Natural and artificial materials. Artificial stone materials. Natural stone materials
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Stone materials
The main properties of building stone are durability, easy accessibility, workability, strength, uniformity, color, texture, etc. The requirements for building stone depend on the nature of the structure.
Resistance (and, consequently, durability) - depends mainly on the porosity of the building stone, since the freezing of water in the cavities leads to the formation of chips and cracks in it. Expansion and contraction associated with temperature changes can lead to cracking.
Vibrates for full penetration into forms. As a measure, 18 liters can be used. The specific application is related to its use and needs reinforcement or not. From materials that will be used in the processes of building architecture, urbanism, landscaping and civil engineering. To enable the learner to recognize in practice the basic materials and their basic properties for use.
Natural and artificial polymers
Structural Stones: Stacking or settling. Coverings: Gasket, gluing, connection. Aside from individual choice, the answer to this question varies greatly depending on the region or period in which you are interested. It also varies depending on whether it focuses on housing, jobs, industrial construction, or large structures. While man-made materials currently dominate construction techniques in Europe, this is not always the case, and it is still not the case in many parts of the world.
Bulk mass is the mass of a unit volume of material in natural state... The bulk density of dense igneous rocks is on average 2.5 and higher, which means the mass of 1 m3 of rock in the massif is 2.5 tons. Crushed stone from this stone, taking into account the voids, has a bulk density of 1.7 m3. The volumetric mass of crushed stone from limestone is 1.6 tons.
Accessibility - depends mainly on the remoteness of the quarry and the conditions of transportation to the construction site. Freshly mined stone contains "quarry moisture", which makes it easier to work with.
Despite the avarice with which we consume travel, few of us realize that the two materials that still dominate the world's habitat are not the ones we are most familiar with, at least as building materials, It is wood and damp earth. For a long time, timber remained the majority in selected habitats around the world. Today it is marginal, but in North America and Siberia, Northern Europe and vast intertropical regions, it is the material king. Renewable resource, recyclable, lightweight, easy to work with, relatively good insulation, wood has only one notorious disadvantage: it must be combustible.
Strength - ability rocks resist mechanical stress.
Materials are divided into five strength classes: - strong and very strong (1st and 2nd classes) - unaffected or slightly affected by weathering - quartzite, granite, porphyry, basalt, marble-like and dense limestone and dolomite. Such breeds are suitable for all types road clothes, their ultimate strength is over 100 MPa; - medium hardness (3rd class) - the same rocks, but affected by weathering, as well as siliceous shales, uneven density limestones and sandstones. Stones of medium strength are widely used in road construction in the form of crushed stone. Tensile strength 60-80 MPa; - soft (4th class) - porous limestones, limestone dolomites, ferruginous, thin-film sandstones. They are used in the form of crushed stone when constructing bases for hard top coatings. Ultimate strength 30-40 MPa; - very soft (5th grade) - weathered igneous rocks, powdery, earthy limestones, weak sandstones, shales. They are used only with binders for the construction of crushed stone bases. Ultimate strength 80 MPa.
This weakness can be overcome, but at the cost of rather heavy chemical treatment. The versatility of using raw land is more amazing. Who knows, in our so-called "developed" countries, that about a third of humanity takes refuge in dry land structures? Who knows that a fifth of the buildings on the list of the architectural heritage of mankind are in the mud? Africa, the Middle East, Central Asia, the Himalayas, China, South America and Central America are full of miracles, the architects of which are the people themselves and whose materials are taken from the very place of construction.
Density is the mass per unit volume of an absolutely dense material without pores.
Uniformity is needed so that the structure does not look variegated.
The color of materials from sedimentary rocks depends on the dissolved mineral salts. In some materials, these mineral salts may cause discoloration spots due to weather conditions. Fading, i.e. the appearance of whitish spots on brick walls is caused by the deposition of salts on the surface during the evaporation of moisture from the masonry mortar and brick. Despite its unsightly appearance, fading is harmless and can be removed with a mild hydrochloric acid solution.
Who knows that in France, too, more than a million houses, mainly in Brittany, in the north, in the Center, in the southwest and in the Rhône-Alpes region, are in mud? Even their inhabitants sometimes do not know what their walls are made of, covered with plaster or cladding. The reason for this versatility of uncultivated land is simple: there is no need to build fertile land. Almost all clay compositions found on our planet lend themselves to the preparation of dried clay bricks - strapping - or compaction in formwork - overlapping.
Dry or compacted soil is not particularly strong or insulating, but it is far enough away to safely build multi-story buildings if the walls are thick enough. Therefore, thanks to the thickness, we get good insulation and, as a bonus, a very strong thermal inertia, which allows extreme temperature fluctuations to be humidified. Much more familiar than damp earth in our eyes, as Europeans are a natural stone, because the architectural heritage that drains France and more generally to Europe, millions of tourists are, in fact, a heritage natural stone.
Water absorption - the ability of a material to absorb water at normal atmospheric pressure. Strong rocks (igneous and sedimentary), due to their density, absorb water weakly. Their water absorption ranges from 0.5 to 1%.
Stone rocks of the 27th class have a higher water absorption -1.5-3%. Water absorption of rocks of the 3rd class - 3.5-8%, 4th and 5th classes 4-15%. Stone material with high water absorption capacity in its pure form is unsuitable for construction. To protect it from moisture saturation, it must be treated with bitumen, which creates a protective film on the stone surface.
Limestone and sandstone, two fairly soft rocks, granite and basalt, two fairly hard stones, separate most of the buildings. Limestone, which becomes marble when it can be polished, also dominates classical antiquity and the Middle East, while sandstone, siliceous and porous rock, is the subject of the temple cities of Southeast Asia.
Artificial stones: baked bricks and cement
An important step forward was artificial stone, which is as strong as natural stone, but capable of being molded rather than carved. Initially, the Mesopotamians realized that baking bricks from dried mud allows for increased hardness and resistance. Since then, cooked bricks have become, everywhere in the world, on all continents, a material for convenient construction, and they remain so. But unlike a stone that, properly cut, can fit dry, brickwork requires a binder.
Frost resistance - the ability of a material to withstand alternating freezing and thawing without significant signs of destruction or decrease in strength. Stone rocks are considered frost-resistant, which, during this test, lose up to 5% of the initial mass, rocks of medium frost resistance lose up to 10 , non-frost-resistant - more than 10%. The breeds of the first three classes are frost-resistant, since they lose up to 10% in weight, the 4th and 5th classes are non-frost-resistant, since they lose more than 15 original mass.
The Mesopotamians used bitumen, which only needs heating to melt and re-solidify in the cold; Egyptians are rough plaster made by preparing impure gypsum. Gypsum - calcium sulfate is a very soft limestone rock. When cooking, it loses some of the water it contains. By mixing the product obtained after grinding with water, the mineral restores the missing water. Then the gypsum crystals were transformed again, forming a ball of needles. As the crystals grow, the material loses its pasty character and becomes solid: it “takes”.
Compressive resistance is the resistance that is determined by the ultimate stress that occurs in a specimen under breaking load, or ultimate strength. Measured in MPa.
Abrasion resistance - the ability of crushed stone or gravel not to change their parameters at maximum loads. For hard igneous rocks, wear does not exceed 5% of the volume, for sedimentary - 6-7%, for soft 15-20%, gravel is considered strong with a wear rate of up to 25%, medium - up to 35, weak - up to 50 and very weak - over 50%.
Lime is another simple binder. It is obtained by calcining limestone rocks, this time containing calcium carbonate. During annealing, the stone loses its carbon dioxide and gives quicklime... Mixed with water, it produces a lime paste or air lime, which gradually absorbs carbon dioxide from the air by quenching. Lime is more water resistant than plaster, but its production requires heating the raw material to a higher temperature. The use of lime was familiar to most ancient peoples, including the Chinese, but it was the Greeks and especially the Romans who developed its use.
Natural stone materials a stone is mined from rocky rocks by mechanical processing: giving a certain shape and size, cleaning, grinding, polishing, obtaining different factions crushed stone and sowing.
Rocks by origin are divided into igneous and sedimentary:
Erupted - obtained as a result of the slow solidification of molten magma in the depths crust or fast solidification on its surface.
The Romans greatly improved the process by incorporating volcanic ash, pozzolana, or crushed bricks into the limestone. This addition gives lime a completely new property that brings it closer to our cements, to “catching” water and even under water. The chemical reaction in question is no longer a simple rehydration or recanification, but a more complex reaction of a pozzolan or brick with lime and water. No progress was made with regard to Roman cement during the Middle Ages, Renaissance, or the Classical era.
In the first case, crystalline rocks are formed: granite, syenite, diorite; in the second, vitreous rocks: liparite, trachyte, andesite, basalt, diabase. All these rocks are widely used in road construction.
Sedimentary - obtained as a result of the destruction of igneous rocks on the surface of the earth under the active influence various factors: water, wind, ice, high and low temperatures, etc.
Expertise was even largely lost and it was not until then, the empirical work of the Englishman John Smeaton, in the middle of the eighteenth century, and especially the French Louis Vick in the early nineteenth century, to understand that it is silica contained in pozzolana or crushed brick, which is the active element. From that point on, it became apparent that instead of baking the earth to make a brick and then shrinking that powdered brick and mixing it with lime that was obtained by calcining limestone, it was more Wiser and easier to calcine limestone and a source of silica in one operation.
They are subdivided into: - loose detrital rocks- consist of fragments of stone rocks of various sizes: boulders, pebbles, gravel, natural crushed stone, sand; - cemented clastic rocks - consist of compacted and cemented stone mineral particles: limestone, dolomite, sandstone, calcareous tuff, conglomerates, breccia.
The clay soil does the trick. Shrinks to powder and mixes with water - this mixing - this rock forms a moldable paste that hardens to form a grayish rock, harder than the binders known until then. All the mysteries of the chemical reaction underlying the catch have not been elucidated. What Le Chatelier has shown, and which remains true, is that when cement is mixed with water, the minerals in the cement grains begin to dissolve. This dissolution is not very noticeable because the paste is usually very concentrated, and the solutes - silica and lime - very quickly reconstruct new microscopic crystals that agglomerate and form a real hardened cement glue.
Stone materials are represented by the following types:
A stone checker is a roughly chipped stone of the 1st and 2nd classes truncated into a cone or pyramid with two processed parallel planes (the upper plane is larger in area than the lower one). It is used for paving in combination with tiles, fixing slopes, ditches, surface trays.
These new crystals have the peculiarity of incorporating water into their crystal structure - hence they are called "hydrates". Contrary to popular belief, the setting and hardening of cement is not due to the drying phenomenon, as is the case with clay brick. It's quite the opposite!
Artificial stone is constantly evolving, it is one of the most used materials in living spaces in last years... These products are, in some cases, attempts to imitate natural stone. Were there any rules for laying natural stone? Historically, our Freemason ancestors even refused to have their name applied to brickwork, perhaps because it was clear to them that the work of a bricklayer had different rules from that of a bricklayer, and that they wanted to preserve this difference. ...
Paving stones - chipped stone of the 1st and 2nd classes, close to a parallelepiped with parallel upper and lower planes. The bevel at the sole of low paving stones should not exceed 5 cm on each side. For medium and high paving stones - 10 cm. It is used in combination with tiles for fixing slopes, arranging a curb, decorative paving, on the surface of open trays.
First rule: avoid boxes. A box is a group of stones that together form a solid rectangle. Mortar solution around the clip. They are usually two to six stones, but may have more. To avoid them, you need to break the connection around the box or add a stone above or below. On the other hand, you have to be careful not to put the box down to a higher rank. It may be impossible under certain circumstances to avoid the box, such as in a small column, pilaster, or coronation of a wall.
Second rule: the height of the vertical joints. There is no vertical alignment in artificial stone like there is in brick. However, we must observe the following rule: never exceed the tallest of your stones. This rule was applied by the Freemasons when laying natural stone symmetric format different sizes... This rule allows for a homogeneous mixture in the facing of the masonry and is avoided.
Side stones (curbs) are parallelepiped-shaped elongated bars of hard and stone rocks with a length of 70 cm to several meters, with a vertical or inclined front face or two side faces and a treated surface of the visible part. Section dimensions: 10 × 20; 15 × 30; 20 × 30.
Stone tile - made of hard rocks of the 1st and 2nd classes by special machine sawing of various sizes and thicknesses. The thickness of the tiles (10-15 cm) makes it suitable for road surfaces; thin tiles up to 5 cm thick are used for cladding various structures, for which its upper surface is polished.
Third rule: length of horizontal joints
Horizontal joints are of paramount importance, they give appearance natural stone of our ancestors. As a general rule, the joint should never exceed four to five feet in length. stone has an effect similar to brick than stone. Little trick, trust your level 4 feet; you are already using it to level up your stone rank.
Fourth rule: crossing stones
Like a brick, a stone must overlap with other stones. What is the minimum overlap length? The rule of thumb points us to more or less four inches. Should this rule always apply? Surely you would place the brick one inch from the other joint? This rule is often ignored on construction sites and leads to a violation of another rule. If your stone only crosses an inch and a half, for example, your vertical hinge runs the risk of exceeding the tallest of your stones.
Rubble stone - pieces of limestone or sandstone - rock (strength class 3) up to 50 cm long and weighing 10-20 kg. It is used for laying retaining walls, pipes and bridges. Can be recycled into tiles with uneven edges and a smooth bottom surface, as well as checker and rubble.
The booth can be torn, platy (flagstone), stele. In the construction of houses, stone is used clean, without cracks, delamination and other defects. For ease of use, the weight of one stone should not exceed 50 kg. The quality of the buta is determined by striking it with a hammer. If the stone makes a clear sound and does not crumble, it is suitable for construction work.
Cobblestones and boulders can be of different sizes and shapes; large stones are split into smaller ones. Before laying, stones must be cleaned of dust and dirt.
Boulder stone is a coarse-rolled sedimentary rock (class 3) with a size of more than 100 mm, found in the North-Western and Central European part of the country, along forests and fields, where it was brought in during the ice age. Large stones are used to decorate lawns, create rocky gardens, and fill the banks of reservoirs. Stones of 10-30 cm (cobblestone) are used to create pavements, fasten slopes and open trays.
Pebbles and gravel - rounded rock fragments less than 100 mm in size; occur naturally in river valleys, on the shores of lakes and seas, in places where glacial deposits develop. If there are more than 50% of sand particles and at least 20% of gravel gravel material is called gravel-sand. According to the size of the fractions, gravel is divided into: very coarse (pebble) 70-100 mm; large 40-70; average 25-40; fine 15-25; very fine 10-15 mm; gravel fines 3-10 mm. Gravel material used for the construction of road bases and coatings, drainages; preparation of asphalt concrete.
Sand - small rounded fragments of rocks ranging in size from 0.1 to 5 mm, clean from clay and other impurities, various in grain size. According to the granulometric composition, the sand is divided into very coarse (grain size 2-1 mm); large (1-0.5); medium (0.5-0.25); small (0.25-0.1); thin - (0.1-0.05 mm). Clean coarse and medium-grained sands are used for pavement construction.
Crushed stone - angular, sharp-angled pieces of rocks of various strength classes, obtained as a result of natural destruction of rocks or their crushing in stone crushers. The shape of the rubble is a cube or tetrahedron. According to the granulometric composition, crushed stone is subdivided into: large (crushed stone size 40-70 mm); medium (25-40); small (15-25); clinically crushed stones (10-15); small stone (5-10); small seeding (3-5 mm).
By strength, crushed stone is subdivided into seven grades: M-1200; M-1000; M-800; M-600; M-400; M-300; M-200. Crushed stone of the first four grades is used in the bases of alleys and main roads, on objects with heavy traffic and pedestrians, in the construction of sports planar structures; the last three brands are used only for the construction of foundations for a hard top coating (tiles, asphalt, cobblestones).
Artificial stone materials
Brick. Ceramic brick made of clay by molding followed by firing in dimensions 250 × 120 × 65 mm. After firing, it is red in color, which is why it is often called red. Silicate is also used in construction, or white brick... It is made from a mixture of quartz sand with air lime. In terms of its performance, silicate brick is worse than ceramic, therefore it is not used in the walls of the underground part of the building and in some other critical structures. To reduce the density of ceramic bricks, burn-out additives are mixed in during its manufacture. Such a brick is called porous or hollow. Strength hollow brick lower than full-bodied, and better heat-shielding qualities. To lighten the mass of the walls and reduce thermal conductivity, perforated bricks and stones with holes of various shapes and numbers are produced. For the front row of external walls, use face brick... It can have a smooth, embossed or textured surface.
All types of bricks and artificial stones, depending on the mechanical strength, are divided into grades. The numbers of the brands correspond to the compressive strength of the brick. Ordinary plastic pressing ceramic bricks are produced in grades 75, 100, 125, 150, 200, 250 and 300. Silicate bricks are in grades 75 ... 250. According to frost resistance for bricks and stones, the brands Mrz 15 ... Mrz 50 have been established. The frost resistance of a brick required for the structure is taken depending on the humidity of the room, the operating conditions of the wall and the durability of the building.
Ceramic materials. For cladding facades, interior walls and floors of trade and public catering buildings are widely used ceramic slabs and stones. Ceramic materials are obtained from clay masses by molding and subsequent firing. Facade ceramics are lightweight, highly durable and beautifully colored. Such materials include facing bricks and stones, carpet ceramics, facade ceramic slabs. Carpet ceramics are small-sized thin-walled tiles of various colors glued to a paper base. It is used in the factory for cladding exterior wall panels. Depending on the method of fastening to the walls, ceramic facade slabs are divided into embedded, installed simultaneously with the masonry, and reclining, which are laid on the mortar after the construction and settlement of the walls. According to the location, the tiles are divided into flat - for facing a smooth surface, corner - for facing outer corners, openings and lintels - for facing lintels over windows and doors. Ceramic facade slabs are manufactured according to the strength of grades 75, 100 and 150 and frost resistance not lower than Mrz 25.
For cladding the internal surfaces of the walls of premises requiring high cleanliness (kitchens, blanks, bathrooms, etc.), ceramic, clay and earthenware tiles, square, rectangular and shaped, covered with white and colored glaze, are used. Tiles, sorted by type, color and grade, are stored indoors.
Ceramic tiles are used to cover the floors of premises with heavy traffic - trading halls, lobbies, stairwells, as well as floors of wet rooms - washing, shower rooms. They have low water absorption, high mechanical strength impact and abrasion. By the appearance of the front surface, the tiles are smooth and rough, in color - one-color and multi-colored. Tiles are produced in square, rectangular, triangular, four, five, six- and octagonal shapes with a thickness of 10 ... 13 mm.
Building mortars... They consist of astringent, water and fine aggregate. Mortars adhere firmly to the surface of the stones, creating a strong masonry. Masonry mortars are divided by density into two types: heavy -1700 ... 2200 kg / m3 and light - up to 1700 kg / m3. Aggregates for heavy mortars are sand, for light ones - slags, pumice, expanded clay. Light mortars are less durable than heavy ones, but have better heat-shielding qualities. Heavy mortars are prepared from cement, lime and sand (mixed mortar) or from cement and sand (cement mortar); lungs - from cement, lime and slag sand or from lime and slag sand.
In terms of strength, the solutions have grades 10 ... 200. The mortar used for laying walls should be easily laid in a thin layer, uniform in density, firmly adhered to the brick surface. The workability of the solution is characterized by its mobility, determined by the depth of immersion in the solution of the metal cone. Often cement mortars turn out to be tough and inconvenient to work, therefore plasticizers are added to them in the form of lime dough or finely ground stone flour. Mortars are also used in finishing works for applying a layer of plaster. In plaster solutions, air lime and stucco (alabaster) are most often used as a binder. For plastering rooms with a wet mode, lime with cement and hydraulic additives is used; under normal conditions, lime, lime-gypsum and cement-lime mortars are used.
Types of stone materials and their use in construction
Natural stone materials in construction are usually used after mechanical processing (splitting and trimming, sawing, grinding and polishing, crushing and sieving). All stone materials used in construction can be divided into two main groups: materials used in their original form, and materials suitable for construction purposes only after appropriate processing.
In some cases, the same material can be used in its original form or after processing. So, sand is used either directly from the quarry, or after preliminary washing, gravel - in its original form or after sorting and washing.
Rubble stone - large pieces irregular shape size 150X500 mm, obtained by the development of limestone, dolomite (less often granite and other igneous rocks). It is widely used for rubble and rubble concrete laying of foundations, underground walls, walls of unheated buildings, etc. Small pieces of rubble stone are usually processed into crushed stone.
Boulder - large fragments (more than 300 mm) of rocks of glacial origin, characterized by a rounded (without sharp corners), often strongly weathered surface. Used to obtain cobblestone and crushed stone.
Cobblestone - small boulders (up to 300 mm) or large split boulders. It is used to cover pavements, slopes. Large cobble stones can be used as rubble, small ones can be processed into crushed stone.
Gravel is a loose accumulation of rock fragments, variously rounded. The size of individual grains is 5-70 mm. Depending on the size, gravel is subdivided into fractions of 5-10, 10-20, 20-40 and 40-70 mm. Gravel is used in construction as a coarse aggregate in cement and asphalt concrete, as well as for paving.
Sand is a loose rock consisting of grains of minerals and rocks 0.15-5 mm in size. Sand as a building material is used for filling the foundations for roadways and other structures, as a fine filler in concrete and mortars. The strength of many depends on the quality of the sand. building materials made on the basis of cement. Therefore, if necessary, the sand is washed to remove dust and clay particles and sorted both by grain size and mineralogical composition.
In addition to the listed materials, materials obtained as a result of processing natural stone materials are widely used in construction.
Crushed stone is a mixture of angular stone fragments of various configurations ranging in size from 5 to 150 mm. It is made from rocks of various qualities, which determines its brand. The quality of crushed stone is determined by the ultimate compressive strength of the original rock. According to its ultimate strength, it is subdivided into grades from 200 to 1200. Crushed stone is obtained by crushing stone in stone crushers.
In construction, crushed stone is widely used for the preparation of asphalt and cement concrete mixtures.
Paving stones - chipped and hewn blocks of stone, in shape approaching a parallelepiped with the outer side in the shape of a rectangle. In terms of height, the paving stones are divided into low-10 cm, medium-11 -13 cm and high-14-16 cm.The width of all varieties is 12-15 cm, length is 15-25 cm.The upper and lower planes of the paving stones are parallel, and the side edges are narrowed down.
According to the type of processing, natural stone materials are divided into the following groups.
Roughly processed:
a) rubble stone - roughly chipped (during blasting operations) pieces of hard rock measuring 15 to 60 cm in diameter, weighing up to 40-50 kg;
b) crushed stone (artificial) - pieces of stone from 0.5 to 15 cm in diameter, obtained by crushing rubble stone to the required size;
c) sand and gravel, mined from natural deposits, without special processing, but sometimes sieved or washed.
Stones of regular shape - slabs and profiled products with variously processed surfaces (rough-chipped, hewn, sawn, ground, polished).
Roofing tiles are tiles obtained by splitting clay shale and trimming the edges without further processing. Slate tiles are made of rectangular or diamond-shaped shapes of various sizes: from 25 × 150 to 600 × 350 mm and a thickness of 4-8 mm. The disadvantage of these tiles is their heavy weight and fragility.
Stone materials
Structural layers of sports fields and fields coverings consist of natural and artificial building materials. Natural include soils, soils, crushed stone, gravel, sand, peat and humus; to artificial - slags in the form of crushed stone or sand, brick or tiled rubble and chips, sowing of construction waste, slaked lime. Bitumen, crushed rubber and rubber crumb are used for the device of covering of flat sports facilities from asphalt or rubber-bitumen mixtures.
When using this or that building material, you should take it into account physical properties- specific and volume weight, density and porosity, relation to the effects of water and the interrelated effect of temperature changes, water absorption and moisture yield, hygroscopicity and water permeability. During the construction of the cover layers, of great importance mechanical properties building materials - strength, hardness, indelibility, their relation to the action of heat and resistance to destruction ™.
Natural materials have high building qualities(durability, strength, frost resistance). They are economical, in most cases available and easy to process.
Rubble is called a building material obtained by crushing rocks, gravel or artificial stones. Crushed stone is classified as detrital rocks. During the construction of sites for the construction of the base of the structure, crushed stone with a size of up to 40-70 mm is used, for the intermediate layer of the structure - with a size of up to 10-20 mm, for skeletal and lean additives in the preparation of special and soil mixtures - with a size of up to 5 mm.
Gravel- the material formed as a result of natural destruction of rocks, - is rounded (with a flat surface) large grains. During the construction of sites for the construction of the base of the structure, gravel or gravel mixture with a particle size of up to 40-70 mm is used, for an intermediate layer - 10-20 mm, for lean additives in the preparation of special and soil mixtures - 3 - 5 mm. The gravel mixtures used for the construction of the bases are not standardized in terms of the grain size composition, frost resistance and the content of dusty particles, but when constructing intermediate layers, the grain composition is limited to the content of fractions up to 20 mm, and when using gravel mix as an enriching additive - up to 5 mm.
Sand is a loose mixture of grains formed as a result of the destruction of rocks or obtained by crushing. For the construction of sports grounds, natural, crushed, fractionated sand, the size of which is not more than 2.5 mm, is preferable. For the construction of layers, gravelly sand is used. It is placed in the base of the structure and introduced as skeletal and emaciated additives in the preparation of special and soil mixtures. Coarse sands are used as a wear layer for the coating and when filling the landing pits, for the structural layers of the training tracks, and unfractionated fine sand is used for the preparation of asphalt and rubber-bitumen mixtures.
Clay soils- loam or clay - during construction they are used as binders, as well as in the form of a filler in the composition of special and soil mixtures. Unconsolidated coarse crushed stone soils are used in the construction of the base and in the intermediate layers of the structure. Sandy soils require preliminary compaction.
The mechanical composition of the soil determines its main specific qualities - strength, moisture permeability, etc.
The soil- one of the main natural building materials. The constituent mechanical elements of the soil are sandy, silty or silty particles. Soils are used for the construction of subsoil and soil layers of lawn coverings, used as components in special mixtures. The soil mixture must be mechanically homogeneous and chemical composition... For the construction of sports grounds, soil is chosen, the composition of which should be close to light loam. The mixture of the subsoil layer is characterized by a high content of coarse sand fractions. Sometimes fermented sediments (decomposition product of sewage water) are used as a component of soil mixtures.
Peat(humus product) is divided into upstream, transitional and downstream. The structure of peat is determined by the degree of decomposition (weakly decomposed - 15-20%, medium decomposed - 20-35% and well decomposed - 35-65%). For sports lawns, only moderately decomposed peat with an ash content of 5-8% is used. For the construction of sports grounds, peat of low ash content is used (in the form of a structurally improving component of a moisture-absorbing layer). Peat with high ash content is used as a component of soil mixtures.
Artificial materials. Crushed slag is obtained by crushing and sorting dump metallurgical slags formed in the process of blast-furnace smelting of metals or during the combustion of mineral fuel. Slag crushed stone is used as skeletal and lean additives to the structural layers of the sites. To create a layer of wear of coatings, slag sands, low-activity slags and coke chips are used.
Brick go tiled rubble made by crushing and sorting brick scrap. Crushed stone (in small quantities) can be replaced sowing debris.
For the device of a layer of wear during the construction of coatings, brick chips must be small and even. Fluff lime is added to the composition of special and soil mixtures. It is obtained by slaking lump lime followed by sifting.
Bitumen for the preparation of mixtures is selected taking into account the temperature conditions in which the coating is to be used.
Rubber crumb prepared from rubber waste with a fraction of not more than 2 mm. The crumb contains particles with a size of 0.1 mm (not more than 5%), its moisture content should not exceed 1.5%.
In some cases, liquid pyridine rubber is added to the crumb rubber as a modifying element.
Mineral powder is crushed limestone or dolomite. It is used as a component of a binder - a mixture of bitumen or bitumen paste - in the preparation of asphalt-bitumen coatings. The powder should be clean, dry, loose, finely ground (except for clay particles).