What are the proportions of concrete for the foundation. Mortar for the foundation Proportions when pouring the foundation

The brand of concrete and proportions for a private house largely determine the durability and reliability of the entire structure.

To make the right choice of mixture, it is important to take into account all the influencing factors, incl. loads and geological features.

It is especially important to ensure the optimal ratio of ingredients when preparing the mixture yourself.

In general, concrete is an aqueous solution of a mixture of binder and aggregate with the addition of ingredients to improve properties. The preparation technology is quite simple - the components are mixed in a certain sequence, the right amount of water is added and everything is thoroughly mixed.

The properties of a material are primarily determined by its composition. The concrete mixture includes such components.

Cement

The basis of concrete is binder - cement, which holds together all the components as it hardens. In private construction, Portland cement grades M300-M500 are used for foundations (the number in the marking determines the strength of the cement).

Placeholders

They provide the bulk of the concrete. In any composition there are such fillers (fillers):

Sand- for the preparation of the mixture, only purified from impurities with a particle size in the range of 1-4 mm is used; in one batch it is not recommended to use sand with a spread in their size of more than 1-1.5 mm. Can be used river, sea or quarry sand that has undergone thorough cleaning and separation of excessively large fractions.
Crushed stone and gravel- strength characteristics are provided by the second important filler - gravel or crushed stone. For the preparation of concrete, raw materials with a fraction size in the range of 7-40 mm are used. The roughness of individual elements improves their adhesion in the final product.
Water. Without it, it is impossible to prepare a solution. It provides the desired consistency. It is best to use ordinary tap or well (well) water. If it is taken from open water bodies (river, lake), then silt and various impurities will be found in the composition, which adversely affect the quality of the solution.

Additional ingredients (modifiers)

They are not considered essential components of concrete for the foundation, but their introduction allows you to obtain specific properties that are sometimes simply necessary during construction or operation. As such ingredients are used:

mortar hardening accelerators or retarders;
plasticizers;
superplasticizers;
antifreeze ingredients.

When adding modifiers, it is important to strictly observe the proportions, because their excessive content can break the solidity of concrete.

The composition of concrete determines all its main characteristics - strength, specific gravity, plasticity, hardening time, frost resistance, water permeability. By varying the brand of cement and the ratio of ingredients, it is possible to change the properties of the mixture depending on specific requirements.

How is the strength grade of concrete formed?

The most important characteristic of the foundation of the house - compressive and bending strength. These parameters largely depend on the strength parameters of concrete. Its marking for strength is made up of the letter "M" and numbers indicating the compressive strength in kg / sq.m.

The modern strength classification provides for a division into classes, denoted by the letter "B" and a number (compressive strength in MPa). However, manufacturers still use the first marking more often.

Depending on composition concrete can be graded from M50 to M800. For the construction of small buildings on solid soils, it is quite enough to use the M200-M250 material. Most often, for private houses, the strength of M400 is recommended, and for the construction of large structures and heavy facades - M500.

When considering the strength characteristics, it is important to take into account that the declared value is achieved after a certain time. The gradual increase in strength as the structure develops is a specific property of concrete.

For standard mixtures, this period is 28 days. By introducing special additives, it can be significantly shifted in one direction or another. In this case, the actual time for reaching the rated strength is indicated in the marking (if there are no instructions, then it is taken as 28 days).

Influence of wall structure and soil composition

The choice of brand of concrete for the foundation should take into account the design of the walls of the house and the geological parameters of the soil.

The wall material forms a load on the base, i.e. the impact on it from above, and the state of the soil is the degree of external influence from below.

When choosing, you can focus on the following recommendations:

wooden walls and porous block masonry - concrete M200-M250 is suitable;
brickwork in a one-story version - M250-M300;
two-story houses with a brick wall - M300-M350;
weighted, load-bearing facade - M400-M500.

The composition of the soil and its condition plays an important role in the selection of material for the foundation. Of particular importance is the depth of groundwater and the level of winter freezing. First of all, in order to increase frost resistance and water resistance, it is necessary to correctly select the brand of cement in the concrete recipe.

For complex soils, the cement grade should be 1.7-2 times higher than the concrete grade (for example, for M250 concrete, Portland cement of at least M400 grade will be required). With hard (rocky) soils, the grades are approximately equal.

If the soil is assessed as clayey or waterlogged, then the concrete strength grade increases by at least 50 units. So, for ordinary brickwork with a design grade M250, it will be necessary to prepare concrete of a grade not lower than M300 (preferably M400).

The choice of concrete for different foundations

Different types of foundation perceive loads differently. So the columnar foundation works only for compression, and and - for compression and bending. This specificity also causes the appearance of different requirements for concrete for these types of house foundations.

In addition to these selection criteria, there are several other important parameters that must be considered:

Frost resistance. In the marking, it is marked with the letter F indicating the permissible sub-zero temperature. For example, concrete grade F50 can be used in almost any climate zone, because. able to withstand temperatures down to minus 50 degrees. For temperate latitudes, material not lower than F35 is recommended.
Mobility (P). It characterizes the fluidity or plasticity of the mortar during construction. When manually pouring, you can use solutions P2-P3. If a concrete pump is involved, then a material of at least P4 will be required.
Moisture resistance (W). This characteristic depends on the presence of special additives that provide moisture resistance. Under normal conditions, concrete W4-W5 is used. With a high rise in groundwater, the material class rises to W10.

In addition, concretes differ in specific gravity. When building the foundations of private houses, a light composition is used. Such concrete can have a density in the range of 600-1600 kg/m3.

Proportions of concrete for the foundation

The ratio of ingredients in the solution forms the brand of concrete and its plasticity during laying. For each brand there is a specific recipe, but the consistency of the solution is determined by the amount of water added. Proportions can be determined by weight or by volume.

The most common is volumetric mixing (in fractions), for which it is enough to have a measuring bucket. When using "dilute by mass" you will have to use a scale.

If the material is prepared by hand, and therefore the exact brand is not always important, then the most common proportion (by volume) is used: cement (1 share), sand (3 shares), crushed stone (5 shares), water (1/2 share).

If you want to get a specific brand of concrete, you can use the following ratios of cement, sand and crushed stone:

M100 - by volume - 1: 4.1: 6.1; by weight - 1:4.7:7;
M200 - by volume - 1: 2.5: 4.3; by weight - 1:2.8:4.7;
M300 - by volume - 1: 1.8: 3.2; by weight - 1:2:3.7;
M300 - by volume - 1: 1.2: 2.3; by weight - 1:1.2:2.6.

When translating volumetric and weight ratios, you can use practical advice:

In a bucket with a capacity of 10 liters, cement 15 kg, sand 20 kg, crushed stone 18 kg are placed.

How to cook with your own hands?

Independent production of concrete mortar is carried out in the following order:

Preparation of ingredients– screening, removal of impurities.
Hanging the components of the mixture. As a rule, a measuring bucket is used.
Mixing with water. There are 2 methods - the dry method, when the components are first mixed together, and then water is gradually added, and the wet method, when half of the total volume of water is poured, cement, sand and gravel are alternately poured into it, and then the remaining volume of water. For mixing, it is better to use a construction mixer or a perforator with a special nozzle.

For work, you will need - a shovel, a construction mixer, a sieve, a wheelbarrow or a stretcher for the delivery of components, a scoop, a measuring bucket, scales (steelyard).

When building the foundation of a private house (see:) it is very important to choose the right grade of concrete for strength and basic characteristics. If the preparation of the solution is done by hand, then it is necessary to strictly adhere to the recipe. The quality of preparation and composition of concrete determines the durability of the entire structure.

Concrete is one of the most commonly used building materials. Only a properly prepared mixture provides good strength indicators and is able to cope with its initial tasks.

Optimal proportions of concrete

In the process of manufacturing concrete, the composition, or rather the proportions of the main components, is determined by its original purpose. Some brands of concrete cannot be used in the construction of the foundation due to weak strength.

The general proportions for high-quality concrete look like this:

10 kg of cement;
30 kg of sand;
40-50 kg of gravel or crushed stone to choose from.

To recreate concrete mixtures, for example, grades M300 or M400, the total weight of all components must be twice as much as the weight of the water used. Thus, in standard proportions, 80-90 kg of dry mixture is used, which will require 40-45 liters of clean water.

If, when making concrete with your own hands, the solution turns out to be too dense, you should add a little liquid to achieve the correct look. It is extremely important that the solution has a high viscosity, otherwise the mixture can be considered spoiled.

The resulting mixture, in consistency, should be easily mixed with a shovel, but also require some effort for this. (see photo above)

It is worth noting that wet sand contains a certain amount of liquid. In order not to spoil the cement mortar, you should first dry the sand or subtract a few liters of water. Also, do not leave sand in buckets for a long time so that it is not saturated with moisture from the air.

Popular brands of concrete for the foundation

Each individual type of foundation has its own brand. This marking, in turn, determines the strength of the solution, which is extremely important in construction work. The most commonly used and suitable for the foundation are solutions M200 and M300.

It is important to note that it is often impossible to calculate exact proportions of a mixture to units. This is due to many different factors, for example, due to monthly storage, a dry mixture can lose up to 10% of its original strength, up to 20% in 3 months, and up to 30% in six months. Such structural changes occur due to moisture in the air, which gradually mixes with the mixture, making it less usable.

The greatest savings can be achieved by using low-grade cement, but the resulting concrete should only be used for small structures.

Each type of concrete requires a unique ratio of components, given the brand of cement. In this case, the amount of liquid, for the most part, is calculated in accordance with half the mass of the dry mixture in kg.

For the manufacture of concrete mortar grade M200 using cement M400, you must follow the proportions:

1 part cement;
2.8 parts of sand;
4.8 parts of crushed stone or gravel.

When using cement M500, concrete has the following proportions:

1 part cement;
3.5 parts of sand;
5.6 parts crushed stone or gravel.

The amount of liquid used directly depends on the desired consistency. Most often, when creating such concrete, less than 50% of the liquid is required. M200 concrete mortar is used in the construction of small buildings, for example, one-story country houses.

M300 concrete mortar is most often used to create a foundation. In its manufacture using M400 cement, it is necessary to adhere to such proportions as:

1 part cement;
1.9 part of sand;
3.7 parts of gravel or crushed stone.

For mortar M300 with cement M500, you need to use:

1 part cement;
2.4 parts of sand;
4.3 parts crushed stone or gravel.

It is best to take the minimum amount of liquid for this solution, since the strength of the future foundation directly depends on the viscosity of the mixture. M300 concrete is recommended for use in the construction of foundations for massive buildings. For example, such a mixture is often used in the construction of country cottages and some city buildings.

Proportions for concrete mixer

The use of a concrete mixer in the construction process is reasonable only if it is necessary to cover an area in excess of 100 m 2. Otherwise, it is best to use a bucket or some suitable container and mix by hand.

The manufacture of concrete must be carried out taking into account the approximate period of hardening of the foundation in order to have time to use all the mixture made before it dries completely. At the same time, on average, laying 1.5-2 m 3 of concrete is required to be completed in 2-3 hours.

When creating concrete in a concrete mixer, it is necessary to adhere to the proportions: 1 part cement, 3 parts sand and 5 parts gravel or crushed stone. For example, for a concrete mixer of 180 liters, you need:

2 buckets of cement;
6 buckets of sand;
10 buckets of gravel.

Water is added depending on the volume of the dry mix. Thus, a 180-liter concrete mixer will require approximately 90 liters of clean liquid.

A mortar of concrete is a mixture of various components (sand, crushed stone, water and cement), as a result of mixing and subsequent solidification of which, a solid, incredibly durable building material is obtained, which is sometimes called "artificial stone". For obvious reasons, no building can do without concrete. It is the main component in the construction of foundations, walls, floor slabs, floor screeds, curb and paving slabs and much more. Therefore, it is very important that the concrete solution be of high quality, which means that the concrete production technology must be strictly observed.

Do-it-yourself concrete - the main components

For one reason or another, it is sometimes impossible to order ready-made concrete in production. Either the manufacturer set the price too high and it is much more profitable for you to make it yourself, or you need very little of it, so there is no need to bring concrete with a mixer.

Before starting work, it is important to remember the following - the proportions of the added components, depending on the brand of concrete, may differ. For example, to get concrete M200- the ratio of the proportion of cement (M400), sand and crushed stone is 1: 2.8: 4.8 (respectively). If you need concrete grade M300- in the presence of the same components, the proportion will look like this 1: 1.9: 3.7 (respectively). Further below in the table you can get acquainted in detail with the exact ratio of components.

Cement

This is exactly the connecting element without which, regardless of the brand of concrete, it is impossible to make a solution. The strength and speed of its solidification will directly depend on its quality.

Necessary marking of cement, for obtaining concrete of various grades, under natural hardening conditions

Now in the construction markets you can find various types of cements that have different indicators in compressive strength. All of them are divided into groups, which determines their ultimate load in the frozen state.

The percentage of additives and impurities is indicated by the letter "D". For example, cement M400-D20 it means content in it 20% additives. It is impossible not to take into account this indicator, the plasticity and strength of the material directly depend on it.

From the products presented on the markets, it is possible to single out the well-proven Portland cement. Among its main advantages are:

Sufficiently long service life;
It has excellent strength indicators;
Resistant to sudden changes in air temperature;
Not afraid of moisture.

Important! Whatever the brand of cement, it should be crumbly, without the presence of lumps in it and not expired.

Sand

For the preparation of concrete mortar according to GOST 8736-93 it is possible to use sand of various fractions of granules ( see fig. 1). The final characteristics of concrete will directly depend on its quality.

rice. 1 The size of the fractions of sand used for the preparation of concrete

Regardless of the type of sand, the absence of clay in its composition is a prerequisite, its presence will significantly reduce the strength of concrete. Usually, quarry sand is used to prepare the mixture, in which there are often many foreign particles (dirt, debris, bark and tree roots.).

Such sand must be washed and sifted through a sieve before adding. If this is not done, voids may form in the hardened concrete, which over time will lead to the formation of cracks in it.

It is also important to pay attention to the moisture content of the sand, which is present in a small amount even in a dry product. In wet sand, the percentage of moisture can reach 12% from its total weight. This point will need to be taken into account when drawing up the correct proportions of the necessary components, in particular water.

Without a special device, you can measure the exact amount of moisture in the sand in the following way:

Prepare a small metal container, an old unnecessary pan will do. Weigh her net weight and record;
Next, pour into it, pre-weighed and prepared 1 kg. sand and place the container on 10-15 min. on a hot stove, while constantly stirring the contents;
Without letting the sand cool down, re-weigh the container along with the hot sand. From the result obtained, we subtract the weight of the container (pan) known to us and multiply it by the number 100 ;
The resulting product will be the percentage value of the moisture content of the sand.

When dry, the sand should have a crumbly consistency.

rubble

Another important component of the concrete solution is crushed stone. This material is made by crushing rocks (limestone, granite, stone) into smaller ones, resulting in crushed stone having various fractions. Their size determines the original product into the following types:

The smallest gravel - the size of the fractions is less than 5 mm. It is applied at internal and external finishing works;
Fine crushed stone - the size of fractions is 5-20 mm. The most commonly used size when pouring foundations and screeds;
Medium crushed stone - the size of fractions is 20-40 mm. It is impossible to do without it in the construction of railways and roads, as well as in the construction of a foundation for large industrial buildings that create increased loads;
Large crushed stone - the size of fractions is 40-70 mm. It is necessary for the construction of large-scale structures that require a huge amount of mortar;

When calculating the preparation of a concrete mixture, it is necessary to take into account another important indicator, such as the void space of the material (VPM). Calculating it is quite simple. To do this, pour crushed stone to the very top in a bucket of 10 liters. After that, with measuring utensils, slowly begin to pour water into it until it appears on the surface. The number of liters of water you fill in is an indicator of void space. For example, if in a bucket of rubble fit 3 liters of water, then the PPM indicator will be 30% .

Required amount of water

How to make a quality mixture? The answer is simple, for its preparation it is necessary to use only clean water. It should not contain impurities of oils, chemical and petroleum products, as well as various household waste. All these substances can significantly reduce the strength characteristics of the finished product.

The plasticity of concrete is also an equally important indicator, which directly depends on the quantitative content of water in it in proportion to crushed stone and gravel. You can get acquainted with the optimal ratio of water to filler in the table below. №1 .

Table No. 1 - the required amount of water (l / m³) depending on the filler

The required level of plasticity of the mixture	Gravel fractions (mm)				Fractions of crushed stone (mm)
	10mm	20mm	40mm	80mm	10mm	20mm	40mm	80mm
Maximum plasticity	210	195	180	165	225	210	195	180
Medium plasticity	200	185	170	155	215	200	185	170
Minimum plasticity	190	175	160	145	205	190	175	160
having no plasticity	180	165	150	135	195	180	165	150

It is important to adhere to this table, since the lack of moisture in concrete, just like its excess, will negatively affect its quality.

Calculation of the composition of concrete

Required brand of concrete;
Required level of solution plasticity;
Marking of the cement used;
The size of the fractions of sand and gravel.

As an example, we will calculate a solution of maximum plasticity, the strength of which corresponds to the marking M 300.

Calculation of concrete by weight - from the first we take the recommended brand of cement M400 with crushed stone filler with medium-sized granules. Using the table №2 we determine the necessary proportions of the mass of water and cement (W / C - water-cement ratio).

Table. No. 2 - W / C indicator used for different markings of concrete

MARKING CEMENT
MARKING CEMENT	M100	M150	M200	M250	M300	M400
M 300	0,74	0,63	0,56	0,49	0,41	—
M 300	0,81	0.69	0.61	0.53	0.46	—
M 400	0,87	0,72	0,65	0,57	0,51	0,39
M 400	0,92	0,79	0,69	0,62	0,56	0,44
M 500	—	0,86	0,70	0,63	0,62	0,48
M 500	—	0,89	0,75	0,70	0,64	0,53
M 600	—	0,92	0,76	0,70	0,64	0,49
M 600	—	1.02	0,78	0,72	0,70	0,54
- the use of gravel. - use of rubble.

Knowing all the data (concrete - M300, cement - M400, filler - crushed stone), according to table No. 2, we easily find the water-cement ratio, which is equal to - 0.56 .

It remains to find the required volume of water in order to obtain the finished product of maximum plasticity, taking into account the use of crushed stone fractions 20 mm. To do this, we return to where we see that the result obtained is equal to 210 l/m³.

After all the basic data became known to us, we calculate the required amount of cement for the preparation 1m³ concrete mix. Divide 210 l/m³ on 0.56 , we get 375 kg. cement. Using the table №3 we derive the final proportions of all the necessary components.

Table number 3. Proportions of the ratio of components (cement, sand, crushed stone)

Concrete grades	Grade of cement
	M 400	M 500
	The ratio of proportions by weight - (cement: sand: crushed stone)
M100	1: 4,6: 7,0	1: 5,8: 8,1
M150	1: 3,5: 5,7	1: 4,5: 6,6
M200	1: 2,8: 4,8	1: 3,5: 5,6
M250	1: 2,1: 3,9	1: 2,6: 4,5
M300	1: 1,9: 3,7	1: 2,4: 4,3
M400	1: 1,2: 2,7	1: 1,6: 3,2
M450	1: 1,1: 2,5	1: 1,4: 2,9

So, if for the preparation of 1 m³ of concrete (M300) we need 375 kg. cement (M400), then, following the calculated indicator of table No. 3, we get sand - 375 × 1.9 = 713 kg., crushed stone - 375 × 3.7 = 1,388 kg.

Methods for mixing concrete

There are two ways to prepare building concrete with your own hands:

Mix the solution manually;
Use a concrete mixer to mix.

Manual mixing of concrete

First, pour the required amount of sand into a clean container;
Strictly observing the proportions, pour cement on top. Mix both fillers well until their color is uniform;
Measure the required amount of water, and add it in small portions to the container with sand and cement, while distributing and mixing the mixture over the entire area. The result should be a gray mass without lumps and visible residues of sand and cement;
The final step is to add crushed stone to the resulting solution. Mixing should take place until each pebble is covered with a solution. To give the concrete the necessary plasticity, add water if necessary.

Among the disadvantages of the manual method, the following can be distinguished:

Quite a laborious and lengthy process;
Immediate use of the solution after kneading. Otherwise, the solution may begin to delaminate, which will lead to a deterioration in its quality.

Mixing with a concrete mixer

Pour a small amount of water into the concrete mixer drum, then add cement there and mix well until a gray milk is obtained. From now on, the drum should rotate continuously;
Further, according to the calculation of proportions, proceed to backfilling of fillers (sand and gravel). Stir for another 2-3 minutes;
Add a couple more liters of water to the resulting mixture until a homogeneous consistency is obtained.

The main advantage of this method of mixing is the possibility of using concrete for another hour after mixing the solution.

The ready-made concrete solution has a plastic composition, which includes four required components: cement, crushed stone (gravel), sand and water. Mixing of materials must occur in strict sequence. The proportions of the components for the foundation are approximately as follows: C - 1 share, Shch - 5 shares, P - 3 shares, V - 0.5 shares (C - cement, Shch - crushed stone, P - sand, V - water).

These figures may vary, as in practice they depend on a number of factors, for example, on the required grade of concrete, the grade of cement used, the physical and chemical characteristics of sand and gravel, on the type of additives and their dosage.

Features of concrete mixes

The key components that make up concrete are cement and water, which are responsible for the solidity of the structure and form a cement stone in tandem. However, when hardening, such a stone is subject to deformation, shrinkage can approach a value of 2 mm per meter.

The process occurs unevenly, internal stresses arise in the material, the result of which are microcracks. No matter how much you look, it is impossible to notice them visually, but the quality of the cement stone will be low. To minimize deformations, aggregates in the form of sand, expanded clay, gravel or crushed stone are included in the solution.

The purpose of the aggregates is to form structural reinforcement, which will have to take the stress of the material from shrinkage. As a result, shrinkage is significantly reduced, while the strength of concrete increases and creep decreases.

Concrete marking

For marking concrete, a numerical designation is used, which follows the letter "M". There is an extensive range of concrete: from M-75 to M-1000. A set of numbers indicates the design resistance of concrete to its compression (measured in kgf / cm2) at the time of its complete hardening, i.e. after 28 days. For example, for the M300 brand, this value is close to 300 kg/cm2. Thus, the larger the digital indicator in the marking, the stronger the concrete.

Areas of use

Even a person ignorant in construction knows that concrete is the foundation of the foundations. Each type of work corresponds to a certain brand.

M-100 and M-150 - used for the installation of pillows under the base of the foundation;
M-200 - the most common brand, used for pouring foundations, floor screeds, retaining walls, blind areas and paths;
M-250 and M-300 - intermediate grades between M-200 and M-350;
M-350 - the most popular brand, which is used for the construction of monolithic foundations, load-bearing structures, road surfaces;
M-400 and M-450 are rarely used, mainly in the construction of hydraulic structures;
M-500 and M-550 are used for the construction of facilities to which special requirements apply (these are dams, dams, subways, etc.).

For small construction work, it is convenient to measure the number of components in buckets. This makes it easier and faster to mix good quality concrete. How many buckets of materials will be required in order to prepare a working composition depends on the amount of work. Here it is important to take into account the fact that all the components of the concrete dough have different volumetric mass: a bucket of cement weighs about 15 kg, a bucket of sand - about 19 kg, and a mass of crushed stone is about 17.5 kg.

The optimal proportions of the components in one cube of concrete dough using buckets are approximately as follows: 2:5:9, where, respectively, cement / sand / crushed stone. Having measured the components, they begin to prepare the m200 concrete mortar, which can be used both for pouring the foundation and for screeding floors, erecting porches, etc. Water is usually added to the concrete composition in an amount equal to half the volume of cement. The preparation of the working solution is carried out immediately before the start of concreting in the amount that is planned to be produced in 2 hours.

For the construction of light frame structures, a columnar foundation is sufficient. Therefore, the concrete mass for pouring it does not imply ultra-high strength.

The preparation of concrete using buckets is relevant in the following cases:

to perform small-scale work;
when the foundation is poured in stages;
inaccessibility of the construction site for special equipment (concrete mixers);
remoteness from factories supplying the finished composition.

Component proportions

Even an experienced concrete worker cannot answer the question: “How many components in weight equivalent should be taken to mix the ideal mortar?”. Everything is too approximate, since in each case the components have different humidity and fraction sizes. One thing remains - to adhere to the recommended proportions. The ratio of components by volume is more convenient to measure in buckets.

Proportion table of cement M-400, sand and gravel:

Concrete marking
M 100	1,0: 4,6: 7,0	78	10: 41: 61
M 150	1,0: 3,6: 5,6	64	10: 32: 50
M 200	1,0: 2,7: 4,9	54	10: 25: 42
M 250	1,0: 2,3: 3,8	43	10: 19: 34
M 300	1,0: 2,0: 3,5	41	10: 17: 32
M 400	1,0: 1,3: 2,5	31	10: 11: 24

Proportion table of cement M-500, sand and gravel:

Concrete marking	Weight of components in kg (C: P: D)	The volume of ready-made concrete obtained from 10 liters of cement, in liters	Component ratio by volume (C: P: G)
M 100	1,0: 5,8: 8,1	90	10: 53: 71
M 150	1,0: 4,5: 6,7	73	10: 40: 58
M 200	1,0: 3,5: 5,5	62	10: 32: 49
M 250	1,0: 2,6: 4,4	50	10: 24: 39
M 300	1,0: 2,4: 4,4	47	10: 22: 37
M 400	1,0: 1,7: 3,3	36	10: 14: 28

Convert to kilograms

It is convenient to measure components with buckets directly on the construction site. However, when purchasing materials, we are accustomed to operating in kilograms. How to calculate how many and what components should be in one cube of concrete? Initially, you should decide on the proportions attributable to the ingredients.

Based on the proportion of 1:3:5 required for the foundation, then the shares are 9 (1 + 3 + 5). One cube contains 1,000,000 cubic meters. cm, we divide this number into 9 shares, it turns out 111111 cubic meters. cm. In 1 cu. cm cement content is 3.33 g, then in 1 cu. m its 333 kg.

Preparing the concrete mix by hand

For work, two buckets and a couple of shovels are needed. One of the buckets and one shovel are for cement only and must be completely dry. The second pair of tools is used for sand and gravel. Materials measured in buckets are lightly compacted with a shovel and leveled on top. For mixing concrete, a wide container is used. Sand and gravel are thoroughly mixed, creating furrows on the surface, into which cement is poured. All components are mixed as many times as necessary to form a mass of uniform color.

The mixtures are shaped into a cone, a recess is made in it and water is poured. The composition from the edges of the cone is poured into a recess with water, it should be completely saturated. Then a cone is again formed from the mass and the previous steps are repeated until the concrete dough acquires the desired consistency.

In the process of kneading, water must be added in small portions, an excess amount of liquid will reduce all efforts to zero.

Compliance with the proportions will allow you to get a concrete mixture of the desired plasticity, uniformity, with no voids. And this means that the design has an impressive operational life.

The stability and durability of any structure directly depends on the strength and reliability of the foundation - the foundation of the house. For its construction requires special knowledge and the availability of qualifications and experience from 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, the climate, the 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 tape, but there are other subtypes and varieties:

Tape. It is installed as a continuous band, which consists of reinforced concrete, laid under all the load-bearing walls of the structure. The depth of the base of the building is formed depending on the level of soil freezing plus an additional 20 cm.
From the indicators of soil quality and climatic zone, two subtypes can be used:
- intermittent;
- continuous.
As a material for this type of base is used:
- Booth, which has excellent strength. The material is not affected by low temperatures and flowing groundwater. A buta stone of the same fraction is used. The construction process requires a lot of labor and money, so it is used very rarely. The depth of the bookmark 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, rubble stone of small size, brick fragments). In terms of strength, it has qualities no worse than rubble, but it is much easier to build 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 a flood foundation, since the material is mixed in a concrete mixer, after which the formwork is filled with it. The period of operation 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 made of difficult materials, as well as the construction of country cottages and houses.
Columnar, which is used for the construction of light-type structures (for example, baths, garden houses, sheds). This version of the base 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.
Ribbon-columnar. It is somewhat cheaper than the strip type of foundation and combines only the best qualities of both types of foundation.

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

Foundation concrete composition

You can prepare a concrete solution for a foundation support yourself, for this you only 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 mass of the casting. Then the formed solution is diluted in the required proportions with water.

The composition of the foundation mortar has been used in construction for more than a year, and every day it is improved and the quality and strength indicators increase.

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 indicators of the solution to ideally match the building, it is necessary to take into account the place of construction and its purpose.

The composition of concrete for the 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 the creation of the solution change.

The main components in the composition of concrete:

Cement- binds together fillers.
Fillers. These include: gravel, crushed stone, sand, loose additives.
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, gravel, cement and water is loaded, and then the device thoroughly mixes the materials together.

Forming a solution with buckets is relevant in several cases:

For construction work less than 4 m 3 solution is required.
Failure to deliver concrete from the plant due to location problems, for example, the production company is far away, and the cost of transporting the material is too high.
The foundation is being poured with interruptions, for example, when several tiers of the structure are formed.
At the facility under construction there is no access to the installation of mixers and concrete mixers.

Proportions of concrete on the foundation in buckets

As a rule, measuring with buckets is used for small amounts of work.

Weight dimensions of the components for the manufacture of concrete mortar:

cement - 1;
sand - 3;
crushed stone (gravel) - 5.

Each component of the concrete solution has a different volumetric weight, for example, the mass 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 changed to crushed stone.

If the construction of the structure is carried out by hand, then a ready-made sand-gravel mixture (PGS) 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 to make concrete?

In most situations, for frame-type buildings, a columnar version of the foundation is used, which does not require a 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 of the mixture you need:

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

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

To create a mixture of concrete of the required consistency, it is best to use washed crushed stone, and only purified river sand, in which there are no various impurities of clay.

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

When choosing cement, initially pay attention to the manufacturer. As a rule, the more famous the organization, the less likely it is to purchase low-quality goods.

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

How to mix concrete correctly?

For preparations of a small volume of solution, a bucket is used as a measure of the weight of the components. The proportions are calculated in accordance with the fact that the components have different volumetric weight. Based on this fact, when preparing the 1st 3 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:

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

When deciding which is the best way to mix the solution, needs and financial capabilities should be correlated. The best option would be to use a concrete mixer, but it is not profitable to buy it for a small building, so it is better to use manual production.

Preparation of concrete mix for strip foundation

For this type of foundation, you will first need to calculate the amount of material needed. 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, on one side of the foundation it is necessary to prepare 10 cubic meters of concrete solution.

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 each. After laying each of them, it is necessary to compact. Then, in order to release excess air, reinforcement should be slowly stuck into the solution every meter or two.

Preparation of concrete for a columnar foundation

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

Necessary properties of foundation concretes

The concrete base of the house has different properties and characteristics. They directly depend on what materials and their initial components are used in terms of quality. Also, the properties of concrete depend on the proportions of its components, which are used for the construction of various types of structures.

Required strength of foundation concrete

The strength of a concrete foundation is a key indicator that determines whether the foundation can withstand the planned load on it. It is measured in kilograms per square centimeter.

You can calculate this indicator by calculating the exact degree of load that the structure will exert on the base. To do this, you need to sum up the total weight of all structures and communications, as well as indicators of the payload 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 brand, 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 found in the tables:

Concrete from cement brand M 500, sand and crushed stone

Concrete from cement brand M 400, sand and crushed stone

Giving concrete special properties

If additional requirements and special properties are imposed on the structure being erected, for example, water tightness 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 frost resistance of the concrete base.

The addition of this type of additive ensures that the foundation can withstand a large number of freeze and thaw cycles.

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. As a rule, they are used in formwork mortars with frequently repeated metal reinforcing mesh. This additive contributes to a better distribution of the mixture around the entire perimeter of the formwork.

Additives are also used that increase the degree of stability of the foundation of the structure 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 a greater thickness - 0.7.

Number of components per cube

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

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

Approximate proportions for the formation of 1 m 3 concrete

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

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