Approximate solutions. When preparing approximate solutions, the amounts of substances that must be taken for this purpose are calculated with little accuracy. To simplify calculations, the atomic weights of elements can sometimes be taken rounded to whole units. So, for a rough calculation, the atomic weight of iron can be taken equal to 56 instead of the exact -55.847; for sulfur - 32 instead of the exact 32.064, etc.
Substances for preparing approximate solutions are weighed on technochemical or technical balances.
In principle, the calculations when preparing solutions are exactly the same for all substances.
The amount of the prepared solution is expressed either in units of mass (g, kg) or in units of volume (ml, l), and for each of these cases the amount of solute is calculated differently.
Example. Let it be required to prepare 1.5 kg of 15% sodium chloride solution; We first calculate the required amount of salt. The calculation is carried out according to the proportion:
i.e. if 100 g of solution contains 15 g of salt (15%), then how much of it will be required to prepare 1500 g of solution?
The calculation shows that you need to weigh out 225 g of salt, then take 1500 - 225 = 1275 g of iuzhio water.
If you are asked to obtain 1.5 liters of the same solution, then in this case you will find out its density from the reference book, multiply the latter by the given volume and thus find the mass of the required amount of solution. Thus, the density of a 15% noro sodium chloride solution at 15 0C is 1.184 g/cm3. Therefore, 1500 ml is
Therefore, the amount of substance for preparing 1.5 kg and 1.5 liters of solution is different.
The calculation given above is applicable only for the preparation of solutions of anhydrous substances. If an aqueous salt is taken, for example Na2SO4-IOH2O1, then the calculation is slightly modified, since the water of crystallization must also be taken into account.
Example. Let you need to prepare 2 kg of 10% Na2SO4 solution based on Na2SO4 * 10H2O.
The molecular weight of Na2SO4 is 142.041, and Na2SO4*10H2O is 322.195, or rounded to 322.20.
The calculation is carried out first using anhydrous salt:
Therefore, you need to take 200 g of anhydrous salt. The amount of salt decahydrate is calculated from the calculation:
In this case, you need to take water: 2000 - 453.7 = 1546.3 g.
Since the solution is not always prepared in terms of anhydrous salt, the label, which must be stuck on the container with the solution, must indicate what salt the solution is prepared from, for example, a 10% solution of Na2SO4 or 25% Na2SO4 * 10H2O.
It often happens that a previously prepared solution needs to be diluted, i.e., its concentration must be reduced; solutions are diluted either by volume or by weight.
Example. It is necessary to dilute a 20% solution of ammonium sulfate so as to obtain 2 liters of a 5% solution. We carry out the calculation in the following way. From the reference book we find out that the density of a 5% solution of (NH4)2SO4 is 1.0287 g/cm3. Therefore, 2 liters of it should weigh 1.0287 * 2000 = 2057.4 g. This amount should contain ammonium sulfate:
Considering that losses may occur during measuring, you need to take 462 ml and bring them to 2 liters, i.e. add 2000-462 = 1538 ml of water to them.
If the dilution is carried out by mass, the calculation is simplified. But in general, dilution is carried out based on volume, since liquids, especially in large quantities, are easier to measure by volume than to weigh.
It must be remembered that in any work with both dissolution and dilution, you should never pour all the water into the vessel at once. The container in which the required substance was weighed or measured is rinsed several times with water, and each time this water is added to the solution vessel.
When special precision is not required, when diluting solutions or mixing them to obtain solutions of different concentrations, you can use the following simple and quick method.
Let's take the already discussed case of diluting a 20% solution of ammonium sulfate to 5%. First we write like this:
where 20 is the concentration of the solution taken, 0 is water and 5" is the required concentration. Now subtract 5 from 20 and write the resulting value in the lower right corner, subtracting zero from 5, write the number in the upper right corner. Then the diagram will look like this :
This means that you need to take 5 volumes of a 20% solution and 15 volumes of water. Of course, such a calculation is not very accurate.
If you mix two solutions of the same substance, the scheme remains the same, only the numerical values change. Suppose that by mixing a 35% solution and a 15% solution, you need to prepare a 25% solution. Then the diagram will look like this:
i.e. you need to take 10 volumes of both solutions. This scheme gives approximate results and can be used only when special accuracy is not required. It is very important for every chemist to cultivate the habit of accuracy in calculations when necessary, and to use approximate figures in cases where this will not affect the results work. When greater accuracy is needed when diluting solutions, the calculation is carried out using formulas.
Let's look at a few of the most important cases.
Preparation of a diluted solution. Let c be the amount of solution, m% the concentration of the solution that needs to be diluted to a concentration of p%. The resulting amount of diluted solution x is calculated using the formula:
and the volume of water v for diluting the solution is calculated by the formula:
Mixing two solutions of the same substance of different concentrations to obtain a solution of a given concentration. Let by mixing a parts of an m% solution with x parts of a p% solution you need to obtain a /% solution, then:
Precise solutions. When preparing accurate solutions, the calculation of the quantities of the required substances will be checked with a sufficient degree of accuracy. Atomic weights of elements are taken from the table, which shows their exact values. When adding (or subtracting), use the exact value of the term with the least number of decimal places. The remaining terms are rounded, leaving one more decimal place after the decimal point than in the term with the smallest number of decimal places. As a result, as many digits after the decimal point are left as there are in the term with the smallest number of decimal places; in this case, the necessary rounding is performed. All calculations are made using logarithms, five-digit or four-digit. The calculated quantities of the substance are weighed only on an analytical balance.
Weighing is carried out either on a watch glass or in a weighing bottle. The weighed substance is poured into a clean, washed volumetric flask in small portions through a clean, dry funnel. Then, from the washing machine, the glass or watch glass in which the weighing was carried out is washed several times with small portions of water over the funnel. The funnel is also washed several times from the washing machine with distilled water.
To pour solid crystals or powders into a volumetric flask, it is very convenient to use the funnel shown in Fig. 349. Such funnels are made with a capacity of 3, 6, and 10 cm3. You can weigh the sample directly in these funnels (non-hygroscopic materials), having previously determined their mass. The sample from the funnel is very easily transferred into a volumetric flask. When the sample is poured, the funnel, without removing it from the neck of the flask, is washed well with distilled water from the rinse.
As a rule, when preparing accurate solutions and transferring the solute into a volumetric flask, the solvent (for example, water) should occupy no more than half the capacity of the flask. Stopper the volumetric flask and shake it until the solid is completely dissolved. After this, the resulting solution is added to the mark with water and mixed thoroughly.
Molar solutions. To prepare 1 liter of a 1 M solution of a substance, 1 mole of it is weighed out on an analytical balance and dissolved as indicated above.
Example. To prepare 1 liter of 1 M solution of silver nitrate, find the molecular weight of AgNO3 in the table or calculate it, it is equal to 169.875. The salt is weighed out and dissolved in water.
If you need to prepare a more dilute solution (0.1 or 0.01 M), weigh out 0.1 or 0.01 mol of salt, respectively.
If you need to prepare less than 1 liter of solution, then dissolve a correspondingly smaller amount of salt in the corresponding volume of water.
Normal solutions are prepared in the same way, only by weighing out not 1 mole, but 1 gram equivalent of the solid.
If you need to prepare a half-normal or decinormal solution, take 0.5 or 0.1 gram equivalent, respectively. When preparing not 1 liter of solution, but less, for example 100 or 250 ml, then take 1/10 or 1/4 of the amount of substance required to prepare 1 liter and dissolve it in the appropriate volume of water.
Fig. 349. Funnels for pouring the sample into the flask.
After preparing a solution, it must be checked by titration with a corresponding solution of another substance of known normality. The prepared solution may not correspond exactly to the normality that is specified. In such cases, an amendment is sometimes introduced.
In production laboratories, exact solutions are sometimes prepared “according to the substance being determined.” The use of such solutions facilitates calculations during analysis, since it is enough to multiply the volume of the solution used for titration by the titer of the solution in order to obtain the content of the desired substance (in g) in the quantity of any solution taken for analysis.
When preparing a titrated solution for the analyte, calculations are also carried out using the gram equivalent of the soluble substance, using the formula:
Example. Suppose you need to prepare 3 liters of potassium permanganate solution with an iron titer of 0.0050 g/ml. The gram equivalent of KMnO4 is 31.61, and the gram equivalent of Fe is 55.847.
We calculate using the above formula:
Standard solutions. Standard solutions are solutions with different, precisely defined concentrations used in colorimetry, for example, solutions containing 0.1, 0.01, 0.001 mg, etc. of dissolved substance in 1 ml.
In addition to colorimetric analysis, such solutions are needed when determining pH, for nephelometric determinations, etc. Sometimes standard solutions are stored in sealed ampoules, but more often they have to be prepared immediately before use. Standard solutions are prepared in a volume of no more than 1 liter, and more often - less. Only with a large consumption of the standard solution can you prepare several liters of it, and then only on the condition that the standard solution will not be stored for a long time.
The amount of substance (in g) required to obtain such solutions is calculated using the formula:
Example. It is necessary to prepare standard solutions of CuSO4 5H2O for the colorimetric determination of copper, and 1 ml of the first solution should contain 1 mg of copper, the second - 0.1 mg, the third - 0.01 mg, the fourth - 0.001 mg. First, prepare a sufficient amount of the first solution, for example 100 ml.
Comments:
Until now, not a single construction or repair can be completed without the use of cement. When deciding how to prepare cement mortar, you must first take into account that the one used for brickwork, floor screed or finishing of walls and ceilings can differ significantly both in composition and in the method of preparation.
When making a concrete mixture, cement serves as a binder that ensures its hardening.
Main components of cement mortar
There are two types of mortar - cement and concrete. Despite the similarity in components (concrete, in addition to the three common components, crushed stone or gravel is additionally added) and the method of preparation, these are two completely different products designed to solve different construction problems.
Classic cement mortar consists of only three components mixed together in a certain proportion: cement, sand and water.
The cement must be dry and free of hard lumps. It is best to use river sand, although in practice they often take ordinary sand from a quarry, but first sift it to separate debris and impurities.
To mix the mixture, it is better to use clean water at room temperature or a little warmer - 21-23°C.
The optimal proportions are: 1 part cement to 3 parts sand. Water is added to the cement solution being prepared as needed, its amount can vary from 80 to 95% of the volume of cement used (i.e., 8 to 9.5 liters of water should be consumed per 10 liters of cement).
This solution can be used to both remove brickwork and perform plastering work. However, it has a number of disadvantages - excessive rigidity and limited time (1-1.5 hours) for using the prepared solution, which makes working with it significantly more difficult.
Therefore, professional builders prefer to add various substances to its composition when preparing cement mortar, making it more plastic and prolonging its hardening time by 2-3 times. The most common option for improving such a mixture is adding lime milk to its composition.
This mixture has almost the same astringent abilities as pure cement mortar, but its use time increases to 3-4 hours.
The second option is to prepare a cement solution with the addition of a small amount of detergent - at the rate of 50-100 g for every 10 liters of mixture (depending on the quality of the detergent).
This additive can significantly increase its plasticity.
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Brands of solution and their use
Like the vast majority of building materials, the prepared cement mortar also has its own marking. There are solutions M10, M25, M50, M75, M100, M125, M150, M200, M250, M300, but in private construction grades from M75 to M150 are usually used.
For example, a mixture of M100 can be obtained from cement M300, M400, M500, and in all cases the amount of cement used for its preparation will be the same. But the amount of sand changes: when using M300 cement, the ratio of sand and cement will be 3:1; when using M400 - 4:1; and when using M500 - 5:1.
When using cement mortar, professional builders advise using a composition of the same brand as the material used for construction. Those. If M75 concrete mortar is used to fill the foundation, then a cement mixture of the same brand must be used to screed the base. If M100 brick is used for forcing the walls, then the mixture for masonry must correspond to this brand.
But in practice this is not always possible. For example, when using M300 brick when laying out walls, there is no point in using a mortar of the same brand to lay it - it is difficult to work with such a mortar, and the financial costs for its production are very high. Brands in the range from M100 to M150 are quite suitable for use. In practice, such masonry is most often performed using a mixture of sand and cement M400 in a ratio of 3.5:1, i.e. approximately M115.
This additive can significantly increase its plasticity.
How to make cement mortar correctly
There are several ways to prepare a high-quality cement mixture. But, regardless of the chosen method, you will need the following tools to prepare it:
- container for mixing components;
- shovel;
- trowel;
- buckets.
The most common classical method of preparing the mixture is to first mix cement and sand dry until a homogeneous composition is obtained, and then this mixture is diluted to the desired consistency with water. Water should not be added all at once, but 80-85% of the required amount, and during the process of preparing the mixture, gradually add it to the composition, achieving the desired thickness.
This rule must be observed especially if it is not a pure cement-sand mixture that is being prepared, but a cement-lime mixture. In this case, you first need to prepare liquid lime by diluting the lime dough with water until it becomes a thin sour cream. Then the solution is prepared in the same way as in the first option, but instead of the missing water, lime milk is added to it at the final stage.
The second method was invented by folk craftsmen to prepare the solution manually. In fact, it is almost a mirror image of the first: first, water is poured into the container (approximately 4/5 of the required amount), then liquid soap or other detergent is added to it. After this, the water must be vigorously shaken for 4-5 minutes so that the detergent is completely dissolved in it and forms the maximum amount of foam.
Then half the required volume of sand and the entire volume of cement are poured into the container. After this, all components are mixed together. Particular care in mixing at this stage is not yet required, the main thing is that the resulting mixture is more or less homogeneous in composition. Then the missing sand is added to the mixture, and here negligence in mixing is unacceptable - you need to knead until the mixture becomes homogeneous. The presence of areas of clean sand without cement is unacceptable.
The main advantage of this method is that in a liquid state, sand and cement mix much faster and better than in a dry state. But in order to properly make a cement solution, at the end of preparation you need to gradually add the missing water, bringing the solution to the desired thickness.
This additive can significantly increase its plasticity.
Little tricks when preparing the solution
Despite the apparent simplicity of the process, even experienced builders are not always able to immediately prepare the cement mortar correctly. Therefore, the prepared solution is divided into 3 types:
- skinny;
- normal;
- fatty.
To determine the type of mixture prepared, no special tools are needed. It is enough to pull out the shovel used for mixing or (in the case of a concrete mixer) stir the finished mixture a little with a trowel. If the working surface of the tool remains almost clean, then the prepared mixture is thin, since it lacks a binder - cement. If the entire surface of the instrument is hidden under a layer of the prepared mixture, then the latter contains too much cement and is greasy.
Only a normal solution is suitable for work, in which the proportions of cement, sand and water are correctly maintained. If the solution turns out to be thin, then you need to add cement to it, and if it is greasy, add sand and water, bringing it to normal. You need to add the components little by little, otherwise it will cost nothing to turn a lean solution into a fatty one and vice versa.
Initially, you should always pour a little less water than normal.
The fact is that its amount depends on the absorbency of the sand - dry sand absorbs much more water than wet sand. Therefore, by pouring it according to the norm and adding slightly damp sand, you risk getting a liquid solution.
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 yet, 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 laying bricks on façade walls, plasticizers are added to the mortar. 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:
- We use M-500 cement, the proportions will be as follows: 1 part cement to 2/10 lime, take 3 parts sand;
- 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;
- 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:
- When using cement grade 500, take 1 part cement to 3 parts sand;
- For cement grade 400, take 1 part cement to 2.5 parts sand.
Helpful information
Masonry methods
- For solid bricks, take a mortar 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!
There are a different number of options to implement preparation of solutions. Let's consider the most reliable, optimal and fastest method.
Water for preparing the solution.
If you are preparing a classic solution in a concrete mixer, then first of all you need to pour water into it. Do not trust any formulas, because it is impossible to determine in advance how much water will be needed. For example, when using wet sand, much less water will be needed. The simplest method of oriented calculation is based on the amount of cement. For example, mixing one bucket of cement will require approximately the same amount of water. To prevent the solution from turning out liquid, add a little less water than normal. Online calculation of the composition of cement mortar.
In the meantime, if there is not enough liquid, then periodically you will have to add sand or cement, or add water. This will take a lot of time solution preparation process. If you add slightly less liquid than normal, then mixing sand with cement will take place many times faster than with a thick solution. After adding the last portions of sand and cement to the concrete mixer, the necessary remaining liquid is added by eye. For faster and better mixing of cement and sand, they must be in a liquid state. At the end of the kneading, the desired thickness of the solution is adjusted. If the solution turns out to be quite liquid, don’t worry, it’s all fixable. Just add a little sand and cement of the required grade (1:4, 1:3, etc.) in the same proportions.
Detergent in the preparation of the solution.
This is a very unusual but useful supplement. With its help, the solution becomes elastic and thereby improves the quality of the resulting solution. For these purposes, it is best to use dishwashing detergent or liquid soap. The quality and brand of detergent does not matter, what is important is that it foams. If you are planning a large amount of solution, then it is much more profitable to buy detergents in five-liter plastic bottles, because it is always cheaper in bulk.
Approximately 50-100 grams of detergent are added to the concrete mixer. It is impossible to calculate its specific amount, since this is influenced by various factors. This component is added after pouring water, then they react well with each other and foam well. Three to five minutes will be enough for the dissolution and foaming process to complete in a running concrete mixer. Do not add detergent at the end of the batch, otherwise it will not affect the solution.
After the detergent has dissolved well, you need to add sand. However, all the sand is not poured in at one time; only half of the amount required for the entire batch is required. For example, for preparing a solution of grade 100 And cement grade 400, when first added, only two of the four required parts are filled in.
Cement in the preparation of mortar.
After half the sand, cement is added to the concrete mixer - in full quantity for mixing. It mixes with sand and water after a couple of minutes.
Sand in the preparation of the solution.
The rest of the sand is added when all the ingredients placed in the concrete mixer are completely mixed. If required, the missing part of the sand is added and upon completion the density of the solution is adjusted. After this, the solution is finally mixed for three to five minutes.
In the end, the solution should be not very liquid and not very thick. The consistency should be very similar to store-bought sour cream. The shape of the solution should hold very well. To make sure of this, you can try to draw or write something on the surface of the solution. The written text should not blur.
Tip: for preparing a high-quality solution double kneading(about eight buckets of sand-cement mixture) will only take fifteen minutes.
Application and production of cement mortars at subzero temperatures.
At sub-zero temperatures, brickwork can be easily erected.
Facial masonry:
Down to minus five degrees, it is possible to produce facing brickwork without using any additives. At low temperatures, without adding such prepared additives, the solution may crumble, especially when the seam was embroidered with a semicircular joint. It is very good to use potash as such an additive, and it is not expensive.
Backfill masonry (rough):
If the temperature drops to minus ten degrees, then backfill masonry is erected. In this case, there is no need to add any special chemical additives, since the strength of the solution will not change. If the temperature drops even lower, then potash is used again.
You can protect mortar and cement from low temperatures in winter in the following ways:
1) Using a warm composition, masonry is produced by freezing;
2) Warm up the masonry artificially, using air heaters, air heating units and other heating devices;
3) You can build a temporary shelter, and also warm it up with heat guns or cover it with PVC insulation and film.
Tips for making cement mixture at subzero temperatures:
- Use hot water to make the solution. You can add high-quality antiphysis to the water;
- It is advisable to prepare sand in advance, storing it in a heated room;
- To avoid cracking of the solution, add potash.
During the construction process, rarely does anyone do without the use of cement mortar. Such material for construction work may be present in various finishing complexes. Cement is a substance that is not mined from natural resources - it is created by exposing the components to high temperatures, crushing them and adding impurities. The work of making cement itself is not high-tech. If you have certain skills, you can even make the mortar yourself, but first you need to find out how to make a cement mortar and what its proper preparation will involve.
What you need to know: composition and properties
Cement compositions for use in the construction process can not only be purchased, but also made yourself. To do this, you will need to mix ingredients, such as sand and cement, in the ratios required for your work.
It should be remembered that creating a cement-based mortar is a tedious task., and sometimes it is even impossible to complete it due to inexperience in evenly distributing the components.
A practical solution could be to use a concrete mixer, but it is not necessary to purchase one - you can simply rent the unit or borrow it from friends.
The most popular cement is the one that can be used in working with brickwork. Most often, cement and cement-lime type mortars are used for this purpose. The first option is used to construct load-bearing walls. As for the second, it is used to carry out work on laying walls inside, and only a small proportion of cement is added to its composition.
If the solution is to be used in winter, a special antifreeze additive will need to be added to its composition, which will prevent the consistency from freezing. However, despite this component, experts say that it is not recommended to make cement paste at a temperature of -20 degrees, since the components lose their qualities. If there is still a need for preparation, then it is important to obtain a solution that will have mobility and elasticity.
Experienced builders recommend adding shampoo to increase plasticity: half a liter of this ingredient is required per cubic meter of mass. Many people prefer to use salt as an anti-frost additive, but this should not be done, as there is a risk of efflorescence.
If the cement consistency is used as a base for creating monolithic hearths with an open source of fire, for a firebox or for constructing a stove, you need to use fire-resistant and heat-resistant solutions, which include a specific composition and clear proportions. So, to finish an open fire, you will need a grade of cement with an index of at least 400. Crushed stone is even added to the mixture, which includes red brick, in a ratio of 1 to 2. Next, two parts of finely ground fireclay sand are added to the composition. If the work concerns the firebox, then the composition will be identical, and the proportions will be as follows: 1: 2: 2: 0.33.
Tools and materials
Before you start mixing cement mortar, you need to familiarize yourself with some parameters that are fundamental in the process of creating a mixture at home. You need to dilute the consistency using components that are easy to obtain, so that later you don’t have to search around the city for the material that was once purchased only because it was exclusive. Due to the absence of one or another component, you can completely abandon the solution.
After all the materials have been prepared, you need to familiarize yourself with the technology for creating cement mortar. It is better not to give preference to complex recipes that a person who does not have a sufficient level of skill in construction cannot repeat.
The first thing to remember during production is that, even if budget materials and primitive creation technology are used, the cement should be reliable and strong.
For preparation you will need:
- plastic or metal containers (buckets, troughs);
- construction type mixer;
- fine sieve;
- water;
- wet sand;
- dry cement.
It should be noted that the list includes a sieve. It will be needed to carry out preliminary sifting of the ingredients, as a result of which the best quality of the batch can be obtained.
How to knead correctly: preparing the components
Before you start preparing the cement composition yourself, all the components need to be prepared. Preparation is an important stage that will be decisive in obtaining a high-quality composition, so you need to know what may be required from a specialist at this stage. Before mixing the ingredients, you need to prepare the container. Its volume must be suitable in terms of consumption indicators for work.
If the prepared container is less than the volume of the resulting consistency, then the material that was obtained during mixing will be poured onto the floor or ground. If the selected container, on the contrary, is larger than the required volume, there is a high probability that the master will not be able to obtain a uniform mass: it will form lumps, resulting in a sloppy appearance, and the resulting construction will be technically dangerous. In addition, the selected container must stand stably on its platform and have increased strength.
Before you start the work process, you must sift the powder from which the mixture will be prepared. In addition, you should also know that it is not recommended to prepare the solution in the fresh air: standard cement can absorb moisture from the environment, as a result of which it will lose its basic qualities. If possible, it is better to knead indoors.
Preparation of the solution
So, after all the materials and tools are prepared, You can start making the solution yourself.
- 1 layer of cement is poured into the container, then a layer of sand, after which all layers alternate. The number of such layers should be at least 6. This way, all components can be diluted more efficiently. Sand and cement should be poured in the form of a bed. The total height should be no more than 300 mm.
- The components poured into the container must be mixed several times with shovels until a homogeneous mass is obtained. Do not forget that the quality of the finished mixture and further work will depend on the mixing process. After everything is mixed correctly, experts recommend sifting the composition again through a sieve with 3x3 mm cells. The homogeneous mass must be absolute.
- After mixing the dry ingredients, you cannot immediately add water or other ingredients, for example, liquid glass. Adding liquid should be done gradually and carefully. Water must be added very slowly, this way you can control the process of acquiring the desired consistency. If the liquid supply is large, gradual addition will prevent the mass from becoming too liquid.
An equally important indicator for cooking is the temperature of the liquid: it should be neither low nor high. Try to use water whose temperature is close to the environment. Ambient temperature also plays an important role: ready-made cement mixtures must be diluted at an air temperature of at least +5 degrees.
As for the consistency of the cement mortar, everything will depend on the area in which it will be used. For example, for masonry you will need thick material, for pouring - liquid.
Try not to make a large amount of solution at once, especially if the composition contains wet sand. In any case, there will always be an opportunity to do the batch again.
For screed
The rules for preparing the solution depend on the purpose for which it will be used. For example, it is easier to prepare a mixture for a screed than for organizing a foundation. Crushed stone is not required here, and the proportions of the remaining components will be as follows: M400 grade cement and sand in a ratio of 1 to 3.
To properly prepare the consistency, follow the steps in the following order:
- lay a sheet of metal on the floor;
- pour 1/3 sand and 1/3 cement onto the surface, mix until smooth, repeat this action until the components run out;
- Make a pile from the resulting dry mixture and make a hole in it;
- Pour some water into this “container” and mix everything well.
The mixture is made as it is used, that is, after finishing one solution, prepare the next one.
For the foundation
As for preparing the mixture for the foundation, the process is more complicated, and the best solution would be to use a device such as a concrete mixer.
Begin the mixing process by adding water. The required amount is determined by a ratio of 1: 4. Experts recommend initially pouring less water, since it can be added at any time. When preparing the cement mixture for the foundation, it is very important to monitor the consistency. It is better if it is liquid, but water must be used carefully. If there is a need for thickness, this indicator can be achieved after the kneading process is completed.
For finishing
The cement mixture is also used for finishing premises. The need for it appears when it is necessary to carry out high-quality plastering of the surface.
The use of components that are contained in cement makes it possible to obtain the required consistency. Please note that this job requires more solution. If there is a need to sand a small area, you can use manual mixing, but in any case, a concrete mixer will make this process faster.
In order to understand whether the consistency in front of you is correct, apply it to the trowel: it should slide off smoothly when tilted.
Application
So, the first step was to prepare the tools and all the necessary working materials to make cement, the second step was to create a solution, and the third was to use the resulting consistency in the work. It is obvious to any builder that such a solution is a material that cannot be stored for a long time after work. This is due to the fact that it has high viscosity and hardens very quickly, which means that its further use will be impossible.