How to properly dilute concrete mortar for the foundation. Proportions of concrete for the foundation. Basic properties of concrete foundation casting

The stability and durability of any structure directly depends on the strength and reliability of the foundation - the foundation of the house. Its construction requires special knowledge and the qualifications and experience of the master.

As a rule, the design for the foundation of any building is selected depending on the soil of the land on which it is planned, the material for the walls, climate, conditions and the nature of the structure itself. There are several types of foundations that are used for construction.

Types of concrete foundations

The most basic types of concrete foundations are columnar and strip, but there are other subtypes and varieties:

1. Tape. It is installed in the form of a continuous strip, which consists of reinforced concrete laid under all load-bearing walls designs. The depth of the building’s foundation is determined depending on the level of soil freezing plus an additional 20 cm.
   Based on indicators of soil quality and climatic zone, two subtypes can be used:
   • intermittent;
   • continuous.

   The material used for this type of base is:

   • Booth, which has excellent strength. The material is not affected low temperatures and leaking groundwater. Ruba stone of the same fraction is used. The construction process requires a lot of labor and money, so it is used very rarely. The laying depth does not exceed 70 cm, and its durability is about 150 years.
   • Rubble concrete, which includes a combination of cement mortar and filler (crushed stone, small rubble stone, brick fragments). In terms of strength, it has qualities no worse than rubble, but it is much easier to construct and more affordable. It is used to build structures made of heavy materials or consisting of several floors.
   • Concrete. This type of house foundation is better known as poured, since the material is mixed in a concrete mixer, after which it is filled with formwork. The service life of the material is over 50 years, and its cost is much higher due to the large volumes of cement used. Most often, this option is used in construction for the construction of walls from non-light materials, as well as the construction of country cottages and houses.
2. Columnar, which is used for the construction of lightweight structures (for example, bathhouses, garden houses, sheds). This foundation option includes sets of support posts located at the corners of the structure and in places experiencing increased load. The pillars are formed from pipes, concrete, rubble and reinforced concrete. This foundation is used on solid soils.
3. Ribbon-columnar. It is slightly cheaper than belt type foundations and combines only best qualities from both types of foundation.

The correct selection of material and type of foundation allows you to make the structure stronger and more durable. It is possible to buy foundation material already ready-made version, in the form of mixtures at enterprises industrial type. But it is much better to make the concrete solution yourself, which allows you to significantly save money.

Composition of foundation concrete

You can prepare a concrete solution for a foundation support yourself; for this you just need to know what concrete is and what characteristics it has.

The solution itself consists of a combination of binders (cement), filler and various additives that impart characteristic qualities and properties to the entire casting mass. Then the formed solution is diluted in the required proportions with water.

The composition of the foundation mortar has been used in construction for several years now, and every day it is being improved and its quality and strength indicators are increasing.

Each individual component is responsible for the specific quality of the concrete solution. Therefore, the final quality of the material depends on the proportions of its components used. In order for the final performance of the mortar to perfectly match the construction, it is necessary to take into account the construction site and its purpose.

Composition of concrete for foundation proportions in buckets

Important! If the proportionality of the concrete solution is determined by buckets, then it is necessary to take into account the brand of cement. If it changes, then the proportions in creating the solution are replaced.

The main components in concrete:

1. Cement– binds fillers together.
2. Fillers. These include: gravel, crushed stone, sand, bulk additives.
3. Water.

There are several ways to mix a proportional concrete solution. The most common option is concrete mixers, into which the required number of buckets of sand, crushed stone, cement and water are loaded, and then the device thoroughly mixes the materials together.

Forming a solution in buckets is important in several cases:

1. For construction work less than 4-3 solutions are required.
2. Failure to deliver concrete from the factory due to problems with its location, for example, the production company is located far away, and the cost of delivering the material is too high.
3. The foundation is being poured with interruptions, for example, when several tiers of the structure are formed.
4. At the site under construction There is no access to the installation of automixers and concrete mixers.

Proportions of concrete for the foundation in buckets

As a rule, measurements using buckets are used for small amounts of work.

Weight dimensions of components for making concrete mortar:

• cement – ​​1;
• sand – 3;
• crushed stone (gravel) – 5.

Each component of the concrete solution has a different volumetric weight, for example, the weight of one bucket of sand is 19.5 kg, cement - 15.6 kg, and gravel - 17 kg. Therefore, in practice, a convenient option for the proportions of cement, sand and gravel is 2:5:9. In some situations, gravel is replaced with crushed stone.

If the construction of the structure is carried out with your own hands, then a ready-made sand and gravel mixture (PGM) is used. The ratio of concrete for the foundation to the mixture is approximately 1 bucket of cement to 5 buckets of ASG.

In what proportions should concrete be made?

In most situations, for frame-type buildings, a columnar version of the foundation is used, which does not require concrete mixture with increased strength indicators. For this type, concrete M 200 is suitable, which is made from cement M 500, sand, crushed stone and water.

For one cubic meter mixture needed:

• 300–350 kg of cement;
• 1100–1200 kg of crushed stone;
• 600–700 kg of sand;
• 150–180 liters of water.

This ratio of materials is formed by their qualities, for example, granite crushed stone has high level strength, in comparison with dolomite crushed stone or limestone, so it can be used in smaller quantities.

To create a concrete mixture of the required consistency, it is best to use washed crushed stone and only purified river sand, which does not contain various clay impurities.

If you use sand with low level quality, holes and potholes may form in the base.

When choosing cement, first pay attention to the manufacturer's company. As a rule, the more famous the organization, the less likely it is to purchase a low-quality product.

Water should also be consumed clean, so that it is free of impurities and salts. If construction is carried out in the cold season, then the water, like other components of the concrete solution, should be heated to +60 0 C to give the solution the necessary consistency and strength.

How to mix concrete correctly?

To prepare a small volume of solution, a bucket is used as a measure of the weight of the components. Proportions are calculated in accordance with the fact that the components have different volumetric weights. Based on this fact, when preparing the 1st 3rd solution you will need a ratio of 9:5:2 (gravel or crushed stone, sand and cement).

The production of concrete M 200 is carried out according to the rules in order to achieve a high quality mixture as a result.

Rules for mixing concrete for the foundation:

1. Mix well first sand and crushed stone between each other so that there are no lumps when adding water. Furrows are made on the surface into which cement is poured. The mixture should be mixed until the color is completely uniform.
2. Shape the mixture into a cone and add water in small portions, mix everything thoroughly.

When deciding what better way When mixing the solution, you should correlate your needs and financial capabilities. The most the best option will use a concrete mixer, but buy it for small building unprofitable, so it is better to use manual production.

Preparation of concrete mixture for strip foundation

For this type of foundation, first of all you will need to calculate the amount required material. The parameters of one tape (length, width and depth) should be multiplied by their number.

Example. Length 20 m, width 0.5 m, depth 1 m. We multiply these values ​​and get 10 cubic meters of concrete solution for one side of the foundation.

Having prepared the required amount of the mixture, it is poured into the formwork. It is carried out in layers, for example, if the depth of the base is one meter, then there should be four layers, each 0.25 cm. After laying each of them, compaction must be carried out. Then, to release excess air, every meter or two you should slowly stick the reinforcement into the solution.

Preparation of concrete for a columnar foundation

Calculations in this type of foundation correspond to the strip version. The difference is that the concrete solution is not poured in stages, but immediately, after which it is compacted.

Required properties of foundation concretes

The concrete foundation of a house has different properties and characteristics. They directly depend on the quality of materials used and their initial components. Also, the properties of concrete depend on the proportions of its components that are used for construction. different types designs.

Required strength of foundation concrete

The strength of a concrete foundation is a key indicator on which it depends whether the foundation will withstand the load planned for it. It is measured in kilograms per square centimeter.

This indicator can be calculated by calculating the exact degree of load that the structure will exert on the base. To do this, you will need to sum up the total weight of all structures and communications, as well as indicators of the useful and possible load that is created by climatic conditions. Then the result should be divided by the area of ​​the entire foundation.

The final strength of concrete should be several positions greater than the planned load on it.

The degree of strength of concrete is indicated in its grade, which means the maximum degree of load on the foundation in kg/cm 2.

According to the calculations obtained, a concrete solution with the appropriate characteristics should be prepared.

The required proportions of the material can be seen in the tables:

Concrete made from cement grade M 500, sand and crushed stone

Concrete made from cement grade M 400, sand and crushed stone

Giving concrete special properties

If the structure being built is subject to additional requirements and special properties, for example, waterproofing or frost resistance, then additives and special concrete of exposure class XD, XF, XM or XA should be used.

To give the concrete mortar special properties, various additives are added to it, which can enhance and improve certain qualities of the material.

Concrete with high frost resistance requires the addition of an appropriate additive, which increases the level of resistance of the concrete base to frost.

Adding this type of additive helps ensure that the foundation can withstand large number cycles of freezing and defrosting.

If, in addition to frost, the structure is exposed to salts, additives with high frost resistance and resistance to thawing salts acting on the base are used.

Additives are also used that can increase the plasticity of the solution. Typically, they are used in formwork mortars with frequently repeated metal reinforcing mesh. This additive promotes better distribution of the mixture along the entire perimeter of the formwork.

Additives are also used to increase the degree of resistance of the structure’s foundation to being washed away by groundwater (waterproof concrete). It is almost impossible to do without them in places where the soil is too saturated with moisture. A solution of a denser consistency is used for buildings with a thickness of 10 to 40 cm, so that the depth of water penetration does not exceed 0.6, and for structures with greater thickness - 0.7.

Number of components per cube

As we already know, the main components for preparing concrete are water, sand and crushed stone. To prepare the appropriate consistency of the mixture, the proportions must be observed.

To obtain 1st 3 concrete mortar you will need the following amount of materials presented in the table

Approximate proportions for forming 1-3 concrete

If you are preparing a solution for the first time, then first prepare trial version. When the sand is wet, it is better to use less water than indicated.

Based on the specified data, you can prepare the necessary concrete solution yourself.

Composition: water, cement, sand and gravel/crushed stone. Proportions: if you count 10 kilograms, then cement - 10 kg, sand - 30 kg, gravel or crushed stone - 40-50 kg. To make concrete grade M300 or M400, you need half as much water as the weight of the other components. Example: in this case, you get 80-90 kg of dry mixture (cement (M500/M600) + sand + gravel/crushed stone), which means 40-45 liters of water are needed. If the solution is too thick, dilute with water. It's best to stick to a consistency that allows the concrete to be mixed with a shovel, but still requires some effort (and so that the solution doesn't flow off the shovel too quickly or easily).

Damp sand also contains moisture. Either dry it or subtract a few liters of water. Also check the sand for cleanliness. The cleaner it is, the better the adhesion in solution.

Use crushed stone or gravel of a small fraction (1-2 cm, no more).

Do not buy cement long before construction. It quickly absorbs moisture and deteriorates. It is better 1-2 weeks before preparing the concrete mixture.

It is advisable to pour any foundation in the warm season. At cold weather you have to heat the water and the solution so that it does not start to set earlier. Otherwise, it will lose a lot of strength, because it will not be firmly connected to the reinforcement and will not be compacted.

How to prepare concrete for a strip foundation

It is better to count each line (ribbon) of the foundation separately, and then add everything up. The length of the tape is multiplied by the height, then by the width. Let’s say one foundation strip has the following dimensions: length – 10 m, height – 1 m, width – 0.5 m. This turns out to be 5 m 3 of concrete per strip.

If you count each tape along its full length (from corner to corner), it turns out that the volume of each corner is counted twice. This is necessary, since it is better to make more concrete than required. The foundation pit is never perfectly smooth.

It is advisable to pour concrete into the formwork in layers. For example, if the height of the foundation is 1 m, then you can concrete it in 4 layers of 25 cm each. When pouring each layer, it is advisable to compact it with a vibrator or at least tapping it with a hammer/shovel. After pouring each layer, you need to release the air from it by sticking reinforcement every 1-3 m (not very quickly). Also, each layer of concrete must be leveled with a board. For clarity, the height of each layer can be marked in the formwork.

The calculation, preparation and pouring of concrete into the grillage is carried out in the same way.

How to prepare concrete for a slab foundation

Dimensions: length and width 10 meters each, height 25 centimeters. 10 times 10 times 0.25. Total: 25 cubic meters of concrete for a slab monolithic foundation.
The slab foundation must be compacted at each square meter area. Since this type If the foundation is a single area, then all the concrete must be poured at once. After filling, it is better to do the leveling starting from the smaller side of the perimeter and move in a snake towards the opposite side. For leveling, you need a wide board with a handle for convenience. Be sure to release air in many places.

How to prepare concrete for a columnar foundation

Concrete for a columnar foundation is calculated using the volume formula, poured all at once and compacted, followed by puncturing the mixture to release air.

Preparation of concrete for pile-rammed foundation

Compared to columnar foundations, only the calculation formula for cylindrical columns of cast-in-place piles changes. You need to multiply the height by the radius squared and by the number “Pi” (3.14). Calculation example: multiply the height of 1 m by 0.0625 (radius 0.25 m2) and multiply by 3.14. It turns out 0.19, rounded to 0.2 cubic meters. This is a calculation for one pile column.

After pouring any foundation, you need to cover it with a protective film from precipitation. On the day of pouring, pour plenty of water over the foundation at night, otherwise it may develop small cracks in the morning, because the top layer dries out quickly. For the first week, moisten the foundation every few hours. From the second week you can do it once a day.

Every building, regardless of its purpose, needs a strong support; the reliability of the building and its durability depend on its quality. The foundation may have different shapes and consist of various materials. However, in any case, the main component of the base is concrete.

Proportions of concrete for the foundation

Foundation concrete is a combination of binder, filler, water and various additives.

The binder is almost always cement, which, depending on the load to withstand, can be of several grades: M200, M300, M400, M500 and M600.

Sand and crushed stone are used as filler. It is best to use river sand, and it should not contain clay impurities. The size of sand grains for high-quality concrete should not exceed 5 mm. It is better to take from crushed granite, as it is characterized by high strength. The fraction size should not exceed 2 cm.

Additives are necessary to give concrete the required characteristics. The mixture of dry ingredients is diluted with water to the desired consistency. Each component of concrete has its own function, so it is very important to choose the correct proportions of the components.

The water for preparing concrete must be clean, so it is recommended to take it from water supplies. If this is not possible, then it is allowed to use water from natural reservoirs, but with preliminary purification.

You can mix the concrete solution in a concrete mixer or manually using a certain amount of components. However, weighing materials is not always possible, so buckets are used for convenient measurement.

• Cement - 1 part.
• Sand - 3 parts.
• Crushed stone – 5 parts.

In other words, for high-quality concrete, take 3 buckets of sand and 5 buckets of crushed stone for 1 bucket of cement. As for water, the calculated amount of this component is determined depending on the amount of cement; most often they take 0.5 parts of water to 1 part of cement. However, there are many factors that influence the amount of water to varying degrees. For example, using wet sand significantly reduces the water consumption to prepare a solution of the desired consistency. In addition, it is necessary to visually control the consistency of the concrete. The main thing is that it is thick and flexible, can hold its shape and not spread.

Proportions of components for preparing 1 cubic meter. concrete

Foundation concrete has several grades, which are determined by the type of future structure, its weight and purpose. To prepare each brand of concrete, a specific brand of cement can be used. In general, these two factors determine the number of components required to prepare one cubic meter of concrete.

In most cases, concrete grade M 200 is used for the construction of foundations; it has sufficient strength and can withstand freezing and thawing many times. To make such a solution, M500 grade cement, medium-fraction crushed stone and water from the water supply are used.

To prepare one cubic meter of M200 concrete, you need to take the following number of components:

• Cement – ​​300-350 kg.
• Crushed stone – 1100-1200 kg.
• Sand – 600-700 kg.
• Water – 150-180 l.

To translate specified values in volume in buckets for more convenient measurement, it is enough to know the approximate mass of each component in one bucket. For example, a 10 liter bucket holds 15.6 kg of cement, 19.5 kg of sand and 17 kg of fine crushed stone. Therefore, to mix a concrete mass with a volume of 1 m 3 you will need approximately 20 buckets of cement, 30 buckets of sand, about 70 buckets of crushed stone and 15-20 buckets of water. As you can see, calculating the proportions of concrete for the foundation in buckets is not so difficult.

Features of concrete mortar

The strength of the foundation largely depends on the correctly selected components, each of which is designed to perform its assigned task.

For example, the main components of concrete are cement and water; their mixture forms cement stone. However, despite the monolithic structure, this stone is easily deformed, shrinking 2 mm per 1 meter. The result of this process is the formation of microcracks, invisible during visual inspection, but significantly reducing the quality of the cement. In the future, to analyze the quality and condition of the foundation.

Reduce the degree of deformation cement stone Fillers help. Most often, sand, crushed stone, gravel or expanded clay are used for this. The filler forms a special structure that absorbs the stress of concrete during the shrinkage process. Consequently, adding a filler to cement makes it possible to increase the strength of concrete several times.

Manual preparation of concrete mixture

To prepare a high-quality concrete solution for the foundation, it is best to use a concrete mixer. However, this possibility is not always available. Sometimes purchasing or renting a concrete mixer is unavailable due to limited budget for construction. There are situations when it is not possible to connect to the power supply. It is possible that using a concrete mixer is not rational due to the small amount of work. Problems of this kind can be solved by manually mixing the concrete mixture.

To work you will need the following:

• Two buckets: one bucket for cement, the other for other components and water.
• Two shovels, one of which is also used only for cement, the other works with sand and crushed stone.
• Wide container with high sides for easy mixing of ingredients.

The process of manual mixing of concrete mixture is as follows:

1. Sand and crushed stone are poured into the container, mixed well and grooves are made on the surface.
2. Cement is poured into the resulting recesses and the entire mixture is mixed until homogeneous.
3. The mixture of dry ingredients is collected into a cone, at the top of which a hole is made.
4. Pour a small amount of water into the recess of the cone and begin to mix. In this case, the kneading is carried out directly at the top of the cone so that the dry mixture is poured into the hole with water.
5. When the poured water is absorbed, a cone is again formed with a depression in the upper part and more water is added. The steps are repeated until the required consistency of the concrete mass is obtained. It is very important not to pour all the water at once, as too much water can reduce the quality of the prepared solution.

Preparing concrete for the foundation is a very important stage, on which the strength and durability of the foundation and the entire structure depends. Therefore, it is very important to correctly select the components for mixing the concrete mass and calculate their proportions as accurately as possible.

Composition of concrete for the foundation

Concrete consists of three main components: cement, sand and gravel (crushed stone). The strength and durability of the load-bearing part of the structure depend on the proportions of the components. There is one problem. It lies in the fact that the same components can produce concrete of different grades.

Cement

So, the first thing you need for the concrete mixture of the foundation is Portland cement grade M 500. It can be purchased at any hardware store.

Sand

The second component that is added to the concrete for the foundation is sand. Special attention it is necessary to pay attention to its graininess. Its grains should be from 0.15 mm to 3 mm. If they are dusty, the cement will not adhere well to the sand, and if they are large, then there will be a lot of air bubbles in the concrete. All this contributes to a decrease in the strength and bearing capacity of the foundation.

Gravel

And finally, the third component is gravel with a grain size of up to 10 mm; you can use crushed stone, the size of which should be from 5 mm to 70 mm. Often, instead of them, broken bricks are added to the foundation concrete, which worsens the load-bearing capacity. But if the load is relatively small, then this is allowed. If the construction of a building is carried out in winter, special additives are included in the foundation concrete for better hardening at low temperatures, such as “Emulsol EKS-M”, “Plastil U”, “Lignopal B2”.

It's easy to prepare. For this it is better to use an electric concrete mixer. If you don’t have one, you’ll have to make do with a couple of hands, a shovel and a bucket.

Proportions

When preparing the mixture, it is necessary to observe the proportions of the components, they should be 1: 2: 3, i.e. For 1 bucket of cement you need to add 2 buckets of sand and 3 buckets of crushed stone (gravel). Pour the first two components into a concrete mixer or bucket in the specified ratio and mix until smooth. Then add crushed stone (gravel), also following the proportions, and mix again. Next, add water; you need to do this in parts, while controlling the thickness of the mixture. If the preparation and pouring of concrete will be carried out in winter time years, special additives should be included in the composition. Their proportions and method of addition should be written in the instructions for use. To check the readiness of the concrete solution, take it with a shovel. It should settle, but not spread and not be in the form of a lump from which pieces fall off. If all conditions are met and the mass is similar in description, then the concrete for the foundation is ready and you can begin pouring it.

Pouring the foundation

Before pouring the foundation, the formwork from the boards should be knocked down. To improve the strength of the structure, it is recommended to install inside it a reinforced frame made of A500C brand reinforcement with a cross-section of 10 or 12 mm. Then you need to mix the concrete solution for the foundation, which is poured into the formwork. During pouring, it should be compacted with a stick. This is done in order to squeeze out any air bubbles that have got there from the solution; they negatively affect the strength of the concrete. After the foundation is poured, the mixture should be allowed to harden. When the solution has set, remove the formwork and leave the foundation until it hardens completely.

Concrete- an important component of any construction. The operational characteristics of the structure being built largely depend on the foundation. Therefore, it is very important to properly prepare the solution for pouring it. Concrete mortar for large-scale construction projects is prepared in a factory.

Private developers, when building a house with their own hands, usually prepare it themselves in order to at least slightly reduce construction costs. Having chosen to prepare it yourself, it is important to observe the proportions for the concrete for the foundation. After all, the strength of the foundation of the house often depends on this.

Choice

The foundation is the load-bearing part of any building. To make it resistant to various loads, you need to choose the right concrete composition for it. In this case, its resistance to compressive loads will be sufficient, which means it can withstand the pressure of the entire house. Various are produced, therefore there are several composition options. Which one to choose for pouring the foundation? This question must be answered taking into account two factors:

1. Features of the structure (number of floors, weight, size of the basement).
2. Features of the soil on the site.

The choice of composition taking into account the first factor is made as follows:

1. M 150 is used for pouring foundations for frame and panel buildings.
2. For light houses made of logs and timber, M 200 is selected.
3. M 300 for block and brick buildings.

The dependence on the characteristics of the site is as follows. The more complex the soil on the site, the higher the grade of concrete you need to choose. So, for rocky soil it is enough to prepare a solution of M 150. For loamy soil, the composition M 200 is suitable.

Components

Any concrete, regardless of its brand, consists of the following components:

1. Cement.
2. Sand.
3. Crushed stones or gravel.
4. Water.

All these components must have required characteristics, taking into account which they need to be selected. Cement is the main ingredient in a concrete mixture because it is a binder. It is produced by cement factories. Cement is divided by grade and by the number of various additives it contains. The most popular Portland cement, it contains many special additives to improve the properties of the material. When pouring the foundation of a house, experts recommend that private developers use cement M 400 or PC 400.

You need to keep in mind, like many building mixtures, the shelf life of cement is limited. After a year of storage in packaging, it significantly loses its activity, which determines the properties and brand of the material.

Sand- This is one of the fillers for concrete mixtures. To obtain a high-quality solution, you need to take its choice seriously. It is worth noting that at the moment the choice of sand on the construction market is huge. If you wish, you can even purchase sand from the seabed, but not every sand material is suitable for concrete.

Thus, experts do not recommend using sand with clay admixtures for this purpose. Because of this, concrete is less durable and frost-resistant. But with river sand you can prepare a solution that is ideal in condition. It is often of very high quality and consists of homogeneous fractions.

and gravel just like sand in the solution acts as fillers. Thanks to them, the solution “shrinks” less, which makes concrete structure more durable and durable. When choosing crushed stone, you should pay attention to its shape. Because the convenience of pouring concrete mortar depends on it.

Flat and angular crushed stone is usually not used for mixing concrete. Because it requires more consumption of other components, which affects the strength of the structure. The best option for pouring the foundation is the use of crushed gravel. It consists of particles ranging in size from 3 to 70 mm. In addition, it is affordable for private developers.

Water. This component can have any characteristics, the main thing is that the water is clean without any impurities. Having all the above components and knowing the proportions of concrete for the foundation, you can prepare a solution of any required brand.

Video

Video on how to make concrete, as well as proportions in buckets.

Component proportions

The correct ratio of components in a concrete solution is the key to obtaining high-quality material. The optimal composition of concrete for the foundation for the construction of a private house is considered to be one part cement powder to four parts crushed stone (1/4). And in the proportion of cement and sand, the ratio is 1/3, that is, for 1 part of cement (M 400) there are 3 parts of sand. In general, the weight of cement in the cement mortar should be 1/4 of the total mass.

But concrete still needs water to harden. An important characteristic of concrete is the proportion of water and cement (the so-called water-cement ratio). The strength of concrete depends on this ratio: the lower its value, the stronger the material. For a concrete mixture used for concreting foundations, the maximum water-cement value is 0.75.

For private developers, for a small amount of work, it is easier to mix the mortar on the construction site. One batch of foundation mortar is made in a concrete mixer in approximately the following proportion:

1. 300 kg of cement powder.
2. 600 kg of sand.
3. 1300 kg of crushed stone.

But the developer does not have the ability to weigh bulk materials when he is at the construction site. A completely reasonable question arises: how to make a foundation mortar correctly. To do this, you need to know the proportions of concrete for the foundation in buckets. Since all components have approximately the same bulk density, you can measure them and then the composition of the concrete for the foundation, the proportions in buckets will be something like this:

• Cement 25 buckets.
• Sand 43 buckets.
• Crushed stone 90 buckets.

When determining the amount of water, they are guided by the measure of cement: for one bucket of cement powder you need to add an incomplete bucket of water. This volume may vary depending on the situation. For example, if it is reinforced, then the concrete is mixed with more plasticity so that it penetrates inside the frame more easily.

It is more practical to make it rigid, this will speed up the hardening. In both cases, you need to add enough water so that there are no puddles in the finished solution. To obtain one cube of concrete of different grades, the optimal ratio of components in volumetric terms is presented in the table.

In these volumetric indicators, the bucket can be replaced by any volume measure, provided that the proportion is maintained.

When deciding how to prepare concrete for the foundation, you need to keep in mind that in addition to the proportions, you need to know in what sequence to lay the components. First, water is poured into the concrete mixer, slightly less than normal. Then half a portion of crushed stone is poured. And only then, cement with sand and again all components are thoroughly mixed.

At the very end, the remaining crushed stone is poured. After this, you need to give the concrete mixer a little time so that it thoroughly mixes all the components. And finally, having assessed the thickness of the solution, depending on the situation, add the rest of the water or leave it as is and mix everything thoroughly again.

Conclusion

After the foundation casting has reached the calculated hardness, to get rid of doubts about the correctness You can check the proportions and grade of concrete. To do this, place the chisel on the surface of the casting and hit it with a hammer. On ordinary concrete M 200 there should be a dent no more than 5 mm deep.