the foam will disappear. Afterwards it is slowly poured in and stirred for another 5 minutes.

Cement-sand mortar should be diluted at a temperature not lower than +5°C. When mixed in a concrete mixer, it will turn out much better than when mixed manual way. The finished composition must be used immediately after production. To improve the thermal insulation characteristics, part of the sand can be replaced with perlite. If you need to mix a large volume, then it is better to first make a test batch and make sure that the ratio of components is correctly selected. To avoid mistakes in proportions, it is recommended to purchase a special dispenser.

Brick buildings are very durable and reliable. They can last for years. Why years! Over the centuries. But brick is not considered a cheap material.

After all, to create a small building you will need quite a lot of this building material. And still, brick houses will never go out of fashion and will not lose their appearance for a long time.

Preparing mortar for bricklaying is the topic of this article. Let's talk further.

For bricklaying façade walls Plasticizers are added to the solution. This solution is very economical and is applied to the surface in an even layer.

Ingredient ratio

To prepare the correct solution you need to calculate the amount of ingredients. For the solution, sand is taken of the middle fraction; the brand of solution can be different, but it is the sand fraction that affects the proportions. For example:

1. We use M-500 cement, the proportions will be as follows: 1 part cement to 2/10 lime, take 3 parts sand;
2. We use grade 400 cement, the proportions will be as follows: 1 part cement to 1-3/10 parts lime to 2.5-4 parts sand;
3. We use grade 300 cement, take 1 part to 2/10 lime to 3.5 sand.

All components of the solution must be mixed well.

This example is for a cement-limestone mixture and for a cement-sand mixture.

Solution proportions:

1. When using cement grade 500, take 1 part cement to 3 parts sand;
2. For cement grade 400, take 1 part cement to 2.5 parts sand.

Helpful information

Masonry methods

• For solid brick take a solution with a mobility of 9-13 cm,
• for hollow bricks take a mixture with a mobility of 7-8 cm,
• in hot weather, take a solution with a mobility of up to 12-14 cm.

Before starting work with bricks and masonry mortars, carefully study all the nuances, select the correct mortar, and prepare it correctly. It’s best to entrust the work to specialists in this field; they must do everything according to the rules. We wish you good luck in your endeavors!

Solutions with a known concentration, which are used to determine the concentration of other solutions, are called standard or working. These are some solutions of acids, alkalis, and salts.

Precision weighing method. It involves working with solutions that do not change their molecular weight and volume when interacting with air. Such substances include oxalic acid, soda, borax (Na 2 B 4 O 7 ·10H 2 O), potassium dichromate and a number of other substances. On an analytical balance (the error of such scales is 0.0002 g) the substance is accurately weighed and transferred to a volumetric flask for dissolution, adjusted to the mark with solvent (water) and mixed thoroughly.

Accurately weighed solutions can be prepared for only a few substances. These substances must meet the following requirements:

Pure substance

Permanent composition

Stability of a substance in air and in solution.

Such connections are called installation. These include: oxalic acid (H 2 C 2 O 4 2H 2 O), sodium tetraborate (borax) (Na 2 B 4 O 7 12H 2 O), potassium dichromate (K 2 Cr 2 O 7). For all other substances, solutions are prepared from inaccurate weighing or dilution.

Fixal method. Involves the preparation of solutions from fixanals. Fixanal is an ampoule with a dry substance or solution with a precisely known concentration. Fixanal is broken down and transferred to a flask for dissolution. This method is considered the most accurate.

Approximate weighing method. Involves working with solutions that change their mass in air, for example, potassium permanganate. It is impossible to work with such solutions, therefore, before using them as standard solutions, it is necessary to titrate them with another solution with a precisely known concentration.

Dilution method. From a solution of precisely known concentration, a solution of a different concentration is prepared by dilution. The concentration of the resulting solution depends on the concentration of the original one.

1.5. Solving problems for the preparation of solutions with a mass fraction (%) of concentration.

Task 1. How to prepare 500 g of a solution of C 6 H 12 O 6 with a mass fraction equal to 10%?

Given: Solution:

m (solution C 6 H 12 O 6) = 500 g

ωC 6 H 12 O 6 = 10% 1. Determine the mass of C 6 H 12 O 6 according to

Formula: m (in-va) =

Find: m (C 6 H 12 O 6) = ? m (C 6 H 12 O 6) =

2. Determine the mass of water according to the formula:

m (solution) = m (solution) + m (substance), m (H 2 O) = m (solution) – m (substance),

m (H 2 O) = 500 – 50 = 450 g.

According to the formula: , where ρ is the density of the solution, m is the mass of the solution, V is the volume of the solution. Define V (H 2 O) = .

Answer: To prepare 500 g of a glucose solution with a mass fraction of 10%, you need to weigh out 50 g of glucose on a scale, measure out 450 ml of water using any measuring flask, place this solution in any suitable container and mix.

Task 2. How to prepare 800 ml of NaCl solution with a mass fraction of 12% and a density of 1.1 g/ml?

Given: Solution:

V (solution) = 800 ml

ρ = 1.1 g/ml 1. Determine the mass of the NaCl solution according to

Formula: m (solution) = 800 ml · 1.1 g/ml = 880 g

Find: m (NaCl) = ? m (H 2 O) = ?

2. Determine the mass of NaCl according to the formula: m (in-va) =

3. Determine the mass of water according to the formula:

m (H 2 O) = m (solution) – m (in-va), m (H 2 O) = 880 – 105.6 = 774.4 g or 774.4 ml, because The density of water is 1 g/ml.

Answer: To prepare 800 ml of sodium chloride solution with a mass fraction equal to 12%, you need to weigh 105.6 g of NaCl on a scale, measure 774.4 ml of water using any measuring flask, place it all in any suitable container and mix.

Problem 3 Prepare 100 g of MgSO 4 solution with ω = 2% from MgSO 4 solution with ω = 10%?

Given: Solution:

ω 1 (MgSO 4) = 10%

m 2 (MgSO 4) solution = 100 g

ρ = 1.1 g/ml 1. Determine the mass of pure MgSO 4

Contained in 100 g of 2% MgSO 4 solution

Find: m 1 (MgSO 4) =? m (in-va) = ,

m (H 2 O) = ? m (MgSO 4) =

2. Determine the mass of the MgSO 4 solution (initial) with ω = 10% containing 2 g of pure MgSO 4, m 1 (MgSO 4) =

3. Determine the volume of the initial (first) solution of MgSO 4 with ω = 10%

V solution = , V solution (MgSO 4) =

4. Determine the mass of H 2 O that is necessary to dilute the original MgSO 4 solution.

m (H 2 O) = 100 – 20 = 80 g or for clean water 80 ml.

Answer: to prepare 100 g of MgSO 4 solution with a mass fraction equal to

2% from a solution of MgSO 4 with a mass fraction of 10% and ρ = 1.1 g/ml, it is necessary to measure 18.2 ml of 10% MgSO 4 solution from a burette, place them in a flask, add 80 ml of water there in a cylinder and mix .

Good day, dear readers!

Very often, during the construction of another house, people passing by are interested in what we add to the cement mortar. It looks like butter and makes you want to spread it on bread!

In this article you will learn:

How to easily, quickly and correctly prepare cement-sand mortar (for masonry).

Features and subtleties of preparing cement-sand mortar.

Features of preparing the solution for negative temperatures(in winter).

How to make a solution of the desired brand.

Where to apply the required brand of solution.

Additives for colored front seams.

How to choose the right materials to prepare a good solution.

1) How to determine the brand of solution?

Very simple: divide the brand of cement by the amount of sand.

Example 1. Making a solution of grade 100:

Cement grade 400, the ratio of cement and sand is one to four, that is, one bucket of cement to four buckets of sand, we solve:

400 (brand of cement) / 4 (buckets of sand) = 100 (brand of ready-made solution).

Example 2. Making a solution of grade 100:

Cement grade 500, the ratio of cement and sand is one to five, that is, one bucket of cement to five buckets of sand, we solve:

500 (brand of cement) / 5 (buckets of sand) = 100 (brand of ready-made solution).

Add 50–100 grams of detergent to the solution (depending on the quality of the detergent) to make the solution more elastic.

Example 3. Making a solution of grade 200:

Cement grade 400, the ratio of cement and sand is one to two, that is, one bucket of cement to two buckets of sand, we solve:

400 (brand of cement) / 2 (buckets of sand) = 200 (brand of ready-made solution).

Add 50–100 grams of detergent to the solution (depending on the quality of the detergent) to make the solution more elastic.

2) Where and what brand of solution should be used.

Theoretically, the brand of mortar should be the same as the brand of material used (brick blocks, etc.).

For example, if we are building brickwork from grade 100 brick, then ideally the mortar should also be grade 100. Then we get a solid (almost homogeneous) brick structure.

But don’t go too far, if you use face brick of grade 350 to build a house, then the mortar does not need to be made of grade 350 either.

Typically, when constructing face brickwork, we use approximately 115 grade mortar. For one batch we put two buckets of cement and seven buckets of sand (one to three and a half). After three weeks, it is difficult to hammer a nail into the seam of such a solution. Not a bad solution at all.

If you mix it one to three, the solution sets faster and it’s a little hard to work with.

If you mix one to four, the seams of the facing brick may crumble.

For the construction of blocks (shell rock, cinder block, etc.), we usually use mortar grade 100.

If, for example, we build partitions from backfill bricks of grade 75, then the mortar can also be made of grade 75 (one bucket of cement, 5.3 buckets of sand).

3) Preparation cement mortar for masonry.

You can prepare the solution different ways. The fastest, highest quality and optimal method of preparing the solution will be described below.

a) Water.

If we are making not a dry mixture, but an ordinary classic solution, then first of all you need to pour water into the mixer. How much water should be poured into the mixer?

If you know the exact formula required quantity water for mixing, the first rain will make it impossible to use it. If the sand is wet, then less water needs to be poured.

The easiest way to navigate is by the amount of cement. If, for example, one bucket of cement is needed for one batch, then about one bucket of water will also be needed. So as not to overdo it with water for the solution (so that it is not liquid). It is best to fill it a little less than normal.

If you fill in little water for the future solution, then you will constantly be adding water, then adding sand and cement. This significantly lengthens the process of preparing the solution.

When you pour a little less water into the mixer than normal, the sand and cement mix in a liquid state much faster than in a thick state.

When you add the last ingredients (sand, cement) to the mixer, you add the rest of the required amount of water by eye.

Summary: in order for cement and sand to be mixed quickly and efficiently, they must be in a liquid state. We adjust the density of the solution at the end of the batch.

If you accidentally poured water into the solution (it turned out to be liquid), then it’s okay, just add a little cement and sand in the same proportion as required for this brand of solution (1:3; 1:4, etc.).

b) Detergent.

Today we add to the solution: dishwashing detergent or liquid soap. We usually buy dishwashing detergent from BIK in five-liter bottles. plastic bottles(to save money).

For cooking cement-sand mortar, we add approximately 50 - 100 grams of detergent to the mixer. Exact amount Determining detergent is problematic and depends on various factors.

Detergent must be added after water so that it dissolves well and foams. Typically, the detergent dissolves and foams in a running mixer in about 3–5 minutes.

If you add detergent at the end of the batch, it will not dissolve well and the solution will not be elastic.

c) Sand.

After the detergent has dissolved well, add sand, but... It is necessary to add not all the sand at once, but half for this batch. If, for example, the batch is 1:4 (grade 100), then add half the sand - two buckets.

d) Cement.

Add all the cement to the mixer. Immediately pour out the entire amount of cement for one batch. We wait 1-2 minutes until the cement is completely mixed with sand and water.

d) Sand.

After the cement is completely mixed in the mixer with all the ingredients, add the remaining sand to the mixer.

If necessary, add a little bit of the missing part of the water. At the very end, we adjust the thickness of the solution.

We wait until the solution is completely mixed for another 3 - 5 minutes.

Total: The solution should be neither too liquid nor too thick. The consistency is similar to store-bought sour cream. The solution should keep its shape; if you write something on it, the letters should not spread too much:

Summary:

To prepare a good solution for double mixing (for 8 buckets of ready-made solution) you need only 12-17 minutes.

4) Materials for preparing a good solution.

a) The water is clean.

Theoretically cannot be used dirty water to prepare a solution such as:

Rain.

Water with oils (or an oil water barrel).

But these are too strict rules that apply to critical buildings and structures ( Atom stations, bridges and the like).

For civil construction (dachas, residential buildings) the water requirements are not so strict. We usually use water to prepare the solution: from wells, tap water, sometimes from lakes and rivers.

b) Detergent.

For a good and flexible solution, it is very important to add detergent so that the solution does not shrink. You can use various detergents(except for cleaning ones).

Previously, we added for the elasticity of the solution, the cheapest washing powder, boiled laundry soap, white clay and even shampoo.

Recently, the manufacturers of “Fagot” bricks have put forward demands to build bassoon bricks only with hard mortar (without detergent). Allegedly, the detergent is causing their brick to burst. As practice has shown, bassoon bricks burst with both hard mortar and detergent.

Note: If you pour a lot of detergent into the batch, then cement mortar will lose strength. Too much a large number of detergent in the solution makes it airy (many air bubbles in the solution) and foamy. It looks like cotton wool.

Therefore, in order for the solution to be strong, detergent must be added to the solution without fanaticism.

c) Sand.

For facing masonry, it is very important that the sand is clay-free and of normal quality.

Eg: built two-storey house and sand for facing masonry was with clay. The customer decided to save money and imported sand at a cheaper price (with clay). Only two years have passed and all the seams of the facing masonry have become full of holes.

This happened because of the clay. Where the clay in the solution came out onto the front seam, it was washed away by the rain and holes formed.

Visually easy to identify good sand(without clay) or not. The photo below shows that the sand is too yellow (not washed), there is a lot of clay in it - this is quarry sand:

It is better not to use such sand for facing masonry. This sand will be used for backfill (dirty masonry) and bedding.

For (reinforced concrete belts, lintel crossbars, etc.) it is also not advisable to use sand that is too clayey.

The photo below shows good alluvial sand, containing almost no clay:

This sand is also mined in a quarry, but due to the fact that it is washed, it does not contain (or very little) clay and stones! We use alluvial sand for facing masonry (if good regular quarry sand is not available) and for critical concrete.

d) Cement.

To make a normal solution, you also need to pay attention to. If the cement is weak, then it needs to be added more per batch.

We usually use to prepare the solution:

Balakleyevsky cement grade 400 marked ShPTs ӏӏӏ/B-Sh-400.

Balakleyevsky cement grade 400 marked PTs ӏӏ/B-Sh-400.

Amvrosievsky cement grade 400 marked PTs ӏӏ/B-Sh-400.

We try not to use Kiev cement grade 400 marked PTs ӏӏ/B-Sh-400 to prepare the solution, because it is weaker. If you have to make a solution from Kyiv cement, then we throw almost twice as much of it into the mixer, and this is an almost double cost overrun.

e) Additives for colored seams.

Sometimes we make a dark or black color for the front seam. The dark seam looks more contrasting and prettier. To make the seam darker, we add soot or graphite.

But unfortunately, after 10 years, the colored seam is washed out by rain and fades from the scorching rays of the sun.

Another drawback from color additives (graphite and soot) is that the grade of the solution is reduced. If too much graphite or soot is added to the solution, the solution becomes brittle and weak.

It is better to use more durable dyes for colored seams.

To make the front seam darker, the easiest way is to make a higher grade of solution, one to three. More cement means darker joint. It is also better to choose darker cement. For example, Balakleyevsky cement grade 400 with the marking ШПЦ ӏӏӏ/B-Sh-400 is one of the darkest cements.

5) Application and preparation of the solution at subzero temperatures.

As you know, brickwork is built at minus 10 degrees and below.

Facial masonry:

During construction brick walls at minus 5 degrees we do not add any additives. If you build brickwork without additives at a lower temperature, there may not be much crumbling on the face seam, especially if the seam is grouted with a semicircular joint.

With more low temperatures Potash has proven itself very well. It is not expensive, the cost of 50 kg is about 14 hryvnia.

Backfill masonry (rough):

If we build backfill masonry at minus 10 degrees, then we do not add any special chemical additives. The strength of the solution at sub-zero temperatures (without chemical additives) is not particularly reduced.

At lower temperatures, add potash.

Preparation of the solution at negative temperatures.

Sand:

The main problem for preparing a solution in winter is frozen sand. It is best to prepare sand in advance. You can bring sand into a house under construction (with a roof and heating).

At large construction sites (in the north), the sand is specially heated.

Water:

It is best to pour hot or heated water into the mixer, then the solution will take longer to cool. IN warm water The detergent dissolves better and the solution is more elastic.

Anti-freeze:

Various means were used to prevent the solution from freezing (liquid and solid additives).

For example, some anti-freeze additives themselves froze in the cold - it’s funny that the anti-freeze additive froze itself! To check which liquid anti-freeze is good and which is not, we simply poured two types of anti-freeze into plastic disposable cups and put them in the cold.

It is best to use potash. How much potash should be added to the solution? Everything is described in detail on the potash packaging.

Conclusion:

Today in this article you learned a lot useful information about the intricacies of preparing cement-sand mortar. What mistakes can be avoided when preparing a solution, how to quickly prepare it, how to calculate the brand of solution and much more.

If you liked this article, please leave a comment! What else could you add to this article?

Solutions with chemical additives.

These solutions are used when building structures need to be completely waterproof. Solutions are prepared on the basis of a dry cement mixture with a composition from 1: 1 to 1:3 (by volume). The mixture should be well mixed.

Solutions based on ceresite

Dry cement mixture seal with ceresite milk. Solutions are consumed no later than 60 minutes. after the retreat.

When applying a layer of primer or covering a layer of plaster made from ceresite mortar, it does not stick well to the previously applied layer, slides off it and does not set for a long time. Therefore, the solution should be applied in thin layers. As a last resort, you can apply a solution on ceresite to damp surfaces, but only when water does not flow over them, otherwise the fresh solution is easily washed away.

The consumption of ceresite per 1 m2 of plastered surface with a waterproofing layer thickness of 2 cm is 0.5 kg, with a thickness of 3 cm - 0.75 kg and with a thickness of 4 cm - 1 kg.

Soluble glass solutions

These solutions set in 2-5 minutes. after the retreat. Therefore, they should be prepared in small quantities (no more than 1-2 liters). The speed at which the solution sets depends on the amount of glass added.

Due to the fact that soluble glass is destroyed by carbon dioxide contained in the air, the spray and primer are applied from solutions with soluble glass, and the covering is applied from ordinary cement mortar prepared with water.

Plastering is done in the usual way: first, a layer of spray is applied, a layer of primer is applied on it, and then a covering is applied, then it is rubbed or ironed, the latter is most effective.

Before starting work, surfaces are carefully prepared.

Higher quality plaster compacts well and becomes completely waterproof.

Solutions with sodium aluminate

Sodium aluminate is added to solutions to make them waterproof. Such solutions are used for sealing various holes in concrete, as well as for plastering on damp, non-drying surfaces made of concrete and brick. Solutions are applied manually and using machines.

Sodium aluminate is delivered to construction in the form of a solution with a specific gravity of 1.44, which is diluted with water (1 part sodium aluminate 10 parts water), obtaining a 3% solution.

To obtain a solution of sodium aluminate of 2.3 and 5% strength, you need to dilute 1 part of sodium aluminate in 15, 10 or 6 parts of water.

To obtain a waterproof mortar, first prepare a dry cement mixture of composition 1:3 by weight (cement, 96), then the mixture is sealed with 2, 3 and 5% sodium aluminate solution.

When performing work, the air temperature in the room should not be lower than +5° C. The water and solution are heated to a temperature of 104-30° C.

The solution begins to set within 10-30 minutes, which depends on the air temperature and the composition of the solution. Therefore, the solution should be prepared in such a quantity that it can be used before setting begins. For greater homogeneity, the solutions must be mixed for at least 5 minutes.

Plastered surfaces should be watered for three days.

When working with solutions prepared with sodium aluminate, workers must wear goggles, rubber boots, gloves and an apron, as these solutions are dangerous to the eyes and skin.

To provide first aid in places, it is necessary to have neutralizing compounds, for example, a 1% solution of acetic acid or a 0.5% solution of bicarbonate of soda. Catalyst solutions should be stored in clean, hermetically sealed glass containers.

Special solutions

A non-heat-conducting, lightweight, quick-drying solution is prepared from 1 part cement, 1 part limestone, 2 parts sand and 5 parts forming agent. They are used for insulation of boilers and hot pipelines

To prepare the solution, cement, sand and asbozurite are mixed, and the resulting dry mixture is mixed with lime milk.

Reinforced mortars are used mainly for plastering mesh surfaces. The use of these solutions makes it possible to quickly close the mesh openings and obtain a thin crust, onto which the solution can then be applied in any way.

Cement and mixed solutions are used.

Cement mortars are prepared from 1 part cement, 3 parts sand, 0.5-1 parts fibrous substances and water.

Mixed solutions are prepared from 1 part cement, 3 parts sand, 0.1-0.25 parts lime paste, 0.5-1 part fibrous substances and water. Fibrous substances can be: knop (wool waste from weaving factories), tow (fine wool), finely plucked felt.

The solution is prepared in the following sequence. First, cement is mixed with sand, and fiber additives are added and everything is thoroughly mixed. Or they prepare lime milk, add fibrous additives to it, pour the milk with fibrous additives into the cement mixture and mix everything thoroughly until a homogeneous dough-like mass is obtained.

Different solutions. Durable, lightweight, waterproof mortars, suitable for plastering damp rooms, are prepared from 1 part cement, 0.5 parts lime paste, 3-4 parts sand and 1 part low-grade asbestos.

Lightweight, non-heat-conducting and non-cracking mortars when dried are prepared from 1 part cement, 3 parts sawdust impregnated with lime milk, or from 1 part cement, 1 part sand and 3 parts of the same sawdust (slag sand can be used instead of regular sand).

What should the sand be like? clay mortar?

To prepare the clay solution, it is advisable to use fine mountain sand, cleared of vegetation and gravel. It must be sifted through a sieve with 1.5X1.5 mm cells. This will allow you to get a thin seam in brickwork. The amount of sand depends on the quality of the clay.

How to check the quality of clay?

Since ancient times, master stove makers determined the quality of clay by rubbing it between their fingers. But for this you need to have a lot of experience and practice.

We offer you three ways to check the quality of clay.

First way

You need to add water to a bucket of clay (10 l) and mix everything until creamy using a long planked board. If the solution is of low plasticity and requires rich clay, it will cover the board with a thin layer (1 mm).

The very plastic solution will cover the board with a thick layer of clay. Sand needs to be added. It is introduced in small portions, adding a liter jar per bucket until the solution reaches normal plasticity.

Clay has normal plasticity if the adhering layer of clay on the board has reached 2 mm and adheres to it in separate clumps.

Second way

This method is used for clay of medium fat content. Liter jar measure out five portions of clay, cleared of large particles. Leave the first portion, add one tenth of the jar to the second

PREPARATION OF CLAY MORTAR

Clay mortar binds the brickwork. It should not crack or crumble.

What determines the quality of the furnace masonry?

The quality of the furnace masonry depends on the correct preparation of the clay mortar, the thickness of the seams, the dressing of the brick and its quality.

What should be the mortar for laying stoves?

For laying stoves, a clay mortar of medium or normal plasticity is required. It is this solution that gives low shrinkage, does not crack when drying, firmly binds the brickwork and does not collapse at temperatures up to 1000 ° C.

A thick or very plastic mortar is spread over the brick without breaks and in a thin layer, but it shrinks greatly during firing and sticks to your hands during the laying process. It is not used for furnace work.

Low-plasticity, or thin mortar, on the contrary, does not shrink during firing, but it easily crumbles from the seams, which means it makes the brickwork unreliable.

What to prepare clay solution from?

To prepare clay mortar, you need to use raw brick. It will ensure the optimal content of clay and sand in the clay solution. This will promote good brickwork during kiln work.

Skinny clay hardly stretches, produces uneven breaks and many large cracks.

How is clay mortar prepared?

First, clay and sand are measured in proportion. The materials are then sifted through a sieve.

To sow the clay, you need to soak it in a box of water, mix well until the consistency of liquid sour cream and strain through a sieve with 1.5X1.5 mm cells. Having added the required amount of sand, the solution is mixed and filtered through a sieve with 3x3 mm cells. If the clay solution is made well, then it is homogeneous to the touch, there are no individual sand or clay clots in it. The mixture slides off the shovel well without spreading on it.

You can adjust the thickness of the solution with water right at your workplace. The solution should be creamy and of medium thickness. It can be used to produce thin joints (3-5 mm) in brickwork.

How to increase the strength of clay mortar?

To increase the strength of the clay mortar, table salt (100-250 g per bucket of mortar) or cement (3/4 l) is added to it. Salt is simply dissolved in water, and cement is mixed with water; until thick sour cream, and then mixed with the solution.

How much solution is needed for stove masonry?

Stove masonry requires a fairly large amount of mortar. It is known that for 100 bricks of sand, the third - one quarter, the fourth - three quarters, the fifth - a full jar.

For oily clay, sand is added in different proportions: leave the first portion, half a jar of sand is added to the second, a full jar to the third, one and a half jars to the fourth, two jars to the fifth.

Water is added to the mixture of sand and clay until a solution is obtained that can be kneaded well with your fingers and does not stick to your hands. Now you need to roll five balls with a diameter of 5 mm from each portion. Then, from two balls of each portion, cakes 2-3 cm thick are made and dried together with the balls in a draft-free room on the floor for 8-12 days.

If the dried balls and cakes do not crack and, falling from a meter height, do not scatter on the floor, then the solution is suitable for masonry. Small cracks along the edges of the cakes are allowed.

It is easy to determine the fatty and lean solution by the dried cakes. The cakes made from a fatty solution crack at the edges, while the balls made from a thin solution do not form cracks, but they crumble when they fall.

There is another way to check the solution in the balls. They are placed between planed boards and pressed on the top of them. The thin clay balls crumble into pieces almost immediately after pressing. On balls of normal clay, thin cracks form when compressed by a third of the diameter. In oily clay, cracks appear when they are compressed by half their diameter.

You can check the clay solution using ropes 1-1.5 cm thick and 15-20 cm long. They are rolled out of clay and tested for stretching around a round wooden form diameter 5 cm.

Fat clay ensures smooth and gradual stretching of the rope, which does not form cracks.

Normal clay promotes smooth pulling of strands, which break off at a thickness of 15-20% of the initial diameter of the strand. And small cracks appear on it when laying it flat and the thickness of the seams is 5 mm, 20 liters of mortar are consumed. For Russian stoves, solution consumption increases by 15-20%.

It should be taken into account that only a plastic solution of the required thickness fills all the unevenness of the brick and ensures strong adhesion. The seams between the bricks become tight and gas-tight. Only by strictly following the technology for making clay mortar can you achieve good quality stove masonry.