Types of sand, their characteristics, extraction and use. Varieties of sand The main varieties of sand and features of their extraction

Natural sand for most is something natural, and not attracting attention. These are small particles that have arisen in the process of destruction and transformation of the earth's surface over millions of years. The main element of the substance is silicon dioxide molecules. Iron, sulfur, calcium, gold, magnesium are also included, but in minimal quantities. The main areas of use are construction and industry, for which sand is ideal if it consists mainly of quartz. But, a pure composition in the natural environment is rare. More often, sand is filled with crushed feldspars, mica, skeletal remains, silt, gypsum, clay and other elements. There are also such types of sand, the particles of which do not contain quartz at all, for example, coral or gypsum. A childishly simple and primitive question: “who created the sand?” Has quite logical answers - the sun, wind and water. As well as all the processes taking place on the planet, including volcanic eruptions.

Sand under the microscope

Sand of different characteristics is presented in trade. The main type of sand, the most popular and irreplaceable, is construction sand, which has an additional classification. It is worth highlighting that, despite the rapid progress in the production of building materials, this inexpensive and common substance today has no full-fledged analogues. For example, natural stone is quite successfully replaced by bricks, concrete products, blocks; iron and wood are giving way to more advanced alloys and plastics. And sand belongs to the unique and unsurpassed types of natural materials. Moreover, the amount available on the planet more than satisfies the needs of industry and construction.

Main types and types of sand

The appearance of sand depends on the conditions of occurrence. The general characteristic of sand is that it is a loose loose mass, consisting of round or angular particles ranging in size from 0.1 mm to 5 mm. Color and properties differ from the conditions of origin. The most common on earth is yellow.

Rarely, red coloration (eg, volcanic sands with corresponding colored rocks) or green (including chrysolite, chlorite-glauconite) is found. There are black ones, which contain magnetite or hematite minerals, as well as purple sands, orange and multi-colored. The photo shows multi-colored sand, the view from above shows a landscape unusual for Russian nature.

According to the method of formation, bulk material is divided into natural and artificial. In turn, depending on the genesis natural sand may represent:

• – marine and lake species;
• - eolian (associated with wind activity);
• - alluvial (brought by permanent and temporary water flows) and deluvial species (deposits on the slopes and foothills of mountains).

artificial type is obtained due to the mechanical impact on rocks or certain production wastes:

• – expanded clay is produced by crushing expanded clay gravel;

• - pure is formed by crushing the original mineral (in nature, pure crushed mineral is extremely rare);

• - perlite sand occurs when crushing volcanic glass;

• – sand slags or thermosites are representative of non-waste production in the industry;

• - marble sand grains are formed when marble is crushed.

If we compare a natural substance and an artificial one, then, of course, the latter wins in terms of the purity of its properties. In the natural environment, all kinds of processes are constantly taking place, which make changes and additions to the structure of the bulk substance.

Types of sand used for construction

Building materials are mined in the fields. The conditions for obtaining and the method of processing determine the name of the product: reservoir, mountain (quarry or ravine) and artificial. The main documents defining the norms for use in construction are GOST 8736-2014 and GOST 8736-93. The most popular types are, and, their use has few restrictions due to their excellent characteristics.

1. – Alluvial (washed) is the best choice for many building processes. Concrete mortar, reinforced concrete products, road construction, preparation of building mixtures and compositions. To obtain this type of sand, a large amount of water and drying devices are used. Clay, dust, debris residues are washed out by pressure. Due to the mechanical action, lumps are broken. After drying and sifting, a free-flowing mass is formed, characterized by purity and uniformity. The strength of an artificial stone or bonding solution depends on the quality of the components used. Impurities violate building technology, and lead to destruction. Therefore, washed quarry material is one of the most expensive and sought-after goods.

1. - seeded. It is an affordable and inexpensive building material. Cheaper is only sand for backfill, which is delivered to the site without preparatory stages for sale. Sifting removes small and large debris in the form of stones, branches, plant elements, and also breaks up lumps. The process takes place at the place of extraction with the help of mechanical devices. For consumers, the cost increases by the amount of effort expended by the developing enterprise.

Features of mountain sand - angularity, a variety of sizes, the presence of impurities. The main determining factors in the use of crushed rock are: a large number of sand pits in our area, and in general on the planet; simple extraction, fast transportation, and as a result, an acceptable cost. On the structural side, career education has the best angularity (adhesion) and cubism of all types. This form contributes to the creation of high-strength products, and is a fundamental criterion for the selection of sand in concrete compositions.

Types of river construction sand and its application

The method of processing the material consists in the process of raising from the bottom of the river and drying. The product is distinguished by its purity and uniformity of composition. Prolonged exposure to water smoothes corners, reduces shape and flushes out clay impurities between grains of sand. Therefore, a product of river origin is a lighter, lighter and more homogeneous composition than a quarry one. Like washed sand, mountain sand is an ideal type for concrete. The differences are in size and flakiness. The river one is more crushed and rounded, therefore it practically does not shrink, unlike the angular cuboid quarry. In addition to concreting, homogeneity serves as the basis for obtaining a smooth surface in the production of plaster and masonry mixtures, the manufacture of filler for paints and grouts.

Quartz sand is the purest material obtained by artificial means.

Mechanical crushing of quartz-containing rocks provides a clean and homogeneous substance. The price of production stands out significantly among similar products of natural education. A distinctive feature is the high angularity and flakiness, which does not have the best effect on strength, but gives the desired effect in grinding processes. The main scope of application is industry and the production of building materials (facade compositions, sand for plastering, landscape design).

Indicators that determine the type of sand required for construction

The purpose and use of bulk material is determined by the coefficients and indicators of the gradation of characteristics.

Environmental Safety- the most important factor for the construction of houses and premises in which people exist. Almost all varieties are toI -th class of radioactivity(GOST 30108-94). Difficulties can arise only with artificially created material. So, the type of quartz sand is suitable for plaster, and another representative of artificial raw materials can go off scale to the permissible norm of the background radiation. Therefore, it will be used only in the arrangement of the railway track. The main role is played by the original mineral or substance that has undergone grinding.

Types of sand fractions (size modulus) affect the density of the sand. By size, sand grains are divided into large (2–5 mm), medium (0.5–2 mm) and silty (up to 0.5 mm). The coarser the sand, the greater the bulk and compacted density, which is important to consider when determining the quantity for construction and purchase. Also, the particle size modulus affects the scope of application. Fine material is purchased for grinding work; coarse quarry sand with clay impurities is suitable for internal plastering. Clean coarse sand is used to build the foundation.

Strength is expressed in grades which are based on the properties of constituent minerals. Grade 300 speaks of sedimentary rocks that do not withstand significant loads; 400th - metamorphic rocks with average values. The 800th grade is the strongest and most expensive, this free-flowing substance comes from igneous rocks that have passed the test of extreme temperatures and conditions.

By hygroscopicity, sand It is divided into a wet composition, saturated with water and low moisture. For construction, only dry material is needed; all proportions are based on it. The wet composition violates the density calculation taken into account, increases significantly in weight, becomes plastic and viscous. The average volumetric-bulk density of sand is 1300 -1500 kg / m 2. If the moisture content of the crushed substance increases slightly, then the density and weight decrease - each grain of sand is enveloped in moisture and creates voids around itself. And if the crushed rock becomes wet, then the weight and density exceed the average.

Filtration coefficient depends on porosity and coarseness. The more pores, the slower the water passes, and the more thoroughly it is cleaned, which is essential for the operation of filters. Large grains of sand (3-5 mm) contribute to the rapid passage of water, this fact is used in the design of the drainage system.

Indicator of the maximum allowable amount of impurities. In the river composition, the standard dose determined by the standards is 0.7%. Washed quarry sand has a small content, while seeded sand has a significant content. Additives can positively and negatively affect the process. So, clay is a plasticizer in plaster, but destroys the adhesion strength of the foundation.

If the buyer is not a builder and does not know how to choose, then difficulties arise. Companies specializing in building materials provide qualified advice. The leading seller of quality building materials in Moscow and the region - MSK-Region.

And artificial material, which has a fraction of rocks. Quite often, it is made up of the mineral quartz, which is a substance called silica. If we are talking about natural sand, then it is a loose mixture, the grain fraction of which reaches 5 mm.

Classification by destruction of rocks

This material is formed during the destruction of rock hard rocks. Depending on the accumulation conditions, sands can be:

• alluvial;
• maritime;
• deluvial;
• eolian;
• lake.

When the material arises in the process of the activity of reservoirs and watercourses, then its elements will have a rounded rounded shape.

The main types of sand and features of their production

Today, almost all types of sand are used by man in various fields of activity and industry. River sand is a building mix that is extracted from the river bed. This material has a rather high degree of purification, which is why there are no small stones, clay content impurities and foreign inclusions in the structure.

Quarry sand is extracted by washing with water in a huge volume, as a result, it is possible to get rid of dust-like particles of clay. Considering the types of sand, you can find quarry sand, which is cleaned during the extraction process from large fractions of stones. This material is quite widespread in the manufacture of mortars that are used for laying foundations and plastering. You can find quarry seeded sand in asphalt concrete mixtures.

Construction sand must comply with GOST 8736-2014, according to which the material is a free-flowing inorganic mixture of coarse grains, the size of which reaches 5 mm. equal to 1300 kg / m 3. Building sand is formed during the natural destruction of rocks, it is mined by the methods of developing sand-gravel and sand deposits without and using enrichment equipment.

The main types of sand also include artificial heavy sand, which has the form of a loose mixture obtained by mechanical crushing of rocks, among the latter should be highlighted:

• slags;
• granites;
• limestone;
• marble;
• pumice;

Features of artificial sand

They may have different origins and densities. If we compare the grains of this sand with grains of natural origin, then the former are distinguished by an acute-angled shape and a rough surface. Artificial sands are commonly used as aggregates in the preparation of plasters and decorative mortars. As a result, it is possible to achieve a tangible texture of the top layer on the outer surfaces.

This material can become part of any layer of plaster, because the fractionation of the grains can be different, depending on the type of mortar. Usually the grain size is assumed to be equal to the size of natural sands. In the manufacture of artificial sand, burnt coal, rocks, as well as unburned particles, in which the sulfur content is low, are taken for processing.

The characteristics of the material will depend on the quality of the coating layer. In the manufacture of decorative plaster from such sand, crushed stone, powder of this rock or crumb can be additionally added to save money, it even benefits from this quality of the texture.

Application and characteristics of sea sand

Sea sand can be used in the production of building mixtures, the manufacture of aggregates, the implementation of plastering work, laying road bases, the construction of fences and barriers, as a filler for building grouts and dyes. The production of such sand is regulated by GOST 8736-93.

Fractions can vary from 2.5 to 3.5 Mk, which determines the fineness modulus. The grain density is equal to the limit from 2 to 2.8 g/cm 3 . In sea sand, foreign impurities should be completely absent, but in some fractions one can find a small content of clay and dust particles. Sea sand is characterized by the labor intensity of production, which makes its cost higher than quarry sand.

Characteristics and price of quarry sand

The main feature of quarry sand is the absence of impurities and frequency. Alluvial quarry material has the following characteristics: a fraction in the range from 1.5 to 5 mm, a density of 1.60 g/cm 3 , and a low content of clay, dust and other impurities. The latter in the composition should not be more than 0.03%.

Quarry sand, the price of which per cubic meter will be 2200 rubles, is used not only in construction, but also in decoration, as well as in the national economy. Especially profitable is the use of such sand in the production of concrete and bricks, as well as in road and housing construction.

Quarry sand, the price for which will be 2300 rubles, can be presented in the form of a material with a fraction ranging from 2.5 to 2.7 mm. In the production of high-strength concrete and reinforced concrete structures, an alluvial quarry fraction is usually used. Quarry material goes to masonry and paving slabs.

Technical characteristics of river alluvial sand and features of its production

Alluvial river sand has a density of 1.5 kg / m 3. If we are talking about density in a state of natural humidity, then this figure will be reduced to 1.45. The composition may contain dust particles, silt and clay elements, but not more than 0.7% by weight. The moisture content of the material is 4%, while the specific gravity is 2.6 g/cm 3 . These types of sand are mined using a dredger, which is fixed on a barge. Such equipment is supplemented with hydromechanical installations, powerful pumps, networks and tanks for dividing the material by composition. The extraction of sand from the beds of dried up rivers is like the extraction of quarry sand.

Conclusion

Almost all varieties of sand can be attributed to the first class in terms of radioactivity. The only exceptions are crushed sands. If we talk about other varieties, then they are radiation safe and can be used in all construction work without restrictions.

The use of sand is quite common today. For example, its quartz variety is used for the manufacture of welding consumables for general and special purposes. As for the construction variety, it is used to obtain structural coatings by mixing with dyes. Sands are also used during finishing work, as well as in the repair of premises. The material also acts as a component that is used in laying roads and in construction.

Initially, in the 19th century, the streets of cities were paved with stones (cobblestone pavement). Starting from the middle of the 19th century, in France, Switzerland, the United States and a number of other countries, road surfaces are being made from bitumen-mineral mixtures. In 1876, for the first time in the United States, cast asphalt was used, prepared using petroleum bitumen. For the first time, asphalt concrete pavement was used to cover the sidewalks of the Royal Bridge in Paris in the 30s of the XIX century. In the early 1930s, in France, in the department of Ain, sidewalks on the Moran bridge over the Rhone River in Lyon were covered with asphalt. The booming road network required new types of pavements that could be constructed as quickly as subgrades. So, in 1892 in the USA, the first road structure of concrete 3 m wide was built by the industrial method, and 12 years later, with the help of an asphalt distributor with a free flow of hot bitumen, 29 km of the road. Asphalt turned out to be the most suitable material for paving. Firstly, it becomes more even, and therefore less noisy and has the necessary roughness. Secondly, you can immediately open traffic on the laid asphalt concrete and not wait until it hardens, unlike cement concrete, which gains the necessary strength only on the 28th day. Thirdly, asphalt concrete pavement is easily repaired, washed, cleaned, any markings adhere well to it.

From Wikipedia, the free encyclopedia

Sand is a sedimentary rock, as well as an artificial material consisting of grains of rocks. Very often it consists of almost pure mineral quartz (substance - silicon dioxide). The word "sand" is often used in the plural ("sands"), but the plural form has other meanings. The Russian surname Peskov is derived from the word "sand".

natural sand

Natural sand is a loose mixture of grains with a size of 0.10-5 mm, formed as a result of the destruction of hard rocks. Natural sands, depending on the genesis, can be alluvial, deluvial, marine, lacustrine, eolian. Sands resulting from the activity of reservoirs and streams have a more rounded, rounded shape.

Heavy artificial sand

Heavy artificial sand is a loose mixture of grains obtained by crushing hard and dense rocks. The shape of crushed sand grains is acute-angled, and the surface is rough.

Sand types:

In trade, sand is classified according to its place of origin and processing:

river sand

River sand is building sand extracted from the river bed, characterized by a high degree of purification and the absence of foreign inclusions, clay impurities and pebbles.

Quarry washed sand

Quarry washed sand is sand mined in a quarry by washing with large amounts of water, as a result of which clay and dust particles are washed out of it.

Quarry mountain sand

Quarry mountain sand is a natural material mined in an open way in quarries. This sand has a fairly high content of clay, dust and other impurities. Although quarry mountain sand, mined in some deposits, has high technical characteristics, which brings it closer in terms of consumer properties to such a type as quarry washed construction sand.

Quarry seeded sand

Pit seeded sand is sifted sand extracted from a quarry, cleaned of stones and large fractions. Pit seeded sand is widely used in the production of mortar for masonry, plastering and foundation work.

construction sand

According to GOST 8736-93, building sand is an inorganic bulk material with a grain size of up to 5 mm, formed as a result of the natural destruction of rocky rocks and obtained during the development of sand and sand-gravel deposits without the use or using special processing equipment.

Application

Widely used in building materials, building site preparation, sandblasting, road construction, embankment, residential backfilling, yard improvement, masonry mortar, plastering and foundation work, used for concrete production , in road construction. In the production of reinforced concrete products, concrete of high strength grades, as well as in the production of paving slabs, curbs, well rings, coarse sand (Mk 2.2-2.5) is used. Fine building sand is used for the preparation of coating solutions. Construction river sand is quite widely applicable in various decorative (mixed with various dyes to obtain special structural coatings) and finishing works of the finished premises. It also acts as a component of asphalt concrete mixtures, which are used in the construction and laying of roads (including for the construction of airfields). Quartz sand is used to make welding consumables for special and general applications.

Sand radioactivity

Almost all sands belong to the 1st class in terms of radioactivity (the specific effective activity of natural radionuclides in them does not exceed 370 Bq / kg, only crushed sands can be exceptions), that is, they are radiation safe and suitable for all types of construction without restrictions.

Rock Sand

English name: Sand

Minerals in the composition of the rock Sand: Quartz

Sedimentary rock, consisting of grains of mountain fossils, was called "sand". Most often, sand consists of a practically purified quartz mineral, it can have both unnatural and natural origin. The grain size of natural material is 0.16-5 millimeters.

Varieties of material

Sand is of the following types.

• Mined from the bottom - material that is mined from the riverbed.
• Seeded - sifted from a quarry, cleaned of large particles and stones.
• Washed sand is a rock that is extracted from a quarry by washing with a huge volume of water. This washing removes dust particles and clay.
• Construction - loose rock, the grains of which have a particle size of up to 5 millimeters.
• Heavy artificial - a material that is mined by crushing rocks.

History of the breed

The grains of sand appeared as a result of crushing the stone. Due to various external natural factors, weathering of rocks occurred. Sand existed even when life on Earth was just emerging.

Today, sand is one of the indispensable materials. This is a universal rock, as it differs in technical characteristics.

What does sand look like?

The material has a soft yellow color. In terms of shade, it is very different. Much depends on the field. Sand grains can be rounded or angular in shape.

Sand mining

Sand is mined in an open and alluvial way. For this, various equipment is used. One or another method is chosen based on the conditions in which the material is mined. A convenient entrance is necessarily organized to the place of extraction. This is important to do for the rational use of funds.

There are sand deposits all over the world. The largest sand deposits of them are located in Russia - in St. Petersburg and the Leningrad region.

Features of use

In the manufacture of various building materials, including reinforced concrete products and building mixtures, including concrete of various grades, sand is indispensable. It is also suitable for creating construction sites, for the construction of embankments and roads, for the improvement of adjacent plots. Sand is also used in the implementation of foundation, plastering, a variety of finishing and decorative works, in sandblasting. Sand is the most important ingredient for making glass. This breed is also suitable for purifying and filtering water.

Rock Properties

• Rock type: sedimentary rock
• Color: yellow
• Color 2: Yellow