Proportions of concrete for the foundation in a concrete mixer: mixing instructions

During the process of constructing the foundation itself, it is simply impossible to single out and designate a specific stage that would be the most important.

And all this is only because all the steps are very, very important in work of this kind. After all, literally everyone depends on the quality characteristics of the foundation, both for the object itself and for its subsequent fate.

In addition to everything else, a correct, organized and competent approach to the construction process will serve as an impetus for high-quality construction.

Thus, your structure will serve you for a long time over many years. But before that, you need to find out from professionals about exactly how to do this or that work, for example, pouring a foundation with your own hands using a concrete mixer, and then you will succeed.

By the way , few people know the fact that one of all the final stages of construction work on a monolith and reinforced concrete foundation is the process of pouring the surface with a mixture of concrete.

Materials and tools

Taking into account the independent preparation of concrete for work, we will need:

PC grade 400 or 500 cement, construction sand, crushed stone, water.
Reinforcement (if the project involves reinforcement).
Boards or formwork panels.
Consumables: nails, grinder cutting discs, annealed wire 1-1.5 mm for tying reinforcement.

The main equipment is a gravity concrete mixer with a working volume of at least 150 liters. We place it as close as possible to the installation site. Ideally, by turning the mixer drum over, we immediately feed the concrete into the structure. You will also need:

Buckets and a shovel for dosing the components of the concrete mixture.
Carpentry kit - hacksaw, axe, hammer, crowbar.
Grinder - cutting reinforcement,
Deep vibrator to compact concrete.
Equipment for marking - tape measure, pegs, level (or hydraulic level), string or thick fishing line.

To make the foundation correctly, you need to accurately position the formwork. To do this, directly in the pit you need to indicate the design position of the axes of the house. We do it this way:

Between the axle reference points, pulling a thin wire or cord. They should pass over the dug trenches (pit), so that, if possible, they do not interfere with work.
Using a plumb line, we transfer the position of the axes to the bottom of the trenches.
We drive pegs in these places and stretch the cord between them.

Now, from the projection of the axis in the trench, we can use a tape measure to plot the dimensions of the foundation and mark the location for installing the formwork.

Preparatory work

Preparing a design for the future foundation

First of all: you will have to order a geodetic study from a design and construction organization to determine the type of soil, how capable it is of freezing in winter, the presence and depth of groundwater on the site. This company will also perform the necessary calculations and draw up a design for the construction of the future foundation.

If the planned construction is small in size, all the necessary measures can be done independently. To build a cottage or other large-scale structure, it is advisable to turn to professionals.

Preparation of materials

Typically, high-quality concrete of grade two hundred is used for such work. You can make the mixture yourself, or you can order it ready-made. The process is quite labor-intensive, which explains the heterogeneity of the base filled in individual portions.

The composition of concrete for the manufacture of strip base includes:

cement, gravel and coarse sand in a standard ratio;
clean sand (river) for arranging a pillow;
2-centimeter planed board for making formwork;
wire for reinforcement and steel rod 8-12 mm in diameter.

Features of laying in parts

When stationary, the concrete begins to set within 45 minutes. The process resembles the growth of crystals in a supersaturated solution. First, individual crystallization points appear. Gradually growing, they merge into complex frames that penetrate the entire thickness of the stone. And if we interrupt the laying work, then after 3-5, and in hot weather after 1-1.5 hours, the concrete will set, that is, this frame will penetrate its entire volume.

If we continue laying after such a break, a so-called cold seam will form at the point of contact between the already laid and fresh concrete. And we will actually get two separate structures, since the adhesion of the old and new concrete is at a cold seam.

Cold seam when pouring the foundation

Concreting the foundation

Guided by the markings and the axes stretched over the pit, we set up the formwork and lay the reinforcement. It is necessary to determine in advance how much volume can be filled in a day and prepare the formwork in the appropriate area.

We prepare a concrete mixture in proportions 1:2:4 (cement, sand, crushed stone) and place it in the formwork, compacting it with a vibrator. We pour concrete, adding it in portions, moving sequentially, not allowing a break in concreting for more than an hour and a half. The formwork can be removed and the next section can be concreted no earlier than the concrete reaches a strength of 1.5 MPa. This requires at least a day, after which we remove the formwork in the place where we will continue work.

The joint between previously laid concrete and fresh concrete is called an installation joint. To better match the concrete in this place, we use an iron brush to clean the surface of the poured structure from any exposed cement laitance. We wash the cleaning area to remove construction dust with a stream of water.

Disadvantages of preparing the solution on site

Some builders who prefer to prepare the cement mortar on site want to save some money. Hired workers will cost less. But we must not forget that by laying the mortar in parts, they worsen the characteristics of the foundation. The foundation will not be of high quality if yesterday’s unused cement mortar is used to lay it.

Construction companies deliver concrete mixture prepared using mixers, the volume of which can be 2-10 m3. Serious construction companies use special vehicles to deliver concrete. Although, if the facility under construction is located at a short distance from the supplier’s company, conventional dump trucks can be used for delivery. However, in this case, the time to produce a solution is very limited.

Requirements for the installation seam

The seam should be located to the corner no closer than 1/3 of the side of the foundation. It is best if the seam is in the middle of the wall, strictly perpendicular to the axis of the foundation. It is strictly forbidden to make assembly seams:

at the corners of the structure;
in places where the foundation differs in height;
in places of concentrated load (for example, installation of a column or pier).

After pouring, we level the surface of the foundation edge, and the next day we sand it with a wooden float. Our foundation is poured. It remains to wait a couple of weeks, and when the concrete gains strength, completely dismantle the formwork and begin laying the walls.

Proportions of foundation solution in a concrete mixer

In order for the concrete to gain the required strength within the prescribed time frame (see the foundation strength gain chart), it is necessary to maintain the correct proportions of the solution.

For a foundation mixture made in a concrete mixer, you need to take one part cement, three parts sand and five parts gravel.

For example, for one batch in a concrete mixer with a volume of 180 liters you will need 2 buckets of cement, 6 buckets of sand and 10 buckets of gravel. When mixing, you can use crushed stone instead of gravel - the mixture for the foundation will be even stronger. It’s just better not to use granite crushed stone, stop at dolomite crushed stone, it will provide better adhesion in the prepared solution.

When pouring a screed in a small room of 20 square meters, when we make a screed 15 centimeters thick, we will need 3 cubic meters of concrete. In order to make a solution for pouring screed in this room, we will need to make 20 batches in a concrete mixer with a volume of 150 liters.

For the entire room you will need approximately 35 buckets of cement, 100 buckets of sand and 200 buckets of gravel or crushed stone.

Which cement to use for preparing the mortar, read the article about the grades of cement and the concrete produced from these grades (M150, M200, M300, M400).

Pouring the foundation with your own hands using a concrete mixer

During the process of constructing the foundation itself, it is simply impossible to single out and designate a specific stage that would be the most important.

In addition to everything else, a correct, organized and competent approach to the construction process will serve as an impetus for high-quality construction.

The main stages in pouring the foundation

As soon as all the work that is in one way or another connected to the ground is completed, the installation of surface elements and the waterproofing itself for the base and the manufacture of the reinforced frame are completed, you can begin the reservation stage with complete confidence.

Pouring a foundation with your own hands using a concrete mixer, just like any other stage, can be done using several methods at once. The sample of absolutely each of them is determined by different characteristics in terms of expenses, both time period and financial resources.

And finally, it is very important to know what method should be followed in the process of building a particular structure with your own hands.

Stage three: installation of formwork for the foundation

This stage is quite important - the formwork must be strong and level. For a shallow foundation, building formwork is as easy as shelling pears - in fact, the formwork for such a foundation of a house is the walls of the trench. The only thing that will have to be added is its upper part, which can simply be put together from boards and supported with stones or reinforcement driven into the ground for strength.

Individual approach to pouring the foundation

It should be noted that the most economical, but more difficult task justifies a very complex and difficult process, with regards directly to the process of pouring the foundation with your own hands, while a concrete-based solution is made immediately on the perimeter where, in principle, all general Job.

And all this is done in a very convenient mixer, which is designed for concrete.

As for the volume, it can be absolutely anything. The smallest installation of this type is designed for fifty liters. Naturally, the availability of cycles will depend on what preference was given in the field of a household concrete mixer. They are the ones that need to be reproduced in order to prepare a calculated volume of this type.

Such work is quite difficult to carry out. Especially for foundations that require more than one concrete cube of concrete profile mortar.

It would be better and simpler, and also the smartest thing, to get at least four people interested in this matter, maybe more. In this case, everything depends on the volume of work. And with all this, it is advisable to use a concrete mixer that will have the largest volume, and which can be assembled even with your own hands.

All this is necessary so that fewer cycles are reproduced, and accordingly, all this will take very little time.

If you look at fairly average indicators, then in order to prepare one such part of the concrete mixture, it will take about five or even eight minutes maximum . The presented device must be installed very close to the place where the filling process will be carried out. And it’s good to pour everything at once so that the concrete gains strength on schedule.

Pouring concrete depending on the time of year

Carrying out construction work at different times of the year requires compliance with certain rules.

This time of year is characterized by a sharp temperature difference, so when carrying out construction work, it is imperative to make accurate calculations and adhere to the construction deadlines. At this time of year, soil moisture is quite high. To protect the foundation from its influence, it is necessary to cover the concrete with plastic film. It is attached to the corners of the formwork panels. To improve waterproofing, cover the inside of the formwork panels with film.

During this period, it is very difficult to dig a pit or trench. The frozen ground is practically unworkable. You can cover the work site with plastic wrap for 1 week and burlap on top. As a result, we will get relatively soft soil.

It is recommended to make formwork panels from solid panel foam. It retains heat well and is ideal in winter. When preparing and pouring concrete, it is necessary to monitor the condition of the water; if it freezes, then the basic qualities of concrete, such as reliability, strength, durability, will simply be lost.

There are 3 ways to control the condition of water:

Use of special additives. So, you can add salt to the concrete solution at the rate of 1 kg per 7 liters of concrete. This will prevent freezing. However, the drying time for such concrete will be much longer. This should also be taken into account.
Self-heating of water. After pouring is completed, the concrete is covered with hay or straw, and on top with burlap and polyethylene.
Heating. Using special heating devices, the entire surface of the foundation is independently heated. This is done during the pouring period and within 5 days after its completion.

You can use a heat or air gun.

High temperatures and constant exposure to sunlight have a detrimental effect on the condition of the base.

Thus, the bulk of the water in the concrete solution can simply evaporate. To do this, every 1.5 - 2 hours it is necessary to independently water the base surface with water. The procedure is carried out within a week. Next, watering must be done 3-4 times a day for 1 month.

Is it possible to fill the foundation in parts?

For most people, sooner or later the question arises: is it possible to fill the foundation in parts? Of course it is possible. But some conditions must be met.

For example, in order to build a monolithic foundation, it is imperative to use more than one cube.

By the way, the entire filling process can be extended over several days. This will give the best result of pouring the foundation with a concrete mixer.

If the difference is not more than a day in time, then you can fill the surface layer around the entire perimeter, and also cover the finished base area with a polyethylene film.

And this must be done exactly after one day, but initially by clearing the surface of other excess mixtures. And only then can you continue working. Perhaps this is a more reasonable and best option for the pouring method, which is carried out in several steps. This method is called a hot seam.

It is best, and also preferable, to go a completely different way and reproduce the cold seam method. Of course, if you have no other option, then it is permissible to fill the next layer when the first, very initial one, has been formed.

As for calculating concrete, you can use our online calculator.

In no case should a variation of an intermediate nature be used, namely, when the concrete has just begun the hardening process, but at the same time has not yet reached sufficient strength.

Thus, be especially careful at all stages of pouring a foundation with a concrete mixer, especially if you are doing it for the first time.

Making concrete at the pouring site yourself

Let's first consider the option when concrete for the foundation is made on site by mixing cement, crushed stone and sand in a concrete mixer.
The volume of such a concrete mixer ranges from 50 to 170 liters on average. To pour one cubic meter of concrete into the foundation, you will need to mix the concrete about 10 times. The concrete mixer is loaded manually, which means hundreds of kilograms. The question of the quality of the resulting concrete also remains open. It takes an average of 4-6 hours to produce a cubic meter. At the same time, it is almost impossible to work alone, because... it is necessary to compact the poured concrete. A lot of time is spent on cleaning containers, shovels and tools. During more or less serious construction, concrete is not made in small portions on site using a mini-concrete mixer, but delivery is ordered by concrete mixer trucks. Check with local contractors to find out which manufacturer has good quality concrete.

There is a mandatory requirement to compact concrete when pouring. If compaction is not carried out, numerous air bubbles remain in the concrete. After hardening, these bubbles disrupt the integrity of the concrete mixture, causing premature destruction and reducing the strength of the product. Compaction can be done in two ways.

The first, most correct way is using a deep vibrator. If you fill it yourself, this useful device can be rented daily. The vibrator is immersed in the poured mixture, turned on, and air bubbles in the vibrating concrete can already escape to freedom. When working, it is important not to touch the reinforcement elements of the foundation.

The second method for “homemade filling” is bayoneting. After pouring, the reinforcement is immersed in the concrete mixture, as if pierced through the foundation, and so many times in all parts of the poured concrete. Since the movement is similar to stabbing an enemy with a bayonet, this process is called bayoneting. In this case, it will also be useful to tap the formwork properly so that air bubbles from the walls of the future foundation are released.

Additionally, when pouring large foundations, you can rent a concrete pump. This unit pumps concrete along its long rods (up to 50 meters), delivering it to any far end of the foundation if the mixer’s access there is difficult, or even lifts concrete to a height of several floors.

Be prepared for the fact that you will have to perform quite large amounts of work. This is especially true for foundations that require the use of more than one cubic meter of concrete mixture. It is best if you invite at least three assistants to participate in this activity.

Before you start pouring the foundation with a concrete mixer with your own hands, you should place the unit at a minimum distance from the workplace. In some cases, the base may be poured in several parts. If more than one cubic meter is required to build the foundation, then the pouring can be extended over two days.

In the case when the interval between the first and second stages does not exceed twelve hours, the first layer can be poured along the entire perimeter of the formwork structure. As for the poured part of the base, it can be covered with plastic film. Thus, the work can be extended the next day. This is the most optimal option for pouring concrete in two steps. This mode is called by specialists the hot weld method.

It is not recommended to use more than two layers when pouring the foundation. If this is not possible, then it is better to fill the base in parts, but to the height of the formwork structure. In such cases, you will have to install intermediate partitions. Each newly poured layer of concrete mixture must be compacted. This is done in order to exclude the possibility of the appearance of any cavities that tend to form near the reinforcement ties.

For this purpose, you can resort to the help of improvised means. So, for example, you can take a piece of reinforcing bar. With its help, the solution must be pierced, as it were. If possible, it is better to use a deep vibrator. Thanks to its use, it becomes possible to achieve excellent results with a significant reduction in time costs.

After laying the protective layer of concrete mixture, the foundation base must be covered with a roofing felt layer. This is a protective layer designed to protect the foundation from the negative effects of various precipitation. After about four weeks, the foundation can be considered ready for full loads. At this point, the process of constructing the foundation can be considered complete.

Of course, this option will be more expensive than the one described above. But you will be able to pour a high-quality foundation for your home in one “sitting”. One concrete mixer can deliver from 4 to 8 cubic meters of concrete; if necessary, you can order several machines at once - it depends on your project and the estimated need for the concrete mixture.

Important! Be sure to pour concrete mortar at several points of the formwork. You should not count on the fact that the concrete will spread evenly over the required volume: it will delaminate, which will lead to a difference in the composition of the mixture in different parts of the monolith. In addition, by pouring at one point, you doom yourself to thankless work - you will have to distribute the concrete throughout the entire volume of the formwork manually!

How much does it cost to pour a foundation this way? Everything is individual and depends on the supplier company, as well as the distance over which the solution is planned to be transported. Be sure to add a couple of thousand rubles here if you fill the foundation yourself - a lot depends on the quality of cooperation with the driver.

This option is advisable to use only in cases where it is impossible to drive up to the construction site, and a gutter several tens of meters long is irrelevant. However, you need to be prepared for the fact that operating a concrete pump is not a cheap pleasure. Just to call such a car you will have to pay about 15,000 rubles.

The only good thing is that with its help it is very easy to fill the foundation, and the solution “lies” evenly over the entire area of the prepared formwork.

Pouring a foundation with your own hands using a concrete mixer video

When is it advisable to mix foundation mortar in a concrete mixer?

Firstly, when the volumes of the required solution are small. If you need to pour a foundation for a house, and you decide to go with the option with a basement or with a slab with an area of 100 sq.m. or more, then mixing the foundation mortar with a concrete mixer looks, to say the least, unreasonable.

When it comes to pouring a large volume of foundation mortar, it is unwise to use a concrete mixer.

The volume of concrete for a foundation of this size will exceed 20 cubic meters, which you cannot mix with your “mini-mixer” in a manageable time.

But when a small volume of solution is required, then a concrete mixer is what you need.
Look, the average batch with a small concrete mixer is from 150 to 300 liters of solution. You will be pouring a large foundation at this rate for 20-30 days.

Secondly, you can mix the foundation mortar with a concrete mixer when it is not possible to adjust the mixer to the concrete receiving site or when it is not possible to reach the concrete pump supply pipe there.

When might such a situation arise? For example, when pouring screeds over large areas under an already installed roof or indoors, on the floors of a house.

There is one “but” in this option... The volumes of concrete produced should also be relatively small. In 10 batches you should produce 1.5-2 cubic meters of mortar, which will be laid within 2-3 hours.

In order for the concrete to gain the required strength within the prescribed time frame (see the foundation strength gain chart), it is necessary to maintain the correct proportions of the solution.

For a foundation mixture made in a concrete mixer, you need to take one part cement, three parts sand and five parts gravel.

For the entire room you will need approximately 35 buckets of cement, 100 buckets of sand and 200 buckets of gravel or crushed stone.

Which cement to use for preparing the mortar, read the article about the grades of cement and the concrete produced from these grades (M150, M200, M300, M400).

After we had done the piping and were ready to start pouring the foundation for the garage, I drove a car with sand to the construction site. I bought cement back in the spring, when it wasn’t as expensive as it is now, at the height of the construction season. I have had dolomite crushed stone since last year, when I used it to raise the level of the site in order to lower the groundwater level - I used this crushed stone as the final layer above layers of soil, sand and geotextile layers.

Pouring the foundation with a concrete mixer with your own hands: from preparation to pouring

Usually, during construction work, all attention is paid to the building itself, but its foundation is not taken seriously. This opinion is wrong. The strength and durability of the building depends on the quality of the foundation construction work. To ensure a strong foundation, several factors should be taken into account. Thus, its durability is facilitated by pouring the foundation with a concrete mixer with your own hands. This fairly easy-to-use technology allows you to obtain a structure of European quality.

From marking to filling

Site marking

One of the important stages is marking the site for the foundation. First, the site is cleared of foreign objects and small debris. Next, all soil from the site is cut off to a depth of approximately 15 cm to limit further rotting processes in the basement of the building.

How is marking done?

Find the location of the first corner of the building axis. Using a plumb line, pegs are installed: they can serve as suitable pieces of reinforcement.
Find the next angles , the second and third, using string and pegs. They install pegs there too.
Pull the cord towards the fourth one from the previous ones, make the correct angle along the square, and also place a peg.
Check the diagonals of the resulting rectangle, repeating the outer perimeter of the building. They should be even if the corners are built correctly.
Similarly, the internal foundation is outlined , as well as its parts for individual components: porch, supports for columns, terrace, load-bearing walls.
Install slats or planks of wood to align the markings in a horizontal plane, and pull a rope through them.

Land works

It is necessary to prepare a trench with a given depth
, calculated in advance (or specified in the project). Digging work begins from the lowest angle so that the hole does not turn out smaller than expected. Its walls must be strictly vertical. The bottom is leveled.
A layer of sand at least 15 cm thick is placed in the dug pit. This cushion will play an important role in redistributing the load on the base. This is especially true for soils capable of swelling. Sand is poured in layers, each of which is soaked in water and compacted well.

Formwork

Using a rope, mark the outline for the formwork. Install supports at the corners. This requires beams 5 centimeters thick.

The formwork is made from edged boards, which are connected using corners with screws or wooden blocks.

The corners and bars are located outside the formwork, the heads of the screws remain inside.

To avoid deformation of the structure when pouring the cement mass, supports are placed on the outside. The formwork must rise above the ground to such a height that the resulting foundation is at least 30 cm. The level to which concrete is poured is marked inside the foundation.

Armature

You will need 8-12 mm metal rod , which is cut into pieces of the required length. They are placed along and across the base, and if it is thicker than 40 cm, then also vertically.
The reinforcement is firmly tied together with metal wire and securely fixed to the walls of the formwork.

The process of pouring a strip foundation for a house

If concrete is ordered, the pouring is carried out at once, simultaneously. Layer-by-layer filling is done if the mass is prepared on its own.

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Step-by-step pouring of strip foundation

First, the concrete is prepared. The sand is sifted, mixed with cement and water, stirred evenly. The prepared composition is poured into crushed stone, the amount of which is equal to the amount of sand. Mix well so that all the crushed stone is evenly moistened.
Concrete mixture is poured into the self-made formwork. To ensure high-quality filling and prevent the formation of bubbles, the concrete is pierced with an iron rod and compacted with a wooden beam. It is more convenient to use a special construction mixer or a hammer drill with an attachment for this.
Fill the formwork with concrete mixture to the marked level. To speed up the settlement of concrete, tap the formwork from the outside.
Smooth the surface of the concrete with a trowel or rule.
The concrete surface is sprinkled with sifted dry cement powder. You can do this evenly through a sieve. This procedure will ensure quick setting of the concrete surface and prevent its cracking or erosion.
The concrete is wrapped with covering material or regular burlap. It is left in this form for about a month to ripen. If the weather is hot and dry, then the top cement layer is periodically wetted to avoid drying out.

Completion of work and useful tips

Only after the final maturation of the concrete monolith can we proceed to further construction and begin the construction of walls.

When the formwork is removed, it is necessary to perform high-quality waterproofing of the base. This will improve the moisture-insulating and heat-retaining functions of the strip foundation, and also increase its service life.

It is better to make sure in advance that the ordered machine will pour concrete mixture from any angle.
It is advisable to take care of making an additional tray: the composition will be supplied into it.
The solution must be checked before pouring - sometimes it hardens a little during transportation.
In the rain, take care of a reliable shelter, otherwise the top layer of cement may be washed away by jets of water.

Foundation: main types

Before studying the technology of pouring a foundation, you should consider the main types of foundation:

Slab. It is a heavy monolithic concrete or reinforced concrete slab. Suitable for the construction of all types of buildings.
Tape. High strength base. The best option for low buildings. Construction is carried out along the perimeter of the building.
Pile. It is a cluster of pillars holding up a building. Piles are installed along its perimeter and in the corners.

Special equipment is becoming increasingly popular during construction work. Thus, a concrete mixer greatly facilitates and speeds up the process of building foundations. It is worth considering which foundation can be poured with a concrete mixer.

Pouring strip foundation

Monolithic concrete strip located under the walls along the perimeter of the building and internal walls. Suitable for light and heavy buildings.

Based on the base material it is divided into:

Rubble;
Concrete;
Rubble-concrete;
Reinforced concrete;
Brick.

According to the depth of the bookmark, this type can be shallow (up to 60 cm) and deep (up to 150 cm). The laying depth is calculated based on the quality of the soil and the weight of the structure.

Preparation of concrete

Before pouring the foundation with a concrete mixer, you need to purchase a concrete solution. You can do it yourself.

Don't skimp on a concrete mixer. A hand-mixed solution will not have sufficient strength and hardness.

The sand is coarse river sand. You can use construction.

Crushed stone is fine (fraction size from 5 to 20).

Cement – class 500.

The water must be clean, without foreign impurities.

Stages of concrete production:

Turn off the concrete mixer.
We calculate the optimal proportions of cement for a concrete mixer.
Pour 1 bucket of water and alternately 2 bags of cement into a concrete mixer.
Turn on the concrete mixer.
After 10 minutes, we begin to pour sand. In total you need to use 8 - 10 buckets. It is recommended to take short breaks every 2 buckets.
Monitor the condition of the solution. If the consistency is too thick, add water.
Gradually pour 8 - 10 buckets of crushed stone into the solution. After backfilling is completed, wait 15-20 minutes.
If there is too much dust in the concrete, add water.

The resulting concrete solution can be used in construction.

Concrete mix components

A concrete solution is a mixture of various components, each of which is responsible for a specific quality of the foundation:

Cement is the main element that binds and determines the quality of the finished mixture;
Sand is an element of fine filling of concrete dough. Use exclusively river and quartz sand with a particle size of 2-3.5 mm.
Solid fillers - crushed stone, gravel. Fractions from 40 to 130 mm are used;
Water.

Additives help give the solution additional qualities:

Slaked lime – makes it easier to lay the mortar;
Plasticizers – give the mixture fluidity;
Reinforcing elements – add strength;
Auxiliary substances are additives that promote concrete hardening at high humidity and low temperatures.

The quantity and composition of additives are regulated depending on the purpose of the concrete.

Self-fill

Every builder is quite capable of pouring a foundation with a concrete mixer with his own hands; he just needs to study the main stages and nuances of the work.

First you need to do some preparatory work. This includes:

Studying the depth of groundwater
Calculation of soil freezing level
Study of the composition and basic characteristics of soil

The strength and durability of the foundation being built depends on correct calculations.

Next, you need to measure and calculate the level of load and pressure of the building on the foundation. Based on this value, it is necessary to choose the optimal type of base.
Calculation and marking on the construction site. To do this, you need to use wooden pegs driven into the ground with ropes stretched between them.
Removing the top layer of soil (10-15 cm).
Construction of a trench.
Installation of a drainage pad made of a mixture of crushed stone and sand.
Construction of formwork from wooden panels.
Creation of reinforcement mesh and its installation.
Pouring the foundation.

Columnar

Used for light buildings: wooden, frame, panel houses, extensions, light buildings made of aerated concrete blocks. It consists of concrete pillars located along the perimeter of the building in increments of 2.5-3 meters. A grillage made of timber, concrete or metal channels is mounted on the top of the pillars, onto which the walls of the building are directly installed.

The pillars are made of concrete, rubble, brick or wood. The pillars are buried to the level of soil freezing. This type of foundation is ideal for sloping areas. The pillars are buried to the level of dense soil.

A columnar foundation is not used if it is necessary to build a basement or ground floor under the building.

Defining Base Layers

Before you begin to fill the base with cement mortar, you should calculate the required number of layers. There are 2 filling options:

Pouring concrete in 2 layers
Filling in parts with orientation towards the formwork panel.

In order to fill the base in parts, it is necessary to mount and install partition panels. This technology takes quite a lot of time, so its use is impractical.

When pouring concrete layer by layer, each layer must be subjected to a compaction procedure. To compact the solution as much as possible, it is recommended to use a special vibration device.

After pouring is completed, it is recommended to cover the concrete with plastic film. This will protect it from drying out and cracking. Also, the concrete should be moistened every 3 to 4 hours. After 7 days, moisturizing is carried out every 7 hours. Duration of moisturizing is 1 month.

Component proportions

For small volumes of work in private construction, the most convenient option for measuring the components of a concrete mixture is in buckets.

The proportions based on the total volume of each batch are as follows:

Cement – 2 parts;
Sand – 4 parts;
Filler – 8 parts;
Water – 1 part.

The characteristics of the resulting concrete depend on the brand of cement used. For the foundation, cement M400 and M500 is recommended. You can calculate the amount of cement required using the following table:

Concrete grade	Cement brand	Mass of cement per 1 cubic meter m.	Number of bags
M250	M400	300	6
M300		350	7
M400		400	8

In domestic construction, concrete above M350 is practically not used. To lay a foundation on ordinary soil, concrete with a strength of M250-300 is sufficient. You can calculate the required volume of concrete in liters using various online calculators.

Features of pouring using a concrete mixer

So, how to use a concrete mixer correctly? To do this, you should familiarize yourself with the main features of the work:

Filling is done simultaneously. All corners of the formwork should be poured at the same time. It is worth remembering that the concrete solution will not spread around the perimeter of the foundation, so simultaneous pouring of all its sides is necessary. Failure to comply with this rule leads to delamination and subsequent cracking of the foundation.
If pouring occurs only in one place of the base, then it is necessary to manually distribute the concrete over the entire surface using a shovel. This method does not guarantee a smooth surface. It is recommended to carry out an alignment procedure.
Formwork panels must be removed 5 days after pouring concrete.

Rules for mixing concrete

The quality of the mixture obtained in a concrete mixer depends on the choice of components, compliance with proportions and loading technology.

The work consists of the following stages:

Installation of a concrete mixer. The device is installed on a flat surface so that the tank is in the correct position, otherwise the mixing of the components will be uneven and the solution will partially form lumps. It is necessary to foresee in advance how the container for unloading the solution will be located.
Loading components. First of all, half the dose of sand is poured, then gravel and then cement is gradually added. Lastly, pour out the remaining sand.
Filling of water. After thoroughly mixing the dry ingredients, add water.
Kneading. Mixing the components of the solution is a simple procedure, but it also has its own characteristics. Do not stir the solution for too long so that it does not begin to set. If the concrete mixer is working properly, it is enough to mix the solution for 10 minutes. After 5-6 minutes of mixing, you can check the quality: take a little of the mixture, make a “blot” out of it and draw several grooves along it. If the grooves do not tighten for a while, the solution is ready.
Unloading. The finished solution is completely unloaded from the concrete mixer. If you take it in parts, conditions will be created inside the concrete mixer for delamination, as the filler will begin to settle.
Cleaning the concrete mixer. There is no need to rinse the internal surfaces of the concrete mixer after each batch, but it is necessary to thoroughly clean the remnants of the previous portion of the solution from the walls and blades. At the end of the work, the concrete mixer is thoroughly washed with water.

To prevent dry components from sticking to the walls of the concrete mixer, before loading them, the inner walls are moistened with liquid cement laitance.