Sand concrete. What is sand concrete M300 and features of the building mixture

Sand concrete appeared on the building materials market not so long ago. Today this dry mix occupies one of the most important places in the construction of buildings. The material is used at almost every stage of the construction of a building object: from the creation of the foundation to the installation of a "warm floor". What sand concrete is and the features of its application will be discussed in the article. What is sand concrete? Sand concrete is a structural building mixture that is used for interior and external works... The standard components of sand concrete are: cement, sand and filler (most often crushed stone). Based on the ratio of elements, the brand and class are assigned to sand concrete. M100-M250 - limestone is usually used as a filler, M300-M400 - gravel, heavy concrete - granite. The strength of the material depends on the brand, and shrinkage depends on the fraction of the sand used. Most the best option for any work today is the M300 brand. Application of the material. Sand concrete is effective remedy for sealing cracks and holes in slabs, the material is also actively used for screed, masonry creation. The material is poured into concrete bases, excellent for leveling floors, used to create a heated floor. With the help of sand concrete, foundations and foundations are created, monolithic concrete structures are produced. They also ennoble the area around the house: they fill in sidewalk paths, playgrounds, parking.
The use of material in construction and repair work. Depending on the choice of the brand, the strength of sand concrete is determined: - Sand concrete M100- has low strength and is easily water permeable. It is usually used for applying plaster. The composition includes river sand size 0.8-1.2 mm. - M150- has a higher strength. It is used for plastering, as well as for imparting stability brickwork... The strength of the hardened material is 150 kg / cm2. Consists of river and quartz sand, fraction 0.8-2.0 mm. The material is not heavy and cost effective. Can be easily fed to a height of 54 meters using special equipment. - M200- It is often used in interior finishing works, as well as to create heated floors. Includes fine-grained river and quartz sand... The hardened coating does not deform and withstands mechanical stress up to 195 kg / cm2 - M250- has increased strength (250 kg / cm2) and durability. Used for the construction of technical facilities. - Mix M300
- used for the construction of all kinds concrete structures high strength, as well as the production of expanded clay and flooring. This brand is the most versatile. Sand concrete of this brand has proven itself well in the construction of monolithic buildings. - M500- used for private purposes is extremely rare. Mainly used in industrial construction.
Sand concrete photo3 The use of the brand depends, first of all, on functional purpose the structure being created. If you need to fill the foundation under private house — the best option will be M250. Where there are no heavy loads on concrete, M100-M200 can be used. M300 - is considered a universal brand and can be used everywhere: from plastering a wall to the construction of a five-story building. In order to correctly choose sand concrete, you need to navigate the brands and classes of the material. You can also seek advice from experienced specialists who will be happy to help you choose sand concrete specifically for your tasks.

Sand concrete- only rare name or a unique "personality"? The product appeared on the market at the beginning of the 21st century. The brand keeps itself apart, presenting itself as something special in the construction world. Meanwhile, those familiar with him know that sand is a component of anyone. What is the secret of the new product? Let's figure it out.

Description and features of sand concrete

Sand concrete - mix construction. First, let's separate it from the cement. It is based on clay and limestone. These are rocks. They are composed of minerals such as ferrite, belite and alite.

Sand is also a rock, or rather a product of its decay, weathering and erosion by water. Winds and currents separate particles from boulders, usually quartz. By chemical composition quartz is silicon oxide. It is not in the cement.

There is always sand in concrete, but it differs in fractions, that is, in particle sizes. So, according to GOST "28013-89", particles of the 1st and 2nd modules are acceptable in plasters.

In primers, sand is used with a maximum grain size of 2.5 millimeters. The same applies to colored plasters for outdoor use and decorative interior decoration... In fact, it comes about cement-sand mortars.

In heavy and fine-grained concrete, "obeying" GOST "26633-91", sand from crushing screenings is used. In them minimum size grains is equal to 5 millimeters. Also, crushed stone, gravel, natural stone are added to heavy concrete.

Buy sand concrete, which means, purchase a mixture of cement, coarse sand and fine gravel. The description corresponds to GOST "26633-91". It turns out that we are dealing with a brand of heavy concrete.

There are different grades of cement in it, mainly the 300th, 400th and 500th. The numbers indicate the maximum allowable load in kilograms per cubic centimeter.

Accordingly, the 300th cement withstands 3 hundred kilos per cubic centimeter, the 400th mixture resists 4 hundred, and the 500th cement can withstand half a ton per cubic centimeter.

The sand and gravel in the concrete strengthens it. That is, in fact, the mixtures withstand greater loads than the cement included in them. This expands the boundaries of the use of sand concrete.

What is sand concrete used for?

Belonging to heavy concrete allows you to use the hero of the article to form structures with increased loads on them. On sand concrete floors goes in factory shops, garages and warehouses.

The surfaces in them are often uneven. In order to negate level differences, a thick floor screed. Sand concrete solves this problem too. The plasticizers included in the composition allow to fill the mixture with a thick layer.

They make concrete more elastic, plastic, hence the name of the components. They are mostly synthetic. Get polymers based on petroleum products. Polymer molecules are characterized by long rows of monomer units.

- another path of the hero of the article. For filling the foundations of buildings, even sand concrete "M-300"... It not only withstands the loads of walls, roofs, but also serves in extreme conditions.

Basin bowls, floor slabs, supporting columns and beams are all about sand concrete. In the case of pouring a foundation, it is justified for monolithic structures.

Consumption of sand concrete when used, it is minimal, since the mixture does not shrink during hardening. The hero of the article is also not prone to cracking. This durability is partly due to the waterproofness of sand concrete structures.

By the way, these include the walls. Sand concrete for them is a popular option. "Bricks" are made by vibrocompression. Simply put, the sand-cement mixture is shaken in the molds, additionally compacted with pressure.

Then, the blocks are given time to gain strength. Walls can be erected 50 days after slab production. However, blocks for foundations are also produced. There are sand cement options for cladding and partitions.

The hero of the article also found application in road construction. Similarly for walls and foundations, the mixture is formed paving slabs and railings for tracks. Curbs are usually reinforced.

This additionally strengthens the concrete, the service life of which, even without a frame, is half a century. More precisely, we are talking about 50 freeze-thaw cycles. Weather drops are the main factor in the destruction of building materials.

Especially porous. The water that penetrates into them freezes, expands and tears the micro-bonds inside the structures. Therefore, there are concretes recommended for covering with waterproof facades and roofs. Sand blocks in their pure form, without foaming and additional components resist external influences without outside help.

The purest form of sand concrete is Portland cement, sand, fine gravel and 1-2 plasticizers. The nuances of using mixtures and their quality depend on the proportions of the components and their characteristics. Sand, for example, can be either 5 mm or 7 or 8.

The types of plasticizers also play a role. Some substances accelerate, while others slow down the hardening of concrete. There are anti-freeze plasticizers. With them, the mixture can be poured into cold weather.

Foaming additives make sand concrete porous. This reduces the strength of the material, but makes it heat-consuming. Air is the worst conductor of both cold and heat.

Types of sand concrete

Depending on the nuances of the composition, they change sand concrete price and its scope. There are, for example, waterproofing mixtures. They have a minimum of pores. The high density of the group's sand concretes allows them to be used in rooms with high humidity, whether it be saunas, swimming pools or bathrooms.

The second purpose of sand concrete is assembly and masonry. The category includes mixtures for filling and plastering, compounds for fastening building blocks, concreting floors. Wear-resistant sand concrete is used on the foundations. It is also used in screeds and to form an overlap.

A separate category is allocated to universal sand concrete. Its parameters are averaged. The lack of specialization allows the use of mixtures in any work. However, the category sand concrete will also be average to meet their requests.

That's why, universal formulations it is customary to take for local, repair moments. For large, important construction sites, they buy specialized sand concrete.

The price of sand concrete and reviews about it

On sand concrete price depends on the volume of the mixture. Basically, they sell 25 and 40 kg bags. The cost of the first starts at 50 rubles. The top bar is 230 rubles.

The price of 40-kilogram bags of the mixture starts from 79, reaching 400 rubles. The exact price tag depends on the name of the manufacturer, the inherent benefits of the store and the nuances of the composition sand concrete.

50 Kg- rare packaging, the price of which starts at 190, reaching 600 rubles. If you take wholesale from the manufacturer, the cost will be reduced by at least 10%. Typically, the savings are around 25-30%.

Range of application of sand concrete

Sand concrete is a mixture in the form of a powder, which is also known as a "dry mix" with the M marking and a digital code from 150 to 300. All these types of sand concrete are used both in construction and during repairs. Sand concrete has proven itself well in restoration work.

Sand concrete belongs to non-shrinking mixtures, therefore it is often used to create high-strength floors that must have increased wear resistance. The most popular type of sand concrete in private construction is M300. It is used for such construction works like masonry, creating foundations, concrete floors and screeds.

Quite often, sand concrete is one of the components in the composition monolithic slabs and wall panels... It is used to clean seams and joints. Due to its high strength characteristics, all constructed structures meet all norms and standards. All surfaces created with the help of sand concrete have increased strength, so it is almost always used in the construction of large industrial complexes, not to mention residential buildings.

This building mixture is so versatile that it does not require special conditions; working with sand concrete is quite simple. You cannot do without it when building a garage or a large basement. Moreover, it is suitable for both indoor and outdoor use.

Properties of sand concrete

1. Fraction of sand - 0 ... 5 (mm);
2. water consumption - 0.15 l per kg of mixture;
3. Consumption of the mixture - 20 kg per sq. m (laying layer no more than 10 mm);
4. compressive strength - 300 MPa (sand concrete m300);
5. drying time and the possibility of full operation - after 1 month;
6.The prepared solution should be used within 2 hours (when temperature conditions not exceeding 20 degrees Celsius).

Advantages of sand concrete:

Used at any stage of construction;
- used for foundation work;
- used in the construction of walls and floor filling;
- universal for the manufacture of screeds,
- suitable for finishing any surfaces;
- the subsequent finishing of surfaces does not matter, since sand concrete m300 (and other brands) create ideal conditions for creating any design;
- complete absence construction waste and dirt;
- provides a high speed of repair and construction work (internal and external);
- frost resistance;
- water tightness;
- high resistance to deformation and corrosion,
- complete absence of shrinkage,
- plasticity.

The most popular sand concrete can be conditionally divided into 2 large groups:

1. Those concrete mixtures that are created by manufacturers in accordance with norms and standards legislative framework country. In this case, there are no expensive and lengthy experiments with the raw material composition, as well as with the study of the physicochemical parameters of the resulting mixtures. The process of making such formulations is more like a simple field mixing of the base stocks, after which the boundary values ​​that meet the standards are reached. The presence of defects in the constructed buildings is attributed not to the quality of the concrete mixture, but to non-compliance technological processes construction.

2. Those concrete mixtures that are produced only after comprehensive research, required element which is the optimization of the composition. Only those mixtures that have shown best performance and physical and chemical characteristics. The final stage of any such testing is the analysis of the final properties of the constructed structure, its operational parameters.

Sand concrete m300 belongs to the second group, but its improvements continue, so it is likely that this particular building mixture will keep the lead on construction market is large enough.

Sand concrete m300 is sold as a dry mix, and in packages of different weights. The optimal amount for any type of construction and repair work will be sand concrete 50 kg. For ease of transportation, the mixture is placed in a four-layer paper bag that can easily withstand any move and will not tear. This packaging will allow you to perform all the necessary manipulations without overpaying. Taking into account the versatility of the mixture, its high strength, plasticity and frost resistance, sand concrete, the price of which will be slightly higher than for a simple concrete mix, It has specific composition.

Preparation and work with sand concrete

Since sand concrete m300 is an almost ready-made building mixture, the only thing that needs to be done before starting work is to dilute the powder with water. The proportions are detailed on each package, but the average indicators can be as follows: for every 10 kg of sand concrete, one and a half liters of water is taken. Water must be poured in gradually, mixing the solution thoroughly. You should get a homogeneous mass. All surfaces on which sand concrete M300 will be applied must be cleaned of dirt and debris and moistened with water.

You can work with sand concrete at temperatures from +5 to +35 degrees. The mixture consumption for each type of work will be different.

Composition of sand concrete

The number of components in each grade of sand concrete will differ. The components themselves may also differ, since a certain type of sand concrete must meet the requirements of specific types of work as much as possible.

In the basic composition of sand concrete m300, the following components can be distinguished:

River sand (construction, washed);
- chips or granite screenings (may not always be present);
- Portland cement;
- coarse sand (diameter up to 0.3 cm);
- plasticizers;
- other additives.

One ton of ready-mixed sand concrete M300 accounts for about 800 kg of sand and chips, up to 240 kg of cement. Each manufacturer will have its own numbers, since the formulation of each type differs from each other not only in the proportions of the basic components, but also in the presence of additives and plasticizers.

If a specific building mixture is needed, then manufacturers can change the composition, improving the required characteristics.

The main types of sand concrete

Depending on the type of work performed, sand concrete is divided into several types:

Waterproofing,
- assembly and masonry,
- wear-resistant (for foundation work, pouring floors and screeds),
- universal,
- plaster.

If only one binder is included in the composition, then the mixture will turn out to be simple, and if there are several, then mixed.

Sand concrete appeared on the building materials market relatively recently - 10-15 years ago, and today it is difficult to imagine any construction project without it. This material is used at almost all stages of construction - from the construction of the foundation to internal finishing works in the premises. Sand concrete is excellent for the installation of castings and durable wear-resistant floors in industrial and warehouse premises, garages and workshops, concreting stairs, performing masonry work, fastening reinforced concrete structures, sealing seams and joints, erecting walls and partitions.

According to its intended purpose, sand concrete belongs to structural concrete, and according to the GOST classification - to fine-grained.

Sand concrete with the addition of expanded clay gravel can serve as the basis for the manufacture of expanded clay concrete.

The composition of sand concrete contains an astringent inorganic substance High Quality(Portland cement), functional filler (river washed sifted sand of coarse fractions), plasticizers that increase the operational properties of the output product. Sand concrete is produced in concrete plants by mixing the necessary components in special concrete mixing plants. Special attention the substantiation of the amount of all compound mixtures is given, since changes in proportions entail changes in the properties of the material. Its proportional composition depends on what it will be used for and what qualities should prevail. Sand concrete is produced in the form of dry mixes and ready-made blocks.

Sand concrete has a number of positive properties that distinguish it from other similar mixtures. These properties include high strength, wear resistance, frost resistance, water resistance of the material. Sand concrete owes such properties, first of all, to the presence of Portland cement in its composition. The larger the volume fraction of Portland cement in the composition of sand concrete, the higher its performance.

You can work with sand concrete at temperatures above 5 degrees Celsius. The working mixture is prepared by adding cold water into dry matter and looks like a viscous mass of homogeneous consistency with high density. Resistance to various influences and mechanical strength of the coating depend on the ratio of water and dry mixture, therefore it is very important to observe correct proportions and dosage. It is necessary to carry out work with such a mixture within 3 hours from the moment of adding water, since it is quite plastic. The technology for using the mixture is simple - the solution is poured onto the base and evenly distributed over the entire area. During curing, it is important not to allow the poured surface to dry out quickly. After two days, you can check the first set of strength, after 7 - carry out further work... The final strength is reached 28-30 days after pouring.

Sand concrete is labeled depending on the fraction of sand included in its composition - the larger the fraction, the higher the grade. The most popular brand is M300 sand concrete. Grades above M300 are used for the construction of bridges, construction of tunnels, below - strictly speaking, they are not concrete, but belong to the category of other building mixtures.

Grade M300 means that sand concrete can withstand a load of 300 kg per 1 cm2. The coarse sand particles contained in M300 sand concrete make it durable and resistant to shrinkage.

The characteristic properties of sand concrete M300 are:

• good spreadability;
• connectivity with any bases;
• safety for the environment- there are no substances in sand concrete that can harm health or the environment;
• special additives minimize the likelihood of cracks and lime deposits on the surface filled with mortar.

Sand concrete M300 is used to solve the most different tasks- pouring and leveling floors, horizontal sand-cement and concrete foundations, elimination of defects in filling, installation of foundations and other construction needs.

Sand concrete M300 is optimal material for underfloor heating, both electric and water. It is used as an intermediate and cover layer in a heating system. Due to its fine-grained structure, the material evenly fills the entire space and accumulates heat well. Ease of use and speed of hardening make it possible to use M300 sand concrete http://www.voscem.ru/catalog/smesi/M300 at home with insignificant time losses - just a day after pouring, you can continue work on the installation of underfloor heating systems.

Before starting work with sand concrete M300, it is necessary to carry out preparatory work- clean the surface from dirt and dust, loose concrete particles, lubricants. If the surface is damaged by fungi, algae or mosses - clean and treat with fungicidal preparations. Surfaces with significant absorbent properties should be coated with a latex primer in several layers.

When preparing the mixture, it is very important to observe the recommended dosage, since an increase in the amount of liquid can cause cracks, delamination and a decrease in mechanical strength leveling layer.

The work is carried out at a temperature of +5 - +30 degrees and a humidity not higher than 80%. Before pouring the entire surface with a solution, it is necessary to fill all cracks and recesses with it. After pouring, it is necessary to cover the structure with a film or tarpaulin to avoid moisture evaporation and premature drying.

The consumption of sand concrete for the manufacture of a floor screed for filling one square meter with a layer of 1 centimeter is 18-20 kilograms of dry mix.

Sand concrete can be purchased at finished form or try to do it yourself. However, it is worth making sure that you have everything in stock. necessary components and that they are all suitable for making mortar of the quality you require. The cost of sand concrete made industrially rather low, which allows you not to save on quality and use material that has passed the factory test, which will successfully serve you for a long time.

it construction material, "Middle" between classic concrete on a coarse aggregate and cement mortar, mixed in the sand. Wide range of applications and good performance characteristics have been supporting the demand for this product for the last 10-15 years. Today the mixture is dry sand concrete - universal material, which is present on almost every construction site.

Composition

Components that make up sand concrete:

• Portland cement M400 or M500, depending on the brand of the finished product;
• coarse sand up to 3 mm;
• fine aggregate - river sand.

GOST 25192-82 describes sand concrete as a high-density material, that is, dense sand is used for its manufacture, overall volume practically does not shrink.

Depending on the specifics of the application, the mixture may include:

• plasticizers and improvers (for frost resistance, anti-corrosion, etc.);
• granite chips (elimination).

The composition of sand concrete resembles an ordinary concrete mixture with the difference that in the first large crushed stone is replaced with coarse sand. As a result, the solution turns out to be more uniform throughout the volume and easy to apply, at the same time, no less durable.

There is also the so-called luxury sand concrete. It contains an increased amount of cement, which makes the ready-made mortar more plastic and quick-setting.

How to prepare sand concrete yourself?

The material is sold as dry ready mixes that you just need to seal with water and use. This is a kind of alternative to purchasing solutions from factories - no need to guess about the proportions and select the appropriate fraction and quality of sand with plasticizers.

To do working mixture for construction work, take required amount packaged dry material and mix it with water in an amount of about 2 liters of liquid per 10 kg of dry components.

Average proportions of sand concrete:

• sand - 1 bucket;
• cement - 3.5 kg (1 part);
• water - 2.8 liters (0.5 parts).

The amount of ingredients may vary depending on technical needs. For example, to get more durable concrete, the amount of cement can be increased or decreased the consumption of sand.

Specifications

The technical characteristics of sand concrete are regulated by GOST 7473-94. According to the document, the material parameters are as follows:

Consumption

The consumption of sand concrete for 1m² is calculated based on the thickness of the layer. So, for a layer 1 cm thick, the consumption per 1 square meter will be 18-20 of the finished solution. Based on these data, you can calculate the amount of material for floor screed, surface repair.

To determine the need for dry material in large quantities sometimes it is necessary to calculate how many bags of sand concrete are in 1m³. This can be done based on the reference density of bulk materials - 2400 kg / m³. Manufacturers offer material in bags of 5, 20, 25, 40 kg. Accordingly, to find out the quantity, we divide specific gravity per package net weight: 2400/40 * = 60 pieces.

* packing weight.

Stamps

Sand concrete is a universal material, like its counterpart concrete. The scope of the material is determined by the brand of the mixture and, accordingly, the finished solution:

• M 100 contains fine sand with a fraction of up to 1.2 mm, therefore the solution has workability, it is used as a plaster for internal and external work. Its strength is 100 kg / cm²;
• M 150 is a plastering solution for interior and external walls, floor screed, brickwork. The strength of the ready-mixed concrete is 150 kg / cm². Its consistency allows for the supply of the solution by a concrete pump;
• M 200 - floor screeds with insulation and heating are made predominantly of this sand concrete. It has sufficient strength for this 200 150 kg / cm²;
• M 250 is a suitable masonry and plaster mortar for the construction of small outbuildings;
• M 300 is a versatile material for cooking masonry mortar, mixtures for pouring floors, erecting buildings and individual designs;
• M 400 sand concrete is used to create critical and heavily loaded structures and structural elements, in special engineering structures.
• M 500 is rarely used in private construction due to the excessively high margin of safety.

Foundation

Different grades of sand concrete are used for construction from the construction of foundations to interior decoration and facade design. This material is used in the same way as usual. concrete mortar, that is, sealed with water and used as directed.

Sand concrete of the M300, M400 brands is suitable for the construction of the foundation. Moreover, the material will be much cheaper than buying a ready-made solution in a factory, and the accuracy of preparation will be similar.

It is noteworthy that the required amount of dry mixture is conveniently calculated - its volume practically coincides with ready-made solution due to minimal shrinkage.

Floor screed

For floor screed, it is better to use sand concrete of the M150 brand if it is supposed to be covered with linoleum, laminate, tiles, or M200, if an electric or water-type heating system will be located in the floor body.

How to make a screed:

1. The base is prepared, debris is removed, thoroughly moistened.
2. Expose beacons - slats that will facilitate the process of leveling the mixture.
3. Starting from the corner, a solution is poured onto the floor and leveled building rule or a long rail.

When arranging a warm floor, a substrate and pipe (electrical) systems are laid on the base before pouring.

The sand concrete floor screed dries for two days, after 2 days you can move on the floor, and after another 3 days you can already make the topcoat.

More on video:

Plaster

Plastering brick or concrete walls is usually carried out cement mortars in view of their strength and good adhesion. Sand concrete for their preparation - the best solution... You don't have to calculate the amount of cement and sand.

For plastering, it is optimal to use mixtures of the M100-M150 grades, which have a fine-grained structure, which allows for an ideal leveling of the surface. Also, the solution can be supplied to the walls by means of a pumping unit.

Summary

Sand concrete is a versatile building material, in fact - a relative of concrete. It is convenient to mix the dry mixture for the preparation of masonry, plaster mortars and the creation of structures for the construction of houses and structures for various purposes.

The material is sold and stored in paper bags from 5 kg.