Crushed stone definition. Crushed stone fractions
Crushed stone is an irreplaceable bulk construction material. It is based mainly on non-metallic rocks and some types of ore. Due to the wide variety of types, its scope covers all areas of construction. When choosing the most suitable type crushed stone, they use a certain classification system for this material, which greatly facilitates the entire process and allows you to create the most durable structures or ensure the durability of other building forms.
To get a clearer picture of the possibilities species diversity, you should first understand the principle of production of this building material. It is mainly obtained during stone mining, as well as during processing. From whole pieces Various stones are crushed to fractions of the required size using special crushing equipment.
Important! This entire process is waste-free. Even the secondary raw materials obtained during the processing of the main material in the form of tiny crumbs find their application.
Principles of crushed stone classification
This material comes in a wide variety of shapes.
Therefore, there are several classification criteria:
- nature of origin;
- density;
- strength;
- geometric shape;
- granule sizes;
- radioactivity level;
- frost resistance;
- color.
Nature of origin
When classified according to this principle, a very long list is formed possible options due to the variety of materials being mined and processed.
For convenience, the following main types of crushed stone are distinguished by origin:
Density
This indicator is inextricably linked with the type of feedstock. The higher the density, the wider the range of applications. In turn, it is this property that determines the strength of the material.
Strength
The strength parameter determines the degree of resistance of the material to deformation under tensile load and destruction under any mechanical influence. To note features according to the degree of strength, a system of grades is used, each of the indicators of which corresponds to certain indicators.
The gradation looks like this:
- Weak - the lower limit corresponds to the M200 brand, the upper does not exceed M600.
- Medium - range of indicators M600-M800.
- Durable - crushed stone, the parameters of which correspond to grades from M800 to M1200.
- High-strength - the upper limit corresponds to the M1600 brand.
Important! All parameters are regulated by GOST standards.
Shape geometry
One of the most important criteria that affects the quality of compaction. The defining indicators are the presence of needle-shaped and plate-shaped granules and their percentage. The determining factor for such particles is their width, the dimensions of which are 3 or more times smaller than the length of the grains.
There are three main categories of flakiness:
- ordinary, in which the volume of such grains does not exceed 35% of the total mass of the stone;
- improved, the percentage of which varies from 25 to 35;
- cuboid, in which the content of both needle-shaped and lamellar granules does not exceed 15%.
Granule sizes
Based on this principle, they distinguish the following types crushed stone fractions:
Important! In addition to the above usual categories, there is also crushed stone non-standard sizes, fractions of which can reach from 120 to 300 mm.
When choosing a material taking into account this indicator, both the consumption of crushed stone and the strength of the formed coating are determined - the more voids, the lower the quality.
Radioactivity level
The natural radioactive background of the material determines the permissible area of application. Classification occurs according to classes:
Frost resistance
The main indicator is the number of drying and saturation cycles in a sodium sulfate solution. Depending on the result obtained, the number of cycles of permissible freezing and thawing without breaking the shape and reducing the strength characteristics is determined.
The principle of difference is the following types of brands:
Hue
Very important criterion, which also directly affects the scope and method of design of structures different types. It is noteworthy that due to the breadth color palette, which is ensured by a fairly diverse composition of components, the use of crushed stone is permissible at all stages of construction - both during rough work on the construction of the base of structures, and during decorative finishing. 
Main types of crushed rocks
This group is represented by a very wide line of products, so we will separately note only those types that are in high demand:
Areas of application of crushed stone
It is quite difficult to limit the range of use of crushed stone, since its use is advisable at all stages of construction in various directions.
Among the most popular solutions, we note the following:
- Preparation of concrete different brands when building walls monolithic structures any scale and laying the foundation.
- Production of block building materials.
- Formation of road surfaces of various types - bulk garden paths, asphalt highways, tiled pedestrian area.
- Arrangement railways, airport runways.
- Landscape design - design of decorative embankments, flower beds, artificial reservoirs.
- Soil improvement - installation of fencing systems and drainage systems.
- Livestock - crushed limestone is added to animal feed as natural calcium.
- Creation of a protective layer on roads during icy conditions.
Video
Watch the video, which clearly shows the entire process of extracting crushed stone.
Conclusion
Considering the diversity of crushed stone species, when choosing, be sure to take into account the full range of criteria. Only in this case will the result correspond to the specified parameters, and the period of operation will be long.
Natural gravel is loose natural material, which was formed as a result of the destruction of rocks.
It is obtained from gravel rocks by sorting and sifting through special sieves. Gravel is a rounded stone with a rough or smooth surface.
The difference between crushed stone and gravel
Crushed stone is obtained by crushing, followed by sorting into fractions, durable rocks, large rubble stones, slag waste or concrete waste.
Unlike gravel, it comes in a pointed shape with a rough surface. In connection with industrial production There are practically no impurities in crushed stone, so it is considered an ideal building material. Natural gravel may contain impurities in the form of fragments of various minerals, up to one centimeter in size.The use of gravel and crushed stone in construction is regulated by GOST 8267-93 “Crushed stone and gravel from dense rocks for construction work. Technical conditions".
Natural crushed stone, which is sharp-angled rock fragments formed due to natural erosion from wind and water, is rarely found in small quantities and, as a rule, has no industrial value.
Natural gravel, unlike crushed stone, has been assigned the first class of radioactivity, so it can be used without restrictions in any area of construction.
Types of gravel
Depending on the natural origin and method of extraction, several types of gravel are distinguished:
- mountain;
- gully;
- river;
- nautical;
- glacial;
- lake
Natural gravel has a loose structure, heterogeneous faded colors, so modern industry has mastered the production of natural gravel from any rocks, a given color, shape and grain size, which can satisfy any demands of the modern construction market.
As an exception, there is an artificial type of gravel produced at factories in furnaces by high-temperature swelling from expanded clay, shungizite raw materials or slag.
Gravel fractions
A fraction is a bulk or lump material defined by strictly defined properties. Hence, gravel fractions are divided according to particle size or grain size, so there is:
- small, representing pebbles ranging in size from 1 to 2.5 mm in diameter;
- medium, having dimensions from 2.5 to 5 mm;
- large, with stone sizes from 5 to 10 mm;
- very large, usually from 10 to 20 mm, less often up to 50 mm.
Gravel of larger fractions existing in nature with a size of up to 120 mm should still be considered rubble stone.
Density
When calculating the need for materials, it is necessary to take into account the density and specific gravity. So expanded clay gravel will have a value from 200 to 800 kg/m3, from shungizite from 400 to 800 kg/m3.
Please note that specific gravity artificial species gravel is lighter than water, with all the ensuing consequences, and it is not suitable for filling paths in low-lying parts of the landscape.
During sales various types and types of gravel, as a rule, the density value is well known to the seller, and the range of values lies from 1400 to 1700 kg/m3; in aggregated construction calculations, the value of 1560 kg/m3 is mainly used. These numbers show the density of gravel poured onto the ground, without mechanical compaction and additional compaction.
Application area
Gravel is used:
- For making a lung concrete;
- in the improvement of parks and stadiums;
- when constructing roads;
- as an element of drainage systems;
- V landscape design;
- for the manufacture of decorative covering films;
- filtering clean water in springs and wells.
Thus, artificially made gravel of sizes from 2.5 to 5 mm is used to sprinkle paths in parks and squares. Fractions with a grain size from 5 to 20 mm are in great demand when arranging suburban areas, How decorative material for filling paths and creating flower beds. The largest fractions up to 120 mm in size, natural gravel, are used in the finishing and decoration of walls, foundations, as well as in the laying of fences.
Artificial expanded clay and shungizite gravel is used as a mechanically resistant heat insulator in construction work.
Gravel of marine or river origin is characterized by smooth surface, which does not promote good adhesion to sand and cement, therefore the use of these types in the production of heavy grades of concrete is not recommended.
Making gravel
Gravel is developed in gravel-sand deposits. The amount of stone in the extracted raw materials does not exceed 35%, therefore the method of using quarries provides for the simultaneous production construction sand and natural gravel.
At the initial stage, sand washers are used to separate the main masses of sand and stone, where using large quantity water, the mined mass is mixed and separated due to gravitational forces when the rock is washed away by water. Next, the separated gravel mixture enters vibrating screens for subsequent cleaning from impurities and sorting by size and fractions; this process is called screening.
Vibrating screens are special devices, where the working bodies consist of one or more gratings.
If there is only one lattice, then the size of the holes in the lattice in the direction of movement of the raw materials changes from the largest at the beginning to the smallest at the end of the structure. If there are several gratings, then they are located in a vertical projection one above the other or sequentially one after the other in a rigidly reinforced vibrating box, which, in turn, is installed suspended on mounted springs or springs. On each grid, the size of the holes is made in such a way that it allows only grains of a strictly defined size to pass through them, which need to be separated from the rock at this stage. Screens are distinguished by the method of creating a vibration impulse and transmitting it to the sorting grids. Thus, there are machines based on the inertial, electromagnetic and eccentric principles of mechanical transmission of energy to sorting sieves.
DIY gravel paths
IN Lately the main area where gravel is still widely used is landscaping country houses and dachas, or as it is now fashionably called - in landscape design. Everyone can show their talent as a designer using gravel of various types, sizes and colors. Build alpine slide or an unprecedented structure made of stone is as simple as painting an oil painting, but making a decorative platform or pouring it over the adjacent territory country house comfortable paths are not as easy as it might seem at first glance, but everyone can do it if they want.
Independent construction of paths made of gravel stones or pebbles can be divided into several stages, the observance of which will allow you to consistently and without extra costs realize your ideas and surprise others with your talent. And so, let's get started:
- The first stage or preparation. Here it is necessary to make a sketch on paper of future decorative areas, paths and other planned landscape elements.
- At the second stage, using a tape measure, pegs and ropes, we mark the location of future construction projects in strict accordance with the developed sketch, or, if necessary, we make adjustments to the landscaping plan for your territory.
- At the third stage, after all the boundaries are defined and outlined, all the pegs are placed and all the ropes are pulled, we proceed directly to the implementation of the plan. Under all future paths and areas, we use a shovel to remove the fertile layer of soil, which, as a rule, is no more than 15 cm. This will save you from weeds and grass for a certain period of time. The resulting soil can simply be spread evenly over existing lawns or stored somewhere for future flower beds.
- On next stage We fill the bottom of the resulting trenches and depressions with coarse gravel or crushed stone and carefully compact it; you can also use solid construction waste from fragments of bricks and concrete. The volume of fill should be approximately one-half to two-thirds the depth of the excavated hole. After compaction, to increase strength, we spill the resulting base with water. It is not recommended to sprinkle the bases of paths and platforms with clay; it is necessary to exclude the possibility of accumulation of large masses of water during rain or heavy melting of snow.
- Next, a layer of purchased or prepared decorative gravel is poured onto the prepared base. Be sure to use gravel or pebbles when backfilling paths. various colors, which greatly diversifies general form landscape. It is also necessary to level and moderately compact the completed surfaces.
- The final conclusion will be mandatory design decoration all landscape design. Here you can use various stones, flower beds and other decorative little things or designer fakes.
Now everyone can enjoy the results of their work and be happy for beautiful design adjacent territory of your country lady.
And in conclusion, we suggest watching a video from original ideas design of pebble paths:
In construction work it is often necessary to use building material such as crushed stone. It is obtained in the process of crushing rocks or waste suitable for this, sometimes different types and meets various characteristics.
When purchasing this building material, delivery of crushed stone can be carried out by the selling company.
Properties of crushed stone
Crushed stone meets the following parameters:
- 1. Radioactivity. This characteristic is taken into account primarily when purchasing crushed stone, since if this material is used for the construction of residential buildings, then its indicator should be low. And you can purchase it only if the seller presents the relevant certificates and research findings.
- 2. The strength of crushed stone is determined by the strength of the rock from which it was obtained, as well as its reaction to testing work this indicator.
- 3. Frost resistance indicates how many times it can withstand freezing and thawing.
- 4. Flakiness determines what shape the crushed stone will be, flat or cuboid. Materials with this different indicator are used for different purposes.
Types of crushed stone
This building material comes in several types, depending on the source rock:
- 1. Granite crushed stone is obtained from the most common rock - granite. It has a granular structure and consists of mica, quartz, and spar.
- 2. Gravel requires sifting of quarry rock, or crushing of stone rock. It is not as durable as the previous type, but it is less radioactive and not as expensive.
- 3. The limestone type of crushed stone is made by crushing limestone. Mainly used in road construction.
- 4. If crushing occurs construction waste, then you get secondary crushed stone. It is not as durable as the described types, but it is cheaper and also has its own areas of application.
- 5. For the production of slag crushed stone, porous and waste slags are used. It is used in road repair and construction work, as well as for filling cement concrete.
Crushed stone is used in the following cases:
- finishing work, decoration of paths, playgrounds;
- base for railway tracks;
- road construction;
- construction of buildings for various purposes;
- decorating fences, ponds, swimming pools.
These are the main types of work where you can find this building material; in addition to them, there are many additional ones.
A video about the production process will help you understand what crushed stone is made of:
Made from natural stone igneous effusive rocks - porphyrites of a homogeneous massive deposit in Karelia and Ukraine.
| № | Indicators | indicator value |
| 1. | Stone Density | 2.75-2.93 t/m3 |
| 2. | Water absorption | 0,05-0,25% |
| 3. | Compressive strength | Up to 2080 g/sq.m. |
| 4. | Porosity | 0,40-4,03% |
| 5 | Chemical composition: | |
| SiO2 | 48-65% | |
| Al2O3 | 15-18% | |
| CaO | 3.5-10.5% | |
| MgO | 2.1-7.2% | |
| SO3 | 0.38-1.01% | |
| Fe2O3 | 7.0-12.5% | |
| 6. | Total specific efficiency of natural radionuclides | 30-137 Bq/kg which corresponds to class 1 |
| 7. | Volumetric bulk density of crushed stone by fraction: | |
| from 0 to 5 mm. | 1.50 t/m3 | |
| from 0 to 40 mm. | 1.53 t/m3 | |
| from 3 to 10 mm. | 1.45 t/m3 | |
| from 5 to 20 mm. | 1.37 t/m3 | |
| from 20 to 40 mm. | 1.41 t/m3 | |
| from 20 to 60mm. | 1.45 t/m3 | |
| from 20 to 90 mm. | 1.48 t/m3 | |
| from 40 to 70 mm. | 1.47 t/m3 | |
| Rubble stone | 1.60 t/m3 | |
| 8. | Frost resistance | F-300 (GOST from F 15 to F 400) |
| 9. | Crushed stone grade by strength | 1400 (GOST from 600 to 1400) |
| 10. | Grade of crushed stone by wear | I-1 (GOST from I-1 to I-4) |
| 11. | Content of weak grains | 0.1-3% (GOST up to 5%) |
| 12. | Content of dusty, clay particles, including clay in lumps | Up to 1% GOST 1% Not more than 0.25% GOST 0.25% |
| 13. | Content of lamellar grains | 12-30% GOST up to 35% |
| 14. | Grain composition | Complies with GOST 8267-93 |
| 15. | Content of harmful components | None |
According to the results of gamma spectrometric studies, the specific effective activity of natural radionuclides in samples of building materials was 30-137 Ek/kg, which corresponds to class 1 of building materials in terms of the content of natural radionuclides.
The useful thickness of the deposit is represented by volcanic rocks of predominantly intermediate and basic compositions; differences in acid composition are also found.
Porphyries and microporphyries, predominantly of dacite composition - 36%. Porphyries and microporphyrites of andesitic, basaltic and transitional compositions - 57%.
Porphyrites are the most widespread in the field, and among them are porphyrites of andesite-basaltic (20%) and basaltic (16%) composition. Less common are porphyrites of andesite composition (13%) and porphyrites of dacite-andesite composition (8%).
Among the acidic varieties, porphyries of dacite composition predominate (22%); liparitic-dacite and trachytic varieties are also found (7% each).
Filsites, microgranites and diabases make up about 5%.
Clastic lavas, lava clastites, tuffs, and tuff lavas are found in limited quantities - 2%.
1. Plagioclase, pyroxene - plagioclase porphyrites, andesite microporphyrites, andesite-basalt and basalt compositions.
The tonsils make up 10-15% of the rock volume and are filled with fine-grained quartz aggregates, chlorite, and epidote.
2. Plagioquase porphyrites and microporphyrites of andesite-dacite composition.
- Plagioclase - 58%
- Quartz - 10%
- Chlorite - 14-16%
- Carbonate - 10-12%
- Sericite - 7%
Porphyritic segregations make up about 10% of the rock volume and are represented by plagioclase. Plagioclase is sometimes replaced by carbonate chloride aggregates. Rutile is noted as ore materials.
3. Quartz porphyrites and microporphyrites, quartz-plagioclase liparitic-dacitic, dacite compositions and felsites.
- Albit - 31-51%
- Quartz - 25-35%
- Chlorite - 10-12%
- Carbonate - 5-14%
- Epidote - 1%
- Sericite - 2-13%
- Ore minerals 1-2% (leucoxene, rutile, magnetite, occasionally sulfides).
4. Microgranite
- Plagioclase (albite) - 57%
- Quartz - 17-20%
- Chlorite - 25%
- Epidote - 1%
- Sphene-leucoxene - 1%
As a result chemical analysis monolithic effusives obtained the following contents of basic oxides (%):
- SiO2 - 48.44 to 65.28
- Al2O3 - 15.6 to 18.07
- Fl2O3 - 7.02 to 12.56
- CaO3 - 3.50 to 10.52
- MdO - 2.10 to 7.26
- SO3 - 0.38 to 1.01
Strength of crushed stone characterized by the tensile strength of the original rock during crushing of crushed stone (crushing) in the cylinder, and wear in the shelf drum. These indicators simulate the resistance of stone material when exposed to traffic passing along the road. Vehicle and mechanical impacts during the construction of road structures (laying and compaction with rollers).
Crushed stone is enriched according to the principle of selective crushing. Crushed stone crushing occurs in one specific mode. Stones of different strengths are passed through it and as a result the crushed product is obtained different sizes. Smaller crushed stones will be made from stones of less strength. Using fractionation, it can be sifted out, resulting in a homogeneous and durable product.
Depending on the brand, crushed stone is divided into groups:
High strength - M1200-1400,
- durable - M800-1200,
- medium strength - M600-800,
- weak strength - M300-600,
Frost resistance crushed stone is characterized by the number of freezing and thawing cycles. It is allowed to evaluate the frost resistance of crushed stone by the number of cycles of saturation in a solution of sodium sulfate and drying. Based on frost resistance, crushed stone is divided into grades.
IN crushed stone normalize the grain content of lamellar ( flakiness- from the word “bream”, i.e. flat like bream) and needle-shaped. Lamellar and needle-shaped grains include grains whose thickness or width is three times or more less than their length. According to the shape of the grains, crushed stone is divided into four groups (content of grains of lamellar and needle-shaped forms, % by weight):
- Group I up to 15%,
- Group II from 15% to 25%,
- Group III from 25% to 35%,
- IV group from 35% to 50%.
Adhesion One of the specific characteristics of crushed stone is adhesion. This parameter reflects an assessment of the quality of adhesion of bitumen binders to the surface of crushed stone. It should be noted that the quality of adhesion is affected by the color of the crushed stone. The best adhesion performance is achieved by gray and dark gray crushed stone.
Water absorption and water saturation- this is the property of crushed stone to lose moisture located in its pores. Moisture release of crushed stone characterized by the amount of water in % (by mass or volume) lost by a standard sample of material per day at a relative ambient humidity of 60% and temperature environment 20 degrees C.
Water permeability of crushed stone - This is the ability of crushed stone to pass water under pressure. Water permeability is characterized by the amount of water passing through a sample with an area of 1 meter and a thickness of 1 meter during 1 hour at equal pressure.
Grain composition each fraction of crushed stone must meet the requirements of GOST 8267-93 “Crushed stone and gravel from dense rocks for construction work.” Based on the requirements of the specified GOST, it follows that in the fraction of crushed stone supplied for construction, for example 20-40 mm, the number of grains smaller than 20 mm should not exceed 10%, and grains larger than 1.25 * D (50 mm) should not exceed 0, 5%.
Radioactivity - important characteristic crushed stone Note that the radioactivity of natural crushed stone from natural granite rocks is always higher than that of limestone or crushed gravel. This is due to the nature of the formation of rocks.
Reactivity crushed stone from 51 to 261 mol/l.
Materials were selected from geological reports of 1951, 1980, 1988.
Crushed stone, its varieties and features.
Crushed stone is one of the inorganic natural materials obtained by crushing rocks or as waste from mining and processing enterprises. This is a bulk material with fractions of at least 3-5 millimeters in size, depending on accepted standards. In accordance with the density, shape and size of the fractions, crushed stone has different areas of application.
First of all, crushed stone is used in construction for the production of concrete when laying the foundation of buildings and production reinforced concrete structures. In addition, crushed stone is used during the construction of roads and bridges. This material also serves as a ballast layer for railway tracks. In landscape design, crushed stone plays the role of a decorative covering for all kinds of paths and platforms.
Among the types of crushed stone the hardest is granite crushed stone. It is obtained by crushing granite rock, which is magma frozen at depth. Such crushed stone can have a gray, red or pink tint, and its composition is based on feldspar and mica. Granite crushed stone is the most durable and frost-resistant in comparison with other types. Usually for production of this material They blow up a monolithic granite rock, and the resulting blocks are crushed in a special machine.
More affordable considered crushed gravel. This variety is obtained by crushing stone rock or sifting quarry rocks. This crushed stone is inferior to granite in strength and other characteristics, but has a low radioactive background. The properties of crushed gravel allow it to be used in the construction of road surfaces and in the production of reinforced concrete structures. In turn, this category is divided into crushed crushed stone and gravel.
Another variety is crushed limestone, also known as dolomite crushed stone. It is obtained by crushing limestone - a sedimentary mountain of rock, the basis of which is calcium carbonate. Unlike previous types, limestone crushed stone is subjected to special chemical treatment. The strength of this material is not so high, but it is enough for the production of small concrete products. Limestone crushed stone is also used in the glass and printing industries.
It should be noted that the quality of crushed stone is determined not only its strength. It has a number of other characteristics, in particular flakiness. This parameter determines the planar characteristics of this material. In addition, the frost resistance of this building material plays a significant role in determining the quality of crushed stone. It is determined by the number of freezing and thawing cycles, which is characterized by the corresponding brand.
Crushed stone is a versatile and economically accessible building material. It is offered by many manufacturers.
The main properties of crushed stone: strength, frost resistance, radioactivity, flakiness.
But before you go purchasing it, it is recommended to find out what types of crushed stone exist. Then it will be much easier to navigate among the huge assortment and make the right choice.
A detailed overview of each existing species presented below.
Granite material
Granite crushed stone is very durable, frost-resistant and has low flakiness.
A very popular type of crushed stone is granite. The demand for this material is high, since it is offered in various fractions. It is produced by exploding a granite monolithic rock. The resulting blocks are sent to a special crusher. The output is granite crushed stone of the following fractions:
- 0-5 mm - this material is usually called. It is used for sprinkling roads, sports and playgrounds. It is also used for finishing facades;
- 5-20 mm - this fraction is in the highest demand. Its application is very diverse: concrete production, pouring bridge structures, creating airfield and road foundations, forming bridge decks, and so on;
- 20-40 mm - this fraction is used in the production of reinforced concrete structures, in the construction of tram lines and laying foundations, and in the construction of industrial buildings;
- 40-70 mm is a fairly large fraction, which is mainly used in the construction of massive structures, foundation laying and road surfaces;
- 70-300 mm - this fraction is rarely used. Use is limited decorative finishing ponds and fences.
As for the technical characteristics, this type of crushed stone is very durable, frost-resistant and has low flakiness. Harmful components, impurities and radionuclides in this material are within normal limits or are completely absent. Its color is different: gray, red and pink with many shades. After polishing, it acquires a mirror surface.
Slag crushed stone
Scheme of physical and technical properties of slag crushed stone.
Another type of crushed stone is slag. This material has excellent technical characteristics. It is produced from metallurgical waste slag. Its main distinctive feature is low cost. As a rule, the price for slag crushed stone is 25-30% lower than for other types. It is offered in various fractions:
- 5-20 mm - such slag crushed stone is used in the manufacture of concrete, including fire-resistant. It is often used to create asphalt pavement and erect industrial structures;
- 20-40 mm - this crushed stone is used to create reinforced concrete blocks, filler for cement concrete, construct and strengthen the bases of asphalt concrete pavements;
- 40-70 mm - such crushed slag stone is used for the manufacture of concrete products, finishing the lower part of facades, and in landscape design.
Slag crushed stone has high strength, which increases noticeably during operation. It tolerates temperature changes well and does not lose its distinctive properties. Crushed slag contains a small amount of sulfur - up to 2.5% by weight. There are no impurities of flue dust, fuel slag and ash in this type of crushed stone.
Construction gravel
The gravel material has high frost resistance, water resistance and low flakiness.
Considering the types of crushed stone, one cannot help but highlight the gravel type. It is obtained by grinding stone rock and sifting quarry rocks. In terms of strength, this type of crushed stone is slightly inferior to granite, but it has its advantages - minimal radioactive background and a very low price. It is offered in various factions:
- 3-20 mm - This gravel crushed stone is mainly used in road construction. Based on it they create upper layer canvases. It is also used in the manufacture of concrete products;
- 20-40 mm - this material has found its application in arranging sites for cars and construction equipment. It is often used to carry out repair work on small areas road surface;
- 40-70 mm - this fraction is used in landscape design and in the construction of reinforced concrete structures.
Gravel material has high frost resistance. It can withstand up to 100 freezing and thawing cycles. The material is waterproof and has low flakiness.
Crushed limestone has excellent physical and mechanical properties and high resistance to temperature changes.
Limestone crushed stone does not have high strength, but it remains one of the most popular building materials. It is made from limestone, which contains calcium carbonate. It is mined in layers, after which it is processed and sifted. Most often, crushed limestone is white. However, if it contains impurities, it can be pink, bluish, yellowish, light gray or red-brown. This material is presented in various factions:
- 5-20 mm - such crushed stone is used in road construction, concrete production and others building mixtures;
- 20-40 mm - this fraction is used when carrying out fundamental work, road construction, creation of reinforced concrete products and concrete;
- 40-70 mm - mainly used in landscape design and when creating artificial reservoirs.
Limestone material does not contain harmful impurities and elements. It is environmentally friendly, has excellent physical and mechanical properties and high resistance to temperature changes.
Secondary granulate
Secondary crushed stone is obtained by grinding construction waste - brick, concrete, asphalt.
Relatively recently, another type of crushed stone appeared - secondary. This material is obtained by grinding construction waste - brick, concrete, asphalt. In the production of this crushed stone, the same equipment is used as in the production of other types. Its main advantage is its extremely low cost. Its purchase will cost at least twice as much. In terms of strength and frost resistance characteristics, it is inferior to materials made from natural raw materials, but despite this it has a wide range of applications and is offered in various fractions:
- 5-20 mm - this fraction is used for sprinkling icy roads and exits, and is used to create the bottom layer of the road surface;
- 20-40 mm - this fraction is used to strengthen utility trenches, pit bottoms and soft soils. It is also used as a filler for concrete;
- 40-70 mm - usually used when improving the areas of country houses.
Dolomite crushed stone is highly frost-resistant, can withstand temperature changes and provides excellent adhesion to solutions.
Many manufacturers offer crushed stone made from dolomite, which is a special sedimentary rock characterized by high hardness. This material has much less radioactivity than other types. At the same time, it is characterized by high frost resistance, withstands temperature changes and provides excellent adhesion to cement and bitumen solutions. Despite the magnificent specifications, dolomite crushed stone is relatively inexpensive. It is offered by the following factions:
- 3-20 mm - used as a raw material for fillers of building mixtures. It is often used in the manufacture of finishing materials;
- 20-40 mm - this fraction is used to create high-strength concrete and reinforced concrete structures. It is also used in road construction;
- 40-70 mm - this fraction is usually used in the construction of industrial facilities. It is often used for decorative purposes when decorating adjacent areas of country houses.
Such types of crushed stone exist today. They have their advantages, distinctive features and a specific scope of application. Draw your conclusions based on the information provided and go shopping for the material that suits you best.