The term “crushed gravel” refers to non-metallic bulk building materials obtained by sifting rock or gravel, or by crushing rocks and boulders. In terms of strength and frost resistance, this variety is inferior to granite crushed stone, but outperforms dolomite and slag. The same applies to cost; gravel screenings and fractions occupy an intermediate position; they are often used as a budget alternative to high-strength grades. The main scope of application includes the production of concrete and reinforced concrete products, foundation and Men at work, some types are suitable for decorating and arranging territories.

Depending on the method of production, there are two main varieties:

1. Gravel - obtained by sifting ASG (a mixture of sand and loose sedimentary rocks). Its strength grade varies between M800-1000, the shape of the fractions is round (pebbles are also classified as this type). Due to its smooth walls and inevitable impurities, it is poorly suited for concreting monolithic load-bearing structures and is more often used as a decorative material.

2. Actually, crushed stone obtained by crushing and sifting the same rocks, but of larger fractions. Its strength rarely exceeds M1000, but due to the presence of rough walls it is better suited for preparing concrete. There are two subgroups: seeded and washed, the second has a minimal content of foreign impurities.

Characteristics of crushed stone for construction work are regulated by GOST 8267-93. Highlight the following indicators and properties:

• Strength – within M800-M100. This means that gravel screenings and fractions contain from 5 to 10% grains of weaker rocks (for high-quality brands this value does not exceed 1.5%), the rest of the mass has the same limit as the original rock.
• Frost resistance - from 150 cycles, the value of this characteristic allows the use of such crushed stone for concreting foundations. In this regard, gravel is at least twice as good as limestone, but slightly inferior to granite.
• The content of dust and clay impurities - the less, the better, the upper limit is 0.6%.
• Flakiness – from 7 to 17%. The proportion of needle-shaped grains is rare. Due to the low flakiness, shrinkage and compaction in construction mixtures when used, it is good; in this regard, the material is many times better than exfoliated limestone rocks.
• Radioactivity class - 1, which implies not only cleanliness and safety, but the ability of gravel to absorb radiation.
• Density: average - 2400 kg/m3, bulk - 1300-1600 kg in one cube in a dry state. Specific gravity crushed stone largely depends on the size of the fractions and the method of production.

On the quality of adhesion with other components mortars The roughness of the walls and the shape of the gravel grains influence; in crushed varieties it is higher than in sea or river pebbles. But at the same time, crushed rocks have a higher percentage of foreign impurities; dry sifting is not enough to achieve the required purity. Regardless of the location and method of extraction, the material has low porosity (and, as a result, good water throughput), it practically does not absorb moisture and dries quickly. All characteristics declared by the manufacturer must be confirmed by an appropriate certificate, and verification of its availability is mandatory.

Scope of application

The functional purpose depends on the variety; gravel allows you to quickly and inexpensively equip garden path, flowerbed or area. In this case, the smoothness of the walls is not a disadvantage, but an advantage; people can safely walk on round pebbles. Rocks from different quarries differ in color; this property is positively assessed by landscape designers. But the main area of ​​use of this material is still construction:

1. Gravel screenings (0-5 mm), in addition to landscaping work, are used for the manufacture of certain grades of concrete and road topping; they are rarely found on sale. Read more about the use of crushed stone screenings in.

2. It is recommended to buy a fine fraction (3-10 mm) for preparing a solution for self-leveling floors and pouring a foundation.

3. 5-10 mm - a popular grade, used in the manufacture of concrete for foundations, loaded structures and other types of reinforced concrete products.

4. Crushed stone fraction 20-40 mm (medium) – the same, plus drainage works. Disadvantages include possible content quarry sand, this brand is most often seeded.

5. Coarse fraction (40-70 mm) – repair, road and drainage work, concreting and strengthening of massive structures. Rarely found on public sale.

In addition to a small concession in strength to the differences between gravel and crushed granite include a reduced background of radioactivity, as a result, this variety is indispensable in the construction of civil structures, it is recommended to choose it for developers of private houses. Due to more affordable price it is often considered as an alternative to high-strength brands, but the admissibility of such a replacement is trusted exclusively to specialists.

The cleanliness of crushed stone plays an important role: washed crushed stone is used almost without restrictions, dry cleaned is not suitable for all concrete, its use extends the work time due to the need for additional preparation.

Material cost

The average price per cubic meter depends on the size of the fractions (demand for the brand), the method of production (crushed crushed stone is more expensive due to better adhesion to cement) and strength. Approximate prices are shown in the table:

Fraction size	Cost per cube when purchased at retail, rubles	The same, when ordering a batch in bulk (over 10 cubic meters), rubles
Crushed gravel
3-10	1650	1550
5-20	1900	1800
20-40	1750	1650
40-70	1650	1550
Gravel
Unfractionated	1400	1300
5-10	1850	1750
5-20	1750	1650
20-40	1800	1700
40-70
Sand and gravel	1650	1500

The cost and delivery distance are negotiated separately; when purchasing large quantities (from 20 cubic meters and above), this service can be provided free of charge. Prices are seasonal; in the period from May to October, crushed stone is more expensive, especially popular brands. In order to reduce costs, it is recommended to buy it in bulk; savings when ordering batches over 100 cubic meters reach 10-20%.

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:

1. 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).
2. Needle grains create voids in the mass of the stone. While creating concrete structure To prepare the mixture, more solution will be needed, and the compressive strength will be slightly less.
3. 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:

1. 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.
2. Sustainable. Brands F150, F100, F50. Used in construction in the southern regions and the Middle Zone.
3. Unstable. Brands F50, F25, F15. Implemented as bedding and drainage at a level below the groundwater level. Is 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	Application area
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 buildings, industrial structures, piles, columns, foundations, fences, supports, filling 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:

1. M1600 - less than 1%.
2. M1400 - M1000 - no more than 5%.
3. M800 - M400 - no more than 10%.
4. 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 practically useful aspects descriptions.

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 look. At the same time, its advantages are undeniable:

1. More quarries, competition.
2. The cost is lower (due to the distribution of raw materials).
3. Mining is easier (granite is harder than rock).
4. 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:

1. 3-10 mm - screening.
2. 5-20 mm - “seed”. Used for small-piece products ( paving slabs etc.).
3. 5-40 mm - used for medium-sized factory products - concrete and well rings, curbs, lintels, etc.
4. 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. Suitable for reinforced concrete products and road construction. Distinctive feature- 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. Torn edges 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 sifting 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 necessary knowledge about choice and advantages different types crushed stone, you can accurately determine its quality and purchase exactly what you need.

The use of crushed stone and gravel in construction work today is simply irreplaceable. These components of the fine fraction are very similar to each other. Each of them is formed from rocks and is widely used in construction. But still, despite the same origin, as well as external similarity, gravel and crushed stone have a significant difference. Each of them has its own application features. In addition, they interact with materials differently, and such indicators are very important during construction.

What is gravel made from?

Gravel is a mountain loose sedimentary rock rounded in shape, with unclear edges. It contains small particles of minerals that are formed as a result of the natural and rather long-term destruction of hard rocks.

Gravel is classified into three types depending on the size of its particles:

• fine (particle size - 1-2.5 mm);
• medium stone (from 2.5 to 5 mm);
• coarse gravel (fractions 5-10 mm).

Industrial stone is used in foundation laying and road construction.

Depending on where gravel is mined, it can be mountain, river, lake, glacial, or sea. Unlike mountain, sea and river minerals have a smoother surface, which is why it was the first type that was found wide application in construction.

Mountain gravel is widely used in road construction, foundation construction, backfilling, as a filler for heavy concrete, etc.

The stones differ in color: they can be black, pink, yellow, brown, blue.

Gravel serves as a good design raw material and is used for arranging gardens and paths, and finishing flower beds.

In the composition of gravel you can often find the presence of various impurities, such as sand, soil, which impairs adhesion to concrete.

Features of crushed stone

Crushed stone is the result of crushing rocks of boulders, granite and limestone, but it is obtained by using special equipment, rather than waiting for natural destruction. The difference between gravel and crushed stone lies, first of all, in appearance: crushed stone is rougher, often has sharp corners, and is also larger in size. All these qualities provide good grip various materials and surfaces.

This stone has different shapes. Due to this property, it is successfully used not only in construction work, but also in landscape design.

Types of crushed stone

Let's consider the types of crushed stone and its application.

Depending on the size of the mineral, they are distinguished:

• Granite screenings up to 5 mm in size. Used for covering sports fields and protecting city roads from ice.
• Crushed stone from 5 to 10 mm. Used for making concrete and floor slabs.
• Sizes from 5 to 20 mm are suitable for making foundations, concrete, roads and bridges, pouring bridge structures.
• The average fraction is 20-40 mm in size. Ideal for building roads, preparing reinforced concrete and concrete, and building foundations for large houses.
• The large fraction is considered to be from 40 to 70 mm. Widely used for building houses and roads.
• For decorative purposes, crushed stone is used, the size of which is 70-120 mm.

Among the advantages are strength and frost resistance.

Gravel and crushed stone: the difference

There is a difference between crushed stone and gravel, but visually it is not very clearly visible. Their similarities are that they have the same origin and both are formed from rocks. In addition, these materials are widely used in construction; crushed stone (or gravel) is used for foundations, etc. There are also external similarities, for example, they can be the same in color.

Crushed stone is different large sizes, more uneven surface, better adhesion. Thanks to all these characteristics, this material is in great demand in Russian market. But it is quite easy to confuse ordinary crushed stone with mountain gravel, since the difference between them is very small. Both of these stones are inorganic, meaning their composition is very similar.

Gravel, as already noted, can be river, sea, etc. Its use and beneficial features. As a rule, it has rounded shapes and a smooth surface, due to which it is often used to decorate facades, gardens, roads, etc.

Differences in cost

Depending on what rock the crushed stone is made from, there are several varieties. Each of them has its own cost. The price for large-sized fractions is slightly lower than for finely dispersed ones.

The final cost depends on the volume of material purchased. To compare the difference between gravel and crushed stone in price, we will indicate the average prices. Cost of 1 m 3 of crushed stone:

• limestone - 1500 rubles;
• gravel - on average 1,780 rubles;
• granite - 2100 rub.;
• secondary - 1150 rub.

The average price of 1 m 3 of gravel is 1,700 rubles.

The cost of these materials, as we see, is approximately the same, despite the fact that the costs of their production are different.

Summarize

So, which is better - crushed stone or gravel, and what are their differences?

Let us highlight the main characteristics of these materials:

1. Crushed stone is formed as a result of mechanical crushing, or rather an explosion, and gravel is obtained as a result of the natural destruction of rocks.
2. Crushed stone has a wider size chart and is used for various construction works. Gravel is used more for decorative purposes, although sometimes it can be used in the construction of a foundation. This is due, first of all, to the shape of the material: gravel is smoother, while crushed stone is angular, resulting in better adhesion to concrete and other building materials.
3. The main advantages of crushed stone are its excellent adhesion and good physical properties, and gravel has a decorative appearance.

The ever-increasing demand for construction and Decoration Materials accompanied by the invention and implementation of more new means used for the construction of structures and their improvement. A person working with certain materials needs to know their characteristics and basic properties. This is the key to high-quality completion of assigned tasks.

The use of minerals and rocks in construction work is simply irreplaceable today. There are many ways to use these components. Despite the same origin, gravel and crushed stone also have differences.

In addition to the fact that their difference is obvious visually, there are also subtleties related to the use of these materials. Depending on the area in which these substances are applied, you can see the difference between them.

Features of gravel

Understand what the characteristics and properties of this natural material possible by understanding its origin. This option is a rock formed by sedimentary methods, quite loose, with inclusions of minerals from destroyed solid elements. There are three types of material:

• small (from 1 to 1.25 mm);
• medium (up to 5 mm);
• large (10 mm).

The nature of origin of the natural mineral is also not the same. There are mountain, river, sea, glacial and lake material. Mountain gravel has the maximum adhesion coefficient, while sea and river gravel are smoother (due to the presence of all kinds of impurities - sand, soil, etc.).

Accordingly, it is the mountain mineral that is most often used in construction. It is used in the construction of roads, for backfilling sites, as a filler, in the manufacture concrete mixture for foundations and for many other tasks.

Gravel comes in various forms color range: pink, blue, yellow, brown. This property allows this material to be used in decorative purposes. The arrangement of garden and park areas is rarely complete without a colored element.

Characteristics of crushed stone

The difference between crushed stone and gravel is visible to the naked eye. The first has a structure with greater roughness and sharp corners. The dimensions of crushed stone, as a rule, exceed the dimensions of gravel, as indicated in. This material is extracted by crushing granite, boulders and limestone.

The natural roughness of the mineral promotes its adhesion to all kinds of surfaces and other building materials. This expands its capabilities in practice. The dimensions of crushed stone determine its purpose and application:

• up to 5 mm is called screening and is used to form roads, platforms, and ice protection;
• from 5 to 10 mm is used in the formation of slabs and concrete production;
• from 10 to 20 mm can be used in the construction of bridges, when creating foundations for buildings and road surfaces;
• from 20 to 40 mm is optimal for the manufacture of complex heavy structures;
• from 40 to 70 mm are used in the construction of multi-storey structures and road surfaces;
• from 70 to 120 mm are widely used in decorative applications.

The mineral has high strength and resistance to low temperatures. There are crushed stones of various groups, depending on frost resistance.

Differences between the two minerals

Having the same origin, both materials are used in various areas of construction and finishing works. What distinguishes gravel from crushed stone is its size and ability to adhere to certain materials.

In terms of adhesion characteristics, gravel is very inferior to crushed stone. It is for this reason that it finds so many uses in modern construction. Its physical form is also practical. The corners and planes of the stone contribute to its better compaction. This material perfectly fills voids.

When choosing gravel, there is a risk of not seeing the difference between granite and mountain varieties. This is difficult to do due to the visual similarity of different types of mineral.

However, marine, river and other gravel options have differences that should be considered when purchasing.

• Having a fairly smooth surface and various options coloring, the stone is ideal for decorative purposes. Decorating roads, house facades, gardens and many other elements is not complete without gravel.

Unlike crushed stone, which is mined by crushing rocks, gravel is an already formed rock that has its own unique dimensions and parameters. This is what makes him more accurate and aesthetic appearance. Like everything made by nature, this component looks like a complete, beautiful mineral.

The angular shape and rough surface of crushed stone ensures the presence of all those qualities due to which it is so in demand in construction. It is an ideal filler and filler, interacting well with concrete, sand and other substances. Crushed stone is not distinguished by a variety of colors, therefore, its use for decorative purposes is minimal. Although, in gardening, it is used quite often.

Conclusions:

• both materials are inorganic in nature, but gravel is formed during the independent destruction of rocks, and the extraction of crushed stone involves their mechanical destruction;
• gravel is streamlined, with a fairly smooth surface, and crushed stone is always arbitrary, acute-angled in shape with a rough surface;
• crushed stone is widely applicable for all kinds of construction tasks, due to its good interaction with materials, and gravel is more often used for decorative purposes;
• the main advantage of crushed stone is its physical parameters and good adhesion, and the advantage of gravel is its aesthetic appearance.

Having understood the main differences between these two minerals, as well as their varieties, you can accurately choose best option. Based on the tasks set, one of these materials will certainly be suitable for a particular case. Good luck with your construction!