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 of crushed stone, a certain classification system for this material is used, which greatly simplifies the entire process and allows you to create the most durable structures or ensure the longevity of using other building forms.
To more clearly imagine the possibilities of 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. Using special crushing equipment, solid pieces of various stones are crushed to fractions of the desired size.
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 celebrate distinctive 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. Determining indicators are the presence of needle-shaped and lamellar 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 damaging the shape and reducing the strength characteristics is determined.
The principle of difference is the following types of brands:
Hue
A very important criterion, which also directly affects the scope of application and the 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 erecting walls of monolithic structures of 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.
Properties of crushed stone
The average density of crushed stone is from 1.4 to 3 g/cm3.
Factions
Standard:
| 1. | from 3 to 8 mm; (so-called Eurocrushed stone) |
| 2. | from 5 to 10 mm; |
| 3. | from 10 to 20 mm; |
| 4. | St. 5 to 20 mm; |
| 5. | St. 20 to 40 mm; |
| 6. | St. 25 to 60 mm; |
| 7. | St. 20 to 70 mm; |
| 8. | St. 40 to 70 mm; |
Non-standard:
| 1. | from 10 to 15 mm; |
| 2. | St. 15 to 20 mm; |
| 3. | St. 80 to 120 mm |
| 4. | St. 120 to 150 |
Flakiness
Crushed stone with increased flakiness.
Crushed stone of fractions 3-8 and 5-20 is used for the production of concrete and products made from it. Fraction 20-40 is most often used during laying the foundations of buildings (as part of the “cushion”), and fractions 25-60 and 40-70 are used in road construction.
Crushed stone of fraction 25-60 can be used exclusively for the ballast layer of railway tracks (GOST 7392-2002). In construction, in accordance with GOST 8267-93, other fractions of crushed stone are used.
Types of crushed stone
Granite crushed stone
Granite crushed stone- This is crushed stone from solid rock with a granular structure, which is the most common on Earth. Granite rock is magma solidified at great depths, consisting of well-formed crystals of feldspar, quartz, mica, etc. And its color is red, pink or gray, due to the predominance of spar and mica in it. Blocks are usually obtained by blasting a monolithic rock, then they are crushed in a machine, and the resulting crushed stone is sifted into fractions. This last stage crushed stone production.
Granite crushed stone fractions
- 0-5 mm (granite screening) is the smallest fraction of granite crushed stone, in the strict sense it does not belong to crushed stone, but is a by-product during its production. Applicable as decorative material for finishing, as well as for filling paths and roads, children's and sports grounds; for the manufacture of concrete products, in particular with the surface of “washed concrete”;
- 5-10 mm is the finest fraction commercially available. Used in the production of concrete and structures made from it to optimize the fractional composition of coarse aggregate, for example in the production of floor slabs using a formless method;
- 5-20 mm (a mixture of fractions 5-10 and 10-20) - is in greatest demand. Used in the production of concrete and structures made from it, in foundation work, when pouring bridge structures, bridge decks, road and airfield surfaces;
- 20-40 mm - average fraction. It is used in the production of concrete, reinforced concrete structures, in the construction of roads and railways, tram lines, in laying foundations and erecting industrial buildings;
- 20-70 mm, 40-70 mm - coarse fraction, used in the production of concrete, massive structures made from it and for work with large volumes of concrete. Also used in road construction within settlements, during the construction of industrial buildings and structures;
- 70-120 mm, 120-150 mm, 150-300 mm (BUT) - rarely used. It is used for decorative purposes, usually for finishing fences, ponds, and swimming pools.
These are the standard, most common ways to use these fractions of granite crushed stone, however, for each of them there are many application options.
By technical specifications granite crushed stone is durable (grade 800-1200) and high-strength (grade 1400-1600), frost-resistant (grade 300-400), with low flakiness (5-23%) and radionuclide class 1 (A (ef)<370 Бк/кг). Показатели содержания радионуклидов , вредных компонентов и примесей отсутствуют или не превышают нормы, что подтверждается соответствующими сертификатами и заключениями, выдаваемыми после проведения исследований.
Crushed gravel is used for foundation work, for concrete, in the production of reinforced concrete products, and in road construction.
There are two types of crushed gravel:
- Crushed stone is ordinary natural or crushed,
- Gravel is round pebbles, usually of river or sea origin.
Slag crushed stone is used not only as a filler for cement concrete, but also in road construction to strengthen foundations and construct asphalt concrete pavements.
Crushed stone grade by strength
The strength of slag crushed stone is characterized by its grade. For crushed stone from blast furnace slag used as a filler for heavy concrete, five strength grades have been established:
Crushed stone of grade M1200 can be used in the production of concrete of grade M400 and above, M1000 - grade M300, M800 - grade M200 and M600 - below grade M200. Low-grade crushed stone is also used in the production of concrete of higher strength, but after appropriate testing and a feasibility study.
Links
- GOST 8267-93 Crushed stone and gravel from dense rocks for construction work. Specifications. Retrieved March 18, 2009.
- GOST 8269.0-97 Crushed stone and gravel from dense rocks and industrial waste for construction work. Methods of physical and mechanical tests. Retrieved March 18, 2009.
- GOST 8269.1-97 Crushed stone and gravel from dense rocks and industrial waste for construction work. Methods of chemical analysis. Retrieved March 18, 2009.
- GOST 26644-85 Crushed stone and sand from thermal power plant slag for concrete. Technical conditions. . Retrieved March 18, 2009.
- GOST 22856-89 Crushed stone and decorative sand from natural stone. Specifications. Retrieved March 18, 2009.
- GOST 5578-94 Crushed stone and sand from ferrous and non-ferrous metallurgy slags for concrete. Specifications. Retrieved March 18, 2009.
Which will be described in more detail below, is a building material obtained as a result of the initial crushing and subsequent sifting of rocks. It is part of the concrete mixture for the foundation, and its characteristics largely determine the strength of the solution. Therefore, before starting construction, you should decide what type of crushed stone will be used. This is especially true for foundations, which are subject to heavy loads during the operation of the house. And the durability of the entire structure will depend on the strength of the foundation of a residential building or building for other purposes.
Classification of crushed stone
This material is classified according to several main characteristics. Among them, we should highlight: strength and frost resistance. In order of increasing strength, the following varieties should be distinguished: secondary, as well as limestone and gravel, with granite last on the list. The most durable and reliable is granite; it acts as the best option for pouring a foundation. But if we take into account two characteristics: efficiency and durability, then the gravel variety is considered the best. Secondary crushed stone is obtained by crushing concrete waste, as well as broken bricks. Before using this material, care must be taken to remove old reinforcement.
Crushed stone, the types whose use in construction is described below, may have different strengths. Depending on this, the material is divided into grades. A rather weak crushed stone is that of the M200 grade; it should not be used to form concrete structures that will be subject to significant loads during operation. If we are talking about high-strength crushed stone, then it contains a small amount of grains from low-strength rocks, their volume does not exceed 5%.
Of great importance for construction in harsh climates is the number of freezing and thawing cycles that crushed stone will be able to undergo without losing its quality characteristics. Thus, in terms of frost resistance, the material can belong to a grade ranging from F15 to F400. Most often, builders pay attention to these indicators, but crushed stone can also be classified according to some auxiliary characteristics, for example, by the level of adhesion or radioactivity.
Main varieties: granite crushed stone
Which is described in the article, may be granite. It is a non-metallic building material that is obtained from solid rock. Solidified magma has the appearance of a monolithic rock, which is extracted from a considerable depth. In the manufacture of this material, state standards 8267-93 are used. If you are interested in the types of granite crushed stone, then you should know that it is divided into fractions. Thus, the grain sizes in the material can be a minimum of 0 to 5 mm, and a maximum of 150 to 300 mm.
The most common among consumers is granite crushed stone, the fraction of which varies from 5 to 20 mm. It is this material that is used in concrete. Granite crushed stone is used when mixing the mortar to form reinforced concrete structures, railway tracks, when laying the foundations of roads, as well as sidewalks and platforms.
Characteristics and scope of use of crushed gravel
This type of crushed stone is made by passing quarry rock through a special sieve or crushing stone rock. GOST 8267-93 is used as a regulatory document for production. This type of crushed stone is inferior in compressive strength to granite. Among the advantages, one should highlight insignificant radioactivity, as well as low cost. Considering the types of gravel and crushed stone, it is worth highlighting the varieties of gravel, among which it is worth noting crushed crushed stone and gravel.
The first is made by processing rock, while the second is made from pebbles of river and sea origin. Crushed gravel is used as a filler in the formation of products, as well as reinforced concrete structures. It is used in civil engineering, in the process of covering pedestrian roads, as well as in the construction of foundations and platforms.
Reviews of crushed limestone
When considering the types of crushed stone and its application, consumers highlight the limestone variety, which is a material obtained using the technology of processing sedimentary rock. The raw material used is limestone, which consists of calcium carbonate and is low in cost. The main varieties, as buyers emphasize, are materials whose fraction ranges from 20 to 40 mm and from 40 to 70 mm. The intermediate value is a limit from 5 to 20 mm.
According to users, crushed limestone is used in the glass and printing industries. It is also actively used in the manufacture of small-piece reinforced concrete products, during the construction of roads, the surface of which will not be subject to a large transport load during operation.
Recycled crushed stone: what you need to know about it
This material is produced using the technology of processing construction waste, namely asphalt, concrete and brick. The material must comply with GOST 25137-82. In this case, the same technology is used as in the production of other types of crushed stone. The main advantage is the low price. In terms of strength and frost resistance characteristics, this material is inferior to natural varieties of crushed stone. It is used in road construction, as a filler for concrete, and also in strengthening weak soils.
What you need to know about crushed stone screening
Crushed stone, the types and characteristics of which are described in the article, is in demand in construction, as is the screening of this material. It is a by-product of production. Crushed stone has a fraction ranging from 5 to 70 mm and above. If the rock grains have a fraction of up to 5 mm, then they are screenings.
Depending on the raw material, three main types should be distinguished:
- granite;
- limestone;
- gravel.
In addition to the above varieties, recently secondary crumb has been produced, which is a waste product that uses broken crushed stone and unusable reinforced concrete products. This type of crushed stone is the cheapest and is used to form the top layer of streets in winter.
Characteristics of crushed stone screening varieties
The main types of crushed stone screenings were presented above, however, if you want to purchase this material, you need to become more familiar with the main characteristics of the material. If we are talking about crushed granite stone M1200, then its bulk density is 1.32-1.34 t/m 3. The fineness modulus in millimeters is limited to 0.1 to 5 mm. Foreign impurities contain no more than 0.4%.
Gravel screening of crushed stone, the grade of which varies from 800 to 1000, has a bulk density of 1.4 t/m 3. The size of the components varies from 0.16 to 2.5 mm. Limestone crushed stone screening can have a strength grade from 400 to 800. It is 1.3 t/m 3, while the grain size varies from 2 to 5 mm.
A little more about dropouts
Crushed stone, the types and characteristics of which are of interest to many builders, is presented for sale in the form of screenings. According to some characteristics and scope of use, crushing waste is close to the described recyclable materials. However, it should be remembered that these materials are completely different, and their difference is that sand screenings have a larger number of foreign inclusions. It may contain large stones up to 100 mm and very fine sand, which limits the scope of use of such raw materials.
Scope of application of crushed stone screening
The use of crushing screenings is varied. They are used in agriculture, construction, printing and in the improvement of personal gardens. Like gravel, it is used for finishing, when casting curb stones and tiles, as follows from consumer reviews. Without losing quality, they can replace gravel in concrete, reducing the cost of the material. Raw materials from limestone processing waste are used as a filler for cement-based solutions, which are used for wall cladding.
Conclusion
Crushed stone, the types of which must be known to the builder before purchasing the goods, may have a certain type of screening. Due to the fact that it is a by-product, the cost is extremely low. For example, the price of gravel screening is much less by 60% compared to the cost of crushed stone.
The article presents the main characteristics of crushed stone as a building material. We will talk about the differences between different types of crushed stone and what each of them is intended for. You will learn how to determine the main performance indicators (fraction, strength) depending on the purpose of the work.
Main parameter of crushed stone
Flakiness is the main indicator for crushed stone of any origin. It reflects the presence of relatively smooth flat edges on individual stones. The larger such edges are in area, the higher the flakiness is considered. Grains with faces of a relatively large area have an acicular (needle-shaped) or lamellar shape. Other grains (with conditionally identical faces) are called cuboid. The performance properties of the mass depend on the percentage of such grains, especially in “dry” bulk form.
Groups of crushed stone according to grain shape
The ability to determine flakiness by eye will help when choosing crushed stone for your own needs. To do this, it is enough to know how this indicator affects the properties of the material:
- Cuboidal grains are more resistant to compaction, resulting in a more dense base. This is important when constructing a foundation cushion and bedding under the road. They are also the most durable (compared to other forms).
- Needle grains create voids in the mass of the stone. When creating a concrete structure, more mortar will be needed to prepare the mixture, and the compressive strength will be slightly less.
- At the same time, voids are useful for drainage. Providing sufficient packing density, crushed stone of the usual group removes atmospheric water.
Characteristics of crushed stone
This material has two main performance indicators that you should focus on when choosing for your own construction - frost resistance and strength.
Frost resistance
Based on their resistance to freezing cycles, grains are divided into 3 categories. Marked with the letter F and a number indicating the number of freezing cycles:
- Highly resistant. Brand F200, F300, F400. It is used for all types of critical structures, bridge supports, reinforced concrete products, high-rise construction, external fills, offshore facilities and for the Far North.
- Sustainable. Brands F150, F100, F50. Used in construction in the southern regions and the Middle Zone.
- Unstable. Brands F50, F25, F15. Implemented as bedding and drainage at a level below the groundwater level. Used for interior work and heated structures.
It should also be noted that laboratory studies of frost resistance of crushed stone are carried out on individual grains. In a structure (in concrete), the grain receives a 30-40% increase in frost resistance due to the pressure inside the structure.
Strength
This important indicator is determined by simulating the actual operation of the embankment - crushing, wear and crushing. This reveals the ability of the material to resist these influences.
Table of dependence of the area of application on the strength grade
| Brand | Characteristics of the group | Scope of application |
| M1600 - M1400 | Heavy duty | Foundations of bridge supports, towers, derricks |
| M1400 - M1200 | High strength | Bridge supports, foundations of high-rise buildings, embankments, hydraulic structures, towers |
| M1200 - M800 | Lasting | Load-bearing walls of buildings, industrial structures, piles, columns, foundations, fences, supports, fills for railway tracks |
| M800 - M600 | Medium strength | Unloaded structures, walls, fill, limited on 4 sides |
| M600 - M300 | Weak strength | Unloaded fill, unloaded (open) drainage, filters, treatment facilities |
| M200 | Very weak strength |
The strength grade depends on the amount of weak rock admixture in the crushed stone mass. In this case, the prototype is subjected to a load of 20 MPa. Permissible content of weak breeds:
- M1600 - less than 1%.
- M1400 - M1000 - no more than 5%.
- M800 - M400 - no more than 10%.
- M300 - M200 - no more than 15%.
Rock with a soft rock content of more than 20% is called gravel and is used mainly for filling local roads, “change houses”, creating temporary structures and other non-critical work. It is quite acceptable to use washed gravel as crushed stone in private construction (except for foundations).
Types of crushed stone
Each item has its own classification based on strength, size, frost resistance and other indicators. We will focus only on the practically useful aspects of the description.
crushed gravel
This type of crushed stone is obtained by sifting quarry rock and blasting the rock. It is somewhat less durable than granite (maximum grade M1200) and has an unsightly gray appearance. At the same time, its advantages are undeniable:
- More quarries, competition.
- The cost is lower (due to the distribution of raw materials).
- Mining is easier (granite is harder than rock).
- Extremely low radioactive background.
At the same time, the maximum grade and other properties of crushed gravel allow it to be used for critical structures in all sectors of the national economy. There are four fractions of this material:
- 3-10 mm - screening.
- 5-20 mm - “seed”. Used for small-piece products (paving slabs, etc.).
- 5-40 mm - used for medium-sized factory products - concrete and well rings, curbs, lintels, etc.
- 20-40 mm is the main material for the production of concrete and road filling.
Limestone (dolomite) crushed stone
Calcite carbonate (CaCO 3), compressed over time to a state close to a rock mass. According to the main indicators, it is identical to gravel. Used for reinforced concrete products and road construction. A distinctive feature is white color.
Granite crushed stone
It is obtained by exploding a granite massif, crushing and sifting the mass. In most cases it has a red tint. The torn edges of the grains provide the best adhesion to the solution. The shiny texture gives a good appearance to polished monolithic floors and other concrete products on granite crushed stone.
This type of crushed stone is recognized as the most popular, because it has the highest strength. Accordingly, enterprises offer the largest range of sieving fractions - from 0-5 mm to 70-120 mm. For each faction there is a whole set of areas of application.
Slag crushed stone
This material is the result of crushing and sifting of metallurgical waste slags and melts. Concrete products based on this crushed stone are 20-30% cheaper than conventional ones.
Recycled crushed stone GOST 25137-82
Material obtained from the targeted processing of construction waste. It is produced in the same way as natural, only the initial raw material is not a rock fragment, but a monolithic element. After the initial splitting, steel elements (reinforcement) are removed from it, then it is sent to the screen.
Such material could save a lot of money: energy costs are up to 8 times less, and the cost of concrete with such crushed stone is 25-30% less. Artificial crushed stone on sale is 2 times cheaper than granite. Although its strength and frost resistance are inferior to natural ones (maximum M800 and F150), there are many areas of application for such indicators.
Having the necessary knowledge about the selection and merits of different types of crushed stone, you will be able to accurately determine its quality and purchase exactly what you need.
Vitaly Dolbinov, rmnt.ru
Types of crushed stone
Perhaps no construction is complete without the use of crushed stone. This applies to the construction of residential premises, administrative buildings, the construction of bridges, laying roads, runways, etc. However, in each case a certain type of crushed stone is required. The purpose of the article is to convey to the site visitor information about what types of crushed stone there are.
According to the method of extraction and production, it is divided into the following types:
- Granite.
- Gravel.
- Limestone.
- Secondary.
- Slag.
Granite crushed stone
Granite crushed stone is extracted from rocks that have a granular structure. As is known, most of the mountains on the planet were formed as a result of solidified magma thrown to the surface during volcanic eruptions, and consisting of the elements of mica, feldspar and quartz. The predominance of one of these crystals over the others determines the color of the rubble, which can be red, pink or gray.
Granite crushed stone of various fractions
Granite boulders that are formed as a result of blasting operations are crushed in special equipment, then it is sifted and separated into fractions, among which are:
a) large fractions;
b) middle fractions;
c) small fractions;
d) and granite screening.
Each fraction has its own characteristics and finds its place in the production of reinforced concrete structures, in the construction of residential and administrative buildings, as well as for laying road surfaces. Granite screenings are often used for decorative purposes for paving paths and arranging flower beds. The largest fractions of granite crushed stone, which are called “rubble stone,” are used for laying the bases of stone fences and metal fences.
The cost of granite crushed stone directly depends on its size: larger fractions will cost less than their small “brothers” for the reason that the production of the latter requires more costs for crushing the material.
Crushed gravel is obtained by sifting quarry rocks, so it is classified as non-metallic stones. Visually, it differs from crushed granite in its more rounded shape and, although crushed gravel has less strength compared to its granite counterpart, it is a very environmentally friendly material.
The technical characteristics of crushed gravel are as follows:
Strength ranges from M600 to M1200.
Flakiness from 7 to 17%.
Frost resistance F150
Crushed gravel of various fractions
An important characteristic of crushed gravel is the size of its fractions, which, based on this, have different applications. For example, fractions up to 5 mm are used for decorative and landscape work, values up to 10 mm are used for the production of concrete and foundation construction, but perhaps the most popular fraction among builders is up to 20 mm, which is used for the manufacture of foundations. Larger fractions up to 150 mm are also used, which, as in the case of granite crushed stone, are used for laying the base of a stone fence.
In principle, crushed gravel finds its application similarly to granite crushed stone, but due to its comparatively lower cost and environmental friendliness it is more in demand among private housing builders.
At its core, crushed limestone (or dolomite) is the result of crushing sedimentary rocks that form plates lying in the earth's crust. The basis of crushed stone is calcium carbonate, obtained from the remains of animals, plant remains and various chemical impurities. These components significantly impair the strength of crushed limestone, but it has good frost resistance, can withstand temperature changes and, in addition, is low in cost.
All these qualities allow it to be used in the construction of road embankments with low traffic. When landscaping an area, many prefer to use this type of crushed stone due to its environmental friendliness and lack of radioactive background. In the chemical industry, it is used to produce soda, mineral fertilizers, and calcium carbide, from which methane gas is then produced in gas generators for gas welding and gas cutting.
Many people are interested in the question: is it possible to use crushed limestone for arranging foundations, producing concrete, and pouring formwork? Specialists in the field of construction do not exclude this possibility, but on the condition that the characteristics of gravel are carefully studied, other proportions of the structures are precisely calculated: sand, and various additives.
Recycled crushed stone is produced from waste from crushing granite crushed stone, which makes it a significantly inexpensive product used to reduce the cost of construction, since its parameters are close to its granite analogue. In turn, secondary crushed stone, depending on the waste from which it is produced, is divided into concrete crushed stone (crushed concrete) and asphalt chips.
Recycled crushed stone of various fractions
Crushed concrete is widely used for constructing foundations, constructing road embankments, pouring open areas, making concrete, and also strengthening slopes to combat landslides.
Given the qualities of secondary crushed stone, such as water resistance and frost resistance, it is widely used in the construction of pipeline cushions and other water structures.
In order to obtain slag crushed stone, slag from the metallurgical industry is used, which is crushed or undergoes special processing. During the crushing process, three fractions are distinguished: small, medium and large, and if the dimensions are considered in mm, we get granules: 5 - 10 mm, 10 - 20 mm, 20 - 40 mm, 40 - 70 mm and 70 - -120 mm. To date, types of concrete with slag fillers have been developed that are in no way inferior to concrete with fillers of other crushed stone analogues. Moreover, the cost of such products is 20 - 30% lower than traditional ones.
Crushed slag stone from steelmaking slag .
Along with waste slag crushed stone, porous crushed stone is also produced, which is formed from alloys with high oxygen saturation. However, slag porous crushed stone is inferior in strength and bulk density to its “brother”. If the density of dump crushed stone is 1000 kg/m³, then for porous gravel this value is 800 kg/m³.
Perhaps the most famous use of crushed slag stone is in the manufacture of cinder blocks. But the scope of application of the material is not limited to this. It is used in the production of asphalt and concrete, in the manufacture of reinforced concrete structures, and sand-lime brick, in the construction of roads.