Crushed stone, whose species will be described in more detail below, is a building material obtained as a result of the initial grinding and subsequent sifting of rocks. It is part of the concrete mixture for the foundation, and its characteristics largely determine the strength of the solution. Therefore, before the construction starts, it should be determined which kind of crushed stone will be used. This is especially true of foundations, which are subjected to heavy loads during the operation of the house. And it is from the strength of the base of a residential building or a building of another purpose that the durability of the entire structure will depend.
Classification of crushed stone
This material is classified according to several basic characteristics. Among them, it should be noted: a species of rock, strength and frost resistance. In order of increasing strength, the following types of crushed stone should be distinguished: slag, secondary, and limestone and gravel, the last in the list is granite. The most solid and reliable is granite, it acts as an optimal option for pouring the foundation. But if you take into account the two characteristics: economy and strength, the gravel variety is considered the best. Secondary crushed stone is obtained by the method of crushing concrete waste, as well as brick bricks. Before using this material, care must be taken to remove the old fittings.
Crushed stone, types, use in the construction of which are described below, can have different strength. Depending on this, the material is divided into brands. A rather weak crushed stone is one that belongs to the M200 grade, it should not be used to form concrete structures that will be subjected to significant loads during operation. If we are talking about high-strength crushed stone, then it contains a small amount of grains from low-strength rocks, their volume does not exceed 5%.
The number of cycles of freezing and thawing, which will be able to undergo rubble, without losing its quality characteristics, is of great importance for construction in a harsh climate. Thus, according to the frost resistance, the material can relate to the brand in the range from F15 to F400. Most often, builders pay attention to these indicators, but gravel can also be classified for some auxiliary characteristics, for example, by the level of adhesion or radioactivity.
Main varieties: granite gravel
Crushed stone, the types of which are described in the article, can be granite. It is a non-metallic building material that is obtained from a solid rock. Frozen magma has the appearance of a monolithic rock, which is extracted from a considerable depth. In the production of this material state standards 8267-93 are used. If you are interested in the types of granite gravel, you should know that it is divided into fractions. Thus, the grain sizes in the material can be a minimum of 0 to 5 mm, and a maximum of 150 to 300 mm.
The most common among consumers is granite rubble, the fraction of which varies from 5 to 20 mm. This material is used in the manufacture of asphalt and concrete. Granite rubble is used when the mortar is closed to form reinforced concrete structures, railways, when laying the foundations of roads, as well as pavements and sites.
Characteristics and area of use of gravel
This variety of crushed stone is produced by the method of passing through a special sieve of a quarry rock or crushing rock rock. As a normative document for production, GOST 8267-93 is used. This type of crushed stone in terms of compressive strength is inferior to granite. Among the merits, there should be little radioactivity, as well as low cost. Considering the types of gravel and crushed stone, it is necessary to distinguish gravel varieties, among which there is crushed gravel and gravel.
The first is produced by the method of processing the rock, while the second is a pebble of river and marine origin. Gravel crushed stone is used in the role of filler in the formation of products, as well as reinforced concrete structures. It is used in civil engineering, in the process of covering pedestrian roads, as well as in the arrangement of grounds and grounds.
Reviews of limestone crushed stone
Considering the types of rubble and its use, consumers distinguish a limestone variety, which is the material obtained by the technology of processing sedimentary rock. As a raw material, limestone is used, which consists of calcium carbonate and has a low cost. The main varieties, as the buyers emphasize, are the materials, the fraction of which lies in the range from 20 to 40 mm and from 40 to 70 mm. The limit is from 5 to 20 mm as an intermediate value.
According to users, limestone crushed stone is used in the glass and printing industry. It is also actively used in the manufacture of small-piece ferro-concrete products, in the process of building roads, on the surface of which there will not be a large transport load during operation.
Secondary rubble: what he does not need to know
This material is manufactured using the technology of processing construction debris, namely asphalt, concrete and bricks. The material must comply with GOST 25137-82. At the same time, the same technology is used as for making other types of crushed stone. As the main plus is a low price. According to the characteristics of strength and frost resistance, this material is inferior to natural varieties of rubble. It is used in the road economy, as a filler for concrete, as well as for strengthening weak soils.
What you need to know about the crushing of rubble
Crushed stone, the types and characteristics of which are described in the article, is in demand in construction, as well as the screening of this material. It is a by-product of production. Crushed stone has a fraction ranging from 5 to 70 mm and above. If the grains of the rock have a fraction of up to 5 mm, then they represent a screening.
Depending on the raw materials, three main types should be distinguished:
In addition to the above varieties, recently produced secondary crumb, which is a waste of production, where broken gravel and unfit ferroconcrete products are used. This kind of rubble is the cheapest and is used to form the upper layer of streets in the winter.
Characteristics of varieties of screening of crushed stone
The main types of screening of crushed stone were presented above, but if you want to purchase this material, you need to learn more about the main characteristics of the material. If we are talking about granite crushed stone of M1200 grade, its bulk density is 1.32-1.34 t / m 3 . The size module in millimeters is limited by the index from 0.1 to 5 mm. Foreign impurities contain no more than 0.4%.
Gravel screening of crushed stone, the brand of which varies from 800 to 1000, has a bulk density of 1.4 t / m 3 . The size of the components varies from 0.16 to 2.5 mm. Limestone screening of crushed stone can have a grade of strength from 400 to 800. The bulk density is 1.3 t / m 3 , while the grain size varies from 2 to 5 mm.
A little more about drop-out
Crushed stone, types and characteristics of which are of interest to many builders, is presented for sale in the form of drop-out. Waste crushing by some characteristics and uses are close to the recycled content. However, it should be remembered that these materials are completely different, and their difference is that sandy screenings have a greater number of foreign inclusions. It can consist of large stones up to 100 mm and very fine sand, which limits the scope of use of such raw materials.
Scope of crushed stone screening
The use of crushing screenings is varied. They are involved in agriculture, construction, printing and in the ennoblement of homesteads. Like gravel, granite screening is used for finishing, when casting curb stone and tiles, which follows from customer reviews. Without losing quality, they can replace gravel in concrete, reducing the cost of material. Raw materials from limestone waste are used as a filler of cement-based solutions that go into operation when facing walls.
Crushed stone, the kinds of which must be known to the builder before purchasing the goods, can have a certain type of screening. Due to the fact that it is a by-product, the cost is extremely low. For example, the price for gravel screenings is much less by 60% compared to the cost of crushed stone.