Sand is a sedimentary rock and man-made material that has rock fractions. Quite often, it consists of mineral quartz, which is a substance called silicon dioxide. If we are talking about natural sand, then it is a loose mixture, the grain fraction of which reaches 5 mm.
Rock Break Classification
This material is formed during the destruction of rock solid. Depending on the conditions of accumulation, the sands can be:
- alluvial;
- sea;
- deluvial;
- eolian;
- by the lake.
When the material arises in the course of the activity of water bodies and watercourses, its elements will have a rounded rounded shape.
The main types of sand and features of their extraction
Today, almost all types of sand are used by man in various fields of activity and industry. River sand is a building mixture 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 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 dusty clay particles. Considering the types of sand, you can find quarry sand, which is cleared in the process of mining from large fractions of stones. This material is quite widespread in the manufacture of mortars that go to the laying of foundations and the implementation of plastering. You can also see seeded quarry sand in asphalt concrete mixtures.
Building sand must comply with GOST 8736-2014, according to which the material is a bulk inorganic mixture of coarse grains, the size of which reaches 5 mm. The density of the material is 1300 kg / m 3 . Building sand is formed during the natural destruction of rock, it is mined by methods of developing sand and gravel and sand deposits without and using processing 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 it should be distinguished:
- slags;
- granites;
- limestone;
- marble;
- pumice;
- tuff.
Features of artificial sand
They can have a different origin and density. If we compare the grains of this sand with grains of natural origin, the former differ in acute-angled shape and rough surface. Artificial sands are commonly used as fillers in the preparation of plasters and decorative solutions. As a result, it is possible to achieve a tangible texture of the upper layer on the outer surfaces.
This material can become part of any layer of plaster, because the grain fractionation can be different, which depends on the type of solution. Usually the grain size is taken equal to the size of natural sand. 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 breed or crumb can be added to save money, this texture even benefits.
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, the laying of road bases, the construction of fences and fences, 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 modulus of fineness. The density of the grain is equal to the limit from 2 to 2.8 g / cm 3 . Extraneous impurities should be completely absent in sea sand, but in some fractions a low content of clay and dust particles can be found. Sea sand is characterized by the complexity of production, which makes its cost higher than open cast sand.
Characteristics and price of quarry sand
The main feature of career sand is the absence of impurities and frequency. Washed open pit material has the following characteristics: a fraction ranging 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%.
Career sand, the price of which per cubic meter is 2200 rubles, is used not only in construction, but also in decoration, as well as in the national economy. The use of such sand in the production of concrete and brick, as well as in road and housing construction, is especially cost-effective.
Career sand, the price for which will be 2300 rubles, can be presented in the form of material with a fraction in the range from 2.5 to 2.7 mm. In the production of high-strength concrete and reinforced concrete structures, coarse bulk sand is usually used. Quarry material goes to masonry and paving.
Technical characteristics of alluvial river sand and features of its extraction
Sand alluvial river 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 dusty particles, silt and clay elements, but no more than in a volume of 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 by hydromechanical installations, powerful pumps, networks and tanks for dividing the material by composition. The extraction of sand from the beds of dried rivers is like the extraction of quarry sand.
Conclusion
Almost all varieties of sand can be attributed to the first class in radioactivity. As an exception, only crushed sands act. If we talk about the remaining varieties, then they are radiation safe and can be used in all construction works without restrictions.
The use of sand is quite common today. For example, its quartz variety is used for the manufacture of welding materials for general and special purposes. As for the construction variety, it is used to obtain structural coatings, mixing with dyes. Sands are also used for finishing work, as well as for the repair of premises. The material also acts as a component of asphalt mixtures, which are used in road laying and construction.