Today, not a single repair, and even more so, not a single construction site is complete without a high-quality mixture. The leading position here, as before, is held by cement mortars and mixtures based on cement. Working with this material requires caution, certain knowledge and the ability to make correct and accurate calculations. But let's talk about everything in order.

The main characteristics of cement mixtures

Today, even in such a matter as the preparation of a cement mixture, everything has been done in order to facilitate a person's work. There are a huge variety of ready-made cement mixtures on the market.

They are divided mainly according to the types of proposed work:

• Mixes universal. Designed for pouring and masonry work. Made from cement and quarry sand with a fraction of 1.5 - 2.3 mm.
• Sand concrete mixes. Designed for pouring work. They are made on the basis of sand fraction 3 mm.
• Plaster mixes. Designed specifically for plaster work. Produced on the basis of cement grade PC-400D0.
• Mixes for assembly and masonry works. Are intended for works with a brick and other materials. They are also produced on the basis of PC-400D0 cement.

Of course, all these mixtures can be prepared independently. As a rule, it costs less, but you will have to calculate the proportions yourself. Having bought the finished mixture in a hardware store, you just need to read the instructions and follow according to it.

The characteristics of dry mixes are determined by their additives. Additives are included in all ready-made cement mixtures. If the solution is prepared independently, then additives can be purchased separately.

There are a lot of supplements on sale:

• plasticizers
• Retarders
• Air-entraining
• Antifreeze
• Reinforcing
• waterproofing
• hardening accelerators
• Pigments

Each of these additives is responsible for its function and determines the future cement mortar.

For example, a waterproofing additive is simply necessary in the construction of dams, and in harsh northern conditions it is necessary to carry out concrete work using antifreeze additives.

Basic calculations

The stage of the beginning of any construction is a period of precise calculations. You need to calculate everything: the amount of materials, the size of the building, the number of required investments. Superficial analysis is not welcome here.

Concrete is calculated in cubic meters. We take as a basis the calculation of concrete for a concrete floor screed in a barn. First you need to remove the old floors, deepen the soil by 25-30 centimeters and fill in about 7 centimeters of sand. Next, a welded grate is laid on the floor so that it strengthens the future foundation.

Now we determine the size of the barn and the thickness of the future floor. Let's say the size of the barn is two by three meters. Accordingly, its area will be equal to six meters. We define the thickness of the floor as equal to 10 centimeters, which is 0.1 meters.

We are looking for the volume by the formula:

6 * 0.1 \u003d 0.6 m 3.

So we calculated that we would need 0.6 cubic meters of concrete. It remains to calculate how much it will take to purchase a mixture to make a solution.

Number of bags in one cube

When it comes to making a cement mixture on your own, it sometimes scares a person. Here you need to have knowledge in the field of proportions for the manufacture of concrete. But there is nothing particularly difficult in this.

We use an example with a cement screed:

• First, we determine which brand of cement we will work with. The M400 brand is well suited for the floor.
• After that, we multiply our 0.6 cubic meters by a factor of 1.02. It takes into account the loss of some part of the solution during construction, since something can spill, something will settle on the walls of the bucket. We get 0.612 cubic meters.
• Now let's determine the proportions of the mixture. Please note that for each brand of concrete it has its own. For M400, 1 kg of cement requires 3 kg of sand.
• Finally, we calculate the amount of material in accordance with the density of the solution. For floor screed, the solution should not be liquid, it should be thick enough. There are certain rules according to which 490 kg of cement is needed for one cube of M400 concrete.

We believe:

0.612*490=299.88 (round up to 300)

As a result, we get that for our floor we need 300 kg of M400 cement and 900 kg of sand.

Now you can get to work! The sand is pre-sifted, if necessary.

Calculation of the volume of the structure

Filling the floor is a fairly simple process, especially when it comes to volume calculations. But what if you need to calculate a complex structure. For example, the foundation of a house, besides a corner one. Or when calculating the pouring of cylindrical piles.

Similar designs are calculated according to standard mathematical formulas:

• If we are talking about the foundation, you first need to divide it into blocks, which are parallelepipeds. Calculate their volumes using the formula above. For convenience, let's repeat it:

  V=S*h, where V- volume, S- base area h- height.

• Formula for calculating the volume of a cylinder:

  V=P*r2*h, where P- Pi, r is the radius of the base circle, h is the height of the cylinder.

For those who are especially lazy, who do not like manual calculations, the Internet offers a large number of complex online calculators that can calculate not only the volume of structures, but also the amount of materials for the screed, as well as reinforcement. No restrictions!

The amount of mixture from the bag

Using the same barn floor example, given a factor of 1.02:

• First, we determine that the floor will need to be poured with a sand-concrete mixture brand M-300 (this is the brand of the mixture, not cement).
• Then we count how many bags will be needed. When working with ready-made mixtures, the consumption for them is indicated directly on the packaging. For example, consumption per 0.01 m 3 of one well-known brand requires 16-17 kg of the mixture. One package is 40 kilograms.

We believe:

0.612*17/0.01=1040.4 kg

Thus, it is necessary to purchase twenty-six bags of the mixture. But most likely you will have to purchase another bag if 400 grams of the mixture is not enough.

Please note that each manufacturer has its own proportions of the consumption of the finished mixture, so you need to determine this only by packaging.

There are no standards as such, since today mixtures are made not only according to GOST in our country, but are also actively purchased from countries near and far abroad, and there is simply no regulation as such for the mixture.

Solution proportions

Depending on the type of concrete work, the proportions of sand, cement, crushed stone and other materials that are fillers are calculated.

Let's talk about everyone:

• Foundation mortar. It is calculated according to the proportion 1:3:5. That is, 1 part of cement, 3 parts of sand and 5 parts of crushed stone. Used cement brand M-300 and above.
• Mortar for plaster. It is calculated in proportions 1:5. Five parts of sand are taken to one part of cement.
• For cement mortars use proportions according to the table. The calculation is shown for cement grades M400 and M500, where C is cement, P is sand, Shch is crushed stone.

Please note that the brands of cement mortars determine not only the proportions, but also the types of work that can be done with these mixtures. More on this below.

If you use specialized additives for concrete, the proportions will change, but this is individual. As a rule, the scope of their application and the method of dilution are indicated on the packages of additives.

Concrete preparation technology

Such an important solution as concrete is made by mixing cement, sand, water and filler, which is crushed stone, gravel, etc. All components must be of good quality, because the safety of future structures depends on this.

The water must be clean, and the cement dry and crumbly:

1. To prepare the mortar, it is first mixed in a concrete mixer cement, water and part of the sand until a homogeneous mixture is formed and only then crushed stone, the remains of sand and water are added.
2. The amount of water prior to manufacture is not measured. The whole point is to ensure uniform mixing of the solution, which will greatly affect the performance of further construction work.
3. Solutions interfere with not very large portions. Some of them pick up pretty quickly. As a result, the solution should be like thick sour cream. When working with multi-apartment multi-storey buildings, solutions are made strictly in accordance with the standards, but it is better not to save money when building summer cottages and cottages.

   Work must be carried out in rubber gloves, if the solution gets into the eyes, rinse thoroughly with water

4. It is better to pour the finished solution in one step. This applies to both floor screeds and foundations. The solution must evenly adhere to each other at the molecular level. Filling is done on a sunny day. If, after the mixture was poured, it began to rain, the entire screed must be covered with polyethylene. Moisture damages concrete.
5. For the strength of the structure, it is necessary to ensure that it dries evenly. As this happens, the evaporation of moisture occurs. If the street is dry and hot, you need to water the concrete daily. This will avoid drying too quickly and, as a result, cracking.

Varieties of cement mixtures

Much has been said above about the varieties of mixtures of cement mortars.

Consider their main characteristics according to the presented brands:

• M100– Suitable for plastering and installation and masonry works;
• M150 and M200– for the manufacture of screeds and vibro-brick panels, as well as for plastering and masonry. Can be used for floor screed, but only when using coarse sand;
• M250- for the installation of unloaded monolithic ceilings and for pouring durable screeds, for example, floors;
• M300- mixture for screeds, concreting of stairs, blind area, fastening of reinforced concrete products;
• M400 and M450- brands with high strength.

As a conclusion

The manufacture of cement mortars, the calculation of structures is by no means a difficult task. As a general rule, concrete work is the hardest part of working hard to build your own home or garage. Knowing all the tricks, you can easily master this work!

The most important thing is that the work is done with high quality, in compliance with all the rules, then the house will stand for a long time, and what is made from it using mixtures will serve well.

Looking at bags of cement and a pile of sand, not every developer feels calm and confident. He is tormented by the question: what proportion should be chosen for the solution so that it turns out to be strong enough and at the same time does not “eat” extra money?

Spilling "by eye" is stupid and dangerous, especially when it comes to critical concrete work on the foundation or brickwork. Following the principle “the more the better” is also not an option. When the bill goes to cubes, such a rule can ruin the developer.

Another question that arises in this regard: how to control the work of builders who are tasked with preparing mortar and concrete? You can’t keep track of everything, so there is no guarantee that it won’t go “to the left”, and the foundation and masonry will not collapse soon.

If the customer knows exactly what is the normative consumption of cement and sand for mortar, it is easier for him to control his costs and monitor the use of purchased materials.

"Grandfather method" or the current SNiP?

Experience is a good thing, but we should not forget about building codes. They take into account all factors associated with the preparation of mortars and concrete (cleanliness, fineness, moisture content of sand and crushed stone, cement activity and water quality).

Therefore, when preparing for work on pouring the foundation, screeding or laying walls, do not be lazy to look into the guest tables. In them you will need only one or two lines. They clearly describe what should be the consumption of cement per cube of mortar to obtain the required strength (grade).

Here is a simple "squeeze" from SNiP, which will help you cook quality mortar for masonry and screed. After studying it, remember that the given consumption rates are slightly different from practical values.

The reason is that they are derived from standard cooking conditions (air temperature + 23C, sand of medium grain size, ideally clean, its humidity is not more than 7%, etc.). It is not realistic to ensure the standard parameters of mixing at a construction site, so it is better to purchase cement with a small margin (10-15%).

The answer to the question of how much cement and sand you need per cube of concrete will be given to you by the following standards:

When making concrete, it is important to know not only the amount of cement, but also the standard volume of sand and gravel. The following table will be useful for calculations.

Volume proportions for various grades of concrete

Required sand consumption per 1m3 solution - 1 cubic meter. Some developers are mistaken in believing that the volume of cement increases the volume of the finished mixture. This is not true. The cement has a very fine grinding, therefore it is distributed in the voids between the sand, without increasing the total volume of concrete and mortar. Therefore, for 1m3 of sand, we can add both 200 and 400 kg of cement, getting the same 1 cubic meter of mortar.

Water is added to the mixture in a simple proportion - half of the total weight (not volume!) Of cement. In this case, it is necessary to take into account the actual moisture content of the sand and pour water in small portions so that the mortar or concrete does not turn out to be too liquid.

The consistency of the solution according to the norms is determined by the amount of precipitation of a standard metal cone lowered into the mixture. At a construction site, you are unlikely to be able to conduct such a test. Therefore, just remember that the density of the masonry mortar should be such that it is not too hard, but plastic enough and does not flow out of the seams. For screeding, mortar and concrete should be of medium density so that they can be easily compacted and leveled with a rule.

What determines the consumption of cement?

Intuitively, everyone understands that the consumption of this binder depends on the degree of strength of the structure that we are going to build. Therefore, for the foundation, we need concrete of a grade not lower than M300, and for the screed there will be enough mortar with a strength of 150 kg / cm2 (M150).

The brand of cement that will be used also matters. The higher it is (seen from the tables), the lower the binder consumption will be.

Consumption of cement for plaster

The "classic" plaster mortar consists of three parts of sand and one part of cement (1: 3).

If the average layer thickness does not exceed 12 mm, then 1.6 kg of M400 cement or 1.4 kg of M500 cement must be weighed per 1 m2 of plaster. The volume of solution per 1m2 is not difficult to calculate: 1m2x0.012 m = 0.012 m2 or 12 liters.

Consumption of cement for masonry

When preparing a cement-sand mortar for brickwork, take into account that the construction of 1 m2 of a wall with a thickness of 1 brick (250 mm) will require at least 75 liters of mortar grade M100. The proportion of cement (M400) - sand here is 1: 4. The consumption of cement for bricklaying with this ratio will be 250 kg per 1 cubic meter of sand.

Water, as we have already said, is taken at the rate of 1/2 of the total weight of the cement used.

Translating into "bucket norms" understandable to everyone, let's say that for one 10-liter bucket of cement (M500), we need four buckets of sand and 7 liters of water. We calculate the amount of water based on the weight of cement in a bucket (10 liters x1.4 kg x 0.5 = 7 liters).

To quickly determine the need for cement masonry mortar for walls of different thicknesses (per 1 m3), you can use the following table:

How many bags of cement to buy?

Until it comes to mixing, it is important for the developer to know how many bags of cement will have to be purchased. Here you should also build on the standard consumption rates.

Let's say we need to calculate the cement consumption for a floor screed. The optimal proportion to ensure high strength is 1:4. Cement for this work we need ¼ cube. To convert cubes into kilograms, an average indicator of the bulk density of the binder is used: in 1 liter - 1.4 kg of cement.

1/4 of a cube is 250 liters. Multiplying them by 1.4 kg, we get 350 kg of cement. So, we will have to buy 350/50 = 7 bags of cement (50 kg each) or 14 bags of 25 kg each.

Calculate the consumption of binder per 1 m2 of screed can be "reverse". With a thickness of 10 cm, 0.1 m3 of solution will be required to fill one "square". It contains 10 times less cement than 1 cubic meter: 350 kg / 10 \u003d 35 kg. For a 5 cm thick screed, we need 35/2 = 17.5 kg of M500 cement.

The rate of consumption of cement is strongly influenced by such an indicator as activity. It is determined experimentally by mixing control samples and testing them for strength. For an ordinary developer, this method is not suitable. A practical method to use when buying and before use is the shelf life.

The loss of cement activity can reach 20% in one month. Therefore, after keeping this material in the garage for three months, instead of the 500 brand indicated on the label, you will get the 400 brand. Using such a binder for mortar or concrete, take the consumption rate for this (reduced) brand. If the cement is waiting for its "finest hour" for six months, then it is not suitable for anything other than taking it to a landfill.

Vigilance should also be exercised when buying a binder, requiring from the seller a certificate for the purchased batch, which indicates the factory release date.

Cement is the basis of any mortar, whether it is a concrete screed, foundation or ordinary masonry mortar for bricks. It is also the most expensive component. It would seem that pour it into a larger concrete mixer, do not spare money - and you will get a solid structure made for centuries. But no - an excess of binder per cubic meter can lead to the fact that a too rigid monolith will simply crack. So to correctly determine the consumption of cement per cube of mortar is not only an economic task, but also the ability to assemble a composition with reliable performance characteristics.

The consumption of the binder in the solution directly depends on the amount of aggregates - crushed stone and sand. Actually, they form the basis of the future concrete structure, and cement is responsible for the fact that the mineral components will hold together as a single monolith. The amount, or rather the ratio of sand and gravel, will determine how much Portland cement is required to hold them together.

Imagine a formwork for the foundation - in fact, this is a container into which crushed stone is poured to the top. There are many gaps and voids between small pebbles, they should be filled with sand. But even after its addition, tiny cavities will remain in the formwork between grains of sand and gravel - the entire remaining volume will be occupied by cement diluted with water.

What happens if the proportions are violated:

1. Excess crushed stone will cause the aggregate to lie very tightly, reducing the consumption of sand and cement. There is nothing good in this, since there is practically nothing to hold the pebbles, and they will crumble from the foundation.

2. Skewed proportions per cubic meter in favor of sand will reduce the need for a binder. However, it will hold mostly grains of sand, which do not have the strength of gravel.

The best option is the binder content in the solution of about 33%. Of course, the consumption of the main components may vary, depending on the grade of Portland cement, the required strength and the purpose of the concrete structure. But there should be no extremes here.

Construction of various structures

The purpose of the mixture also determines how much Portland cement is required per 1 cubic meter of solution. For various operations, there are formulas and standards that allow you to find out the correct ratio of components. Focusing on them, you will be sure that the work is done efficiently, and unnecessary costs have been avoided.

For the construction of structures that will have to experience high loads, you need a strong solution that, after solidification, creates a particularly strong monolith of the M300 brand and above. But finishing like performing a horizontal screed or plaster, on the contrary, will require more mobility from the mixture, but not too high strength from M100 to M150. The production of products like cinder block does allow the use of the M50 brand.

1. Brick laying.

The cement-sand mixture for such work is produced without coarse aggregate - the building blocks themselves do an excellent job with its role. And the task of the solution is to securely fasten them together. To determine how much cement is required per cubic meter of masonry mortar, you can use the traditional volume ratio. There is just one thing to keep in mind:

1 m3 of dry mix contains 1 m3 of sand. Cement only fills the cavities between the grains, compacting the solution, but not increasing its volume.

Standard proportions are prepared in two versions:

• 1:3 - binder content - 33% of the cube or 0.333 m3;
• 1:4 - 0.25 m3 of Portland cement is required for 1 cube.

It is customary to give proportions in units of volume, but you have to buy components for them by weight. To convert the volume into kilograms will help knowledge of the bulk density of materials. And the total consumption for masonry is calculated based on the fact that a cubic meter of the mixture goes to 4-5 m3 of a brick wall.

To determine how many bags of cement you need per cube, you can use a simple calculation. Let's take the CPU ratio of 1:4, that is, the binder in a cubic meter will take a quarter (250 liters). The density of cement is about 1.4 kg / l. Then, in the cube of volume, its weight will be equal to 1.4 250 = 350 kg. The standard packing of bags is 50 kg, that is, you need to buy 7 packages of building materials for each cubic meter of masonry.

2. Screed.

It is more convenient to calculate the screed solution for the entire scope of work at once. To do this, you need to know only the area of ​​\u200b\u200bfilling and the height of the floor leveling. Let's say you need to make a 6x6 screed 5 cm thick - this is 1.8 m3 of solution:

• The proportion of the CPU mixture for such work is assumed to be 1:3.
• The volume of cement, respectively, 1.8 / 3 \u003d 0.6 cubic meters.
• Binder consumption: 0.6 × 1400 = 840 kg or 17 bags of 50 kg.

According to building codes, M500 screed will require 460 kg per cube, M400 - 575 kg / m3. Our calculation showed consumption at the level of 467 kg/m3, which corresponds to SNiP.

3. Construction of the foundation.

Approximate data for pouring foundations under buildings with concrete of different grades can also be found in SNiP. But the mortar for the foundation requires extreme accuracy in the calculations, since deviations will lead to a loss in the bearing capacity of the foundation and a decrease in the service life of the entire building.

Mixes of different brands

The brand of concrete, as well as the brand of cement for its manufacture, is selected at the design stage of the building. It all depends on the loads exerting pressure on the structure, since it is they who will determine the desired strength characteristics of concrete.

To simplify the calculations, standard proportions for solutions of different brands have already been derived by specialists. According to the table below, you can determine how many dry components are required per cubic meter:

Despite the strict requirements of building codes, the consumption of cement for the construction of a foundation or other construction work sometimes has to be increased. This happens when one of the components is not of the best quality or simply does not match the design data. From the current situation at the construction site, they come out the same way - they increase the consumption of cement:

• by 30% with a decrease in the grade of cement by 100 units;
• by 10-20% with clay-contaminated sand.

To determine how much sand, cement is needed per 1 cubic meter of mortar, it is important to know its purpose. For the preparation of masonry, plaster, foundation and other types of mixtures, a different ratio of dry materials is used. The consumption of sand and cement per 1 m3 of mortar varies for each type of work, and often other dry or liquid compounds are added to the composition, which increase moisture resistance, strength, change the rate of solidification of the mixture, etc.

What determines the consumption of cement for different solutions

The preparation of cement mortar, the proportions of which may differ, requires strict adherence to technology and the correct determination of the ratio of components. For the application of concrete of different grades, different amounts of cement and sand are used. Remembering the proportions of cement and sand is not enough for quality construction, it is better to understand the principle.

Requires strict adherence to the technology of preparation of cement mortar

The main factors affecting the consumption:

• the amount of fillers in the mixture. The greater the proportion of crushed stone, sand, the higher the consumption of cement per 1 m3 of mortar. Cement is a binder component, which is responsible for bonding all the fillers together. The ratio of bulk mixtures determines the amount of cement;
• brand of cement. As the grade increases, the strength of the final structure increases. At the same time, it is worth remembering that the brand of the final mixture is much lower than dry cement, since sand is added to the composition, and gravel or slag can also be introduced;
• brand of solution. The cement-sand mortar also has a division into grades. For all types of work in GOST there are recommended brands. After determining the desired brand of building mixture, you can choose the right brand of cement. For example, to obtain a mixture of M100 from M500 cement, you will need to mix 1 part of Portland cement, 5.8 parts of sand and 8.1 parts of crushed stone. If the ultimate goal is a solution of M450, a proportion of cement M500 (C:P:Sch) 1: 1.4: 2.9 will be required;

The density of cement here plays a secondary role, since it directly depends on the brand of cement, but it is necessary to know it in the calculation process.

Conclusion: how much cement is required per 1 m3 of mortar depends on the required strength of the mortar and the grade of the initial mixture.

Variety and brands of mixtures

The introduction of the concept of "grade of cement" helps to calculate the consumption of cement per cubic meter of mortar with knowledge of the input parameters. To prepare a mortar with the same building characteristics from different brands of cement mixture, different proportions of fillers will be required. In production, cement is produced, starting from the M100 grade, but due to the low strength of the structure, the material is practically not used.

The most popular are M400 and M500 cements, but some other types have also become widespread. The choice of mixture depends on the scope of the material.

The main areas of use of brand cement:

• M300 cement is used in assembly construction, as well as during the manufacture of monolithic structures;
• M400 cement is successfully used in monolithic construction and during the preparation of reinforced concrete;
• M500 cement is actively used in the construction of buildings or slabs that must be resistant to moisture or are in water. The areas of application of this concrete mixture are quite wide: the creation of sidewalks, the construction of asbestos-cement structures, the formation of large concrete masses and all kinds of foundations;

• cement M600 is used to create prefabricated structures and foundations, which create a high load;
• M700 is a suitable cement grade for the construction of highly loaded and stressed structures.

Consumption rates of materials per cubic meter of different solutions

Today there are 4 main areas of concrete use: foundation, masonry, screed and plaster. In each case, special requirements are imposed on the building mixture, which makes the choice of cement and its consumption different. The highest consumption of cement per cube of concrete occurs when it is necessary to make masonry or plaster. The consumption of materials per 1 m3 of foundation mortar is somewhat lower due to the use of a large fraction of the filler: slag, crushed stone or gravel.

GOST has records of cement consumption rates per 1 m3 of mortar, taking into account the purpose of the mortar. Designation of concrete in a cube. meters is the generally accepted system of measurement.

Consumption rates per 1 m3 using M500 cement:

• on M100 - 170 kg;
• on M150 - 200 kg;
• on M200 - 240 kg;
• on M250 - 300 kg;
• on the M300 - 350 kg;
• on M400 - 400 kg;
• on the M500 - 450 kg.

Consumption rates of cement and sand per cube of mortar for the foundation

Calculation of cement for the foundation calculator is the easiest way to understand how much material is needed and the number of necessary components. Calculation of concrete can be made with high accuracy and manually.

To determine how much cement is needed per 1 m3 of mortar, we recommend that you follow a simple instruction:

1. We determine the appropriate brand of cement mortar. Usually, during the creation of the foundation, it is advisable to use a solution of M100-M300. For low-level buildings, M100 is sufficient, if it is planned to build several floors - M150, and M200 and above is used in the construction of multi-storey buildings and any structures that are subject to increased strength requirements. If the foundation is being built under a wooden building, a solution of M50 is sufficient.
2. We select the brand of cement. For standard tasks, M300-M400 is suitable in a proportional part of cement to sand 1 to 3. When using M500 cement - 1 to 5.

How many kg of cement in 1 m3 of solution:

• in M50 when using M400 - 380 kg;
• in M100 when preparing concrete from cement M300 - 214 kg;
• in M200 with cement M400 - 286 kg;
• in M300 with M500 - 382 kg.

The data is presented if the cube includes 2-4 parts of sand and 3 parts of crushed stone.

Consumption rates of cement and sand per cube of masonry mortar

For the preparation of cement mortar for the construction of a wall, a ratio of 1 to 4 is most often used. Thus, the cement consumption per cube will be 0.25 m3 or 325 kg, and the sand consumption per 1 m3 of mortar will be 0.75 m3 or 1200 kg.

Table 1: Consumption of mortar on walls of different thicknesses

To calculate how many bags of cement you need, just multiply 325 kg by the consumption per cube, for example, walls in one brick - 0.221. It will turn out 72 kg of cement for laying 1 m3 of a wall, provided that there are no other components in the composition (lime, clay, etc.).

Consumption rates of cement and sand per cube of mortar for screed

The consumption of cement per 1 cubic meter of mortar is calculated according to the same rules as in previous mixtures. The recommended mixing ratio is 1 to 3. Difficulties in calculations often appear even at the stage of determining the volume of the solution, so let's look at a good example. It is necessary to pour a surface of 3x4 m or 12 m2. The layer thickness will be 30 mm.

Calculation of cement for screed from the example:

1. We calculate the required volume of the solution: 12 m2 * 0.03 m = 0.36 m3.
2. We determine the brand of cement, the M200 solution is often used, and we use it as an example. We will cook from M500, and according to the standards, the consumption will be 410 kg.
3. We consider the required number of bags of cement: 410 kg * 0.36 m3 \u003d 148 kg - these are 6 small or 3 standard bags of 50 kg.
4. We determine the cost of sand. To do this, we multiply the specific gravity of 1 m3 of sand by the required amount of the finished mixture: 1600 kg / m3 * 0.36 m3 = 576 kg, and since the share of sand in the total solution is 75%, we also multiply by 0.75 - 432 kg of sand. Sand consumption per 1 cubic meter of solution is approximately 1200 kg/m3.

Consumption rates of cement and sand per cube of mortar for plaster

The consumption of cement per 1 m2 of plaster strongly depends on the quality of the wall covering, the required layer thickness and the number of large pits. Again, for clarity, we will give an example of the calculation, remembering that a mixture of 1 to 4 is usually used. Input parameters: it is necessary to cover 60 m2 of the wall with plaster 2.5 cm thick.

Calculations of cement consumption per 1 m3 and sand:

1. Quantity of materials in cubes. For 1 m2, 1 * 0.025 \u003d 0.025 m3 of mortar will be required, where a fifth is cement, and the rest is sand. Using elementary mathematics, we determine that 0.02 m3 of sand and 0.005 m3 of cement will be required.
2. The entire wall area will require: 0.02 * 60 = 1.2 m3 of sand and 0.005 * 60 = 0.3 m3 of cement.
3. The specific density of cement is on average 1400 kg/m3 (fresh 1100-1200 kg/m3, and caked 1500-1600 kg/m3). We determine the consumption of cement: 0.3 * 1400 = 350 kg.
4. Required sand weight: 1.2 * 1600 = 1920 kg, we remind you that 1600 kg / m3 is the specific gravity of the sand.

All calculations are simple, it is only important to choose the right brand of the initial mixture and the desired brand of solution at the outlet. Everything else is easily calculated in a few mathematical steps.

Cement is the main building material that is used in almost all sectors of the national economy. With the help of this substance, it is possible to obtain very durable products that can withstand high loads and withstand external influences. But all these characteristics also depend on the components used and the technology of preparation. Cement mortars are widely used in construction, as they make it possible to simplify many operations.

Peculiarities

Cement mortars are artificial mixtures that, after hardening, form a strong structure. A similar product consists of several main components.

• Sand. It is used as the main component, as it combines a fine structure and relatively high strength. For the preparation of solutions, river or quarry sand can be used. The first type of material is used in monolithic construction, making it possible to obtain very durable products.
• Water. This component is needed to bind sand and cement. The amount of liquid is selected depending on the brand and purpose of the solution.
• Cement. This is the main substance, which is characterized by high adhesion with other materials. Today there are several brands of cement designed for use in various conditions. They differ in terms of strength.
• plasticizers. Technically, these are various types of impurities that are intended to change the physical or chemical properties of the solution. They are not used as often, as this can significantly increase the cost of the product.

Similar products are used to solve the following types of problems:

• plastering - walls are covered with some solutions to protect the building material, as well as to level the base;
• masonry - cement mixtures perfectly bind bricks or gas blocks together, so they are used as a kind of glue located inside each seam;
• creation of reinforced concrete structures.

Types of compositions and requirements

The main characteristic of cement mortar is its strength. It is due to the ratio of cement and sand. The composition of the product can be changed individually, which allows you to get several types of mixtures. Each of them is intended for use in certain conditions. Therefore, it is important to properly prepare products during the construction of various facilities.

Types

One of the criteria for separating cement mixtures into types is the proportions of internal components. It is worth paying attention that only one brand of cement can be present in one composition. But they can also change, since the strength will depend only on the concentration of the components. Conventionally, they are divided into several brands.

• M100 (M150)- these mixtures are characterized by low strength. For their preparation, cement grades M200–M500 can be used. But at the same time, it is necessary to correctly select the proportions of cement-sand components.
• M200- This is one of the most common types of solutions. It is used very often in everyday life for the construction of paths and or the formation of coatings that are not amenable to significant loads. This mixture dries relatively quickly, but it requires compliance with certain microclimatic conditions.

• M300- this type of solution can already be attributed to concrete types. It is used for the preparation of concrete, from which durable floor slabs are made, foundations are poured, and much more.
• M400- this is durable concrete, which consists of high-quality cement grades (M350, M400, M500). It is used in the construction of foundations for multi-storey buildings. This solution forms the basis for the manufacture of reinforced concrete floor slabs and other similar products.
• M500- this is the most durable concrete that can withstand very high loads. It retains its original properties over the years and when exposed to various irritants.

Additives

The quality of the cement mortar depends on almost all of its components that are present inside. Sometimes the properties of the sand-cement mixture are not enough, so you need to adapt them to certain conditions.

This problem is solved by adding various impurities to the composition. With the help of such additives, the so-called liquid glass is obtained. These products are used for plastering walls and other surfaces.

Today, several products are used as cement slurry additives.

• Lime. As additives, only quenched species are used. The introduction of this substance allows you to slightly increase the vapor permeability and strength. But in order to prepare such products, the exact proportions must be observed. Very often, plasters are made on the basis of lime, which are perfectly applied to the walls.
• PVA. Glue improves adhesion and plasticity of the solution. It is important to choose the correct concentration of the additive in order to get a good mixture.
• Detergents. Such products affect the plasticity of the solution. They are added to the composition only after water. Here, the exact dose of impurity per unit volume is also necessarily observed.
• Soot or graphite. These substances practically do not affect the physical properties of the mixture. They are used only as dyes to change the color of the finished product.

The ratio of sand and cement

It is possible to prepare a cement-sand mortar even at home, as it consists of available components. These are fairly easy to find at almost any hardware store. But the solutions differ in the ratio of cement and sand, on which the consumption and physical characteristics of the material depend.

Brickwork

Bonding bricks is one of the main tasks of cement mortars. For such purposes, not very strong brands (up to M400) are used. To obtain such a mixture, experts recommend using sand of medium fraction with a minimum level of moisture. You can prepare masonry mortar using various brands of cement. But at the same time, the ratio of cement and sand will already change. Some proportions are shown in Table 1.

Table 1. Ratios of components depending on the brand of cement

Please note that it is desirable to carry out the calculation according to only one unit of measure. In most cases, all parts are calculated per 1 m³. But at the same time, the masses of different materials in a cube may differ.

concrete preparation

Concrete structures are also very commonly used in modern industry. These materials are manufactured in factories or directly on construction sites. The strength of such products also depends on the cement that is planned to be used. Technically, concrete can also be made from a solution of the M100 brand, but it will not withstand the load and have a minimum service life.

Another feature of concrete is the presence of crushed stone and other auxiliary components in the composition. They are introduced in order to change the technical characteristics of the product.

It should be noted that they can be mixed in various combinations, which depends on the environment in which concrete is used.

Today, many specialists use such a ratio of the components of concrete solutions as:

• 4 pieces of rubble;
• 1 part cement;
• 2 parts sand;
• ½ part water.

Please note that the proportions may change if you plan to use different polymer additives. In such cases, it is advisable to pay attention to the recommendations of the manufacturers of these impurities.

For plaster and screed

Filling the floor very often involves the use of relatively liquid cement mortars. This consistency allows you to evenly distribute the mixture on the base and get a horizontal surface. Plaster almost always consists only of pure sand, cement and water. Its density may be different, as it all depends on where it is planned to be used.

The most common proportion for obtaining plaster mixtures is the ratio of cement to sand 1: 5. The consistency adapts to the needs of the master.

Particular attention should be paid to screeds that are subject to significant and constant loads. For such surfaces, materials with a threshold strength of at least 10 MPa should be used. This is achieved through the use of concrete grade not lower than M150. The proportion of the preparation of the screed solution depends on the following factors:

• the use of mixtures to hide various communication elements;
• surface leveling thickness. If you just need to strengthen the floor with small differences, then use more liquid formulations. For thicker layers, it is desirable to use durable types of solutions.

Table 2. Proportions of sand and cement in screeds

Please note that the proportions of the components are repeated in most cases. But at the same time, the strength of the resulting solution at the outlet is different. This is important to consider if the products will be used in specific operating conditions.

How to breed?

The process of preparing cement mortars involves mixing all the components in a certain sequence. Such a procedure can be described in several successive steps.

• First of all, you need to decide on the type of solution that you need. At the same time, attention is paid to the strength of the resulting mixture. If this indicator is important, an additional calculation of all components should be carried out. Particular attention should be paid to norms or standards.