Crushed stone, the types of which will be described in more detail below, is a building material obtained as a result of initial grinding and subsequent sifting of rocks. It is part of the concrete mix for the foundation, and its characteristics largely determine the strength of the mortar. Therefore, before starting construction, it should be decided which kind of crushed stone will be used. This is especially true for foundations, which are subjected to heavy loads during house operation. And it is precisely on the strength of the foundation of a residential building or building of another purpose that the durability of the entire structure will depend.
Gravel classification
This material is classified according to several main characteristics. Among them, it is worth highlighting: a variety of rock, strength and frost resistance. In order of increasing strength, the following types of crushed stone should be distinguished : slag, secondary, as well as limestone and gravel, the last in the list is granite. The most durable and reliable is granite, it acts as the best option for pouring the foundation. But if you take into account two characteristics: profitability and strength, then the gravel variety is considered the best. Secondary crushed stone is obtained by crushing concrete waste, as well as brick bricks. Before using this material, care must be taken to remove the old fittings.
Crushed stone, the types whose use in construction are described below, can have different strengths. Depending on this, the material is divided into brands. A rather weak crushed stone is the one that belongs to the M200 brand, it should not be used to form concrete structures, which during operation will be subjected to significant loads. If we are talking about high-strength crushed stone, then it contains a small number of grains from low-strength rocks, their volume does not exceed 5%.
Of great importance for construction in harsh climates is the number of freezing and thawing cycles that will be able to undergo crushed stone without losing its quality characteristics. Thus, in terms of frost resistance, the material can belong to the brand in the range from F15 to F400. Most often, builders pay attention to these indicators, however, gravel can also be classified by some auxiliary characteristics, for example, by the level of adhesion or radioactivity.
Main varieties: crushed granite
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 hard rock. Frozen magma has the appearance of a monolithic rock, which is extracted from considerable depth. In the manufacture of this material used state standards 8267-93. If you are interested in the types of crushed granite, then you should know that it is divided into fractions. Thus, the grain size in the material can be equal to a minimum of 0 to 5 mm, and a maximum of 150 to 300 mm.
The most common among consumers is granite crushed stone, the fraction of which varies from 5 to 20 mm. This material is used in the manufacture of asphalt and concrete. Granite crushed stone is used when mortar is shut for the formation of reinforced concrete structures, railway tracks, when laying the foundations of roads, as well as sidewalks and platforms.
Characteristics and area of use of gravel gravel
This type of crushed stone is made by passing through a special sieve of quarry rock or crushing stone rock. As a normative document for production, GOST 8267-93 is used. This type of crushed stone is inferior to granite in compressive strength. Among the advantages should be highlighted low radioactivity, as well as low cost. Considering the types of gravel and gravel, it is worth highlighting the varieties of gravel, among which it is worth noting crushed gravel and gravel.
The first is made by processing the rock, while the second is pebbles of river and marine origin. Gravel gravel is used as a filler in the formation of products, as well as reinforced concrete structures. It is used in civil engineering, in the process of covering pedestrian roads, as well as in the construction of foundations and sites.
Reviews about limestone crushed stone
Considering the types of crushed stone and its application, consumers emit a limestone variety, which is a 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 buyers emphasize, are materials whose fraction lies in the range from 20 to 40 mm and from 40 to 70 mm. The intermediate value is a limit of 5 to 20 mm.
According to users, limestone crushed stone is used in the glass and printing industries. It is also actively used in the manufacture of small-sized reinforced concrete products, in the process of building roads on the surface of which there will not be a large transport load during operation.
Secondary crushed stone: what does it need to know
This material is made according to the technology for processing construction waste, namely: asphalt, concrete and brick. The material must comply with GOST 25137-82. In this case, the same technology is used as in the manufacture of other varieties of crushed stone. The main advantage is the low price. According to the characteristics of strength and frost resistance, this material is inferior to natural varieties of crushed stone. It is used in the road sector, in the role of aggregate for concrete, as well as in the strengthening of soft soils.
What you need to know about gravel screening
Crushed stone, the types and characteristics of which are described in the article, is in demand in construction, as is the screening of this material. It is a byproduct of production. Crushed stone has a fraction ranging from 5 to 70 mm and above. If the rock grains have a fraction of up to 5 mm, then they represent a screening.
Three main types should be distinguished depending on the raw materials:
- granite;
- limestone;
- gravel.
In addition to the above grades, lately, secondary crumb has been made, which is a waste of production, where broken crushed stone and unusable reinforced concrete products are used. This type of crushed stone is the cheapest and is used to form the upper layer of streets in winter.
Characteristics of varieties of crushed stone screening
The main types of crushed stone screening were presented above, however, if you want to purchase this material, you need to familiarize yourself with the main characteristics of the material in more detail. If we are talking about granite rubble brand M1200, then its bulk density is 1.32-1.34 t / m 3 . The fineness modulus in millimeters is limited to 0.1 to 5 mm. Foreign impurities contain no more than 0.4%.
Gravel screening of crushed stone, the 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 strength grade 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 dropouts
Crushed stone, the types and characteristics of which are of interest to many builders, is presented for sale in the form of screenings. Crushing waste by some characteristics and scope of use is close to that described by recyclables. However, it should be remembered that these materials are completely different, and their difference is that the sand screenings have a greater number of foreign inclusions. It may contain large stones up to 100 mm and very fine sand, which limits the area of use of such raw materials.
Scope of crushed stone screening
The use of crushing screenings is diverse. They are involved in agriculture, construction, printing and in the refinement of household plots. Like gravel, granite screenings are used for finishing, when casting curbs and tiles, which follows from consumer reviews. Without losing quality, they can replace the gravel in concrete, reducing the cost of the material. Raw materials from limestone processing wastes are used as a filler of cement-based mortars, which are used for wall cladding.
Conclusion
Crushed stone, the types of which should be known to the builder before purchasing the goods, can have a certain type of screening. For the reason that it is a by-product, the cost price is extremely low. For example, the price of gravel screenings is much less by 60% compared to the cost of gravel.