Preparation of a concrete mixture from screenings and cement. Concrete from the dropout - general information, types of dropout, proportions for the preparation of the solution Crushed stone pillow

The initial and key stage in the construction of any structure is the foundation. At the design stage, along with other design work (engineering and geological surveys, geodetic surveying, placement on the site, architectural and construction part, supply and coordination of networks, arrangement of access roads, fire passages and other works), a lot of time and attention is paid to the calculation of the thickness and type of foundation.

Paraphrasing the famous phrase of Captain Vrungel “As you name a ship, so it will float” from the famous work of A. Nekrasov, you can say how you will lay the foundation and you will operate the structure in the future. Well, the most famous work tells the story of a couple of characters, smart and stupid, who decided to build their own houses. One built a house on a solid foundation, the second used a foundation of sand and it is known what the result was. "And the downpour went, and they came up from the banks of the river, and the winds blew, and came upon that house, and it fell, and there was a great fall."

Foundation takes over the load from the building, and redistributes it further to the ground. That is, he, as it were, protects the building, ensuring the rigidity, solidity of the structure. To additionally strengthen the building under construction, a bedding under the foundation, the so-called pillow, is called upon. She levels the pre-compacted area under the foundation, additionally balances the load from the erected structure, excluding subsidence in especially tense places, performs waterproofing functions. Laying the foundation correctly ensures the longevity of the structure, and a cushion of sand and rubble underneath adds confidence to this guarantee.

Foundations are classified depending on the material used in the manufacture, and according to the design chosen in the design for many factors.

The materials used divide the foundation into:

1. Stone(rubble, rubble concrete, brick).
2. Reinforced concrete(monolithic or prefabricated.
3. Wood.
4. Aerated concrete.

The structure divides this element of the structure into:

• columnar(when using concrete - monolithic or rubble concrete);
• tape (prefabricated or monolithic);
• pile(prefabricated or monolithic);
• pile-grillage;
• slab.

Columnar can be called the foundation of the economy class... Low-cost, but at the same time designed for long-term use, suitable for buildings whose walls are planned to be built made of relatively light materials... Such as wood or foam blocks. A pillow under the foundation is poured about forty centimeters high, sand or a similar substance is used for this.

Unlike the first option, tape type increases the cost of this stage of construction by one and a half times, but it also allows erect capital structures... It is a closed perimeter contour made of concrete (reinforced), laid under all the load-bearing elements of the house. The higher weight of the structure also places higher demands on the foundation itself.

In addition to the requirements for reinforcement, which, in order to better bond with concrete, must have a changing cross-section, and jewelry accuracy of the reinforcement of corners, which are weak point due to high loads, require due attention and vertical loads on the foundation... For their even distribution, a sand cushion is constructed. Crushed stone under the foundation is capable of performing a similar task with no less success.

Erosion of the cushion by groundwater is prevented by the installation of waterproofing. To give additional strength to the structure under construction is designed pile foundation... As a rule, piles made of wood or metal are driven into the ground with heavy equipment. Concrete or reinforced piles are placed in the ground using a different technology, but backfilling under them is not required in most cases.

The following type of grounds is another matter. Pile-grillage foundations are used in unfavorable geological conditions construction (fragile soils), as well as in the impossibility of other types of devices, or the high cost thereof. When the frame (grillage) is located on the ground, it is imperative to use an averaging layer under it.

Sand cushion for the last option acts as a drain, levels the site under the foundation, equalizes the load. A crushed stone cushion for a slab foundation is allowed with an economic justification. This type is used for construction small spaces, on unfavorable soils. The proximity of groundwater causes subsidence or swelling, uneven subsidence of the earth. Rigidity slab foundation allows you to neutralize possible distortions when using other foundations, as well as movement with the soil.

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Purpose of the pillow under the foundation and their types

To summarize the purpose of the pillow under the foundation, we highlight several main functions that it performs.

levels the site, on which the base of the entire structure is installed. The foundation will be made of the same height, which will exclude uneven erection of structural elements; even distribution of the load on the soil from already finished structure... Extending the service life of the building, thanks to its sustainable base. By eliminating the subsidence of the foundation, distortions of window and doorways, the occurrence of cracks and other reasons that make the premises unusable;

drainage... The base will serve its purpose longer if you exclude the effect of water on it.

Based on this, the requirements for high-quality bedding are determined. The material must be heat resistant, which in this case means do not lose their qualities at different temperatures, without prejudice to yourself, pass water, not be heaving, do not contain impurities (vegetable and combustible) in its composition.

Base cushions are classified according to the materials used for them. There are:

1. Sandy.
2. From rubble.
3. Concrete.

Each option has its own unique advantages and disadvantages. When choosing a specific type, one should take into account a number of specific features of each material, its interaction with the type of foundation used, as well as with the geological features of the construction site, in order to improve the quality and durability of the building. Concrete, as a specific and very time-consuming option, will not be considered in the article.

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Benefits of a sand pillow

For economical builders, a sand cushion is perfect. Among the advantages, it stands out cheapness and availability in almost all regions... The question of what kind of sand for the foundation cushion is suitable is not being asked by chance. Sand is recommended with large or medium fractions... The quality of the base of the foundation depends on what kind of sand is used under it.

If the sand dry, it needs to be moistened at the tamping stage... Wet sand is compacted immediately with special rollers or rammers. The trench for the foundation has been dug, leveled, has sheer walls, which means it's time to pour sand. The thickness of the layer depends on the type of structure, and its size is present in project documentation.

Sand is poured in layers, with layer-by-layer compaction, and watering if necessary. The quality of the seal is checked by henchmen, or, in this case, it is more appropriate to say, by "foot" material. You need to go through the resulting prism, and if no footprints are visible, the seal is considered sufficient... Before further pouring the foundation, waterproofing work is carried out. They consist in laying a special film or bitumen on the sand. For a one-story building, a sand pillow is perfect for a foundation. But this material also has a drawback.

When erecting multi-storey buildings, it may not withstand the load from the building. At the stage of calculating the foundation, the designers choose whether sand or something else will be used. Besides, pressure on the sand gradually turns large grains of sand into small ones, and small ones into dust... And the sand cushion stops performing its functions, with all the ensuing consequences.

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Advantages of a crushed stone pillow

The choice of a crushed stone pillow is due an impressive mass of future construction and better performance than sand... As well as latest material, crushed stone perfectly withstands temperature changes, has outstanding drainage and thermal insulation qualities. When constructing a crushed stone cushion, a sanding layer is used, the construction of which does not differ from the creation of a sandy base, but its layer is much smaller. Uncritically different from sand and crushed stone pillow. In accordance with the project, the required thickness of a layer of crushed stone is placed in a prepared trench and compacted.

Sealing is necessary to eliminate voids, and the most tight fit of parts to each other. It has the following disadvantages. More expensive than sand, not present in all areas, that is, transportation adds price to the product. Crushed stone is made of gravel, granite, limestone. The first is durable, radioactively neutral.

It is extracted by screening rocks or by crushing stones in crushers. It has a low cost. The second is obtained by processing granite, is extremely durable, used in civil engineering. Limestone is the most unassuming type, obtained from limestone rocks, lagging behind in strength from the two previous types.

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conclusions

Substrate under the foundation of sand and rubble objectively necessary part of construction, designed to extend the operational period of the building, without additional costs at this stage. As a material, sand can be used, a cheaper, more affordable and excellent material for medium-sized structures. Crushed stone, especially granite, offers to “endure” more serious loads, is suitable for large buildings, but is more expensive and is not available everywhere. Each specific case of construction will determine the choice of material, and not only in terms of economic parameters.

How to make a bedding under the foundation

Laying the foundation of a house is the first and crucial stage of construction, however, this is preceded by the preparation of the foundation under the entire building spot on the site.

The type of foundation, its structure and characteristics depend on the bearing capacity of the soils at the construction site, as well as the strength of the house that will be erected later.

Even at the design stage, it is necessary to determine the properties of soils and determine what kind of filling sand or crushed stone under the foundation will be relevant as a preparation.

What is the bedding for?

It is somewhat incorrect to raise the question of choosing a bedding for a foundation made of sand or crushed stone. The key to a solid and sustainable home is a solid and reliable foundation, which must meet a number of requirements:

• High strength and density of the soil, capable of withstanding the distributed load of further development;
• Groundwater should not linger under the base, therefore a high drainage capacity of the soil is important;
• When wet or dry, the base should not lose its basic characteristics.
• It should not contain organically active components;
• The presence of combustible or rotting plant residues is not allowed.
• Cold heaving of the soil is not allowed;
• Uneven shrinkage or deformation is not allowed.

In progress construction works the base should not deform even under the load of the involved construction equipment or the activity of builders.

The strength of the surface layer must be sufficient to accommodate all necessary elements such as reinforcing frame, formwork, etc.

Since the type of soil on the site cannot be selected in advance, you should work with what is in fact. If the soil does not meet the specified requirements, a bedding under the foundation is used from:

• sand;
• gravel;
• sand and gravel mixture (ASM);
• gruss (crushed rock of fragmentation type);
• crushed stone;
• skinny concrete.

Since the properties of each of the listed materials differ, as well as the methods of their use, the choice of bedding should be based on the final requirements for the base for the foundation.

The main conclusion: filling under the foundation of sand or gravel is needed to adjust the properties of the soil on which the house will be built. It is included in the preparation of the foundation and is not an unconditional component.

Anyway by the type of soil, the optimal type of foundation is first determined(tape, pile, monolithic slab, etc.) and after that, if necessary, the type of bedding that will be required is selected.

A quality preparation for a strip foundation or a monolithic slab is to fill the bottom of the pit with lean concrete to level the level and prepare a solid foundation. Sand or gravel is for the most part a cheap alternative to keep your overall construction costs down.

A simple and quite effective option for filling under the foundation. A well mechanically compacted sand cushion is able to accept the same strength and density as the base soil, while at the same time easily molded to match all the unevenness of the bottom of the excavation.

Advantages of backfill sand:

• With high-quality compaction, it is possible to achieve the strength of the base equal to the initial value for the soil;
• It fills well all the unevenness of the pit and transfers the load evenly;
• The sand retains its drainage properties;
• Easily molded and leveled;
• Does not require the involvement of heavy construction equipment.

• Poor mechanical strength of lateral point load.
• The sand is washed out over time by groundwater.

The ideal option for backfill sand is in the case of using ready-made reinforced concrete blocks and slabs, allowing the load to be transferred evenly over the entire base.

Sand for backfilling is selected in coarse and medium fractions without clay inclusions. Even with full ramming, the drainage properties of the base are retained, and cold swelling has almost no effect on the strength of the base.

The thickness of the bedding can be from 10 to 60-70 cm depending on the properties of the soil. The depth of soil freezing in many regions of the country exceeds 30 cm, and cold heaving can appear even under a well-insulated foundation during prolonged winter cold snaps.

The optimal height of sand filling is considered to be 45-60 cm. It is difficult to compact such a layer of sand at a time, therefore, the material is gradually covered with 5 cm thick layers and gradual compaction and mandatory moistening.

It is rather difficult to determine the required amount of water to wet the sand. A common mistake is excessive wetting of the sand, from which the entire mass acquires plasticity and diverges more on the sides of the rammer than compresses.

The volume of liquid should be determined individually so that the sand is easily crumpled in the hands, keeping the shape of the cake. On the other hand, with mechanical compaction, water should not protrude over the sand.

The degree of compaction of the sand is quite simply determined. If there are no traces left on the prepared sand cushion when walking on it, then the base is ready for further work.

For backfilling, medium and coarse gravel is used in those situations when under the base of the foundation it is necessary to ensure the maximum throughput of the drainage layer in combination with the distributed drainage system, focused on the drainage of groundwater from the base of the foundation.

Gravel is often used as a cheap substitute for lean concrete in the preparation and strengthening of soil under the foundation. To do this, it is rammed and mixed with the soil mechanically or manually.

However, this is not the best solution, since without binder, in the role of which cement can act, such a base is subject to erosion by groundwater with a subsequent loss of bearing strength.

More often, ASG is in demand - a sand and gravel mixture for the formation of a flat area under the foundation. In combination with sand, the mixture is easier to give density and strength comparable to that of the parent soil on construction site, while maintaining the drainage capacity of the bedding.

Benefits of gravel bedding:

• Low water content of the substrate, the liquid is poorly retained in it, and the surface area of ​​gravel for wetting is much lower than that of sand;
• Backfill strength and high loading capacity and resistance to washout or side loading.

• Under heavy loads, even distributed ones, gravel bed can "sink"... reducing its own strength and strength of the parent soil;
• It is difficult to bring the backfill surface to the level;
• When pouring concrete, part of the cement laitance is aimlessly lowered through the backfill, weakening the main body of the foundation.

If gravel is used for backfilling under a strip foundation or a monolithic slab, then, of course, it should be pre-insulated to prevent the concrete from loosening. However, this is often more costly than using inherently lean concrete.

What is better sand or crushed stone

On the requirements for the preparation of the foundation pit for the foundation, strict instructions are required in the construction project based on the analysis of the bearing capacity and properties of the parent soil.

The best preparation for a strip foundation or monolithic slab is lean concrete and only in some cases is it allowed to replace concrete with sand, gravel or ASM to reduce overall costs. At the same time, sand has a wide range of advantages and comes out more practical.

Gravel is suitable only in cases where a high throughput is required when it is necessary to equip a drainage layer with a low water capacity. At the same time, it is difficult to isolate the bedding from the volume in which the foundation will be poured.

Gravel bedding is perfectly combined with pile foundations, where it is enough to remove excess moisture from under the base of the house, and at the same time, a significant load will not be exerted on the bedding itself.

Under the strip foundation

By definition, sand filling is needed only in the case of using ready-made reinforced concrete slabs and blocks in order to distribute the load evenly along the plane of the base.

With the help of sand, it is easier to level the bottom of the excavation, and the rammer gives the sand the necessary density and bearing capacity.

However, this is only relevant if there is an opportunity to place a massive vibrating plate in the trench for mechanical compaction of sand. In most cases, it is safer to use a lean concrete footing for leveling and preparation.

Sand is also relevant in the case of significant differences in height along the bottom of the prepared trench. To reduce costs and reduce the volume of concrete solution, sand or crushed stone with layer-by-layer compaction and moistening is used.

Under a monolithic slab

It is important to strictly deduce the plane of the foundation of the excavation and prepare the soil for the installation of the reinforcing frame and pouring. Either lean concrete or sand compacted in layers is used.

stages of construction monolithic foundation

Sand is mainly used in cases where it is necessary to significantly raise the bottom of the pit for the foundation after sampling the entire fertile soil layer to the base of the parent soil.

When forming the backfill, it is important to pre-distribute the trays for water drainage, supply lines of communications that will pass through the foundation slab, and also mark the required planes of the future foundation.

According to the requirements, a base is formed under the monolithic slab not strictly in one plane, but with a slight elevation in the center of the building and with a slope of 2-3% in all directions, for effective removal of moisture from the substrate of the future foundation.

Particular attention is paid to the quality of sand compaction. So the density of the backfill for the foundation should be from 1.65 t / m3 and preferably not less than the density of the parent soil with an error within 0.05 t / m3.

Backfill height is defined as the difference between the level of the bare base of the soil after removal of the fertile layer and the design level of the base of the foundation.

Under the pile foundation

The backfill primarily performs the function of drainage for the removal of groundwater, and also acts as a substitute for the fertile layer of soil in order to remove from under the foundation a volume of material containing organic or combustible impurities.

backfilling device for pile foundations

For these purposes, it is best to use coarse and medium gravel, crushed stone. Expanded clay beddings are often used, which additionally increase the thermal insulation properties of the base.

Types and arrangement of a pillow under the foundation

• • Sand cushion
  • Rubble pillow
  • Concrete foundation pillow

Formation of the foundation is one of the important processes in the construction of a house. Compliance with all the requirements when laying it will make it possible for the building to serve for a long time without causing various kinds of problems to its owner.

Foundation device on a sand cushion.

A pillow under the foundation is of great importance in the construction of the base. Thanks to its correct organization:

1. The load is distributed evenly along the entire perimeter of the base.
2. With its help, the bottom is leveled under the bookmark.
3. Drainage is in progress (melt and rainwater are discharged).
4. Freezing of the lower section of the structure does not occur.

Foundation cushion device

Before starting construction, trenches for a strip base or a foundation pit for a monolithic base are dug on a cleaned and marked area. All loose soil is removed and the bottom of the trench is leveled. Then a layer is formed under the foundation of crushed stone. sand, gravel or concrete.

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Sand cushion

Diagram of a sand cushion device for a strip foundation.

To create a sandy layer under the base, you will need:

1. Sand with coarse to medium grain without various inclusions (especially clayey).
2. Geotextile or roofing material - will serve as a barrier against groundwater.
3. Level, pegs and rope.

Before starting the device of the interlayer, all loose soil is removed from the bottom of the trench. Geotextiles or roofing felt with an overlap (10 cm) are laid on its bottom. These materials will prevent the sand from mixing with the soil. Also when filling important point is observance of the horizon line. To do this, use pegs and a rope to set the desired level.

Sand is poured over the laid material.

The filling is carried out in small portions and moistened with water.

Then each layer is compacted using a vibrating plate. Compaction is carried out until traces remain on the surface. Each layer should be approximately 10 cm high.

Forming the foundation cushion. usually its height is in the norm of 20-30 cm. For the calculation, the maximum permissible height you need to triple the width of the tape. The created interlayer should resemble a trapezoid in its section. Its narrowest part should be located at the bottom (an angle of inclination of 30 degrees is desirable).

The organization of this variant of the layer under the strip foundation is relevant:

1. If leveling of the bottom of a trench or excavation is required.
2. If it is required to replace the soil with strong heaving with sand.

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Rubble pillow

For arranging a crushed stone pillow under the strip foundation, the following material is required:

Construction of rubble concrete foundation.

1. River sand with coarse grains.
2. Crushed stone or gravel 20-40 mm in size.

The formation of the crushed stone base begins with the embankment of a layer of sand. Its thickness is 10-15 cm. The resulting layer is necessarily moistened and the compaction process is carried out using the same devices as in the previous version.

Crushed stone about 20 cm thick is poured onto the compacted layer. In total, the height of crushed stone and sand should be 30-40 cm. The crushed stone is compacted. As a result, the crushed stone must lie strictly in the horizontal plane. The width of the interlayer is equal to the width of the planned base tape with the addition of 15-20 cm on one and the second side.

Such a simple version of the base for a strip foundation will withstand the load from a structure of several floors.

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Concrete foundation pillow

This version of the device is more expensive, but also justified. When properly formed, the foundation with a concrete cushion will become a solid foundation for the future structure. For its construction you will need:

1. Concrete.
2. Crushed stone or gravel.
3. Boards.
4. Vibratory plate or homemade rammer.
5. Metal rods.

To begin with, crushed stone 10 cm high is laid on the bottom of a leveled trench under the strip foundation. It is tamped using a homemade device or a vibrating plate. Then a formwork from boards is mounted on a crushed stone substrate. Its height should be equal to the height of the future pillow (up to 30 cm). The width of the interlayer is the width of the foundation plus 15 cm on both sides.

To increase the strength, reinforcement (strengthening) of the pillow is carried out using metal rods with a diameter of 8-12 mm. A frame is created from the material for reinforcement by welding or bonding structural elements together.

Concrete is poured into the formwork with a metal frame. The brand of this material will depend on the weight of the future structure. After the pouring process, the concrete is compacted using a deep vibrator. Rods 40-60 cm long are inserted into the prepared base for further adhesion of the concrete sole to the foundation. They should look out above the surface by half their length.

When forming concrete preparation for the construction of a lighter structure, crushed stone can be replaced with sand. Form a 10 cm layer and sprinkle with water to seal. The following manipulations are identical to the above described variant of the device.

For a strip foundation, a concrete cushion will become a solid base with a fairly long period of use. With its correct organization, it will withstand the significant weight of the structure and will serve as an excellent foundation.

Each type of pillow has a right to exist. Despite the fact that the formation of the foundation for the foundation can be carried out from different materials, with a properly performed process, any of the above options will be a reliable support for the future structure.

Ivan, in this case, you need to push off from a bucket with a volume of 10 liters. Fill a full bucket with sand and add 1/3 of the cement, everything will be mixed with 10 liters. or.

How is the calculation of ready-made concrete for 1 square meter of a 5 cm thick screed? How much sand and cement is required for this? So as not to buy too much. Want.

For different grades of concrete, if measured by volume, then only the ratio of sand and crushed stone to cement changes, and exactly half of the volume of cement is always taken water.

Several additions: 1. If you need to perform high-quality waterproofing liquid rubber, it is advisable to apply geotextiles over the entire surface. Consumption.

How and how to make the upper border of the foundation cladding (natural stone, slab)?

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Foundation pillow: sand, crushed stone, concrete - why is it needed and how to do it

Everyone knows that the foundation of the house is the foundation. If the underground part is done correctly, then the structure will stand for a long time. During the period of operation, cracks will not appear on its facade, the windows will not be distorted, and the base will not collapse. The foundation cushion is the first layer of the foundation of almost every building. It is considered an important functional component, and its structure obeys certain rules.

Why do you need a pillow

It would seem, what are the pillows for the foundation for if there is a dense layer of soil under it as a base? But it turns out that it is thanks to them:

• the uniformity of redistribution of incoming loads on the ground is observed;
• there is a decrease in point pressure;
• the impact of frost heaving forces on underground structures is minimized;
• the bottom of the recess is leveled, and you can do it yourself;
• the horizontal position of the foundation sole is guaranteed;
• the groundwater level decreases, and rain and melt water is diverted from the foundation;
• the stability of the position of the entire structure is ensured;
• shrinkage of various origins is minimized.

For a stable foundation, it is required that pillow under the foundation is of the correct dimensions, adequate compaction and alignment. Its width should be greater than the width of the foundation sole, and its height should be selected taking into account:

• depth of soil freezing;
• groundwater level;
• the approximate value of permanent and temporary loads;
• geological conditions.

Backfilling under the foundation is a kind of ballast that protects the structure from contact with the soil and from seasonal movements of the soil.

Often, a foundation cushion replaces an unsuitable or weak soil layer. In this case, it is removed, and coarse sand is poured in its place. To prevent it from washing out or silting up, at a high level of groundwater, geotextiles are placed in the recess.

When installing foundation pillows, you can use:

• river and quarry sand;
• crushed stone and gravel;
• concrete solution.

Clarifications on the composition and dimensions of the underlying layer are given in the design documentation. As a rule, it takes into account the availability of materials by region and their acceptable cost. But the main argument, nevertheless, remains geological conditions. For example, for soft soils, a gravel-sandy cushion under the foundation is laid in the proportion:

Some craftsmen offer the construction of a clay foundation pillow. They argue that the leveling layer will have a waterproofing function. Of course, clay will be able to protect concrete from capillary water absorption. But this soil is heaving, therefore, when freezing, it increases in volume and begins to put pressure on the underground structure. From this it follows that the judgment that clay can be used for the foundation under the foundation is absolutely wrong.

Sand pillow

It is better to make the device of the underlying layer with your own hands from sand, since the material is quite available in many regions of the country. Inexperienced developers often have a question about what kind of sand is needed for the foundation and cushion - river or quarry, and what fraction of grains should be.

You should start with how river sand differs from quarry one. The first is considered much cleaner, since the natural dislocation of the material and technological features extraction means the absence of foreign particles in the composition. It does not contain clay inclusions that are too dangerous for the construction of the base. When mixing concrete mix and device foundation cushions it is better to use river sand or washed quarry, which will cost a little less.

Quarry sand is extracted in large volumes from open pit mines. That is why there are many different impurities in its composition, such as clay, large stones and dust particles. Without additional processing it is used only in some cases, for example, when laying roads.

It is not recommended to use dirty quarry sand for the foundation and cushion, since the presence of even a small amount of harmful inclusions in it can adversely affect the stability of the underground part of the house and its durability. Why risk one-off savings when there is a better quality alternative?

It is possible to distinguish river bulk material from pure quarry sand by outward appearance grains. You just need to look at them through a magnifying glass. In the first case, the particles will be rounded, and in the second - with sharp edges.

Sand for the foundation and cushions are selected in coarse fractions.

As mentioned above, making a sand pillow for the foundation with your own hands will be a snap. This will require the material itself, rammer and water. With a large building area, it would be better to use a special vibrating plate or roller. And when compacting the underlying layer in the trench, you can also use proven old-fashioned tools, for example, a log with a transverse handle.

A sand cushion under a strip foundation or a concrete slab is filled up in layers. Each layer is leveled, moistened and carefully rammed. Abundant watering contributes to better compaction of the sand and ensures the maximum density of the substrate. At a high level of groundwater, crushed stone is poured onto the bottom of the trench. It takes over the functions of the drainage layer. In its absence, the base of the house will sooner or later be eroded.

• a one-story house is being built;
• light materials are used for the above-ground part of the building;
• groundwater is at great depths.

Even before starting work, you should decide on the thickness of the sand cushion for the foundation. As a rule, it is 10-20 cm, but when installing a base under a concrete slab or when replacing a weak soil, the size can increase to 50-80 cm. For belt structures, the maximum sub-base height is limited to three times the belt thickness. As for the width of the cushion, it should be 20-25cm larger than the same size of the sole or slab for the foundation.

Crushed stone bedding

A crushed stone pillow under the foundation is considered stronger previous version base devices. You can also do it yourself. At the initial stage, the bottom of the excavation is covered with coarse sand with a layer of 10-15 cm, after which it is leveled and thoroughly tamped with moisture.

Next, the crushed stone of the middle fraction (20-40mm) is laid in a layer 20-25cm thick. A vibration plate should be used to seal it. What for? Yes, only because it will be too laborious to do it using old-fashioned methods.

A crushed stone pillow under a strip foundation is capable of taking loads from brick and stone houses of low rise.

Often, the project provides for a crushed stone-sand base. It is filled up in layers with alternating materials and compaction. This type of bedding has proven itself well in the construction of facilities on weak soils.

Concrete base

The most expensive and reliable sub-base. The concrete pillow can even be used for the foundations of apartment buildings. The technology for its implementation is quite simple and available for independent work. The process consists of several stages:

• leveling the bottom of the groove;
• adding crushed stone with a layer of 10 cm and tamping;
• installation of formwork at a height, according to the project;
• waterproofing flooring;
• laying reinforcement;
• pouring concrete solution;
• set by the monolith of design strength;
• dismantling the formwork.

For strong adhesion of the base to the foundation, steel rods protruding above the surface are installed in the cushion. They serve as connecting anchors to maximize the reinforcement of the underground structure.

Conclusion

The three main types of foundation cushions can be used either separately from each other or in various combinations. The choice depends on many factors, and the final decision is made by the designers.

Sources:

Concrete screening: can it replace sand?

Many home craftsmen, who prefer to independently solve construction and repair issues on the site, ask the question: is it possible to replace sand in concrete with screening materials? To understand this, it is worth clarifying that different types of screenings are formed when crushing a stone, these are those fractions that are too small to be considered crushed stone. However, they retain the characteristics of the original material: granite, limestone or gravel. Since such a product is a by-product of the production of crushed stone, the price for it is lower than for sand.

As for the possibility of replacing sand or crushed stone with screenings when mixing a concrete mixture, experienced builders use this method to reduce the cost of mortar. It is not recommended, however, to completely replace the sand with this material; moreover, it is better to replace part of the crushed stone with screenings, and leave the proportions of sand unchanged. This will allow you to create high-quality, durable concrete, while reducing its costs. If you want to use screenings for mortar, it is preferable to replace no more than half of the coarse filler fraction with it.

The only exception is the use of screening materials when mixing concrete for the foundation for the construction of a fence, a floor in a garage, paths in a backyard or a blind area of ​​a house. However, it is still recommended to slightly increase the amount of cement in the recipe. Screenings are also filled with solutions for laying shell rock or rubble: 1 part of cement, 2 parts of sand and the same amount of screenings are used.

Please note that the quality of the mixture will greatly depend on the amount of impurities in the screening material, as well as its origin. The screening should contain as little foreign inclusions as possible: clay, dust, organic matter. It is preferable to use granite materials as they have good strength values. Much less commonly used in construction is gravel and very rarely limestone screenings. To improve the quality of the filler, it is sometimes additionally washed, but this is a laborious task, which is usually the initiative of the buyer.

When using this building material, it is advisable to use equipment for vibration compaction - the finished foundation or track will be more durable. Thus, the screening fraction cannot replace sand, but it can fully or partially satisfy the need for crushed stone.

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Using crushed stone screening

Along with those traditionally used in the preparation of cement and concrete mixtures, relatively inexpensive natural material- crushed stone screening, the use of which allows to reduce the cost of concrete without reducing its strength.

Granite is gray and color pink, the latter is often used for decorative purposes.

What is the screening of crushed granite? Fragments of sufficiently strong stones, the grain size of which does not exceed 5 mm. In fact, the fraction is comparable to coarse sand, but costs a little less as it is a by-product and not a main product in the quarries. At the same time, it remains granite with the preservation of the main property due to which granite is used in concrete mixtures: strength. Is its use in construction work justified enough? In what proportions can it be used so that the quality does not suffer, and to obtain tangible savings, for example, when pouring a strip foundation?

Savings in use

In construction, especially in private, crushed stone screening is used to reduce the cost of concrete. They can partially replace gravel in a hard concrete mixture, while the strength of the finished concrete will not suffer, and it is easier to lay it.

The particle size is 0-5 mm.

You just can't just replace the crushed stone or part of it with screenings. Larger fractions require less grout to fill the gaps between them. The explanation is simple. The total area of ​​the planes of any polyhedron is much less than the sum of the areas of the surfaces of several polyhedrons that can result from the split of the original.

Depending on the brand of cement when casting a strip foundation, the weight part of the coarse fraction can be partially reduced by screening out crushed stone. For example, for cement M200, when the approximate ratio of cement / sand / gravel is 1: 3: 5, you can use 3 instead of 5 parts of the coarse fraction, and replace two with screenings. It is possible to take screenings to replace more gravel in the mixture.

To be sure of the quality of the concrete mix, it is necessary to make several trial mixes.

A press is used to determine the strength of a test specimen of concrete.

It should be borne in mind that the size of the particles is something between sand and gravel, so it is not worth replacing the coarse fraction of the filler completely with it, but under certain conditions it is possible if the amount of cement is increased.

Depending on where the concrete mix is ​​planned to be used, the required volume of crushed stone can sometimes be completely replaced by granite screening. For example, when a foundation is being cast for a fence, a floor in a garage, walkways or a blind area of ​​a house, the strength of concrete, in which the large fraction is completely replaced, will be sufficient. The crushed stone screening used in the solution in no way replaces sand! Despite its small size, the screenings are still crushed stone (gravel) and perform the function of a strong filler, while sand plus cement form an “adhesive” composition.

Concrete mixing

If there is an opportunity to contact the laboratory of the nearest enterprise for the production of reinforced concrete products, then they will help to draw up an almost ideal proportion of cement / sand / screening / crushed stone, taking into account the materials purchased by the developer. Such a procedure will cost a certain amount of money, but it will save time on trial mixes, which will experimentally allow you to select the appropriate composition, taking into account in order to make the most of the screenings.

Fixtures and tools needed to make a test batch:

• kneading container;
• trowel (both as a measure and for mixing);
• several wooden forms for a cube with a side of about 10 cm.

The use of granite screening for the preparation of concrete mix will reduce its cost.

Kneading is done as follows. Take 1 part of cement and 2 parts of sand, mix thoroughly until smooth. Only after that 2 parts of the crushed stone screening are added, after it uniform distribution 3 parts of gravel are poured into the mixture and, in the process of mixing, water is added in small portions. We must not forget about the water-cement ratio, which should be the minimum possible. The concrete solution is ready when the lump, taken in the hand, does not leave traces of cement on it.

The concrete mixture is compacted into a wooden mold, well moistened with water. After about an hour, the cube should be easily removed from the mold, while maintaining the relative smoothness of the edges. If the sample delaminates, increase the cement ratio or lower the dropout rate and try again. You can immediately make several batches with slightly changed proportions and determine the optimal composition of the concrete mixture based on the results of the hardening of the samples.

Granite is well suited as a filler in cement mortar for masonry buta or shell rock. The composition of such a solution: one part of cement and two parts of sand and screenings. The higher the grade of cement, the greater the amount of dropout that can be introduced into the mixture without loss of concrete strength.

Since the cost of crushed stone screening is commensurate with the cost of sand, and where to apply it, there is always, it can be safely taken "in reserve". For example, to decorate tracks on garden plot... Unused during construction, it will not disappear.

Dropped concrete: how to replace sand in grout

During the preparation of a concrete solution for a foundation, concrete goods, paving slabs and other construction needs, it is imperative to use a filler. Traditionally, sand plays this role, but to obtain quality concrete it is important that the filler is clean and of good quality. Therefore, sand can be successfully replaced by screening. This material is a by-product of the manufacture of crushed stone, the smallest residual fraction. There are screenings obtained from crushing crushed stone, recycling concrete or concrete with bricks.

Granite is considered the most durable, however, when mixing building concrete without harm to the final structure, other screening materials are also used. Regardless of the origin, such a product is environmentally friendly, capable of completely or partially replacing more expensive sand and crushed stone. The main thing is that there should be no graphite (black inclusions) and clay (yellow particles) in the mass of screenings. As with other materials, the screenings must be clean.

An approximate recipe for concrete from screening is as follows: one part of cement grade M400, eight parts of screening, about 20% water. As a result, concrete M150 is obtained, which can be used for pouring sites or screeds, surfaces with reinforcement. If necessary, you can use cement of a higher grade, but you should not increase its share on your own - this will not add additional strength to dried concrete. Also, screening materials can be added in combination with sand, crushed stone, distributing proportions.

Direct mixing of the solution is best done in a concrete mixer. First, the dry components of the mixture are combined, after which water and additives (if any) are added little by little. It is important that there is not too much water, you can use even less than indicated in the recipe you have chosen. Excessive liquid can have a detrimental effect on the strength of concrete. When the cement and water are well mixed, a slightly moistened screening can be added. This will allow it to easily connect to the dense mass.

Today, many proven recipes have been created using various screening materials. By varying the proportions and composition, it is possible to obtain concrete with different properties, corresponding to the intended purpose. note that ready mix must be fully used in the first two hours from the moment of preparation, so it makes sense to knead it for private construction in small portions.

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Foundation concrete. Learning to make the main component of a strong support for our house

Any foundation at a certain stage of its construction requires concrete pouring. Concrete is a dense mixture. The constituents of the concrete mixture are: water, a substance with an astringent characteristic, fillers and various special additives. The binder is usually cement. A filler for concrete mix, maybe screenings, sand, crushed stone, etc.

In modern housing construction, there are no restrictions on the choice and purchase of building materials. Likewise, the concrete mix can be ordered and purchased at finished form... That is, it will be delivered to your address in a special machine - a concrete mixer truck, concrete pumps will be given out on a rental basis and work for yourself, please continue on your own.

This offer is quite tempting, but no one is responsible for the quality and quantity of cement used in the batch, and the discrepancy between its brand and proportion to the work carried out will only show time in the form of destruction and cracks on the foundation. In order for the concrete mixture to correspond to the properties and composition, it is necessary to correctly select the proportions of its components. And the strength of concrete depends on the quality of the materials used: cement, stone filler, quarry or river sand and water. The most important thing is that the composition of the concrete mix is ​​formed based on its purpose.

In our article, we will consider several important tips and rules for those who are not lazy and will prepare the concrete itself at the construction site.

The main constituents of concrete for foundation work

To prepare the concrete mixture, we need the following materials: aggregates for concrete of a coarse fraction - crushed stone or gravel; fine aggregates - screening or sand; water and, of course, cement. Let us examine further the constituents of concrete according to their characteristics.

For example, sand for the construction of the foundation can be ordered with delivery to the construction site. River sand is recommended. But the area of ​​development can also regulate the delivery of sand, available and mined in this region. For foundation work, quarry sand is also perfect. The main thing is that the sand is clean and does not contain silt and clay impurities, which can significantly reduce the quality of the concrete mix. According to the standards, sand can contain no more than five percent impurities. The sand for the preparation of the concrete mixture should not be too fine, the particle size of the material should be 1.2-3.0 mm. The dirtiness of the sand can be checked by pouring it into an ordinary plastic bottle and fill with water, shake. The water should be practically clean, at best, a little cloudy. If the water becomes too cloudy and, during settling, a clay sediment appears, which means that sand with a high content of clay impurities and it is not recommended to use it to prepare a concrete solution.

Regarding gravel, crushed stone, you can also argue for a long time which type to give preference to: rolled or crushed. You can be almost one hundred percent sure that you will acquire material obtained in a given area. At the same time, it is recommended to wash and clean the crushed stone from foreign inclusions before use. You can wash the rubble at the construction site, for example, with water from a hose, but you should make sure that no earth gets into the composition. The earth contains a fairly high amount of organic matter, which affects concrete with a destructive effect. Gravel or crushed stone is better suited for one with a particle size of 1-5 cm.

It is believed that very the right decision when preparing a concrete solution, apply screening. Sifting gives particular strength to concrete. Screening is most often used as an additional filler, since its price is much higher than sand. For example, one part of sand and crushed stone is taken away from the composition of the concrete mixture; instead of these parts, two parts of the screening are added. Sometimes, screening in the solution plays the role of the main filler, instead of sand.

The amount of water in the concrete mixture should be about 20% of the total mass, just enough so that the solution has an average consistency. The water-cement ratio also depends on the brand of cement used, so it is better to familiarize yourself with the instructions and characteristics of the cement. Note that sea water is categorically not suitable, it is better to use drinking water. If the proportions of the components of the mixture are not maintained, and there is a lot of water in the concrete, then the aggregate floats in the mass, and the foundation shrinkage will be too large. Excess water in the concrete mix leads to a decrease in the bearing capacity of the concrete and its further cracking.

Next, let's talk about the most important component of concrete - cement. Cement is made from cement clinker obtained from natural raw materials or from an artificial raw mixture. The raw mix contains three parts of limestone and one part of clay, but instead of clay, minerals such as diatomite, tripoli or other silicate rocks similar in chemical composition to clay can be used. The raw material lends itself to firing before sintering, where in the process after firing, a sintered solid mass is obtained, which is the cement clinker. This mass consists of grains the size of a dark walnut gray, which are further ground in a ball mill to a fine powder.

Often, to improve the quality of cement, when grinding, hydraulic additives are introduced into the powder: about 3% gypsum, up to 15% tripolite or diatomite. Cement is considered to be of high quality and has a high adhesion ability if the clinker is crushed as much as possible to ultrafine grinding, since chemical reactions during such grinding are accelerated, and the reunification of the material with water occurs over the entire surface.

Cement is subdivided, in its kind of production, into grades, which are indicated in numbers: from 100 to 600. The numbers indicate the strength of the prisms of the samples in compression in the range of 10-60 MPa. This means that the grade of cement is determined by its ultimate strength. This happens in this way, by pressing the prism samples are compressed with each other, and they are made from a solution: one part of cement is mixed with three parts of sand with a grain size of 40x40x160 mm. Cement with the 600 mark is not used in private housing construction, due to its too high cost. This brand of cement is used in the construction of military facilities, for example, missile silos, bunkers, etc., and is called "Military".

For private construction and the construction of foundations, cement is used, most often, grade 500, less often - M-400. Of course, when choosing a brand of cement, the choice stops according to a specifically developed architectural project, but the cost between brands is not much different, and you should not save on your own comfort and safety.

Cement is also subdivided into types: Portland slag cement, Portland cement and pozzolanic cement, as well as their variants of fast-setting cement. All species have the same nature, but some peculiarities. For example, slag Portland cement has increased moisture resistance, but reduced frost resistance, which affects the rate of strength development. Portland cement is the most common material used in the construction of any type of structure, including the pouring of monolithic foundations. Portland cement, in contrast to slag Portland cement, has less moisture resistance, but greater frost resistance. For the construction of underground and underwater structures, it is recommended to use pozzolanic Portland cement, since when it is used outdoors, its strength qualities are lost and we get a large shrinkage.

To speed up foundation work, you can use fast-setting cements, but it is worth knowing that it is also necessary to work with them very quickly, which is extremely impractical during construction. Therefore, experienced specialists in the construction of a monolithic foundation recommend using Portland cement.

Note that it is recommended to purchase cement before starting direct work with it. The recommendation is explained by the fact that cement, stored in a warehouse for about a month, loses about 10% of its strength; three months in warehouses - 20%; after a year of storage, about 40% is lost, and a couple of years takes away more than 50% of the strength of the cement. If, when opening a bag of cement, you find lumps inside, or maybe completely hardened cement, you should not be upset, because if the lumps collapse under the squeeze of your fingers, then the cement can be safely used. Opened bags of cement should not be left open overnight. Advice, it is not recommended to increase the proportion of cement in the concrete mixture, this will not add strength to the concrete, but, on the contrary, will reduce it. The recommended optimal composition of concrete for foundation work can be seen in the table above.

We select the correct composition of the concrete mixture

The proportions of concrete materials for pouring the foundation can be as follows: for example, if we take at the rate of ten kilograms, then for 10 kg of cement, we take 30 kg of sand, 40 kg of gravel, or 50 kg of crushed stone. For cement, for example M400, you need to mix water half the weight of all other components. For example, if the weight of a dry mixture of cement, sand, gravel or crushed stone is about 90 kg, then about 45 liters of water must be taken. The solution should be dense enough, but not too, but not quickly drain from the shovel. If the mixture is too dense, you can add water.

It is worth remembering that raw sand also contains moisture, so it must either be dried or used a few liters less water. Note that the sand in the composition of concrete should be half as much as gravel. Concrete mixing can be done in an iron bath, on wooden deck either an iron sheet, in a wooden trough, or in a concrete mixer. The main thing is to make sure that no foreign impurities get into the mixture, and the mixture is thoroughly mixed until smooth. To do this, first, we will fill in the dry compound ingredients, mix them thoroughly with a shovel and gradually add water. The concrete mixture should be evenly mixed and completely moistened, and after preparation, it should be used within a couple of hours.

It is advisable to fill the foundation during the warm season. Often, foundation work takes place during the cold season, so we recommend using heated water for concrete. This will accelerate the hardening of the concrete mixture after pouring, and during mixing, it will not harden earlier. In hot weather, concrete should be poured with the addition of cold water into the mixture so that setting does not occur very quickly. After pouring the foundation, in order to remove excess air in the mixture layer and compact the concrete, we will use a special deep vibrator, or an ordinary piece of reinforcement, with which we sprinkle a layer of concrete pouring in several places, and knock the formwork with a hammer from the outside.

We calculate the required amount of concrete mix for work

Competent and economically feasible construction of the foundation consists in the correct calculation of the required volume of concrete. The surplus of purchased material will be fraught with wasted funds to the wind, and the lack of concrete mix at the construction site will lead to unnecessary running and wasted precious time. In this regard, it is necessary to take a rather responsible attitude to the exact calculation of the required amount of concrete.

We can easily determine the grade of concrete. Cement must be selected very carefully by brand, since, for example, M-200 cement may no longer correspond to its labeling due to long-term storage, and meet the characteristics of M-180. Accordingly, after kneading, pouring and other work, we will get a grade of concrete, at best, about 100. Concrete we will get a grade one and a half or two times lower than the grade of cement. The table shows the values ​​of the water-cement mixture.

Concrete, the grade of which corresponds, for example, 100, will withstand a load of about 100 kgcm2, therefore columnar foundation made of this grade of concrete, with a cross-section of pillars of 20x20 cm, with a cross-sectional area of ​​400 cm2, can withstand a load weighing about 40 tons. Accordingly, four such pillars can carry a house weighing 160 tons. When using M-400 cement, keeping the mixing proportions, we will end up with M-200 concrete. Of course, the strip foundation will distribute the weight of the entire house over a larger area, so even if you deviate from the technology of mixing and pouring the foundation, it will remain strong enough and will not collapse.

Each grade of concrete gives a different shrinkage, so it is necessary to find out exactly the value of each parameter, since the greater the shrinkage coefficient, the more concrete mixture we will need for pouring. For example, a parallelepiped-shaped foundation will require a volume of concrete solution, which can be recognized by the following formula: the width of the foundation is multiplied by the length and by the height (V = abh). The resulting indicator is multiplied by the shrinkage coefficient of our concrete grade. The final value is divided by 1.05. A value of 1.05 defines the approximate volume of additional elements such as reinforcement. If the shape of the projected foundation is not the shape of a parallelepiped, but, for example, a parallelogram, at the base of a trapezoid, and so on, then we are looking for knowledge in school geometry, where formulas for calculating the volumes of various figures are definitely available.

Aggregate materials used in construction and industrial production come in a wide variety.

To accurately select them for a specific type of work, special knowledge is required.

Therefore, the question of which is better - sand or screening for concrete, is relevant for many novice builders.

Use of sand and screening for concrete production

The main components for the production of concrete mix are crushed stone, sand, cement and water. When self-preparing this building material, the question often arises: is it possible to use screening instead of sand?

Screenings are made by crushing rocks. The resulting material retains the characteristics of the raw material - natural granite, gravel, limestone. In fact, this is the waste that is obtained during the production of crushed stone, their cost is much lower than the sand composition. Therefore, by replacing some of the components, many seek to minimize costs.

Professional builders do not recommend using instead, or rather, a complete replacement of one component with another. More suitable option is the inclusion in the composition of crushed rock instead of a part of crushed stone, and it is advisable to leave the proportion of the sand mixture unchanged. This "recipe" will allow you to reduce the cost of production costs and get a high-quality, durable product.

It should be borne in mind that the quality of the final product will largely depend on the composition and purity of the screening material. The amount of clay and organic impurities should be minimal, not more than 3.0%.

It is best to add granite chips, which provide high strength of the concrete structure and has the following advantages:

• Democratic cost. If you replace the crushed stone with granite sieve, you can reduce the cost of making concrete mortar several times.
• Possibility to partially use screening instead of sand in concrete.
• Attractive look. Small crumbs with a dark red tint make the material in demand when creating elements of landscape design, when carrying out finishing work, in the production of decorative structures.
• Improving the performance of facilities. If the ratio of the main components is observed, a high-strength building material is obtained, which ensures the reliability of the building structure.

Experts advise using quality certified raw materials that fully comply with the standards state standards, keep the proportions exactly, and also take into account the following recommendations:

• For partial replacement of the sandy substance, crumb 15 to 40 mm in size is suitable. A finer fraction will significantly reduce the quality of the concrete mix.
• Concreting using a solution based on screening raw materials should be carried out in combination with reinforcement.
• Yellow and black crumbs are not used in concrete solutions due to the content of clay impurities and graphite.

To reduce the budget for the improvement of the site, it is recommended to lay paving slabs for screening out granite or gravel rocks. The fraction of bulk material is identical to coarse sand, has better drainage properties and is 10-15% cheaper. The torn edge of the particles is ideal for backfilling the screenings into the seams of curly paving elements - they wedge under their own weight, practically do not blow out and do not wash out from there.

Dropout selection

This bulk material is of interest to individual developers in terms of reducing transport costs:

• it can be used as an underlayment;
• to make curly paving elements and curbs from the same product, if necessary;
• lay paving slabs on it;
• and even fill up the screenings in the seams at the end of the work.

However, this is true only on soils with a high design resistance at a low groundwater level. On wet soils and fresh embankments, you will have to additionally order the delivery of coarse gravel and purchase geotextiles to prevent mutual mixing of nonmetallic material with the ground.

In principle, the technology of laying paving slabs for screening is no different from paving FEM elements on sand or.

Paving technology

Having decided what sorting out is needed, and having bought it in sufficient quantity, it remains to prepare the base, mount the curbs, and lay curly paving elements on the non-metallic material. For paving slabs, a rigid space box is required to prevent slipping of individual elements during operation.

Layout of paving areas

To ensure earthwork, the cords along the paths of the garden paths are pulled with their own hands on the rags taken out 1 m from the corners of the paving zones. Curved sections are placed lime mortar or paint on the ground.

Track markings.

Rice. 3 Layout of garden paths

Before you lay the FEM with your own hands, you need to create a sketch of the site on a scale and indicate on it the slopes for stormwater trays 2 - 4 degrees.

Sketch to scale for the improvement of the site.

Excavation

Since the construction standards of the joint venture prohibit any work on the arable layer (gray or black soil) due to the possible subsidence of the soil rich in organic matter, before laying the paving slabs for screening, it is necessary to remove the fertile layer and replace it with non-metallic material. The technology looks like:

• removal of black soil - usually 40 cm or two bayonets of a shovel;
• production of slopes to gutters and stormwater inlets - for drainage;
• removal from the site or application in landscape design, on the beds of excess soil;
• covering material - the bottom of the pit or trench is lined with dornite or other non-woven material so that the screenings do not mix with the ground.

Excavation.

If on the site upper layer the soil is sand, and the groundwater level is below 1.5 m, the trench is dug only to a depth of 8 - 10 cm (5 cm dropout layer for laying and 3 - 5 cm thickness of FEM elements).

Underlying layer

On dry ground, a rigid base can be made with your own hands to ensure stable geometry of the pavement and drainage of drains that penetrate through the numerous joints of the tiles:

• the screenings should be laid in layers of 10 - 15 cm, compacting each of them with a vibrating plate or rammer, until traces of shoes no longer appear on the surface;
• the recommended layer thickness is 20 cm, however, when excavating fertile soil of 40 cm, the height of the underlying layer is adjusted individually.

Crushed stone ramming with a vibrating plate.

Important! It is necessary to take into account the thickness of the FEM elements, their level relative to the curb, leave 5 cm to screen out the contact layer, which is not rammed before installing the tiles.

Installation of curbs

To lay curbs with your own hands along garden paths or along the perimeter of the parking lot, you must adhere to the following technology:

• deepening of the trench, taking into account the height of the curb;
• dumping of crushed stone and compaction of a 5 cm layer with a manual rammer;
• installation on a cement-sand mortar;
• fixing on the sides with mortar additionally by "blotting" with a trowel in several places.

Installation of curbs.

Important! Since a storm drain should be installed on one side of the path, a curb along the opposite edge is sufficient. The tray has sufficient height for reliable fixation in the ground, completely replaces the curb, providing the rigidity of the space box. During installation, take into account the slope for gravity drainage.

Contact layer alignment

To facilitate your work on the manufacture of a contact layer from the dropout, on which the curly paving elements are directly laid, it is necessary to take into account the nuances:

• there are three technologies for laying beacons (guides);
• the usual rule or plank with notches along the edges is used.

Until recently, it was used classical method:

• beacons were mounted at the level of the lower surface of the paving slabs;
• bulk material was poured between them;
• as a rule, the surface was smoothed, excess sand / screenings were removed.

Classic technology.

However, after retrieving shaped pipe or a galvanized profile, deep grooves remained in the contact layer, which had to be filled in additionally, which is very inconvenient for the master. Therefore, it is better to use the following technologies:

• T-shaped profile as a beacon - after removal, a narrow groove remains, which you can not fill up;

Narrow T-profile guides.

• ordinary guides, but laid at the level of the lower edge of the tile - after removing them, you do not need to level anything additionally, however, a special configuration rule is required.

Semi-dry screed tool kit.

Such a rule is sold in tool sets for semi-dry screeds, or the tool can be made independently by cutting out steps on the sides, depending on the thickness of the curly paving elements used at a particular object, as in the lower photo.

Homemade rule from the board.

The tile set includes a fixed cutout rule that may not work with purchased paving slabs. Therefore, for a one-time paving on your own, it is easier to make it from a dry edged board yourself.

Laying tiles

Traditionally, for finishing surfaces with small-format claddings, the most time consuming is the fitting of pieces in the places where they interface with structural elements:

• areas around storm water inlets;
• adherence to curbs when using paving slabs of complex configuration or diagonal layout schemes;
• surfaces near hatches, steps.

Therefore, first, it is necessary to put on the prepared contact layer the entire solid tile according to the selected layout scheme according to the following method:

• installation of FEM elements begins from the curb, blind area or wall of the building;
• laying is carried out on straight sections in order or in a ledge ("ladder");
• the tile is placed in front of him, the master moves along the laid pavement surface facing forward, without damaging the aligned screenings.

Installation of tiles

After that, the whole tile is cut with a diamond disc or a stone tool, fixed in the angle grinder. It is not necessary to knock out the FEM elements in height if you bought a high-quality tile of the same thickness. However, in difficult areas, with an insufficiently aligned dropout layer or changes in thickness, the FEM within one batch can be knocked out from above with a rubber mallet.

Tile marking for cutting.

Advice! After leveling the dropout by the rule, this layer of nonmetallic material is not compacted, providing adjustment of individual elements in height. Subsequent ramming with a vibrating plate completely corrects possible defects in the flatness of the coating.

Making seams

Depending on the fraction of the screenings used for paving, the seams of paving slabs can be covered with the same bulk material or sand can be used. In the latter version, it is better to use material with large grains of ragged shape - quarry or quartz sand. It wedges between concrete products under its own weight, is not blown out or washed away by the rain stream, therefore it lasts longer.

River sand has a rounded particle shape, so it is better not to use it. Backfilling is carried out immediately after laying the cut pieces in the nodes of abutment to curbs, hatches, stormwater elements, before compaction with a vibrating plate according to the technology:

After vibration compaction, part of the nonmetallic material can protrude on the surface, therefore it is necessary to re-sweep the paving area with a brush.

Attention: efflorescence

Unlike facing brick masonry, efflorescence on paving slabs can occur at any stage, starting from the moment of storage in a warehouse before selling. If you bargain with the manufacturer, then you can buy curly paving elements with stains on the surface much cheaper, and getting rid of them will not be difficult.

Efflorescence on paving slabs.

The following products are most in demand for eliminating efflorescence:

• Neomid
• Batichem
• CL-Clean
• Facade-B manufacturer Perhim
• Prosept CC
• Antisalt of various brands

Thus, budget option paving paving slabs is a method of laying FEM for screening without adding cement, but with the obligatory compaction at the end of the work with a vibrating plate. The appearance of efflorescence can be prevented by special treatment of concrete surfaces or to get rid of salts when they appear on the surface of the pavement.

Advice! If you need a master for repair, there is a very convenient service for their selection. Just submit in the form below detailed description works that need to be completed and you will receive offers with prices from private craftsmen, repair teams and firms by mail. You can see reviews of each of them and photos with examples of work. It is FREE and non-binding.

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Laying paving slabs on sand or screening

Publication date: 30-04-2015

• Preparation of the base for paving slabs
• Choosing the right underlayment technology
• Description of the tile laying process
• Direct tiling

First of all, you need to make a markup and stakeout. After this stage is passed, you can move on to one of the most significant issues - the preparation of the underlying layer.

Tile laying scheme: 1 - Ground, 2 - Curb, 3 - Concrete, 4 - Crushed stone or slag, 5 - Sand layer, 6 - Paving slabs.

The sub-base is a compacted bulk material that is located between the tile and the existing soil layer. Crushed stone, sand, screenings, cement-sand mixture and so on can act as materials for such a layer. The underlayment can serve two purposes:

1. Protection of the pavement from any ground movements in winter period time.
2. Conclusion of elevations at the specified values.

The sub-base structure consists of the following elements:

• tile;
• granite screening either
• crushed stone (thickness up to 20 cm);
• existing natural soil.

It is worth knowing that there are some specific technologies related to the arrangement of the underlying layers:

The scheme of paving the sidewalk with tiles.

The first option is intended for difficult cases (the movement of freight vehicles, problems with existing natural soils, and so on):

• cement mortar (thickness 3 cm);
• reinforced concrete(thickness 10-15 cm).

The second option is intended for the passage of cars:

• screening or sand (thickness 10 cm);
• crushed stone (thickness 20 cm).

The third option is used for the construction of footpaths:

• cement-sand mixture (DSP) (thickness 3 cm);
• sand (thickness 10 cm);
• crushed stone (thickness 10 cm).

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High-quality laying of paving slabs largely determines not only the architectural appearance of the site, but also the durability of the paved surfaces.

The choice of technology will depend on the requirements that must be imposed on the tile sheet during operation in the future. In the event that a paving slab path will be intended for pedestrian movement, there is no need to concrete it using the first option. This can lead to unnecessary costs. Money.

In the event that the soils are prone to subsidence, by arranging, according to the second option, an underlying layer for the passage of cars, it will be possible to get difficulties with the sidewalk in the future.

It is recommended to entrust the choice of the appropriate technology to a highly qualified specialist, in addition, it is worth knowing that quite often there are combined options, in which several technologies are applied at one facility (for the passage of light motor vehicles - option 2, for sidewalk paths - option 3, and so on). In this case, the cost of money for installation will be optimal.

It is worth mentioning the most economical option for arranging a base for paving slabs. It will be about the device of paving slabs exclusively for screening or sand. There is an opinion that this option deserves attention and can be quite reliable with an appropriate approach. In order to use it, you must comply with the following conditions:

1. The existing natural soil must be of natural long-term compaction (this is very important, you should not neglect it).
2. In no case should the sand be allowed to wash out from under the paving slabs. To do this, you will need to grease with a solution all the joints between the curbs, and especially from the inside.
3. The drainage of rainwater must be carried out in an organized manner, strictly according to trays, which must be installed on the solution.

If these three conditions are met, the paving slab can serve its owner for a long time. At the same time, the cost of work in conjunction with the laying of tiles will be much less.

Below will be considered the components of the underlying layer.

Laying scheme for paving slabs.

1. Crushed stone. Both granite and limestone, fractions of 20-40 mm can be used. In the case when such a fraction is too large, that is, the elevation marks do not allow its use, a fraction of 5-20 millimeters should be used. The use of sludge can significantly reduce the cost of the underlying layer.
2. Screening or sand. A similar material is used by technology in order to arrange the top leveling layer. It is possible to use any sand or granite screening of fraction 0-5 mm.

Visually, you can divide the tiled canvas into some categories.

By color:

1. Single color (which consists of tiles of the same color).
2. Multicolor (which consists of tiles of several colors).

In the direction of the seam:

1. Radial (the seams are radial curvatures or circles).
2. Unidirectional (the seam can be clearly seen in one or more directions).
3. Chaotic (there are no patterns in this case).

After the owner of the territory decides on the installation option and chooses color range, you will need to bind it to the surrounding objects. Binding should be done to the inputs and outputs. The main entrance to the building will be the priority. Subsequent priorities are determined along the way.

Laying contains such a thing as “tile trimming”. The tiles must be trimmed in places where their shape does not allow them to occupy the appropriate space. An example would be the distortion of the geometric size of a building. It is worth noting that this is actually not uncommon.

Trimmed tiles will not look very nice, but this is a normal action that cannot be avoided on many objects.

There may be no undercutting, for example, on sidewalk paths, which determine the width at which the tiles can become without undercutting between the existing curbs. You should drive this size the entire length of the path.

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After organizing the base (clearing the place of laying), sand is poured about 5-7 cm high around the perimeter of the laying and moistened with water from a hose so that deep holes do not form on the surface of the sand.

Next, you should proceed to the description of the process of laying paving slabs. There are several technologies for laying such material, but the most common of them will be considered: laying along the guides.

In order to get started, you will need:

• 1 assistant;
• shovel;
• thread, fishing line or nylon twine;
• level-rule 3 m;
• 3 guides (square or round pipe 25x40 mm) 3 m each;
• level 1 m;
• bucket;
• Master OK;
• rubber mallet;
• panicle;
• paving slabs.

A nylon twine connects the elevation marks, which are carried out on pegs along the perimeter. Thus, it will be possible to obtain the top of the future tiled canvas.

It is important to know the main rule of styling.

By connecting any point of the nylon twine, which is stretched between the pegs with height marks on one side, with any point of the second stretched nylon twine, between other pegs with other elevation marks, it will be possible to get the top of the future sidewalk. If there are doubts about the elevation marks anywhere on the sidewalk being manufactured, this rule should be used.

Laying is done in strips 3 meters wide, and the length is determined by the distance from one taut twine to another.

With the help of a shovel, excess sand or screenings are removed. Next, a cement-sand mixture is added to the level of the greater height of the exposed pipes. At the end, it is necessary to compact the base well without knocking down the pipes.

Then, together with the assistant, we take the rule and, resting it on 3 pipes at the same time, moving left and right, we cut off the excess soil. The result is a flat surface with three visible pipe surfaces from the mixture.

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You will need to carefully remove the pipes. The mixture is poured into the niches that remain from them. As a result, you will get a flat area that will be ready for laying paving slabs.

Next, the tiles are laid out by tapping each one as needed. After the small section has been completed, it should be checked if the workforce has laid the tiles correctly. To do this, you need to measure the dimensions from the outermost tiles from the axis. If the canvas leaves, you need to try to bring the dimensions in line by hitting the ends of the extreme tiles.

How is screening for paving slabs laid?

Screening for paving slabs is used for laying garden paths, playgrounds and courtyards on personal plots. This material is much cheaper than sand, and can significantly save money when laying tiles over large areas.

Composition of the base for laying paving slabs.

The technology of laying for screening involves the creation of a special cushion that prevents the tiles from sinking. Next, we will consider how to create such a layer and the sequence of its inception.

What is dropout?

Screening is a fine-grained material that is a by-product of crushing natural stone (granite or gravel). The maximum size of individual particles of the screening out is no more than 5 mm, therefore, in terms of properties, it is close to sand, and its cost is somewhat lower, which saves funds intended for construction work.

This material is used both in the production of paving slabs (as one of the main components of the forming mixture) and for its laying. In the latter case, it is needed to evenly distribute the load and drain moisture into the drain.

Screening from granite can be used as independent material for bulk paths. Due to the fact that it has the natural color of natural granite, this material harmoniously fits into the structure of landscape design. They also fill the seams between the paving slabs. Possessing great permeability, without retaining water in itself, the screenings do not sag and do not wash out during the rain.

This fine-grained material is supplied both in bulk and packaged in containers of 25-50 kg, so it can be purchased for both large-scale and small jobs.

Materials and tools for work

Tools and materials for laying tiles.

To create high-quality tiled masonry with your own hands, you will need the following materials and tools:

• paving slabs;
• crushed stone of medium or fine fraction;
• granite screening;
• quartz sand;
• cement;
• curbstone;
• rubber hammer;
• brush for grouting.

Depending on the size, you may need to hire construction equipment to dig troughs for tiles, a concrete mixer, and a vibratory rammer, but for small jobs, manual labor can be done, although it will be longer and more difficult.

Technology for laying paving slabs for screening

When laying paving slabs for screening, it is necessary to take into account the peculiarities of the operation of the path. If it will be used for road traffic, then individual tiles can sag, so it is best to design driveways to a house or garage on a cement base.

Screenings, due to their size, are perfectly leveled and rammed.

Screening stacking technology is more suitable for pedestrian and bicycle paths, courtyards and areas in front of the house. The load acting on the tile in these cases will be evenly distributed and not cause destruction of the masonry.

The process of laying paving slabs can be roughly divided into several stages:

1. Preparation of the installation site. This stage includes planning the location of the track or area that will be covered with tiles, calculating the gutters and digging a "trough" for the underlying cushion.
2. Laying the pillow. A quality base for paving slabs should consist of several layers of material of different fractions. The sequence of filling the pillow will be discussed below.
3. Installation of tiles.
4. Grouting of tile joints.

The first stage begins with detailed planning of the location of future tracks. To do this, it is advisable to draw up a diagram of the site and mark on it the locations of the zones on which the tiles will be laid. It is recommended to pave all areas at once where paving slabs are expected to be present. This will ensure that all lanes are on the same level, while a time gap in work increases the likelihood of uneven subsidence of individual sections.

So that water after precipitation does not linger on the surface of the tile, forming puddles, the paths are made with a slight (1-2 °) longitudinal or transverse slope.

For pedestrian paths and areas near the house, a pillow depth of 20 cm is sufficient. For access roads along which traffic will be made, this parameter increases to 50 cm. After removing the soil layer to the required depth, the bottom of the "trough" is carefully leveled and compacted.

Laying schemes for paving slabs.

To create a reliable and relatively inexpensive pillow, it is possible to increase the dropout content in its structure. In this case, the lower layer (10 cm thick) will consist of medium-sized crushed stone, and the upper one (about 15 cm thick) - from screenings. If possible, lay a 2-3 cm layer of sand on top of the screenings. It will fill the free space between the screening grains, thus preventing moisture from stagnating in the pillow. After laying each layer, the material is carefully compacted, so that the thickness of the layers should be taken a little higher, taking into account the shrinkage.

It is possible to directly install paving slabs for screening, but this method is only suitable for footpaths and areas that will not be heavily loaded. This solution allows you to slightly reduce costs, but for better quality it is still recommended to give at least a small layer of sand under the tiles. It not only fills the free space, preventing water from accumulating, but also prevents the appearance of vegetation in the inter-tile space.

The installation of tiles is carried out in different ways and depends on its shape and size. Before laying the covering, the underlying layer is carefully leveled and compacted. The tiles are fitted tightly together with a rubber mallet.

The last stage is grouting with sand or a cement-sand mixture of the joints between the tiles. Quartz sand should be chosen. Pay attention to the absence of organic impurities, as they contribute to the development of vegetation. Grouting is done by sanding the joints and then using a mop or brush to fill the space. After the end of the work, the tiles are poured with water using a hose with a divider. Under no circumstances use a strong continuous stream of water: it easily flushes sand out of the cracks.

Advantages and Disadvantages of Screening for Paving Slabs

Like any other building material, screening has its pros and cons. The main advantages of dropout are its relatively low cost and ubiquity. This material is produced both in convenient small packaging and in bulk, which is important for work of various scales.

The disadvantages of screening are that it consists of particles of different sizes, which will behave differently during operation. Small fragments quickly get wet, turning into a kind of "porridge", as a result of which screening is recommended to be used only as an intermediate material between crushed stone and sand. This cross-sectional position ensures the overall stability of the entire cushion.

Another benefit of screening is that it can be used as an inexpensive filler for homemade paving slabs, which are now very common in production. In this case, it is part of the molding mixture, creating a framework for future products.

Screening is a relatively inexpensive but high quality material used to create a cushion when laying paving slabs. It is used both independently and as part of a layered base, which includes sand, crushed stone, gravel and cement.

Possessing high throughput, screening does not retain moisture, preventing material from getting wet and frosty swelling of tiles.

Despite popular belief, screening is a fairly reliable material. It can withstand the stresses arising from walking on pedestrian paths and small equipment... To increase the operational properties, it is recommended to introduce cement into the screening layer in a ratio of 1: 4.

Ease of use and manual ramming capabilities make screening an excellent material for self styling paving slabs at your summer cottage or personal plot.

Features of laying paving slabs

• 07.02.2014

• Laying technology
• Errors when laying paving slabs

The paving slabs are laid on screenings or sand, in which it is best to add cement in a ratio of 1: 4, then the tiles will be fixed more securely.

Laying scheme garden path for screenings.

When performing all work independently, you must adhere to the accepted building codes and rules, then you will succeed quickly, simply and reliably. The durability of the paving pavement will depend not only on the quality of the tiles themselves, but also on the observance of the technology for preparing the bed and laying. When paving tiles, the result of the work will be influenced not only by how it will be laid and by whom, but also by the quality of preparation of the bed for laying. This stage must be performed, adhering to the rules, for any type of installation.

The tool you need to work

Tools for laying paving slabs.

If you decide to lay the paving slabs yourself for screening, you will need:

• wooden pegs;
• cord;
• Master OK;
• building level;
• rubber hammer;
• rake and broom;
• the watering hose on which the diffuser should be;
• Circular Saw or a grinder with a diamond disc;
• tamping device.

Before starting work, it is necessary to study the site where the installation will be carried out, and decide where the water will flow. Precipitation must be diverted from the blind area of ​​the building either into special wells or onto lawns; slopes for water sap can be both longitudinal or transverse, and longitudinal-transverse. There are a lot of varieties of paving slabs, but when choosing it, you need to look not only at the color, but also at the shape, since it will have to be cut. You also need to ask the seller for what loads it is designed for, pay special attention to the roughness of the surface so that it is not slippery in winter.

Crushed stone screening is a by-product resulting from crushing natural or artificial stone. No less than the crushed stone itself, consumers are interested in properties, characteristics and the price of dropout per cubic meter. And this is not surprising - after all, its use is becoming more and more popular.

What is screening, its types and purpose

After crushing rocks, the finished crushed stone is sifted. Depending on the diameter of the sieve mesh, a free-flowing product with a particle size of 0.1 to 5 mm is obtained. Due to the fact that the granules are very small, the mass resembles sand in appearance. The colors are varied: red, pink, ash, dark gray (similar to the original raw material).

Peculiarities different types dropouts

The product of crushed stone processing has properties characteristic of the parent rock. Depending on it, the material is divided into the following groups.

1. Screening of crushed granite.

After crushing solid natural stone a fraction of 0.1-5 mm is obtained. Its bulk density is 1330 kg / cubic meter. m. Outwardly, it resembles sand, but unlike it, it almost does not contain clay impurities, organic matter and dust (their share is normalized at the level of 0.4% of total weight). The percentage of needle grains does not exceed 15%, so the mass is easily stacked and rammed. The screening is strong: the permissible pressure limit is 120 MPa (grade M1200). The material is resistant to low temperatures, environmentally friendly. The relatively high cost of granite screening is determined by excellent physical and mechanical characteristics.

Differs in a wide range of applications in construction, road repair, landscape design. Sand is added to mixtures for the manufacture of reinforced concrete products, paving slabs, road curbs. The use of colored granite chips is popular for decorating flower beds, filling footpaths in parks and in personal plots.

2. Gravel screening.

Crushed granite and gravel have external similarities, since they are formed from inorganic rocks. At the same time, they differ in properties, which is due to the narrower use of gravel. This is a rather loose sedimentary material interspersed with mineral particles that appear in the process of natural destruction of hard rocks. Gravel is less durable, its adhesion to other components in building mixtures lower than that of crushed stone.

The resulting screening (gravel crumb) is characterized by a grain size from 0.16 to 2.5 mm. In terms of strength, it corresponds to the M800-M1000 brand, the proportion of dusty and organic inclusions is no more than 0.6%. The bulk density of the crumb is 1400 kg / cubic meter. m. The use of gravel screening: restoration of the roadway, production of plates for the decoration of sports grounds, backfilling of paths in gardens and park areas.

In private construction, significant savings are achieved when replacing the main material with screenings, since its price per cubic meter is much lower than that of crushed stone. When laying a strip foundation, gravel is partially replaced by screening, and when concreting a blind area or fence - completely (while the amount of sand is not reduced).

3. Screening of crushed limestone.

Sifting crushed limestone allows you to get a stone with a grain size of 2-5 mm, characterized by astringent properties and capable of dissolving in water. A cubic meter of dropout weighs about 1300 kg, the strength grade fluctuates between M400 and M800, impurities do not exceed 2% by weight.

Screenings are introduced into cement mixtures, from which porous wall blocks, facing tiles are formed, cement-containing plaster mixtures are made. The use of lime crumb is practiced as a feed additive for animals and inorganic fertilizer for growing crops. The material is used in winter as an anti-ice bedding for roads.

4. Screening of secondary crushed stone.

It is a product obtained from the disposal of concrete structures after their dismantling or destruction. Crushing technology makes it possible to efficiently use construction waste and at the same time achieve real savings in construction and road works. Screening of concrete crushed stone with a granule size of 0.1-10 mm is used as a filler for cement mortars, filling under paving slabs. With the help of crushed secondary raw materials, temporary access roads and areas for cars are equipped.

Price

These tables will allow you to find out how much a dropout cube costs in Moscow and the capital region.

Crushed stone screening (variety)	Average price, rub / cubic meter m
Gravel	1000
Granite	1800
Lime	500
Secondary	800

When you start preparing a concrete solution with your own hands, it should be borne in mind that many factors affect its parameters. In particular, the type and quality of the filler plays an important role, therefore, it is also necessary to approach it very responsibly. The most traditional filler is sand, however, screening is often used for these purposes, to which this article is devoted.

Screening of granite

General information

So what is called dropout? Most often it is a rock crushed and sorted into fractions. Also on sale you can find screenings of recycling of various building materials.

In any case, regardless of the type of crumb, it is an environmentally friendly and safe material for humans. Due to its availability and low cost, it has become almost indispensable for many construction and decorative works.

In particular, the crumb is used in housing construction, in the road sector, in the production of reinforced concrete products, etc. In addition, screening is often used for landscaping.

The main performance indicators of this material include the size module.

Concrete screening

Dropout types

As mentioned above, there are different types of screenings.

Most often, the following types of concrete are used in the manufacture of concrete:

• Granite;
• Concrete;
• Concrete with bricks.

Now let's take a closer look at the features of different types of crumbs.

Granite

Granite screening is the most popular type of filler. It is a crumb with a size of fraction in the range of 1-10 mm, which has a gray or reddish color. Due to various shades of red, granule sifting is actively used in the manufacture of paving slabs and all kinds of reinforced concrete products, in addition, granot sifting is widely used in gardening.

Pink granotsew

I must say that the concrete from the granulation screen is distinguished by its high strength and density. The only thing is to observe the proportions of concrete from granite screening. The crumb can be used as a complete or partial substitute for sand. Accordingly, in different cases, its proportions will be different.

Due to the low cost of this filler, construction costs are reduced. In particular, such concrete is much cheaper than a solution with the addition of crushed stone. Its other advantages include the fact that it does not affect the performance characteristics of concrete structures.

Concrete

The main advantage of concrete screening is its low price. Crumb is obtained by secondary processing of concrete. As a result of crushing reinforced concrete products, the size of the crumb fractions is 1-10 mm.

Concrete screening has found wide application in the following areas of construction:

• In the field of road construction;
• In the manufacture of various reinforced concrete products;
• In industrial construction;
• When landscaping, etc.

In the photo - a crumb of brick and concrete

Screening of concrete and brick

This material is a mixture made from products of destruction or products of processing of bricks and concrete. In addition to breaking bricks, such crumbs contain some of the cement stone and fractions of other building materials.

Concrete preparation

As stated above, using dropout as a filler is more a profitable solution than sand with gravel. As a rule, screening concreting is performed with reinforcement. When pouring screeds, where such a filler is most often used, the layer thickness is 7-10 cm.

To obtain a sufficiently strong material for pouring, for example, a yard, it is necessary to observe the following proportions of concrete from the granulation cutter:

Cement М400

This proportion allows you to get concrete grade M150. If a more durable material is needed for construction work, higher grades of cement can be used. For example, if you prepare a solution based on M500 cement, then this proportion will make it possible to obtain concrete of the M250 brand.

However, one should not make a common mistake among novice builders - to increase the content of cement in the solution. A high content of cement will not increase the strength of the material, but, on the contrary, will reduce it.

Note! It is forbidden to use screenings yellow color, which contains clay, as well as black chips, i.e. with graphite content.

If the grain screening does not completely replace the sand, then the following proportions of screened concrete can be used:

With this proportion, the addition of crumbs will practically not increase the volume of the solution, since it will fill the voids between the crushed stone and at the same time strengthen the bonds of the sand with the crushed stone.

Preparation of the solution

Now let's look at how to make concrete from a granulation screen. To do this, you will need a concrete mixer, especially if the composition contains crushed stone, since it is very difficult to stir such a solution on your own, even if it is mixed in a small volume.

The instructions for preparing concrete mortar are as follows:

• First of all, you need to mix the dry ingredients.
• After the mixture of screening, sand and cement is well mixed, water is gradually poured into the composition... If necessary, a plasticizer and other additives are added at this stage. Recommendations for their use are always found on the packaging.
• After obtaining a homogeneous mass, crushed stone or gravel, purified and soaked in water, is added to the composition.... Then all components must be thoroughly mixed. If necessary, you can add a small amount of water, however, its excess should not be allowed, since in this case the filler will destroy the structure of the concrete, moreover, the excess water content will increase the shrinkage.

Ready solution

Note! For the preparation of high-quality building material, it is necessary to use fresh cement without impurities, as well as clean (preferably drinking) water. For a year of storage, cement loses up to 40 percent of its strength. Also, various impurities in the water can significantly reduce the strength of the cement stone.

This completes the solution preparation process. It is necessary to develop the resulting mixture within two hours.

The use of screenings as a filler for concrete has received wide use among builders, as a result of the many merits of such a solution. In addition to saving, crumb allows you to get a strong and durable material. The only thing for this is that it is necessary to strictly observe the proportions, and also pay attention to the quality of all components of the mixture.

You can get more information on this topic from the video in this article.

Screening is the material resulting from calibration, screening, crushing of rocks or building materials. The use of this material is carried out in construction, in road works. Dropout and cement concrete is considered a durable and economical building material. What types of screenings are there? How to properly make a concrete composition from a cement-screening mixture? What proportions are used during the preparation of this composition? This is what will be discussed in this article.

Dropout varieties

Among the varieties of this material are:

Granite screening

The material obtained after crushing granite is sieved through a special sieve and calibrated. Each fraction is used for certain types of concrete composition, the use of which is carried out in any construction. If, instead of granite, we take crushed stone, then such a composition will be much more expensive, and, accordingly, it is not cost-effective to use it. On performance the resulting solution will not be affected in any way.

Concrete screening

Concrete screening is more common. Its use is carried out much more often than other similar materials. And all thanks to the fact that concrete screenings are easy to get. It is enough to mechanically process, grind waste concrete material. Such material is used for laying roads, erecting walls, it is used for landscaping sites, territories, and is used in the preparation of asphalt mortar.

Screening of concrete and brick

Occasionally, brick chips extracted from used bricks are added to the concrete screening. A drop-out composite is suitable for laying the foundation for a building.

Positive qualities of the concrete mix from the dropout

The strength of a concrete solution with added screenings is an order of magnitude higher than that of a mixture with sand. Therefore, builders often prefer the first concrete option. This kind of composite has a high density, which is good for its operation.

The efficiency of this building material allows you to reduce costs for construction process, which cannot be said about sand and crushed stone used in the manufacture of various concrete solutions. Correspondence of the price and quality of the screening mixture makes it indispensable in most types of construction.

If cement, as well as screenings, are added inside the solution according to the recipe, then a high-quality, high-performance final product will be released. Screening can be a complete or partial substitute for sand. The diameter of the screening granules is allowed from 1.5 to 4 mm. Smaller screenings are not suitable for mixing concrete mortar, as it can reduce its characteristics.

It is no secret that the main component of the mortar is cement. Therefore, in order to obtain a high-quality concrete mixture, it is necessary to choose the right brand of cement for the type of construction. Since the screening can be replaced in the composition, it is really possible to make coarse concrete from it, however, the largest screening fractions should be taken, the grain size of which is at least 1 cm.

The process of calibrating screening for fractions

During the crushing of large stones or already used building materials, different-sized crumbs are released, the sizes of which vary from centimeter pebbles to dusty particles. For the concrete solution, separately selected screening particles of the same size are used.

Sorting crushed screenings has been accepted for a long time in a well-known and effective way - the material is sieved through several special sieves installed one above the other, starting with the smallest one, and further upward by increasing the diameter of the holes in the sieve. The stone chips to be calibrated are poured onto the uppermost, coarse sieve. Smaller particles of the contents of the first sieve are sieved into the second, and further down through all levels of the so-called filter. At the end of the process, pebbles of the same size will remain on each sieve. Thus, the screening material is divided into fractions.

Volumes of components

The quality and strength properties of the final product depend on the correct ratio of added ingredients. In order to accurately determine the required amount of concrete screening, one should take one part of the sand aggregate and crushed stone from the generally accepted proportion, replace them with two parts of the screening aggregate.

To select the type of screening chips for mortar, you should find out the expected degree of load on the future structure or road surface. As mentioned above, a mixture based on granite chips is more advantageous than a mixture of sand and gravel. It is worth paying attention here to the temperature indicators during the operation of a concrete structure or flooring.

If you plan to fill the territory near a private house, here you should use a reinforcing mesh, which is poured with concrete mortar no more than 7 cm thick.To make such a mixture, subject to the use of granite chips, the following proportion is observed:

• 1 portion of cement grade M400;
• 8 servings of granite chips;
• maximum 20% of total water.

As a result, a mixture with M150 strength will be released. Note that before pouring the site onto it, it follows, which can be made from granite screening, having thoroughly trampled it down before pouring. The height of such a pillow should be at least 5 cm.

It is known that none of the mortars is complete without cement, the quality and brand of which determines the performance characteristics of the concrete composite. The higher the marking of the raw materials used, the better the concrete's ability to adhere to various surfaces.

As for the shelf life of cement, it is impossible to keep it unused for a long time, as it loses its properties over time. Within a month, the strength of the material decreases by 10%. You can find out its suitability by scooping it up with your palm and squeezing it lightly in your hand. If the cement is friable, it means that it has not yet lost its quality, the solution from such a binder will turn out to be good.

Recall that the level of strength of the composite depends on the marking of the cement. For laying the foundation, brands M400 or M500 are used, since a large load is assumed on this structure from concrete or brick walls future building. The brand of cement also affects its cost. The most expensive will be the one with the highest marking and the best performance.

An important point is the quality and quantity of the poured water. You need to add it so much to get a mass of medium density. If you overdo it with liquid, then the structure of the composite will be changed, which in the future can lead to a large shrinkage of the structure, and, consequently, to cracking of the walls. With regard to quality, for a high-strength concrete composite, not technical, but drinking water should be used.

Screening is the material resulting from calibration, screening, crushing of rocks or building materials. The use of this material is carried out in construction, in road works. Dropout and cement concrete is considered a durable and economical building material. What types of screenings are there? How to properly make a concrete composition from a cement-screening mixture? What proportions are used during the preparation of this composition? This is what will be discussed in this article.

Dropout varieties

Among the varieties of this material are:

Granite screening

The material obtained after crushing granite is sieved through a special sieve and calibrated. Each fraction is used for certain types of concrete composition, the use of which is carried out in any construction. If, instead of granite, we take crushed stone, then such a composition will be much more expensive, and, accordingly, it is not cost-effective to use it. This will in no way affect the performance of the resulting solution.

Concrete screening

Concrete screening is more common. Its use is carried out much more often than other similar materials. And all thanks to the fact that concrete screenings are easy to get. It is enough to mechanically process, grind waste concrete material. Such material is used for laying roads, erecting walls, it is used for landscaping sites, territories, and is used in the preparation of asphalt mortar.

Screening of concrete and brick

Occasionally, brick chips extracted from used bricks are added to the concrete screening. A drop-out composite is suitable for laying the foundation for a building.

Positive qualities of the concrete mix from the dropout

The strength of a concrete solution with added screenings is an order of magnitude higher than that of a mixture with sand. Therefore, builders often prefer the first concrete option. This kind of composite has a high density, which is good for its operation.

The efficiency of this building material allows you to reduce the cost of the construction process, which cannot be said about sand and crushed stone used in the manufacture of various concrete solutions. Correspondence of the price and quality of the screening mixture makes it indispensable in most types of construction.

If cement, as well as screenings, are added inside the solution according to the recipe, then a high-quality, high-performance final product will be released. Screening can be a complete or partial substitute for sand. The diameter of the screening granules is allowed from 1.5 to 4 mm. Smaller screenings are not suitable for mixing concrete mortar, as it can reduce its characteristics.

It is no secret that the main component of the mortar is cement. Therefore, in order to obtain a high-quality concrete mixture, it is necessary to choose the right brand of cement for the type of construction. Since the screening can be replaced in the composition, it is really possible to make coarse concrete from it, however, the largest screening fractions should be taken, the grain size of which is at least 1 cm.

The process of calibrating screening for fractions

During the crushing of large stones or already used building materials, different-sized crumbs are released, the sizes of which vary from centimeter pebbles to dusty particles. For the concrete solution, separately selected screening particles of the same size are used.

Sorting crushed screenings has been accepted for a long time in a well-known and effective way - the material is sieved through several special sieves installed one above the other, starting with the smallest one, and further upward by increasing the diameter of the holes in the sieve. The stone chips to be calibrated are poured onto the uppermost, coarse sieve. Smaller particles of the contents of the first sieve are sieved into the second, and further down through all levels of the so-called filter. At the end of the process, pebbles of the same size will remain on each sieve. Thus, the screening material is divided into fractions.

Volumes of components

The quality and strength properties of the final product depend on the correct ratio of added ingredients. In order to accurately determine the required amount of concrete screening, one should take one part of the sand aggregate and crushed stone from the generally accepted proportion, replace them with two parts of the screening aggregate.

To select the type of screening chips for mortar, you should find out the expected degree of load on the future structure or road surface. As mentioned above, a mixture based on granite chips is more advantageous than a mixture of sand and gravel. It is worth paying attention here to the temperature indicators during the operation of a concrete structure or flooring.

If you plan to fill the territory near a private house, here you should use a reinforcing mesh, which is poured with concrete mortar no more than 7 cm thick.To make such a mixture, subject to the use of granite chips, the following proportion is observed:

• 1 portion of cement grade M400;
• 8 servings of granite chips;
• maximum 20% of total water.

As a result, a mixture with M150 strength will be released. Note that before pouring the site onto it, it follows, which can be made from granite screening, having thoroughly trampled it down before pouring. The height of such a pillow should be at least 5 cm.

It is known that none of the mortars is complete without cement, the quality and brand of which determines the performance characteristics of the concrete composite. The higher the marking of the raw materials used, the better the concrete's ability to adhere to various surfaces.

As for the shelf life of cement, it is impossible to keep it unused for a long time, as it loses its properties over time. Within a month, the strength of the material decreases by 10%. You can find out its suitability by scooping it up with your palm and squeezing it lightly in your hand. If the cement is friable, it means that it has not yet lost its quality, the solution from such a binder will turn out to be good.

Recall that the level of strength of the composite depends on the marking of the cement. For laying the foundation, brands M400 or M500 are used, since a large load is assumed on this structure from concrete or brick walls of the future building. The brand of cement also affects its cost. The most expensive will be the one with the highest marking and the best performance.

An important point is the quality and quantity of the poured water. You need to add it so much to get a mass of medium density. If you overdo it with liquid, then the structure of the composite will be changed, which in the future can lead to a large shrinkage of the structure, and, consequently, to cracking of the walls. With regard to quality, for a high-strength concrete composite, not technical, but drinking water should be used.

Screening is a unique composition based on material obtained after crushing rocks.

Granite is used for the production of reinforced concrete products, for sprinkling roads and sidewalks in winter in order to reduce the sliding coefficient.

In the process, a special individual sieve is used for each individual type. It turns out a granite composition by the method of opencast mining, namely by the explosive method. The loot is crushed and sorted into fractions. It is widely used today in road, housing and other spheres of construction; it is able to provide facilities with the necessary reliability and durability. It is also widely used for landscaping, including for decorative purposes.

Among the main performance indicators are the modulus of material size and strength. The size module determines the fractionality. Screening is an environmentally friendly product for humans. Its availability and low cost sometimes make the material indispensable in construction and decorative work.

Different kinds

Granite crushed stone is obtained as a result of embossing the remnants of crushing rocks on special sieves.

Granite is a crumb, the size of which varies approximately in the range of 0-10 mm. A similar one may have a reddish and in gray... Various shades of red allow the use of granite in the manufacture of products, paving slabs, in gardening.

Concrete is the most affordable material that is obtained after recycling concrete. This material contains the smallest fraction of secondary crushed stone, from 1 to 10 mm, which is obtained in the process of crushing products. Concrete is used in the production of reinforced concrete products, in the field of road construction, and in landscaping. In the production of concrete products, it is widely used in industrial construction, in the manufacture of asphalt and wall materials.

Concrete with brick is a mixture made from products of processing or destruction of brick and concrete. Recycled products imply the fight of bricks with some of the concrete, cement and other building materials.

The solution is obtained
much stronger.

In a solution based on granite, the final material acquires the necessary strength and density. Such material is cheaper than that made from crushed stone, and its use significantly reduces construction costs. But the main thing can be considered the fact that concrete obtained from cement and granite is not able to influence the operational characteristics of the resulting structure or structure, which makes this material indispensable in many areas of construction.

With the correct preparation of the mixture, a high strength of the final product can be achieved. In this case, it is important to use screenings in the correct proportion. The main use of granite is to replace sand or to use it as a partial substitute. The latter option is usually used more often.

Preparation

Concrete from granite screening and cement is a much more profitable solution than using sand and crushed stone in the base.

In order to fill the yard, you must first decide what loads the coating will undergo, as well as at what temperature regime it will be used ... Solution from granite screening and cement - a much more profitable solution than using sand and crushed stone in the base. The solution, as a rule, is reinforced with a mesh, and the material itself is poured with a layer within 7 cm and above. The following proportions when preparing on the basis of granite: cement M400 - 1 part, elimination - 8 parts, water - no more than 20 percent - will make it possible to obtain a solution whose strength will be equal to M150. This strength should be sufficient to fill the yard. It is not allowed to use yellow material, in which the composition contains clay, or black, which contains graphite.

Granite is also suitable for pouring the foundation. But when pouring the yard, you should first make a pillow made of sand. You can also use screening for this, which then has to be tamped, and only later you can start pouring. In this case, a layer thickness of 5 centimeters should be used.

The table shows the composition and proportions for preparation based on granite and cement.

It is worth remembering that it is more rational to use granite as an additional filler. In this case, part of the sand and part of the rubble should be taken away from the required composition, adding two parts of the dropout instead. The exact proportions of preparation based on granite and cement are shown in the table. No matter how strong concrete becomes with the use of granite, cement is still its main component. The stronger the final product, the higher the adhesive capacity of the cement, the level of adhesion to the surface is also important.

Do not forget that after storage for a month, cement will lose 10 percent of its strength, three months will cause a loss of strength in the amount of 20 percent, six - 30 percent, a year - 40 percent. If the cement is stored for two years, it will become 50 percent less durable. As a rule, if lumps of slightly hardened cement remain soft, crumbling from slight compression, it still contains normal proportions of moisture and base, which allows efficient use of the material. It should not be changed by increasing its content in the composition, this will not help to increase the strength, on the contrary, it will reduce it.

In order to make a high-quality solution from the dropout, you should take into account the correct proportions of each component, as for water. The solution should be of medium consistency, as indicated in the table, water should be about 20 percent of the total mass of the solution. An excess will lead to the fact that the aggregate will disrupt the structure of the solution, in addition, after pouring, such a composition will give significant shrinkage, which will cause cracks, and its bearing capacity will be reduced. It should be remembered: cement and water must be of high quality. So, to obtain high-strength concrete in the factory, drinking water is used at all. Seawater is also not suitable for concrete.

When you start preparing a concrete solution with your own hands, it should be borne in mind that many factors affect its parameters. In particular, the type and quality of the filler plays an important role, therefore, it is also necessary to approach it very responsibly. The most traditional filler is sand, however, screening is often used for these purposes, to which this article is devoted.

General information

So what is called dropout? Most often it is a rock crushed and sorted into fractions. Also on sale you can find screenings of recycling of various building materials.

In any case, regardless of the type of crumb, it is an environmentally friendly and safe material for humans. Due to its availability and low cost, it has become almost indispensable for many construction and decorative works.

In particular, the crumb is used in housing construction, in the road sector, in the production of reinforced concrete products, etc. In addition, screening is often used for landscaping.

The main performance indicators of this material include the size module.

Dropout types

As mentioned above, there are different types of screenings.

Most often, the following types of concrete are used in the manufacture of concrete:

• Granite;
• Concrete;
• Concrete with bricks.

Now let's take a closer look at the features of different types of crumbs.

Granite

Granite screening is the most popular type of filler. It is a crumb with a size of fraction in the range of 1-10 mm, which has a gray or reddish color. Due to various shades of red, granule sifting is actively used in the manufacture of paving slabs and all kinds of reinforced concrete products, in addition, granot sifting is widely used in gardening.

I must say that also by density. The only thing is to observe the proportions of concrete from granite screening. The crumb can be used as a complete or partial substitute for sand. Accordingly, in different cases, its proportions will be different.

Due to the low cost of this filler, construction costs are reduced. In particular, such concrete is much cheaper than a solution with the addition of crushed stone. Its other advantages include the fact that it does not affect the performance characteristics of concrete structures.

Concrete

The main advantage of concrete screening is its low price. Crumb is obtained by secondary processing of concrete. As a result of crushing reinforced concrete products, the size of the crumb fractions is 1-10 mm.

Concrete screening has found wide application in the following areas of construction:

• In the field of road construction;
• In the manufacture of various reinforced concrete products;
• In industrial construction;
• When landscaping, etc.

In the photo - a crumb of brick and concrete

Screening of concrete and brick

This material is a mixture made from products of destruction or products of processing of bricks and concrete. In addition to breaking bricks, such crumbs contain some of the cement stone and fractions of other building materials.

Concrete preparation

Proportions

As mentioned above, the use of screening as a filler is a more profitable solution than sand with gravel. As a rule, screening concreting is performed with reinforcement. When pouring screeds, where such a filler is most often used, the layer thickness is 7-10 cm.

To obtain a sufficiently strong material for pouring, for example, a yard, it is necessary to observe the following proportions of concrete from the granulation cutter:

This proportion allows you to get. If a more durable material is needed for construction work, higher grades of cement can be used. For example, if you prepare a solution based on M500 cement, then this proportion will make it possible to obtain concrete of the M250 brand.

However, one should not make a common mistake among novice builders - to increase the content of cement in the solution. A high content of cement will not increase the strength of the material, but, on the contrary, will reduce it.

Note! It is forbidden to use yellow screenings, which contain clay, as well as black chips, i.e. with graphite content.

If the grain screening does not completely replace the sand, then the following proportions of screened concrete can be used:

With this proportion, the addition of crumbs will practically not increase the volume of the solution, since it will fill the voids between the crushed stone and at the same time strengthen the bonds of the sand with the crushed stone.

Preparation of the solution

Now let's look at how to make concrete from a granulation screen. To do this, you will need a concrete mixer, especially if the composition contains crushed stone, since it is very difficult to stir such a solution on your own, even if it is mixed in a small volume.

The instructions for preparing concrete mortar are as follows:

• First of all, you need to mix the dry ingredients.
• After the mixture of screening, sand and cement is well mixed, water is gradually poured into the composition... If necessary, a plasticizer and other additives are added at this stage. Recommendations for their use are always found on the packaging.
• After obtaining a homogeneous mass, crushed stone or gravel, purified and soaked in water, is added to the composition.... Then all components must be thoroughly mixed. If necessary, you can add a small amount of water, however, its excess should not be allowed, since in this case the filler will destroy the structure of the concrete, moreover, the excess water content will increase the shrinkage.

Note! For the preparation of high-quality building material, it is necessary to use fresh cement without impurities, as well as clean (preferably drinking) water. For a year of storage, cement loses up to 40 percent of its strength. Also, various impurities in the water can significantly reduce the strength of the cement stone.

This completes the solution preparation process. It is necessary to develop the resulting mixture within two hours.

Output

The use of screening as a filler for concrete has become widespread among builders, as a result of the many advantages of this solution. In addition to saving, crumb allows you to get a strong and durable material. The only thing for this is that it is necessary to strictly observe the proportions, and also pay attention to the quality of all components of the mixture.

You can get more information on this topic from the video in this article.