The blind area is quite an important architectural element of the building. Therefore, when pouring it, certain technologies must be followed. First of all, it is important to properly prepare the solution. If the proportions of concrete for the blind area are not respected, it will not last long in the future.
Appointment
The main function of the blind area in the building is, of course, to protect the underground part of the foundation from rain and melt water. By arranging this architectural element, thus, you can significantly extend the life of the base of the house. If the ground near the foundation remains dry, among other things, the load on it will decrease in the spring, during the heaving of the soil. Sometimes in the building, the blind area also performs one more function - it serves as a pedestrian path. If a lawn is adjacent to the house, it is also very convenient to water from it.
Requirements for the blind area
When erecting this architectural element of the building, the following SNiP standards are observed:
- for class I soil should not be less than 1 m, for class II - 2 m.
- The maximum thickness of the compacted soil under the concrete belt is 0.15 mm.
- The minimum slope of the blind area is 0.03 m.
- The thickness of the sand cushion under the tape should not be less than 3 cm.
In the process of pouring, the blind area is necessarily reinforced using a metal grate. Crushed stone should be used to arrange the drainage layer.
What the quality of concrete can depend on
Some owners of country houses believe that, since this element of the building structure does not bear any special load during operation, any mixture, even not a very good mixture, can be used for it. However, this is not the case. The proportions of concrete for the blind area must be observed. Indeed, when it is destroyed (cracks and chips appear), the foundation of the house immediately begins to be exposed to moisture. As a result, the service life of the entire building is significantly reduced.
According to the SNiP standards, for this architectural element of the house, it is allowed to use a concrete solution of a grade not lower than M200, which corresponds to class B-15. In order to prepare such a mixture, you must choose the right cement, sand and filler. And, of course, you need to mix them in the correct proportions.
What brand of cement to buy
This component, to a large extent, determines how high-quality the composition of concrete for the blind area will ultimately be. The proportions of the remaining components are mainly determined by the amount of cement. For concrete mix of class B-15, you need to choose material of the M400 brand. Such cement has the following technical characteristics:
- The setting time is 2-4 hours at an air temperature of +18 ... + 22 ° С.
- The working temperature range is from -60 to +300 ° C.
- The service life of the structures is up to 100 years.
Ready-made concrete of the M200 brand, made using practically impervious to water, is amorphous in relation to most types of solvents and is not afraid of sudden temperature changes.
What should be the filler
The proportions of concrete for the blind area of \u200b\u200bthe house must be observed without fail, but it is equally important to choose the right filler for the mixture. This element in the solution serves as a kind of "reinforcement" that takes on all internal stresses. It is allowed to use gravel or crushed stone as a filler for a solution intended for a blind area. If desired, you can replace these elements with a medium-sized
How to prepare sand
The strength of the concrete mix also depends on the quality of this component. In this case, it is better to take large river sand. But, of course, not all owners of country houses have the opportunity to purchase such material. If it was not possible to buy river sand, you can replace it with quarry sand. However, before mixing the mixture, such material must be sieved through a grid with a cell of 2-3 mm. It is better to perform this procedure in windy weather. In this case, the finely dispersed component (dust) will also be separated from the sand.
How to add water
The concrete mix should be diluted in such a way that it becomes sufficiently plastic and convenient to work with. Warm water should be added to the solution for the blind area. You can use a conventional borehole or well. It is allowed to take water from the summer cottage storage. But in this case, you should make sure that it is clean.
Ultimately, the diluted solution should not drain off the shovel. Do not make the mixture too thick. If it crumbles or sticks to the shovel in large pieces and is difficult to clean, it should be slightly thinned. After mixing, the good solution with water separation does not split.
Concrete proportions for the blind area: calculation
Of course, to prepare a high-quality solution, you should not only choose the right materials, but also mix them correctly. The proportions in this case are usually as follows:
- cement - 1 part;
- sand - 3 parts;
- crushed stone - 4 parts;
- water - 0.5 parts.
In this way, the proportions of concrete for the blind area in buckets are usually determined. For wide belts, it is better to make a more durable mixture by adding three to 1 bucket of cement - crushed stone or gravel. When pouring tape around an outbuilding, you can, on the contrary, save on material and use not three, but four pieces of sand.
When calculating for the blind area, one can take into account the fact that enterprises take 280 kg of cement, 1.4 tons of crushed stone, 840 kg of sand to prepare 1 m 3 of a solution of the M200 brand. All this is filled with 190 liters of water.
Thus, we have found out what proportion of concrete for the blind area is the most suitable. But, of course, in order to get a high-quality solution at the exit, it must also be mixed correctly. It is worth preparing material for pouring the blind area using a concrete mixer. In this case, it will turn out to be of much better quality. The concrete mixer itself should be placed on a flat surface before starting work. The components are poured into it in the following sequence:
- cement;
- sand;
- crushed stone.
After the dry ingredients are mixed, water is added to the drum. The total preparation time for the solution depends on the type of equipment. For compulsory devices, it is usually 2-3 minutes, and for gravitational equipment - 5-6 minutes. It is impossible to reduce or increase the procedure execution time. In the first case, the mixture will turn out to be heterogeneous, and in the second, it will be too dry.
If there is no concrete mixer on the farm, it is allowed to make a solution for the blind area manually. In this case, the easiest way is to use a trough and a hoe. With manual cooking, all dry ingredients are also thoroughly mixed first. Then the required amount of water is added to the trough. When manually mixing, the solution is not as homogeneous and of high quality as when using a concrete mixer. Therefore, in this case, it is worth taking more cement.
This is how it is performed for the blind area. The proportions of the components for the solution must be observed exactly. In this case, the mixture will turn out to be plastic, of high quality, and it will be easy to work with it. The very same blind area, made with its use, will come out strong, neat and durable.
Any base for a building needs protection from erosion, therefore an additional barrier is created around it from a mixture based on cement, gravel and sand. With its help, you can not only extend the durability of the structure, but also improve the aesthetic characteristics. In the process of the device, you will have to find out what kind of concrete is needed for the blind area, which also serves as a track.
About the material used
The hardened mixture is an artificial stone which is widely used in the construction industry. A modern binder-based material has been used since 1844. Over time, special additives that improve performance began to appear in its composition.
Applicable classes
The basic indicator characterizing the composition is the compressive strength, which allows the prepared mixture to be assigned to a certain category. When carrying out work, it is necessary to correctly select the class of concrete for the blind area, so that its strength characteristics are suitable for specific operating conditions.
Directly in SNiP 2.03.01-84, the designation of categories is used by the Latin letter "B", next to which there is a number that reflects the transferred pressure in MPa. However, the composition class is a numerical characteristic with a guaranteed security of 0.95. Thus, in 5 cases out of 100, the condition may not be met.
| Class | Matching brand | Strength in kgf / sq. cm |
| B15 | M200 | 196 |
| B20 | M250 | 262 |
| B22.5 | M300 | 295 |
| B25 | M350 | 327 |
| B30 | M350 | 360 |
Note!
Knowing the class of a suitable composition, you can easily understand what grade of concrete is needed for the blind area.
The table shows the correspondences with a mixture variation coefficient of 13.5%.
More about brands
Along with the grades, the strength of the mixture can be set in a different way. The letter "M" of the Latin alphabet with a number denotes the limiting value for compression in kgf / cm².
The concrete grade for the blind area should not be lower than M200, otherwise damage to the created platform is possible.
- М200 - the main purpose of the composition is to create structures with a small load on the surface.
- М250 - the mixture can be used for structures that are exposed to moderate impacts.
- M300 is the most common brand of concrete for the blind area, as it can withstand quite tangible loads.
- M350 - a similar solution for the installation of a protective barrier around a building is rarely used.
Attention!
The price of the composition increases with an increase in the brand, therefore, in order to save money, it is recommended to select it as accurately as possible, taking into account the possible loads on the surface.
Requirements for the main components
All the materials that make up the concrete for the blind area must meet certain conditions, otherwise it will simply not be possible to obtain a high-quality mixture.
In this regard, the service life of the structure can be significantly reduced.
- The basic ingredient is cement, which binds the components into a single whole. The main task is to choose the right brand of binder. The presence of impurities must also be considered.
- For the preparation of the mixture, it is recommended to use sand, the fraction of which ranges from 1.5 to 5 mm. The strength characteristics of the mortar can be negatively affected by the presence of impurities in the form of construction waste and plant residues.
- The best aggregate is a crushed rock material that provides good adhesion to other components. Suitable gravel sizes range from 8 to 35 mm.
- Ordinary water is used as a solvent, but it should not contain alkaline and acid inclusions.
Addition!
Some experts add slaked lime to the mix to make it easier to lay.
With this option, surface leveling is facilitated.
Solution preparation process
In the process of work, the most often used composition is M300, which belongs to the class B22.5. Therefore, it is worth considering its personal preparation. The following is an instruction for preparing a mixture without a concrete mixer.
It shows the main proportions of concrete for the blind area.
- 2 buckets of sand are poured into the prepared container so that a small slide is obtained.
- A bucket of M400 cement is added, after which the two components are thoroughly mixed in dry form.
- Water is gradually poured into the composition, the amount of which is usually 0.5 mass of the binder.
- After mixing, 4 buckets of gravel aggregate are added to the slurry.
Important!
When mixing the concrete composition with your own hands, you cannot add too much water, otherwise the porosity will be very high, and this will lead to a decrease in strength properties.
- If, after the mixture has hardened, it is necessary to separate a fragment of the blind area, then the reinforced concrete is cut with diamond circles.
- Pouring the finished composition should be carried out within 24 hours, until it grabs, otherwise notches are made.
- To insert pipes or other mortar, holes are diamond drilled in the concrete.
- If the blind area is made in the cold season, then the solution must be heated without fail.
As a conclusion
The preparation of the concrete composition should be carried out taking into account the points of SNiP 5.01.23-83 and GOST 7473-94. The submitted documents reflect the general rules taking into account the density and ratio of materials. For more information on this topic, see the video in this article.
A stone path around the house is a blind area. The structure adjoins the building wall with one of its sides. The other edges are bordered by the soil of the site where the building stands.
A self-built blind area protects the foundation from water and creates a convenient passage. Therefore, the brand is selected according to the operating conditions of the structure.
Concrete calculation calculator
Proportions and components
The blind area does not carry the load as the foundation of the house. You can save a lot on the components for the mixture, but this does not mean the poor quality of the raw materials. The composition of the concrete for the blind area - proportions 1: 2: 3:
- clean sand;
- high-quality cement;
- differently fractional crushed stone;
- water.
A high-quality concrete composition is mixed from pure sand. No clay or silt. Because of them, the elements of the mixture do not adhere well to each other.
Cement without special requirements. But the higher the grade of the material, the stronger the future concrete. The finished product will support more weight.
Crushed stone should not contain lime. Instead of gravel, the addition of gravel or plasticizer is allowed. This will increase the frost resistance, strength and waterproofing of the structure.
Running water is used.It is not difficult to knead concrete for the blind area of \u200b\u200bthe building with your own hands: two containers of sand and three rubble go to a bucket of cement. The proportions are exactly observed. The composition is kneaded with a shovel or hoe. As a result, the concrete solution should be like thick sour cream.
Material quality
Do-it-yourself concrete for the blind area of \u200b\u200ba house under construction includes the main component - cement. Marking from M200 to M500. To prevent the constructed structure from cracking after a year of operation, it is necessary to choose high-quality cement for mixing the mixture.
The counterfeit material can consist of a piece of lime or dolomite. This results in poor quality concrete slurry.
Cement is purchased only from reliable manufacturers or exclusive dealers. The properties of the material are retained if stored correctly (dry place) for three months. After this period, up to 30% of the qualities of raw materials are lost.
The main factor when purchasing a material is the date of its manufacture. Per-second markings should be indicated. No two packages can have the same time. Fake boxes are marked one day.
Material marking
The brand of concrete used for the blind area of \u200b\u200ba house under construction determines what strength the mortar will have. The M200 brand is used for the construction of the building. Scope of application includes:
- concrete screeds for leveling surfaces;
- stairs;
- blind areas;
- different types of tracks.
Due to its characteristics, the M200 is advantageous in terms of price-quality ratio. The marking means the limit of the load on the structure (kg per 1 cm2). That is, the M200 brand can withstand a weight of 200 kg per 1 cm2.
When deciding what brand of concrete to buy for the blind area, we stop at M200. Advantages over other types - low price and a wide range of applications in construction.
The M300 brand is used for blind areas, paths and foundations. Less commonly, support walls and overhead slabs.
M250 brand - transitional marking. In terms of properties, it practically does not differ from other types of concrete. It is used for the construction of strip structures, blind area and lightly loaded ceiling slabs.
The M400 and M500 grades are used in the construction of large facilities. The use of this marking of concrete in small construction is unprofitable. Or it is used for the manufacture of concrete mortar of the M200 brand - a proportion of 1: 3: 4 and half of the water from the composition.
The nuances of mixing the solution for the blind area
What should be the concrete for the blind area after mixing the solution - a frequent question in the construction of a structure. Excess water - low strength indicators of the finished composition.
When making a mixture with your own hands, the water must be completely absorbed into the cement. We need a solution of the consistency of thick sour cream.
If the liquid is not sufficiently absorbed into the cement, then part of the water remains in its pure form. In the future, the concrete will quickly collapse.
For the blind area of \u200b\u200bthe house, it is used from 5 to 20 mm, made of river gravel or rock. Small aggregate - high quality of adhesion and concrete strength. The size of the crushed stone affects the proportion of water: the finer the gravel, the more liquid is added.
The sand is sieved to remove lime, clay and silt before being added to the cement.
Calculation of the grout
The blind area is a narrow concrete slab. To fill it with your own hands, you need to calculate the amount of the finished solution.
- The area of \u200b\u200bthe structure is calculated: the width of the rectangle is multiplied by the length. The result is multiplied by the height of the blind area.
- To the resulting number, add 15% of the stock mixture.
The blind area is 20 m2, height - 15 cm. Calculation: 20 * 0.15 \u003d 3 m3 of the mixture. Plus a spare percentage. As a result, 3.5 cubic meters of mortar are required for a construction of 20 m2.
The procedure for mixing and pouring concrete mortar
Blind area concrete is the proportions of marked cement, sand and crushed stone, the ratio is 1: 2: 3. The correct solution is a thick mixture.
Do-it-yourself concrete preparation and pouring.
- Water is poured into a mixer or other container (large basin, trough, unnecessary bath). Cement is added to it, the mixture is mixed to "cement milk" - a light turbid solution.
- Crushed stone is added. The filler “bathes” in the composition for some time, about 30 minutes. After that, sand is added. Proportions are respected.
- The concrete solution is kneaded until smooth.
- The boundaries of the blind area are indicated: a small block is installed parallel to the building wall one meter from it and fixed with pegs. This is the formwork for the structure.
- The resulting composition is poured into the formwork and leveled with a trowel or spatula. The tool makes a small slope from the wall of the house to the opposite edge of the structure: water from rain will not accumulate on the concrete.
A self-made concrete blind area is not protected from various environmental factors. Further refinement of the structure is required. Paving slabs or stone will increase the lifespan of the blind area.
The composition of concrete for the blind area updated: February 26, 2018 by: zoomfund
Comments:
Concrete for the blind area can be prepared in different proportions, depending on what functions this structural element should perform. The main purpose of creating a concrete blind area is to protect the foundation and other structural elements of the building that are in contact with the ground from the negative effects of moisture from the soil.
The constant penetration of moisture into concrete, its freezing and defrosting lead to negative consequences for concrete structures. The operational characteristics of the foundation will be significantly reduced, which can lead to its partial damage or complete destruction. If this happens, then the entire building may be at risk of destruction. Moisture from the soil or rainwater flowing from the roof can adversely affect the foundation.
In addition, the concrete blind area serves as a path along which it is more convenient to walk along the house. This part of the structure will serve as a kind of sidewalk. The surface of such a track must be flat.
Primary requirements
When preparing concrete for the blind area, it is necessary to take into account that it is desirable to make the blind area economical, reliable and easy to manufacture. It must also provide sufficient protection of the structural elements of the building, which perform the load-bearing function, from moisture.
Execution for the blind area should be easy enough. Only in this case, repair work, if necessary, can be carried out in a timely manner. The base material must be durable and insensitive to temperature changes, and also not deteriorate from regular contact with moisture.
The concrete surface of this structure must be cut with thermal expansion joints in the transverse direction. This will prevent breaks in severe frosts. To create seams, wooden slats are needed, which should be soaked in bitumen mastic. Such peculiar lighthouses should be located at a distance of no more than 2.5 m from each other.
Blind concrete can be purchased ready-made. Concrete plants provide their customers with the highest quality products. Special additives are added to professionally prepared solutions, which improve their quality. However, subject to the basic rules of preparation and requirements for the finished solution, you can prepare it yourself.
Back to the table of contents
Cooking process
To make the blind area strong and of high quality, it is necessary to pay special attention to the preparation of concrete mortar.
This is a budget option for those who cannot afford to purchase a ready-made solution, as well as for those who like to carry out all construction work on their own. To prepare a good solution, it is necessary to use crushed stone, sand and cement in a ratio of 3: 2: 1. During the mixing process, you need to carefully monitor the amount of water in the solution. Its consistency should not be too liquid.
First, water is poured into the concrete mixer (not too much, it is better to add a little later than to prepare a too liquid solution), then cement is poured into the water and these components are thoroughly mixed until uniformity is achieved. Next, add crushed stone and mix well again. Only then can the sand be filled in. Additionally, you can add ash or potash to the solution. These components must be added to the water before the other ingredients are poured into it. To strengthen the concrete, if it will not be reinforced, you can add table salt.
The ready-made solution is poured into a prepared trench with formwork, its surface is carefully leveled and tamped. Finally, ironing is performed: the surface is covered with a thin layer of dry cement. For the most efficient tamping, you can use a special vibrator. But since the structure is small, there is no need for this.
A blind area is a waterproof covering around a building. It is made of concrete and runs with a slope along the perimeter of the object. The foundation is protected from floods and rainwater. The width of the blind area cannot be less than 100 cm, the final parameters depend on the type of soil and the removal of the roof eaves.
The grade strength of the material used for pouring the base is determined by the load parameters, the depth of the groundwater, the architectural features of the structure.
- when carrying out work on soft soils and arranging a shallow or medium-deep foundation, it is permissible to use reinforced concrete М150, but in the event that it is planned to build light wooden and frame structures;
- m200 / M250 brands it is advisable to use when pouring bored piles, buried strip foundations, slab soles or bases for pillars with a heaving nature of soils. Such a base is able to withstand a block or brick house;
- brands М300 / М400 - are necessary for the construction of buried belts, bored pile structures. The material is used if the construction of a multi-storey country house is supposed to be made of brick, reinforced concrete or cement blocks.
For example, concrete M300, the proportions of which are 1.00 / 1.90 / 3.70, requires the use of M400 cement. The volume of water depends on the characteristics of the sand. For the blind area, a lower brand strength is suitable - M200
Composition, proportions
The composition of any concrete mixture is standard - it is cement, sand, crushed stone (gravel), or ASG and water. The proportional ratio of components depending on the grade of material is indicated in the tabular data.
| Reinforced concrete, grade M | Component proportions, C / P / U |
| 100 | 1.00/4.60/7.00 |
| 150 | 1.00/3.50/5.70 |
| 200 | 1.00/2.80/4.80 |
| 250 | 1.00/2.10/3.90 |
| 300 | 1.00/1.90/3.70 |
| 400 | 1.00/1.20/2.70 |
| 450 | 1.00/1.10/2.50 |
The basic parameter that characterizes the quality of the mixture is the compressive strength... This helps to categorize the working solution. The correct selection of the material required for arranging the structural element allows you to obtain the optimal characteristics of the finished coating, suitable for real operating conditions.
Composition for the blind area
The composition of the working mixture is based on the required strength. The grade of concrete for the blind area of \u200b\u200ba private house must be at least M200 / B15. Using Portland cement M400, the proportions of the constituent components, according to the table above, will be as follows: 1.00 / 2.80 / 4.80. The ratio of water to cement (VC) is taken as 0.65, taking into account the moisture content of the sand, that is, it is corrected on the spot.
We select the composition of concrete for the blind area with our own hands:
- cement M400 - 287 kg;
- granite crushed stone, fraction 5-20 mm - 1135 kg;
- PGS - 751 kg;
- purified water - 185 liters.
Alternative option:
- cement M400 - 287 kg;
- sand - 803.6 kg;
- crushed stone - 1377.6 kg;
- water - 186 l.
Sequencing:
- water is poured into the concrete mixer;
- cement is introduced;
- the ingredients are mixed to form a laitance;
- crushed stone is introduced;
- sand is introduced.
If, during mixing, coarse-grained crushed stone is used, the liquid content can be reduced, then the grade of concrete for the blind area of \u200b\u200ba private house will not decrease
The proportions of concrete for the blind area are in accordance with applicable rules and regulations.
Feature functions
The purpose of the structural element is revealed as follows.:
- decorative properties, creating architectural completeness;
- protection of the base from any moisture, drainage;
- reducing the level of soil freezing, heat conservation.
- protection of the base from damage by the root system of plants.
Requirements for the production of works
Having determined what grade of concrete is needed for the blind area, you should familiarize yourself with what requirements for its arrangement:
- the width of the strip is calculated as follows - ledge of the cornice (cm) + 20 cm;
- the coating strip must form a continuous layer;
- there must be a slight slope from the wall.
SNiP grade
Modern norms and rules in force in construction recommend adhering to all proportions of ingredients, using the specified brand of cement, otherwise weak concrete will not be able to provide full protection of the base.
All ingredients required to obtain a mixture of the M200 brand must be of high quality and pure, free of impurities and foreign inclusions.
In conclusion, it should be noted that construction is carried out at temperatures not lower than -5 ° C. If it is necessary to carry out all work in a colder period of the year, warming up the working solution is mandatory.
The cost
The average price for 1 m³ of M200 grade material is 2400 r... The final costs depend on the area of \u200b\u200bthe house, the width of the strip, the services of a team of professional builders.
How the blind area is made and the composition of concrete for the blind area with your own hands is shown in the video: