The production of concrete involves the use of a number of components that affect its technical and operational characteristics. Fillers play an important role in this. In order to answer the question, what is better to take for cooking? concrete mortar– crushed stone or gravel, you need to analyze and compare their properties.

Comparative analysis: pros and cons

The most important characteristics of a concrete mixture are strength, frost resistance, and water resistance. Depending on the purpose, indicators of the economic feasibility of choosing certain components also play an important role. Let’s compare how crushed stone and gravel meet these requirements.

Crushed stone. Crushed stone is hard bulk material non-metallic origin with a granular structure, which is obtained as a result of mechanical crushing of granite rock or other mountain deposits. The size of the structural unit varies from a minimum of 5 mm to 70 mm. Anything larger is . According to technical characteristics, it is the most suitable filler for dense, heavy, high-quality concrete. Among its advantages:

• the highest strength indicators (from 800 to 1600);
• low level flakiness (no more than 20%);
• frost resistance;
• cubic grain shape with a rough surface, which provides excellent adhesion to the cementitious substance.

The disadvantages of crushed granite include:

• high cost;
• more pronounced radioactive background compared to other similar raw materials.

Gravel. The use of this term is not entirely correct, since in this context we can talk about crushed gravel and natural gravel, which, despite a similar picture of origin, are different materials.

River or sea gravel are multi-colored rounded spherical pebbles ranging in size from 5 to 70 mm. It is not suitable for concrete due to its smooth structure - it does not adhere well to cement-sand mortar. Gravel is mainly used in decorative purposes– for the design of artificial reservoirs, alpine slides, other landscape design objects.

To prepare concrete, crushed concrete is used, which is produced by crushing rocky boulders and sifting sedimentary rocks. Unlike its river counterpart, it consists of grains of irregular angular shape with rough walls.

The advantages of crushed gravel include:

• low level of radioactivity, which almost never exceeds 370 Bq/kg, which corresponds to class I;
• favorable price;
• it is easier to prepare concrete manually.

• lower strength compared to its granite counterpart;
• presence of clay and organic impurities in the composition;
• a higher percentage of flat particles (flakiness).

How to choose the right filler?

When choosing components for a concrete mixture, several factors are taken into account.

Firstly, the purpose of the concrete is taken into account. If, to fill the foundation of a two-story mansion, it is preferable to take granite crushed stone, then for concreting support posts or garden path It is not economically feasible to use expensive material; gravel will do. Professional builders They believe that granite crushed stone is necessary as a component if, according to GOST, concrete M300 and higher is required for certain work.

Secondly, faction is of no small importance. For concrete, the most suitable filler size is 5–20 mm. Larger pieces will fill the mixture unevenly and thus deteriorate its properties.

Experienced experts recommend using granite ordinary continuous aggregate by mixing two fractions to obtain high-strength concrete grades. Grains ranging from 5 to 40 mm are closely adjacent to each other, improving the quality of the finished product.

Thirdly, be sure to pay attention to flakiness. Cubic crushed stone with a small content of flat stones (5–10%) is better compacted, so concrete with it is stronger. Products with a large number of flakier particles have drainage capabilities and are suitable for concreting platforms and paths.

Let's sum it up

1. To prepare concrete we use granite or crushed crushed gravel. We leave the gravel for landscaping.
2. In concrete mixtures of grade 250 and below, feel free to put gravel material, 300 and above - granite.
3. Concrete M400 and M500, which are common in the construction of buildings and structures, require a filler with a strength of at least M1200.

Construction Materials

What is the difference between crushed stone and gravel - we learn to distinguish and apply it in practice

From the author: Hello, dear readers! Any beginning builder at the beginning of his practice is faced with many questions. After all, we know that theoretical study is only half the battle, or even a third. When it comes to applying the information received directly to work, it turns out that we don’t know everything.

One of these difficult tasks at first is the problem of choosing a material. After all, without experience, it is difficult to say how this or that, say, insulation will behave in practice. An even more important decision has to be made when it comes not to finishing or construction, but to construction.

Indeed, in this case, an incorrect choice is fraught with the destruction of the building or obtaining the wrong qualities that were necessary. That's why it's important to study comparative characteristics materials before getting started.

Today's article is devoted to just one of these problems of choice. The matter is complicated by the fact that the materials in question are externally similar. Let's move on to specifics. Today we will talk about the difference between crushed stone and gravel, in what cases the use of each of these materials is justified and why.

To understand what exactly the main differences are, let's first take a detailed look at the characteristics of each type.

Crushed stone

Crushed stone is stones obtained from crushed rocks, as well as from substandard waste from processing and heavy industry. Its fractions are called grain. The size of each, according to standards, exceeds 0.5 cm (in Europe this figure is 0.3 cm).

The main indicator that you need to rely on when choosing is flakiness. This is the size of the flat edges on each individual grain. High flakiness means the presence of large flat sides. This is usually characteristic of needle or plate crushed stone. If all faces are approximately equal in area, then such grains are classified as cuboid.

The flakiness index is important factor determining the purpose of using crushed stone. There are three quality groups into which the material is divided:

• group 1 - cube-shaped crushed stone, the content of lamellar and needle-like grains varies up to 15% of the total amount;
• group 2 - improved crushed stone, contains up to 25% lamellar and needle grains;
• group 3 - ordinary crushed stone, it contains up to 35% lamellar and needle grains.

Let's look at how this indicator affects the use of the material:

• cube-shaped fractions are more suitable for use as a foundation cushion. They also make an excellent topping for road surface. Such grains are very well compacted and have high level strength, which is extremely important for such work;
• Due to the needle-shaped fractions, voids are formed in the stone mass. If you use such grain in the manufacture concrete structure, then much more solution will be lost than with any other material. In addition, strength finished product will not be too high;
• the same voids, on the contrary, sometimes come in very handy. For example, for drainage. Crushed stone, which belongs to the ordinary group, compacts well and drains water perfectly, so its use when necessary is optimal.

Main characteristics

For almost any material used in construction, two parameters are most important: resistance to frost and, of course, strength. If both indicators are low, then the structure will not last long, which is why so much attention is paid to them. Let's take a closer look.

Frost resistance

• to the material with high stability include grades 200, 300, 400. They can be used everywhere, including for structures that will be entrusted with great responsibility - for example, for bridge supports or high-rise buildings. Withstands from 200 to 400 freezing cycles (depending on the number on the label). Performs its functions perfectly even in harsh conditions Far North;
• for crushed stone with average frost resistance, more favorable climatic conditions are suitable, that is, either the south or Middle Strip. The markings of such material indicate the numbers 50, 100 and 150;
• Crushed stone, which is completely unstable to frost, is used only to create a drainage layer or bedding. In this case, work is carried out either indoors or in heated places. Indicators on the label: 15, 25, 50.

The markings usually begin with the letter F followed by a number. It indicates how many times crushed stone can be frozen without losing its qualities. That is, for example, the F400 brand means that the material will feel great up to four hundred frosts.

It is important to consider that the frost resistance indicator is calculated on the basis of one individual fraction. When crushed stone is used in any structure, the level of resistance to cold increases by about a third. This occurs due to the resulting pressure.

Strength

There is no need to talk about the importance of this indicator - it is clear that it must withstand heavy loads. When testing crushed stone for strength, it is placed in aggressive conditions: they try to crush and crush it, and also simulate wear.

Depending on the test results, the group is assigned a marking designation, which affects where the crushed stone can be used:

• the weakest strength is M200. Suitable for treatment facilities, as well as for drainage and backfill, which are not subject to load;
• weak strength - M300–M600. Used for the same purposes as the previous one;
• average strength - M600–M800. Suitable for walls and structures that are not subject to load. Also used for backfill limited on four sides;
• normal strength - M800–M1200. Can be used for load-bearing walls in buildings to create production premises, foundation. Also suitable as fill for railway tracks;
• high strength - M1200–M1400. Suitable for heavily loaded structures: bridge supports, towers and foundations of high-rise buildings, hydraulic structures, as well as embankments;
• the highest strength is M1400–M1600. It is used mainly for the foundations of structures that are subject to a very large load: towers, bridge supports, various derricks.

The strength indicator depends on what percentage of the total mass the weak rock occupies. There are specific acceptable numbers for each brand.

If weak rock occupies more than 20% of the total mass, then it is no longer crushed stone, but gravel. But we will talk about this material below.

Varieties

There are several specific sets of indicators of strength, frost resistance and other characteristics. Each of these groups is separated into a separate type:

• gravel;
• limestone (dolomite);
• granite;
• slag;
• secondary.

Let's look briefly at the main qualities of each type.

Granite

It is extracted, in accordance with the name, from granite. The rock is blasted, crushed and sifted. The size of the fractions of this variety varies from 0 to 120 mm; this variety allows the use of crushed granite stone for many types of work.

Externally, the material is quite attractive; it usually has a reddish tint and a shiny surface. Therefore, products made from it - for example, floors - look very good. In addition, the edges of the fractions are torn, which provides high-quality adhesion to the concrete mortar. The end result is a beautiful and durable product. Therefore, the granite variety is the most popular.

Gravel

Extracted from stone rock by blasting and sifting. The strength here is a little worse than that of granite - crushed gravel, according to its characteristics, can only reach the M1200 grade, no more. In appearance, it also loses to the previous variety. Unprepossessing and gray, it does not provide a decorative effect.

But, nevertheless, crushed gravel has a lot of advantages. It is mined in many quarries, and the process is not very complex - the rock is less durable than granite. The cost of such material is lower than that of granite, which is also important. A separate advantage is the low level of radiation.

In addition, although crushed gravel is inferior to granite in terms of strength characteristics, grade 1200 is often sufficient for use in various designs designed to withstand a certain load. The target orientation depends on the size of the fractions:

• from 3 to 10 mm - for screening;
• from 5 to 20 mm - only for small products, such as sidewalk tiles;
• from 5 to 40 mm - suitable for medium-sized structures: various borders, concrete rings etc.;
• from 20 to 40 mm - most often used in concrete production. Also suitable for road filling.

Limestone

This material is a carbonate calcite that, over a very long period of time, has been compressed to such an extent that it looks like rock. Crushed limestone has exactly the same characteristics as gravel, the only difference being its white color. Area of ​​application: road and railway fillings.

Slag and secondary

These varieties are much cheaper than those mentioned above, but their characteristics are much weaker. Slag crushed stone is made from various metallurgical wastes, secondary - from construction waste.

It is clear that the strength and frost resistance of such materials are not very high. But there are still many areas where the use of just such crushed stone is optimal.

Gravel

Gravel is, roughly speaking, pebbles formed in a natural way. Rock tends to break down over time. The resulting particles are exposed to wind or water for some time, depending on the location of the source. Gradually they become more rounded, without sharp edges.

There are several possible locations for this material:

• mountains;
• ravines;
• rivers;
• lakes;
• seas;
• glaciers.

Some characteristics of gravel depend on the source. For example, color: fractions can be black, white, brown, yellow, blue-gray, pink. It makes the gravel pretty decorative material, that’s why they like to use it for decoration summer cottages and for landscape design in general.

The surface structure of the fractions also depends on the location. When exposed to water it becomes very smooth. Therefore, lake, river and sea gravel looks beautiful, but at the same time its adhesive properties leave much to be desired.

Unlike water gravel, mountain gravel has a rough surface. This allows it to be used not only for decorative, but also for construction purposes. Such material also gives good appearance, and good structural strength.

Properties

Like almost anyone construction material, gravel is divided into groups with certain characteristics. Each group is used only in those areas of work for which its characteristics are suitable. Among them are:

• density;
• volume weight;
• form of factions;
• strength - indicated by markings DR8, DR12, DR16, DR24;
• abrasion - this indicator is important for those varieties that are used for production road surface. After testing, they are assigned markings from I-I to I-IV;
• frost resistance - according to this parameter, gravel is also divided into groups marked F15–F

The size of gravel fractions varies from 5 to 70 millimeters. The smallest varieties are usually used for various bulk surfaces: sports fields, small beaches, children's walking areas.

Larger gravel (10–20 mm) is used as filler at . Fractions of 20–40 mm in size are successfully used in the construction of structures whose use involves a large load. As a rule, these are bridges, highways, runways and the like.

The largest material (from 40 mm or more) is used as decorative decoration. It makes excellent landscape design elements, aquarium decorations, and sidewalks.

Differences between crushed stone and gravel

So, we have analyzed the main characteristics of both materials and now we can confidently highlight the differences. Let's put them in a comparative table.

As you can see, there are not many differences, but they are quite fundamental. We hope that our article helped you understand the issue, and you will not confuse these two materials in the future. In order to better understand the information, we recommend that you carefully look at the photos and videos presented in the article. Good luck!

Use of crushed stone and gravel in construction work today it 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 of a rounded 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 more smooth surface, therefore, it is the first type that has 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 are different color scheme: 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 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 coatings sports grounds, ice protection of city roads.
• Crushed stone from 5 to 10 mm. Used for the manufacture of 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 larger in size, has a more uneven surface, and has 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 dimensional grid 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.

Rocks and rocks are widely used in construction work. natural materials. The main ones are gravel and crushed stone, the differences between which are not always obvious to the layman. They need to be understood, since the characteristics and properties of minerals determine their scope of application.

Main characteristics of gravel

Natural gravel is formed during the destruction of rocks in natural conditions and can have a variety of geological origins - river, sea, mountain, glacial. Its extraction involves collection, further washing, sizing and sorting if necessary. Artificial (expanded clay) material is manufactured industrially.

The natural mineral has many varieties, the basic physical and mechanical properties of which vary greatly and depend on:

• the type of rock from which it was formed;
• geographical location of the mining site;
• composition of the mixture.

Important indicators are determined experimentally for each batch. These include:

• Fraction. It can have a range of 1–70 mm - according to this indicator, the mixture is divided into several groups.
• Strength. Most types of gravel are loose material. If the mineral was formed from fragments of granite, marble or quartz, then it has high strength indicators.
• Abrasion– from 10 to 50%.
• Density– from 1.43 to 1.61 t/cub.m.
• Frost resistance– from 15 to 300 freezing cycles without loss of strength.

The acceptability of using gravel for certain purposes is determined by the hardness and roughness of the mineral. The higher the indicators, the more durable the product can be obtained. The most commonly used material in construction is hard rock, and technical requirements it is regulated by GOST 8267-93.

Crushed stone is obtained as a result of the deliberate destruction of large blocks of limestone, granite, dolomite, large fractions of gravel or secondary raw materials by crushing using special equipment. Excellent ability to adhere to the components of the building mixture due to the sharp angles that the material receives during mechanical crushing is the main difference between crushed stone and gravel. This is the main thing technological property material, which determines its widespread use for the production of concrete solutions.

Other important characteristics include:

Flakiness. This is the percentage in the total mass of individual fractions of a flat, lamellar shape. The lower this indicator, the higher trademark has material:

• up to 15%– cuboid;
• 15 –25% – improved;
• 25 – 50% - ordinary.

Fraction. The dimensions of crushed stone are regulated by GOST. There are several groups, each of which is used for specific purposes:

• dropout up to 5 mm– as an anti-icing material;
• 5–10 mm- for the manufacture of concrete slabs and solutions;
• 10–20 mm– as a base for roads and buildings;
• 20–40mm– for the production of complex heavy structures;
• 40–70 mm– for construction multi-storey buildings, highways;
• 70–120 mm– for decorative purposes.

Differences between crushed stone and gravel

Both materials are of natural inorganic origin. Understanding the difference between gravel and crushed stone will help you right choice for one task or another.

Form of factions. Crushed stone can be immediately identified by its sharp edges. Sea and river gravel has a streamlined shape, which is a consequence of the long-term influence of water. The mountain species has a slightly rough surface.

Color. There is only crushed stone gray. Numerous types of sedimentary mineral have different natural shades.

Grip index. Thanks to the rough irregular shape crushed stone easily combines with other components of the concrete mixture. The adhesive properties of its opponent are significantly lower due to its streamlined shape.

Application. The differences between crushed stone and gravel determine their areas of use. The main purpose of the first material is as a filler for concrete solutions. Only some types of gravel (mountain, shungizite, washed or glacial) are suitable for making building mixtures. Most often the sedimentary mineral is used as:

• foundation cushion to prevent water stagnation;
• embankment for highways;
• natural filter for natural wells and household appliances;
• material for landscape design, decoration artificial reservoirs, formation of garden paths.

Gravel is a unique decorative mineral. In some cases suitable for concrete mixtures with moderate strength - its use allows you to reduce the cost of the solution. For the production of heavy solutions and products with increased requirements, crushed stone must be used as a filler.

What is alluvial and seeded sand in construction?

How does crushed stone differ from gravel in origin and properties?

Bulk density of sand - technological and commercial significance Density of crushed stone for construction - features and nuances Sand for construction - types and characteristics Supply of washed and river sand in the Moscow region Places and methods of extracting granite crushed stone What is the convenience of sand in bags? Which backhoe loader should you choose to rent? Sand in bags of 50 kg. Advantages and disadvantages. Features of work on removal of soil dumps and construction waste Sand for road construction. Main selection criteria Sand for children's sandboxes Construction of a road made of crushed stone with a sand cushion What construction equipment to rent Choosing crushed stone for the blind area of ​​a house Drainage system on a plot for a residential building Compaction coefficient of sand and crushed stone How to properly raise a plot of land? Rent a backhoe loader in Shchelkovo Rent a backhoe loader in Zelenograd Rent of a leveling excavator in Moscow Pile cutter. What is it and how can I rent a pile cutter? Renting a front loader in the Moscow region Rent a backhoe loader in the Istra region What do you need to rent a dump truck without a driver? Hydraulic hammer. Technical specifications and rental in Moscow Rental of construction equipment in Dmitrov Rental of construction equipment in the Moscow region Advantages of renting GCB equipment Comparison of wheeled and crawler excavators Rental of special equipment in Shchelkovo Front loader. Description and characteristics Crushed stone frost resistance indicator Characteristics and varieties of granite crushed stone and screenings Classification and characteristics of river sand Properties of river sand Vessel classification Types and features of using natural gravel Properties, types and scope of application of black crushed stone

How does crushed stone differ from gravel in origin and properties?

Materials obtained from rock, which are solid particles of various sizes, in fact - fragments of stone of various origins, gravel and crushed stone have fundamental differences. The high value of these materials in the construction industry forces us to pay attention to their properties, which may largely depend on the origin, type of source rock, shape, size and strength characteristics of the grains.

The possibility of using crushed stone and gravel in construction practice, landscape design and road construction is determined by its composition, fraction size and flakiness index. The closer the grain shape is to cubic, the higher the value of the material for construction and concrete production.

For large construction projects related to the need to form concrete monolithic structures, crushed granite stone 20-40 with a flakiness index of 5 - 15% is suitable. For forming a foundation and pouring structures into individual construction crushed stone of fraction 10-20 is used, and often, for reasons of economy, material of limestone origin is purchased.

Differences between crushed stone and gravel - main features

One of the most frequently asked questions- these are the differences between crushed stone and gravel, which determine their properties and possibilities of use.

These differences can be listed at clear example, imagining the grains of the material - most of the main features and characteristics are visible to the naked eye:

• the shape of the grain - gravel particles, exposed to natural influences for thousands of years, are always round, they are ground and polished by water, wind, sand rubbing against stones;
• the relative unity of the rock is characteristic of crushed stone, which is obtained by blasting and crushing mechanically rock masses;
• a sign of flakiness is the ratio of cubic, lamellar and needle-shaped particles in the massif, characteristic of crushed stone, the quality of which increases with the increase in the number of cubic grains;
• extraction path - gravel is the result of a natural process, crushed stone is a product of industrial destruction and grinding of the original rock.

The main indicator that makes up the value of crushed stone in construction practice associated with concrete is the shape of the grain. Granite crushed stone of low flakiness consists of 85 - 95% cubes. In such an array there are few particles in the form of plates or pointed fragments, which do not give a predictable effect high density when filling a concrete monolith.

The use of crushed stone in construction practice

Crushed stone extracted from “ragged stone” of rocks destroyed by an explosion may have different composition. The greatest construction value is made of granite and basalt materials. These are rocks of volcanic origin that have maximum strength and minimum water permeability. Accordingly, they have high frost resistance - as a rule, granite and basalt crushed stone can easily withstand up to 350 freezing cycles.

Limestone crushed stone is of sedimentary origin, and therefore less durable. Its properties make it possible to use medium and large fractions in construction if the project does not provide for significant loads on the foundation and concrete wall monoliths. Small fractions are suitable for filling roads and sites, but with a limited weight load and throughput. For the construction and formation of powerful bulk foundations, it makes sense to buy crushed stone 40 - 70, and for use in the foundation of a lightweight monolith - fractions 10-20 and 20-40 of crushed stone of sedimentary origin.

Gravel - applications and properties

Gravel mined in quarries is the result of the destruction of rock or sedimentary rock during water, wind or sand erosion, natural destruction and grinding of the original rock. Gravel deposits are usually located in existing or dry reservoirs, where the flow of water has brought ground, naturally rounded stones for thousands of years.

During the extraction and processing of gravel, it is divided into fractions, passing sequentially through sieves with different mesh sizes. The sizes of fractions within one deposit differ slightly, as does the composition of the massif, which is usually distinguished as mountain lake, sea, glacial and river. The more grains spend in flowing water, the more rounded their shape will be.

Gravel stone can have high strength if the source rock is granite, basalt, feldspars and other volcanic emissions. An indicator of strength is the level of abrasion of grains placed in a drum with metal balls that rotate during testing.

The sizes of fractions and other characteristics of the gravel massif are determined according to the standards of GOST 8269.0-97. To save money, it is allowed to mix different fractions if gravel is used for decorative purposes, where its strength and packing density will not affect the quality characteristics of buildings or foundations. The use of gravel in the formation of concrete monoliths is undesirable - its grains without edges cannot create an internal structure that gives the concrete casting the required strength.

Depending on the type of material, the frost resistance of gravel can reach 400 cycles, but the flakiness indicator is practically inapplicable to it - the shape of the grains is very diverse.

Difference in cost of gravel and crushed stone

The price of crushed stone per 1 m3 reflects the whole range of its properties, advantages and possibilities of use. It also takes into account a rather expensive mining process, in which rocks are initially torn apart by explosions, then large fragments are moved for crushing, and only then they are screened, divided into fractions and determined by flakiness and strength.

In modern project construction, granite crushed stone filler is used in the composition of concrete mortar, and the material is used in pure form used to create drainage bases and cushions. Small fractions are actively used in the creation of road surfaces. In some cases, the use of crushed concrete of secondary origin and gravel stone is allowed, but as a rule, such foundations and drainages are not designed for high strength and heavy weight of the structure.

Return