What is better: PGS or crushed stone: opinion of builders

PGS is a mixture of crushed rocks (gravel and sand), which was formed during the process of weathering under natural conditions. If you sift, wash and separate the material into fractions, you can get an enriched sand and gravel mixture, or OPGS.

In some regions, ASG is of high quality and is cheaper than crushed stone or PShchS, so the mixture is often purchased for preparing concrete in private construction. There is no high-quality sand and gravel material in the Sverdlovsk region.

But first of all, let’s answer the question: is it possible to use a sand-gravel mixture to prepare concrete? What are the advantages and disadvantages of this material? We will talk about this further.

Execution of work

We found out whether a pillow is needed for a strip foundation and what materials are best used for this.
Now all that remains is to figure out how to properly arrange such a foundation with your own hands. In order to level the bottom of the foundation trench or pit, a layer of sand or gravel ten centimeters high is poured. In places where it is planned to expand the walls, concreting is used. The same option with a concrete pad is used when it is planned to build a strip foundation with reinforced piles from FBS blocks.

The crushed stone backfill is easy to install; just remember that the height of the embankment should not exceed the base, and the width parameters will be twice as large as the same foundation size. As a rule, the crushed stone layer is thirty centimeters, one share of which is sand.

Having leveled the base, we begin to arrange the pillow. First, a layer of sand is poured, which is spilled with water and compacted. The same applies to the gravel layer.

The most reliable option is a concrete pad. The process of arranging it takes a lot of time, but it can be done on your own. Just remember that you will have to spend money on the necessary materials. The thickness of such a support should exceed the parameters of the foundation by thirty centimeters.

Sand backfill

This type of foundation is the easiest to implement and most economical option, and is chosen by developers who are trying not only to save money, but also to speed up the construction process.

And although at first glance such a base does not inspire confidence in its reliability, it copes quite well with the tasks assigned to it. Sand under the foundation saves it from being washed away and ensures acceptable load effects on its lower part. The bulk material is leveled and compacted with a vibrating plate, periodically sprinkled with water.

If the soil is weak-bearing, gravel is used in addition to sand

Preparatory measures of this kind practically eliminate the shrinkage of the foundation, and here it is very important to perform the compaction correctly

Construction of crushed stone cushion

Before pouring this material, a sand layer up to fifteen centimeters high is arranged, which is leveled and compacted. After this, crushed stone is poured, the size of the stones being 2 - 2.5 cm, and also compacted. The crushed stone layer should be twenty to twenty-five centimeters.

During work, it is necessary to ensure that the stones lie tightly next to each other, filling all the empty areas. To complete this process, you will have to use a vibrating plate, which is guaranteed to help create the desired density.

The construction of the foundation will begin with a crushed stone layer, so the height of the cushion should reach zero level. Such a substrate for a strip foundation allows you to construct objects from any materials.

Concrete pad

Now let's figure out how to mount a concrete mortar platform. This design has only one negative point - it is quite expensive compared to other options, and everything else in this project is a complete advantage.

To begin with, it should be noted that the base will be durable if you follow the technological process, which looks like this:

the construction site is cleared of vegetation and other debris;
the soil is leveled;
a layer of crushed stone is poured, the height of which is ten centimeters;
compaction is performed;
a formwork structure is installed around the entire perimeter of the cushion;
the entire site is reinforced with steel rods before pouring the mortar;
a concrete mixture is poured, the grade of which is determined taking into account the mass of the future object;
the solution is carefully compacted with deep vibrators;
It will take at least four weeks for the structure to fully gain strength.

The basis for the construction of the facility is ideal, but requires significant financial expenses.

Preparation of concrete

You can make the solution yourself. The best way to do this is to use a concrete mixer. If this construction machine is not available, any container for preparing a future batch will do. To prepare concrete from screenings and cement, precise proportions must be observed in order to obtain the desired performance properties. Each component plays a significant role.

Figure 4. Preparation of concrete mixture

Proportions

The mixture is made taking into account many factors. Cement plays a significant role in mortar. To create a high-quality mixture, it is important to choose the appropriate brand of cement. Highly graded raw materials provide better adhesion of concrete to different surfaces.

It is important to observe the shelf life of cement, since, being unused, its performance properties are reduced. For example, after a month the strength decreases by 10%. There is a way to find out if the cement is suitable. To do this, scoop it into your palm and squeeze it. If the cement has a crumbly structure, then it will make a good solution. The marking of the material directly affects the price. But the higher the number next to the letter “M”, the better the performance of the cement.

The specific type of screening is chosen taking into account the level of loads that the coating will withstand. Temperature operating conditions are also important. The solution that was made from granite and cement will be cheaper. A more expensive option is mixing sand with crushed stone. An example where the task is to flood the yard. Here, an additional element is the reinforcing mesh. The thickness of the pouring layer is 7 cm. The granite-based mixture is prepared in the following proportion: cement M400 (1 part), screenings (8) and no more than 20% water. The prepared mass will have a strength of M150. Granite comes to the rescue if you need to pour a foundation. In the case of a yard, you will need a sand cushion. However, the latter easily replaces the screening itself, which is first compacted and then poured. The thickness here is required to be at least 5 cm.

The proportions of water play a significant role. The final mass should have a medium consistency, and this is what they start from when determining the amount of water. If there is too much of it, the structure of the mixture will be disrupted and will shrink greatly during use. This not only reduces the load-bearing capacity of the material, but also often leads to the formation of cracks. Water quality is also important. When producing high-strength concrete, enterprises use drinking water rather than industrial water.

The proportions for a mixture without sand were described above. It is not necessary to eliminate it completely; it is enough to replace it partially. But you will have to add crushed stone. The proportions will look like this:

cement M400 – 1 part;
elimination – 1 – 2;
crushed stone – 3;
sand – 3;
water – no more than 20%.

Important! At this ratio, the added screenings do not increase the final volume of the mixture. Its auxiliary role is reduced to binding sand with crushed stone.

According to construction newcomers, the more cement you add, the stronger the concrete. This is a misconception: excess cement will only reduce the quality of the material. The only thing that matters here is the brand.

Preparation of the solution

If you plan to produce a large volume of concrete, it is more convenient and faster to work with a mixer. Not only is doing the job by hand more difficult, it will also affect the final quality of the product. All prepared components in the correct ratio are poured into a concrete mixer or a special container. Then they are mixed until a homogeneous mass is formed. Only at the end, and then in small portions, is it necessary to introduce water. At this stage, constant stirring is required. The mass and moisture content must be uniform - only this solution is ready for use.

The prepared mass should be used within the next two hours from the moment of preparation. Further, its properties will begin to be lost. It happens that moisture evaporates during kneading. You are allowed to add as much of it as is necessary to achieve the desired consistency. Often the mixture is made using already wet components - this can cause a decrease in the amount of water.

Figure 5. Adding water to the mixture

Types of gravel

The following types of colored gravel are distinguished:

River. This type of raw material is extracted from river beds, after which the material is sifted to separate the sand from it. River gravel is frost-resistant and durable.
Mountain. The main difference between this raw material is the rough surface of the particles. Mountain gravel contains many impurities (clay and dust), so it is more often used in road construction.
Decorative. This material is widely used in landscape design (for making gravel paths in the country, for creating a drainage system for plants and decorating ponds). Decorative material comes in a variety of colors and fractions.
White gravel. This type of gravel is used both for country paths and for decorating flower beds. In addition, the decorative material allows you to: slow down the growth of weeds, reduce temperature changes in the soil and reduce moisture evaporation. This stone looks especially beautiful in proper lighting in the evening.
Rounded. This decorative material is used for flooring and roofing. It also makes beautiful and practical gravel paths.

However, today not only colored gravel is used, but also specialized:

Building

Inorganic bulk building material has the following properties:

Fraction size from 3 to 150 mm.
Bulk density from 1.4 to 3 g/cm3.
Specific gravity is about 1400 kg per cubic meter.
Compressive strength 1.5 t/cm2.
Frost resistance from F15 to F

This raw material is also considered the most durable.

Shungizite

This environmentally friendly raw material is considered a universal thermal insulation material with a long service life. If you use shungizite gravel as a filler for concrete, you will get a lightweight and frost-resistant building material. It also makes high-quality gravel paths that will not accumulate moisture.

Silicic

Raw materials of this type are most often used as a bottom filter for country wells. Due to its properties, silicon stone is able to retain organic matter and heavy metals. Water that passes through the filter is purer and has better taste.

Glacial

This raw material has good adhesive properties, which is why it is often used in the construction of monolithic concrete structures. Concrete made with such gravel is characterized by increased strength and durability.

Washed

Unlike other types of gravel, only washed raw materials contain no impurities that can worsen the characteristics of the concrete solution. Thanks to the use of washed gravel (it is better to buy land gravel rather than river gravel), the concrete mass will not crack and empty cavities will not form in it.

There is also a type of gravel called gravel mixture.

Gravel mixtures

Today, enriched sand and gravel mixtures, or, as they are also called, OPGS, are often found on sale. Such compositions are mixed with cement and water to obtain a higher quality building material.

During the cooking process, it is important to adhere to certain proportions and quality of components, otherwise the use of OPGS will not be justified

Healthy! Natural mixtures contain no more than 20% gravel; after enrichment, its content increases to 75%.

The sand-gravel mixture contains the following components:

crushed gravel or gravel of different fractions – 70%;
sand without impurities – 30%.

Clay content is also allowed in the composition, but not more than 1%.

Along with enriched sand-gravel mixtures, gravel screenings are also available on sale. Essentially, this raw material is waste that is obtained during the crushing of rocks.

The cost of such screenings is much lower, so thanks to this material it is possible to significantly reduce the cost of construction work. Gravel waste is used both in the manufacture of reinforced concrete structures and in site design (gravel paths as in the photo, sports fields, flower beds and much more).

To determine the difference between gravel and crushed stone, consider the features of another building material.

Is it possible to use ASG in concrete?

It is possible to use ASG for the production of concrete. Concrete mortars are made from it, which will then be used for the foundations of utility rooms, small private houses, for fence posts, pouring courtyards, parking lots and paths in the garden. In other words, the material (in most cases) is suitable for not the most critical work. It can replace both coarse and fine fillers. But for this, the ASG must contain durable gravel and a minimum of harmful impurities (clay lumps, dust, boulders).

It is profitable to buy a sand-gravel mixture in those regions where it is available and costs less than crushed stone. First of all, these are areas where there are large rivers and sand quarries. From such material it is possible to make concrete with strength grades from M25 to M200 (sometimes up to M250 and M300). For manufacturing, it is better to take M400 or M500 cement.

Among the advantages of PGS are:

Multicomponent The mixture consists of two components at once - sand and gravel, which act as fine and coarse filler. In other words, instead of buying two materials (sand and crushed stone), you can buy only one.
Low price Purchasing one ASG allows you to save money on purchasing sand and crushed stone separately. In addition, in some regions the price of sand and gravel mixture is significantly lower than for other similar materials.

But PGS also has a number of significant disadvantages:

Different ratio of components The ratio of components in the material may be different. Thus, according to state standards, the gravel content in ASG should be no more than 90% and no less than 10% of the total mass. The spread is as much as 80%! Therefore, the composition of the mixture can vary greatly even in neighboring quarries.
Poor adhesion of gravel Adhesion is the property of a material to adhere to cement. It depends on the surface of the rock. The rougher it is, the stronger the material is bonded to cement, the higher the strength of concrete. The surface of the gravel is smooth, the stones are round. Therefore, it interacts worse with cement than the same crushed stone.
Contamination PGS is often contaminated with clay and silt and may contain many dust particles and large boulders. This is due to the fact that the material is extracted from rivers or quarries and sold without additional processing.
Lack of GOST standards regulating the characteristics of ASG for concrete . There is no state standard that describes specific indicators of ASG for concrete. GOST 23735-2014, with technical conditions for sand-gravel mixtures for construction work, directly states: “this standard does not apply to ASG used as aggregates for concrete.” This means that in this case you can only focus on the requirements for other materials.
Poor quality of ASG in our region In the Sverdlovsk region there is no sand and gravel material suitable for concrete solutions. You can read more about this on the Application of PGS page or at the end of this article. In addition, the price of our mixture is higher than that of higher quality crushed stone.

As you can see, ASG has many disadvantages. Even in those regions where the material is purposefully mined, it is not always easy to find high-quality material.

If you order PGS without processing (it is also called natural), it is difficult to predict its composition. Therefore, to eliminate the disadvantages of the mixture, it is better to use the enriched version. It is cleared of impurities, dust and large inclusions, and the ratio of its components is known.

Next we will describe what properties of the sand and gravel mixture you should pay attention to when purchasing.

Our own concrete production and laboratory, as well as a large fleet of equipment guarantee high quality products and accurate delivery times

Concrete - production and delivery

Concrete pumps - rent

Pros and cons of PGS

The structure of the sand-gravel mixture is a natural non-metallic material. It is an economical option for filling all kinds of concrete mixtures and serves as an excellent base for the road surface.

Many are attracted not only by the affordable price, but also by the versatility of the product. PGS has a wide range of applications and there is no shelf life as such. It is also worth noting the ease of use and ability to withstand temperature changes.

Main advantages of PGS:

Environmentally friendly, without harmful additives.
Does not rot or decompose.
Long service life.
High rock strength.
Moisture resistance.
Frost resistance.
Low cost.

If the mixture meets the quality standard, the dust content and length will be minimal. Despite all the advantages, there are also certain disadvantages.

A few disadvantages of the sand-gravel mixture:

Often the composition contains foreign impurities, which reduces the quality of the raw material.

Roads made from ASG are dusty, so it is not recommended to construct paths and sidewalks from them.

Enriched ASG has a high cost.

Types of sand and gravel mixtures by extraction methods

The extraction of ASG is a large-scale production, since this mineral composition is necessary for various construction and industrial works. The extraction of this type of sand is equal to half the extraction of all non-metallic materials in the country. According to the extraction method, ASG is divided into three main types. To obtain complete information about the material, it is necessary to study each type separately.

In rivers and lakes

ASG is often mined in various bodies of water. A hydromechanical method is used, which allows the output to be a very pure mixture that can be sold at very reasonable prices. Specialists install suction equipment, with which the pulp is removed to a depth of approximately 30 m or higher. The maximum value is several hundred meters, but it all depends on the quality of the selected equipment, as well as the depth of the field.

The extraction equipment is designed in such a way that the suction of stones is combined with filtration, with the help of which the ASG is immediately washed. After this process occurs, the water returns to the reservoir, and therefore there can be no talk of draining the reservoirs.

Extraction of ASG on the lake

This is the most modern method that does not harm the ecosystem when extracting ASG. A mixture of different fractions is extracted from different deposits. The weight of the resulting product will depend on this. The higher the gravel content, the more the ASG weighs, thereby reducing the compaction coefficient.

In the seas

This species is similar in its extraction method to the previous version. The output is a homogeneous material that is ideally suited in particle configuration for construction needs. Using this extraction method, it is possible to achieve the formation of ASG without impurities, and therefore this is the material that is used to make concrete.

In the quarries

To extract ASG in a quarry, it is necessary to use modular units. These types of equipment consist of high-performance hydraulic dredgers. After mining the ore, it is necessary to thoroughly wash the mixture, and for this purpose a washing and sorting unit is used using a diesel generator. Washing and screening units are divided into several types:

Vibro washing.
Unit with installed spiral bucket washer.

Requirements for components

When purchasing PGS, you must ensure that the strength of the gravel that is part of the mixture meets the requirements of GOST 8267-93. Frost resistance and grain content must meet precisely this GOST to ensure good quality PGS.

The sand that is part of the mixture in its grain composition must fully comply with GOST 8736-93. Sand can be coarse, fine and medium, and also very fine

It is also important to make sure that the particles contained inside the ASG passing through the small sieve N014 do not exceed 20%, enriched with 10% composition throughout the mass

Clay and dust particles in the ASG should not exceed 5%, otherwise the quality of the mixture will greatly deteriorate. The proportions must be precise to obtain the best quality.

Before purchasing an ASG, make sure that it complies with GOST

If all the indicators correspond to the above data, then we can say with confidence that the ASG is suitable for construction and you can safely use the composition for critical work.

Also, in order to purchase a good and high-quality composition of ASG or OPGS, you need to make sure that it does not contain clogging inclusions.

Sand-gravel mixture for foundation

For serious construction projects, it is recommended to use ASG with the highest gravel content from 50 to 75%, this will ensure strong adhesion and the concrete structure will withstand any load. Mainly for road construction, ordinary natural ASG is used, and for landscape decoration or the production of concrete structures, it is recommended to use an enriched sand-gravel mixture.

A large load is placed on the foundation, walls and roof, so natural ASG is not a very good option. It contains a lot of clay and dust particles, which can reduce the quality of the material. The best option is ASG for the foundation 23 735 - 2014. Enriched ASG is manufactured according to special orders and the amount of gravel predominates in it.

Characteristics of PGS:

First class - 15% to 25% gravel grain.
Second class - 30% to 40%.
Third class - 40% to 50%.
Fourth grade - 50% to 65%.
Fifth grade - 65% to 75%.

Peculiarities

The sand-gravel compound belongs to the group of non-metallic rocks mined on the banks and bottom of water sources, in open-pit mine workings. The percentage proportions of the sedimentary elements of gravel and sand component depend on the location of the rock mining site.

There are two types of fossils found on the building materials market.

Natural - used in the installation of playgrounds, sidewalks and roads. Advantages: availability of several different types of composition, affordable price. A special feature is the absence of mechanical and chemical treatment.
Enriched - used for construction work. Advantages - the presence of mineral components that improve the technical parameters and quality of the material. Feature - undergoes technological processing with enrichment with auxiliary chemical compounds.

Natural ASGs are mined in three types:

mountain or gully - consists of particles of different diameters with sharp edges, contains a high percentage of the presence of mountain elements, is not used for the manufacture of concrete solutions;
lake or river – has a homogeneous composition with a high content of contaminated natural impurities, consisting of smooth particles;
marine - has a universal composition with round elements, used for the production of concrete mixtures.

Experts divide PGS into different types based on the following characteristics:

percentage combination of sand particles and sedimentary rock elements;
diameter of sedimentary gravel;
indicators of resistance to mechanical damage;
the presence of additional components;
resistance to low temperatures.

Experts highlight several main advantages of PGS:

environmental Safety;
versatility;
high percentage of strength indicators;
resistance to sudden changes in temperature and negative environmental influences;
long period of operation and no shelf life;
preservation of universal qualities and parameters during long-term storage;
the ability to increase the strength and durability of concrete mortar;
affordable price;
wide scope of use.

Crushed gravel as a filler for concrete mixtures

High-quality crushed gravel is consistently highly popular among representatives of the construction industry. To obtain large fractions of non-metallic material, solid rock is crushed. Small fractions are the result of sifting the crushed rock.

The advantages of crushed gravel include:

Good indicators of strength and frost resistance.
There is no unwanted background radiation.
There are no harmful impurities.
Affordable cost of material.

What is the main purpose of the PGS?

Sand-gravel mixture is actively used both in private construction and at industrial facilities, so it is used almost everywhere. But still, it should be taken into account that PGS has a certain percentage of radiation and the more gravel it contains, the higher the activity of radionuclides will be. Reading reviews on forums about the purpose of ASG, you will see that some may even argue on this topic. For some, the cheap price of PGS is an indicator of low quality. We have also published a video in which you can see our arguments.

It has been observed that ASG is mainly used in road construction. In road construction, for a long time, it has been actively using both natural and enriched ASG.

At the same time, it is important to take into account the percentage of sedimentary rocks, since a large amount of impurities will negatively affect the quality. If you plan to use a sand-gravel mixture as a cushion under the main road or to level out holes and depressions, the percentage of gravel and sand is not so important

PGS - industrial civil engineering

The second decoding of the abbreviation PGS means industrial civil construction. Construction workers are one of the most in-demand professions.

currently. They are the ones who arrange the environment, making it suitable for human life and erect masterpieces of architecture. Engineers trained in the PGS specialty are engaged in:

construction of industrial facilities;
project documentation;
construction and installation of various facilities;
design of engineering systems and drainage;
inspection of various structures;
geodetic and environmental surveys;
management throughout all stages of construction.

Thus, the ASG includes all stages of construction

, from design documentation to finishing of the finished structure. Engineers play a huge role in shaping the appearance of a village or city, from creating models of settlements to constructing and restoring various structures. Project activities include:

carrying out engineering surveys;
selection, analysis and systematization of received materials;
creating a layout of the finished object.

Management is the organization of the work process, making important decisions and responsibility for their implementation. The inspection of structures means carrying out an inspection of the facility, analyzing the data obtained and reconstructing the finished facility.

In conclusion, it is worth repeating that the abbreviation PGS implies two definitions

: mixtures of sand and gravel for construction, as well as industrial civil engineering. Mixtures are divided into classic or natural and enriched. The first option is used mainly in road construction, but the second is preferable for landscape design. Industrial and civil construction involves the development, analysis and support at all stages of construction of an object necessary for human life.

ASG stands for sand and gravel mixture. The main area of use of this mixture is concrete production. In addition, the use of concrete mixtures in road, railway and housing construction is common.

And another area of use of sand-gravel mixture is the production of high-quality reinforced concrete products.

PGS has the following characteristics: a high content of gravel and sand, a large gravel grain size, as well as indicators that meet state standards: grain composition, strength, the presence of weak grains, frost resistance, as well as the presence of clay, dust or silt particles in the mixture, and pieces themselves clay. Indicators for assessing sand are also established by state standards and include: the grain composition of sand, the level of particle size, the presence of dust and silt particles, similar to the composition of gravel.

A high-quality natural mixture contains at least 10% gravel grains that are larger than 5 mm in size. In this case, the largest possible gravel size can be up to 70 mm. As a rule, ASG does not include clogging elements.

There are also enriched ASGs - they are obtained, as the name suggests, by enriching natural ASGs. The main area of use of enriched natural gravel mixtures is various types of construction work. It is this type of mixture that best matches the requirements of most building codes. But there are absolutely no restrictions on natural ASG, which are used as a preparation for subsequent processing. Therefore, most often the use of natural sand and gravel mixtures involves the creation of a top layer of the future road surface and the construction of a drainage system in the case of road construction. Due to the low cost of this material, the company has the opportunity to purchase it in large quantities and use it for its intended purpose freely and without trying to save money.

Defense of the PGS diploma

PGS is a sand and gravel mixture. It is used to make mortars. It should be said that solutions containing ASG are an excellent material for road construction.

ASG concrete for foundation

The foundation of a building is the most loaded structure that can be filled with concrete based on enriched ASG. In this regard, we will consider the intricacies of preparing concrete from PGS for the foundation of a low-rise building.

As already mentioned, there are no official data regulating how much PGS is needed per 1 cubic meter of concrete for pouring a foundation. Therefore, private developers who have chosen this product as a filler should be guided by the empirical proportions of concrete made from ASG:

1 part of cement TsEM I 32.5N PTs (old designation M400) or TsEM I 42.5N PTs (old designation M500).
8 parts of enriched ASG of the fifth group.
Grinding agent (water) 0.5-1 parts from cement.

The amount of water may differ to a lesser extent depending on the humidity of the ASG. By mixing the components in the specified proportions, the final result is ready-made concrete that corresponds to the GOST grade of heavy concrete M150.

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 it is preferable to use granite crushed stone for pouring the foundation of a two-story mansion, then it is not economically feasible to use expensive material for concreting support columns or a garden path; gravel will also do. Professional builders 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.

Features of crushed stone

Crushed stone is an inorganic raw material that is mined by crushing granite, boulders, limestone and other rocks. The main difference between crushed stone and pebbles is its rough surface and the presence of very sharp corners. In addition, crushed stone is large in size, so it is rarely used for country side walkways. Thanks to larger fractions, this material has good “adhesion”, so it is successfully used as a filler for building mixtures.

Healthy! If we talk about the differences between crushed gravel and ordinary gravel, then you should pay attention to the method of extracting raw materials. Crushed gravel is mined by crushing rocks, so it has sharper corners

Ordinary crushed stone forms independently, under the influence of water.

If we talk about the sizes of stones, then according to GOST there are the following categories:

Up to 5 mm (screening), suitable for paths, platforms and as protection against ice.
From 5 to 10 mm, used as filler for concrete mixtures.
From 10 to 20 mm, used to create a foundation for construction.
From 20 to 40 mm – for complex structures of heavy weight.
From 40 to 70 mm – for the construction of road surfaces and multi-storey buildings.
From 70 to 120 mm - as decorative elements.

It is also worth paying attention to how much a cube of crushed stone weighs

Type of crushed stone and scope of use	Specific gravity, 1m3/kg	Bucket weight (12 l), kg
Slag (rarely used)	1500	18
Granite (used for making hard concrete, for pouring foundations, for road construction)	1470	17,5
Limestone (for low-rise construction, in the production of reinforced concrete concrete, wells and much more)	1300	15,5
Sandstone (road construction)	1300	15,5
Marble (landscape design: paths in the country, de-icing coatings, drainage systems)	1500	18
Waste waste (road coverings)	1150	14
Tuff (rarely used)	800	9,5

Based on this, we can conclude that the bulk density of some types of crushed stone is significantly lower than that of gravel.

The cost of crushed stone is about:

1,500 rubles per 1m3 of limestone raw materials;
2,100 rubles – granite;
1,150 rubles – slag.

What is better for concrete: gravel or crushed stone?

Almost no construction can do without concrete. Foundations, floors and other structures are made from it. However, the functional purpose of this material directly depends on the filler that underlies it. What is better for concrete: gravel or crushed stone? Let's try to understand this issue.

At first glance, there is no significant difference between gravel and crushed stone, since both materials essentially perform the same function, they are visually similar, and they are made from the same source material - rock. In fact, there are clear differences between them, which are taken into account when producing concrete mixtures.

What is gravel and crushed stone?

Crushed stone is obtained by crushing rocks. Crushed stone can be of different sizes and shapes - based on these parameters, separate fractions are distinguished. Medium diameter material is used for the production of concrete, small diameter is used for sprinkling sports fields, and large diameter is used in landscape design.
Gravel is a product of natural rock destruction. Its characteristic feature is a smooth surface, as well as the presence of impurities in the form of sand or soil. It is these factors that negatively affect the adhesion of the material to concrete.

NOTE! Gravel can be mountain, sea or river, but mountain gravel is used in construction. Other types of material are used in landscape design to decorate the territory.

Differences between gravel and crushed stone

Concrete using crushed stone

The most significant difference is the appearance. Gravel has a smoother surface, while crushed stone has sharp corners and a rough surface. Crushed stone has a larger fraction size and a predominantly even color. Gravel can have a wide variety of colors and shades.

It is good adhesion to cement mortar that makes crushed stone an ideal filler for concrete production. Gravel performs primarily decorative functions.

So, to the question of what material is best to use for the production of concrete, there is a very obvious answer - crushed stone. It provides high strength and solidity of concrete structures. Crushed stone allows them to withstand enormous physical stress without any consequences. At the same time, the performance characteristics of concrete will also depend on the type of crushed stone, because it also has different origins, shapes and fraction sizes.

Gravel is not used in the industry of reinforced concrete structures, however, it has its own wide range of applications.

Buy granite crushed stone, the price per ton of which is the most favorable in Moscow, by simply dialing the phone number +7 (495) 229-39-07!

kupi-scheben.ru

Application environment for granite screenings

Considering the technical indicators and cost of this raw material, it is valued all over the world, and its scope has no boundaries. It is used by individuals, it is in demand in various industries, and it is used by large and small construction companies.

In winter, city utility companies use it to remove ice from roads and sidewalks. Due to the presence of stone dust particles in its composition, it lies tightly on the ice, does not get wet like ordinary sand and makes the surface rough. In addition, they rarely simply sprinkle sand; salt is added to it, which corrodes our shoes and car tires.

This material is also used in decorating parks, squares, and fountains. Quarries produce granite of different colors, after crushing it either gray or reddish granite screenings are obtained. Due to the variety of colors, it has a share of use in landscape work. These are paths, flower beds, flower beds, etc.

Granite screening for walkways is the ideal solution. Weeds in park recreation areas do not grow through it, and pedestrian paths look neat and well-groomed. The track from the screenings is rolled with a roller, after which it acquires a very dense consistency, similar to asphalt, but much cheaper. Often such paths are made two-color, colors are combined.

Hard coverings for playgrounds must meet certain requirements: your feet should not sink in it like in sand, it should be hard, and the covering should not float after rain. Such an ideal material is granite screening - it is dense, durable, stable, and is not liked by animals that like to defecate in the sand. It does not contain clay, which sticks to shoes and spreads everywhere.

Similar requirements for surfaces for playgrounds are tennis courts and outdoor volleyball courts. Water passes through it easily and there will never be puddles on it.

Such a coating will be reliable, durable, and will not have to be changed every season, which will ultimately save money.

Due to the high bulk density, after compaction or rolling, screenings are sometimes used instead of expensive asphalt. In addition, in the sun, such material does not emit a smell, unlike asphalt.

Screening is constantly used in the production of concrete and products made from it.

It is used in the production of paving slabs and curbs; the 2-5 mm fraction is in demand in the production of high-strength ready-mixed concrete. These are products for bridges, floors, and places with high loads. It is also used in the production of asphalt concrete and in the repair of roads for various purposes.

Due to its reasonable price, it is successfully used as a backfill in concrete mixtures instead of sand or as an additive. Special equipment is used to extract sand, therefore its cost is more expensive.

Permanent use in dry building mixtures for finishing wall coverings. The 5 mm grain fraction is used in mixtures for “bark beetle” coating, which can often be seen on the walls of houses or buildings.

Blocks made using this screening are also especially popular among the population. They are used to build houses and premises for various uses. Low price of the block, excellent thermal insulation, ease of operation, speed of installation - these are the main factors that attract developers. They are environmentally friendly, easy to transport and store. Walls made from such blocks can be built thinner, thereby adding interior space and reducing the load on the foundation.

Types and classification

Classification of concrete on gravel into types is made in accordance with the diameter of the gravel used:

1-2.5 mm. This type of concrete has low strength. Therefore, it is used only for decorative finishing of premises.
2.5-5 mm. Such concrete has acceptable strength indicators. Used in construction work.
5-10 mm. This concrete has excellent strength properties. In terms of quality and adhesion, such concrete is considered the best of its kind.

Based on mobility, concrete on gravel is classified:

mobile;
hard;
super hard.

To make concrete moveable, more water or plasticizing additives are added to the mixture. The second option is more profitable, since water reduces the strength level of concrete.

Based on frost resistance properties, concrete is divided into types:

F 15, 25, 50 - do not tolerate frost well.
F 100-150 is the standard most often used in Russia. Guarantees that a concrete object will be in use for up to 100 years.
F 150-200 - types of concrete that perfectly withstood the effects of frost. Suitable for use in harsh climates.
F 300-500 - types of concrete with a high level of frost resistance. Suitable for use in freezing and humid regions.
F 500-1000 - highest frost resistance.

Practical recommendations

We have specifically presented for you all possible calculation options for creating the ideal concrete mixture. Now you, as a concrete production specialist, can give advice to inexperienced craftsmen. But finally, we have a super life hack that will allow you to prepare concrete without complex formulas and tables.

Prepare a piece of paper with a pen, a jar (1 l), a bucket (10 l), cement, ASG, water. Let's get started:

First, let's measure how much water fits into a 10-liter bottle of water. It’s logical that 10. Let’s write it down on paper.
Now let's fill a full bucket of crushed stone and pour water to the top. Don't forget to count the number of cans that fit in the bucket. Let it be 4 liters. Let's write down the number on a piece of paper and empty the container.
We pour sand in an amount equal to the volume of water from step 2. This is again 4 liters. Pour water to the top of the cement. This quantity will indicate the measure of cement that will fill the smallest voids. For example, it turned out to be 2 cans. Let's write it down in notes.
We derive the formula. To mix the correct solution you will need: 10 parts of ASG, 4 parts of water and 2 parts of cement.

And in conclusion, here is a small reminder with tips for working with concrete:

Always check the expiration date of the cement before purchasing. Use only high-quality fresh cement from well-known manufacturers.
To create foundation concrete, purchase ready-made enriched material. Self-enrichment of natural PGS will not help save money, but will require additional physical effort.
When preparing each component, make sure of their suitability (no fossils in the cement powder, cleanliness and transparency of the water, no silt or clay in the sand).
Water should be free of dirt, odor and chemical additives.
Add waterproofing additives and plasticizers strictly following the instructions.

Features of granite screenings

As mentioned earlier, the main advantage of this material is its low cost and high strength indicators. This allows the product to be used for a long time without repair or replacement.

Its production does not require special equipment, everything happens automatically, because it is an accompanying material.

In view of these arguments, granite screening is a universal material, the demand for which is constantly growing. After all, everyone wants to get a final product of excellent quality, without cracks and constant repairs, which everyone is already tired of. The quality of life improves with environmentally friendly building materials.

It is safe to say that its use is aimed at reducing the cost of the final product.

Use of broken slate

This broken or chipped material can be used instead of crushed stone in any grade of concrete. Yes, slate is practically concrete in composition. The only difference is that the sand is replaced with fibrous asbestos.

It is this asbestos that causes serious problems. Yes, in solution and under a layer of finishing materials it does not come into contact with people and is completely chemically inactive. However, asbestos fibers fluff easily and can enter the respiratory system. And there they provoke serious oncological changes, and in a variety of organs.

Therefore, when crushing slate, you will have to use personal protective equipment and water curtains. It is also advisable to wet the building material thoroughly before crushing. This will significantly reduce the intensity of dust emissions.

What else can replace crushed stone?

In some cases, it is a good idea to use brick (or rather, broken brick). It becomes an excellent replacement for more expensive building materials. Combat is used:

in concrete solution (mixture);
for preparing a cushion under construction screeds;
when decorating sidewalks and street and garden paths;
as a decorative solution when designing territories;
for the purpose of leveling roads (fall asleep and rake in an even layer).

Concrete is very powerful and can withstand heavy loads and high temperatures. It can be safely used for the foundation

What is important is that the appearance of cracks, which are an unpleasant consequence in any construction, is eliminated. As for the use of expanded clay, this is quite possible, for example, for the ceiling, but not everywhere

Expanded clay concrete is often used in individual construction. Low thermal conductivity makes it an excellent option for arranging lintels and partitions. It can also be used in a subfloor screed. However, concrete based on expanded clay can withstand relatively small loads. In addition, it cannot cope with the effects of water, which greatly narrows the scope of expanded clay as a filler for masonry mixtures in ASG.

But it is quite justified to make small household and country buildings from such a composition. The use of expanded clay as a filler does not require any complex technological equipment. The reduced specific gravity allows the use of such blocks even on soils with weak bearing capacity.

Crushed stone can also be replaced with slag from metallurgical production. This material was used several centuries ago for arranging foundations, building houses and laying roads. Today it finds use even in the most developed countries as an excellent practical solution. However, a number of examinations have shown that this material can contribute to the contamination of the area with toxic substances.

As for pebbles, they almost completely correspond in parameters to high-quality crushed stone. However, pebbles, due to their smoothness, are not strong enough when laid in asphalt or poured into a cement floor. It will inevitably sag and fail. But pebbles work well as a concrete filler. Moreover, it is even more reliable than crushed limestone.

Sometimes pebbles are also used when repairing dirt (not asphalt!) roads. Screenings can be used as a replacement for sand. But they can only partially replace crushed stone. The main task of the screening mass is to increase the uniformity of load distribution and maintain the optimal volume of the finished product. Since screenings have a greater variety of particle sizes than sand, they improve the quality of internal cohesion in cement.

It also has the following advantages:

chemical reactions of small grains with cement, which form insoluble compounds;
preparing heavier and denser concrete;
increasing the strength of the mixture.

In a number of other regions of Russia (including the Urals), screenings cost significantly less than sand. It is recommended to use a more durable material of igneous origin. The optimal rock is one that is mainly composed of particles measuring 1.5-4 mm. We will have to control radioactive radiation. Normally, it is up to 370 Bq per 1 kg maximum.

But it is also important to remember that the following should absolutely not be placed in concrete or asphalt:

tree;
glass;
any kind of garbage and household waste, even those that are hard and durable.

Scope of application

Taking into account the natural origin of the components, when using them as raw materials and semi-finished products for various building materials, the level of natural radioactivity is regulated according to the Aeff parameter.

In particular, PGS and OPGS are used:

For the construction of residential and public buildings with an acceptable Aeff level of no more than 370 Bq/kg.
For roads and preparation of infrastructure of populated areas, as well as for construction, repair and maintenance of industrial buildings - from 370 to 740 Bq/kg.
For the construction of infrastructure facilities, including airfields, far from populated areas - 740 Bq/kg to 1500 Bq/kg.

supplies standardized ASG in natural and enriched composition to customers in Tula and the Tula region. Delivery is made by the supplier's transport in an unlimited volume. All shipments are provided with the necessary certificates.

Composition and characteristics

ASG available in construction stores is characterized by several main nuances:

The amount of sand and gravel in the mixture.
Grain size. This indicator is checked according to the specially established GOST 8267-93.
Sand is assessed according to GOST 8736-93.

What PGS looks like
Since the natural sand-gravel mixture and its characteristics are documented according to GOST, anyone has the opportunity to purchase an exceptionally high-quality product that meets the main building standards.

Properties:

ASG has great strength and is therefore resistant to negative and high temperatures. ASG can withstand low temperatures due to the presence of large fractions of crushed stone in the composition. This indicator is extremely important under operating conditions in Russian conditions, when temperatures in winter and summer vary greatly.

Durability. This property suggests that even with long-term use or storage, ASG will retain all its properties, and the mixture can then be used without compromising quality.

If after construction there is excess ASG left on the site, then it is not necessary to remove it and order expensive equipment for this. The material can be easily recycled by using it to prepare concrete. This is also very convenient, since the strength properties of the composition will increase.

Builders prefer to use this material because it has a very low cost, but at the same time high productivity. Thus, at a relatively low price, it becomes possible to purchase high-quality material used for basic construction work.

The mixture is as environmentally friendly and natural as possible, and therefore does not harm the human body. For this reason, ASG is safely used for the construction of children's and sports grounds.

Features of gravel

If we talk about what gravel is, then first of all you should pay attention to the shape of this mineral. Multi-colored, round-shaped stones are obtained through the natural destruction of rocks.

Depending on the fraction of this raw material, three types of gravel are distinguished:

from 1 to 1.25 mm – fine gravel;
up to 5 mm – medium;
10 mm – coarse gravel.

Raw materials cost about 1,700 rubles per cubic meter.

Since this material is extracted from different regions, there are quite a few varieties of this raw material.

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 a solid bulk material of 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 a rubble stone. According to its technical characteristics, granite crushed stone is the most suitable filler for dense, heavy, high-quality concrete. Among its advantages:

the highest strength indicators (from 800 to 1600);
low level of 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.

The quality of such crushed stone is beyond doubt

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 used mainly for decorative purposes - for the design of artificial reservoirs, alpine slides, and other landscape design objects.

To prepare concrete, crushed crushed gravel 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.

Its disadvantages can be considered:

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

Gravel building material is indispensable for concreting road surfaces and in low-rise housing construction

What kind of crushed stone is needed for the foundation: crushed stone fraction, tips for choosing

Among the ingredients of the concrete mixture that are used to create the foundation are not only inorganic binders in the form of cement and sand, but also crushed stone. Its characteristics determine the strength of the structure. For this reason, before construction, you should decide what kind of crushed stone you need for the foundation.

Classification of crushed stone

Crushed stone can be divided into several types, among them the material should be distinguished by:

rock used in the production process;
strength;
frost resistance.

As for raw materials, the material is obtained by crushing rock. As a result, crushed stone with different strengths is obtained. Slag has the least amount, followed by secondary and limestone. Gravel and granite varieties of crushed stone have higher strength. Granite is the most durable, so it acts as the best option for a foundation.

If you are deciding what kind of crushed stone you need for the foundation, then you can choose the gravel variety, since it has an ideal ratio of efficiency and strength. By crushing concrete waste, recycled material is obtained. Brick can also serve as a raw material. Before using it, the old fittings must be removed.

When deciding what kind of crushed stone you need for the foundation, you should also pay attention to its strength. The material is divided into grades that determine compressive strength. The M200 grade is weak, so it is not recommended for use in creating concrete structures that will undergo significant loads. The highest grade is M1600. In this case, we are talking about a high-strength material in which the content of grains from low-strength rocks is low; their volume should not exceed 5%.

Crushed stone is also classified according to frost resistance. For the construction of structures in temperate climates, this factor is of great importance. The higher the frost resistance, the more freezing and thawing cycles the material will be able to withstand without deteriorating performance characteristics. In this regard, brands ranging from F15 to F400 are distinguished. The best in this regard is granite crushed stone.

When deciding what kind of crushed stone you need for the foundation, you should first of all pay attention to the above indicators. However, the described filler can also be classified according to some auxiliary indicators, among them the degree of adhesion and the level of radioactivity should be highlighted.

Recommendations for selection

The requirements for concrete and crushed stone are determined by the type of concrete structure. For example, the foundation of a building will undergo permanent and temporary loads from the structure throughout the entire life of the building. Therefore, the most stringent requirements are imposed on concrete and crushed stone.

If you are making a foundation of crushed stone and cement, you must decide on the brand of aggregate. As practice shows, M1200 grade crushed stone is most often used for foundations. However, for the construction of a small country house, you can purchase less durable crushed stone.

Experts also advise paying attention to the geometric characteristics of the grains that are included in the composition. In this case, we are talking about the fraction and the permissible degree of flakiness. The fractional composition of elements refers to the average grain size. To form the foundation, a crushed stone fraction ranging from 5 to 40 mm is used. The intermediate value is the fraction from 10 to 20 mm.

The shape of the grains is also of great importance. For ideal binder consumption and easy compaction of the mixture, it is better to use cube-shaped crushed stone. In this case, the grain sizes must be the same. The composition also contains flakier grains, which have a needle or lamellar shape. The use of material with a high content of such grains causes excessive consumption of binder to prepare the same volume of mixture. Among other things, vibration compaction becomes more complicated.

Flaky grains are also bad because they can cause voids in the mixture, which distinguishes them from cube-shaped grains. Their adhesion to the material is worse, and the frame is not so rigid. Depending on the content of flakier grains, some types of crushed stone are distinguished, among them:

cubiform;
improved;
ordinary.

Cuboid crushed stone has flakier grains in a volume of up to 10%. In the improved material, the number of such grains is limited to 25%. Ordinary crushed stone can contain flakier grains up to 50% of the volume. Taking into account the fact that the foundation is a critical structure that undergoes loads, improved or cube-shaped crushed stone should be used for it.

Recommendations for choosing crushed stone based on additional characteristics

When choosing crushed stone for a strip foundation, you should pay attention to a number of other properties of the material. For example, high-strength crushed stone is more radioactive compared to M600 grade crushed stone. For this reason, it is desirable that a batch of aggregate be subjected to radiometric monitoring.

You should not try to save money by purchasing crushed stone. On the market you can find offers of secondary crushed stone, which is represented by crushed concrete and brick. This option has only one advantage - low cost. However, there is no need to talk about the strength of such a building material, because after use, brick and concrete could change their original properties.

Choosing crushed stone based on appearance and extraction method

Experts advise paying attention to the surface of the elements. It is better to use cube-shaped grains with a rough surface that have well-defined ribs. Quite often, the mistake of builders is to use river gravel, which they try to replace crushed stone with. Although it has good strength, as well as a low content of flakier grains, it has one important drawback, which is expressed in a smooth surface polished with water. Therefore, it is impossible to achieve the required contact between grains. But the use of mountain gravel, which has sufficient roughness, is acceptable.

How to get a solid foundation?

In the mixture for the foundation, crushed stone elements form a macroframework, and it bears the operational loads. Cement and sand act as fastening agents and void-filling ingredients. For this reason, you should choose crushed stone that will not collapse under loads, and the grains must be firmly bonded to each other.

If this condition is met, then the foundation will be truly reliable and will last for decades.

Foundation mortar proportions

In order to obtain high-quality concrete and a reliable foundation, it is necessary not only to choose the right components that will meet all the requirements, but also to maintain the proportions for the foundation. Sand, cement and crushed stone are added in the following ratio: 2:1:4. Water is taken in a volume of 0.5 parts.

It is with this composition that factories supply the solution to construction sites. If you are building the foundation yourself, the proportions will depend on the brand of concrete. Usually M200 or M300 is enough for the foundation of a house.

How to avoid mistakes?

When choosing the proportion for the foundation, sand, cement and crushed stone must be added in the required volume. If there is more cement in the mixture, the solution will turn out to be hard, and it will not be very convenient to lay it.

If there is an excess of crushed stone or sand, the concrete will not set well. But with a fairly impressive volume of water, you will get porous concrete.

How to decide on the fraction and amount of crushed stone?

When choosing a fraction of crushed stone for the foundation, you should pay attention to the material, the dimensions of the elements vary from 20 to 40 mm. The crushed stone should be cube-shaped. It is most suitable for residential construction. This will allow for high compaction of the filler and the absence of air in the composition.

If you are faced with the question of how much crushed stone is needed for the foundation, then you can use the following proportion, which is most often used by developers: 3 parts sand, part cement and 1.5 parts water. For this ratio you will need 5 parts of crushed stone.

Conclusion

Crushed granite, although it is the best material in terms of strength, has the highest cost. When constructing foundations, its characteristics make it possible to guarantee high structural strength.

At the same time, the material may be unprofitable for light commercial buildings. Therefore, granite crushed stone is quite often replaced with gravel.

fb.ru

Characteristics of washed (alluvial) sand

The process of processing quarry sand to obtain seeded sand that complies with GOST standards requires special equipment and skills.

The presence of harmful impurities in the bulk substance in excess of 0.3% is unacceptable;
the predominant number of medium-sized fractions is 1.6-2.4 mm;

This process consists of sifting the mined material through sieves, the sections of which have different sizes. Thus, division into factions occurs. The structure of the sand obtained after such processing becomes homogeneous, which significantly improves the quality of the mixtures in which it will be used.

According to its characteristics, seeded sand is no worse than washed sand, but costs an order of magnitude lower. Seeded sand of classes I and II, with a fineness modulus from 0.2 to 3.5, is more expensive, which is due to the following performance characteristics:

high bulk density of homogeneous material – 1800 kg/m3;
environmental safety of sand;
resistance to temperature changes;
filtration coefficient – 11 m3/day;

When choosing seeded sand, you need to take into account the tasks facing the construction organization purchasing this material.

Technical properties of crushed stone

Depending on the type, crushed stone has certain technical characteristics. When choosing the type of crushed stone, it is necessary to take into account not only its fractionation, but also its characteristics. Different construction works require different types of crushed stone, and the quality of the entire work can depend on the correct choice of fraction.

In accordance with GOST, the following main characteristics of crushed stone are distinguished:

Frost resistance. This property shows the ability of crushed stone to withstand alternate freezing and thawing in a wet state while maintaining its properties and structure. According to frost resistance, types of crushed stone are: highly resistant (F200,300,400), resistant (F50,100,150) and unstable (F15,25).

Strength characterizes the ability of crushed stone to withstand loads of a certain magnitude. By strength, crushed stone is distinguished: super-strong (M1400-M1600), high-strength (M1200-1400), strong (M800-M1200), medium strength (M600-M800), weak strength (M300-M600), very weak strength (M200).

Flakiness

This is the main and very important property of crushed stone, showing the presence of relatively smooth edges (sides) on the “grains” in the total mass of crushed stone. According to the flakiness, crushed stone is: cuboid - group 1, improved - group 2, normal - group 3

The most effective is crushed stone of the 1st flakiness group. It is easy to tamper and more durable. Cuboid crushed stone is an excellent material for creating foundations and road surfaces.