Forest is a raw material for the production of building materials. Raw materials for the production of building materials. Forest building materials

PAGE 3

Lecture 2 on the discipline “Building materials” for 1st year (bachelor’s degree)

Subject. Raw materials for the production of building materials. Natural stone materials

1. Natural raw material base for the production of construction materials and fishing

The raw materials for the manufacture of all inorganic building materials (stone and metals) are rocks.

Building materials from rocks can be obtained in two ways: mechanical processing and chemical processing (most often roasting).

Natural stone materials in construction are stones obtained by mechanical processing of rocks - crushing, sawing, splitting, textured surface treatment. Natural stone materials preserve the structure of the rock. Some rocks, destroyed by nature itself, may represent a ready-made construction material(sand, gravel, etc.).

Stone casting products are produced by melting stone and then pouring the melt into molds. The technology of stone casting is called petrurgy (the word “petr” means stone). Petrurgy is used to produce non-porous stone products or products of complex shapes.

By chemical processing of rocks, such common materials (binders) as lime, cement, building gypsum, etc. are obtained. One of the most accessible rocks for mining, clay, has been subjected to chemical processing and firing since ancient times. As is known, bricks and ceramics, including construction products, are made from clay.

Metals are also obtained from rocks called ores. Ore is a rock containing a significant percentage of metal. At the same time, it must be technologically acceptable and economically feasible to extract metal from such a rock. For example, ores containing iron oxides in a free state are the main raw materials for metallurgy. But widespread rocks called ferromagnesian silicates are not used for the extraction of iron or magnesium. They contain a small percentage of metal, and extracting it from the rock is difficult and expensive.

The main raw materials for organic materials oil and coal can also be classified as rocks. Bitumen and tars are obtained from oil and coal and are used for roofing materials and road construction. Petroleum and coal processing products are used to produce construction plastics

The oldest building material of organic origin is wood. Mechanical processing of wood produces materials that preserve its structure. These are not only well-known logs and boards, but also, for example, decorative and finishing materials - veneer made from valuable wood species.

2. Secondary raw materials in the production of construction materials and fishing

Along with natural raw materials, so-called man-made waste is used in the production of building materials. Industry produces significantly less finished products than it consumes raw materials. For example, to produce 1 ton of cast iron, 1.5... 2 tons of raw materials are consumed. Therefore, 0.5... 1 t is production waste.

Man-made waste may include gaseous, liquid and solid products. Many of them pollute air and water. It is known that the capture and neutralization of hazardous waste began to be carried out only in connection with the rapid development of industry in the late 19th and early 20th centuries. This problem has not yet been completely resolved.

Technogenic waste, including those obtained during the purification of industrial wastewater, gas and dust emissions, can be reused as raw materials in the same or another production. Of the industries that consume industrial waste, the most intensive is the construction materials industry. It has been established that the use of industrial waste can cover up to 40% of construction needs for raw materials. The use of industrial waste makes it possible to reduce the cost of producing building materials by 10...30% compared to their production from natural raw materials. In addition, industrial waste can be used to create new building materials with high technical and economic indicators.

It is convenient to classify waste by industry.

Ferrous metallurgy slags. Among them highest value for the construction industry, blast furnace slag is a by-product of iron smelting in blast furnaces. As is known, ore is melted in a blast furnace. The melt is divided into two layers: metal at the bottom and slag at the top. Thus, the slag is a fused stone. In metallurgical areas, solidified slag dumps occupy a lot of usable land (slag yield is about 0.5 tons per ton of cast iron). The construction industry consumes both monolithic slag after crushing into crushed stone, and specially prepared granulated slag. The simplest method of granulation is dry: a thin stream of molten slag pours from a great height, dividing into drops, which solidify and form slag granules. There are also wet and semi-dry granulation methods. The purpose of granulation is to obtain non-crystallized (amorphous, glassy) stone, which is chemically more active than the slag crystallized in dumps. The granules are ground into powder and used in the production of cement. Crushed stone obtained by crushing waste slag is used as a filler for concrete. For lightweight concrete, slag pumice and porous slag are made. The essence of making slag pumice is that molten slag with a temperature of about 1300ºC is processed cold water. Due to the instantaneous evaporation of water and the associated rapid cooling of the slag, the viscosity of the slag increases. Steam bubbles cannot overcome the plastically viscous state of the melt, they get stuck in it and swell it. The result is a light, porous material reminiscent of natural pumice.

Sludge general name for sedimentary suspensions obtained in metallurgical and chemical industries during liquid processing of various materials. For example, from nepheline when producing alumina from it ( Al2O3 ) the result is a sludge containing white Ca 2 SiO 4 . Belite is part of Portland cement, so belite sludge is used in the production of binders. When aluminum is washed out of clay using acid treatment, a sludge rich in SiO2 (sishtof), which is also used as an additive to cements.

The given examples of sludge are waste from non-ferrous hydrometallurgy. Sludge is also generated in many other industries. For example, in the pulp and paper industry, mechanical wastewater treatment produces sludge containing cellulose fibers and kaolin particles, which can also be used in the production of building materials. When ores are enriched by flotation, slurries (flotation tailings) are also formed, which contain the so-called “waste” rock (the name is in contrast to the concentrate, which after enrichment contains a lot of metal). For builders, “waste rock” is crushed stone that can be used in the production of unfired materials.

Ashes and slags of thermal power plants (TPP)mineral residue from combustion solid fuel. One medium-power thermal power plant discharges about 1 million tons of ash and slag into dumps per year. Fuel ash and slag contain all the bound or free oxides that are present in building stone materials. Therefore, they can be used in the production of almost all building materials and products.

Overburdenwaste from open-pit mining of various minerals (in quarries). This, as they say, is up to 3 billion tons per year (for the entire country) of the same stones, i.e. an essentially inexhaustible source for the building materials industry.

Wood waste, generated at cutting sites, sawmills, during the production of furniture, i.e. during mechanical processing of wood, amount to about 500 million m per year 3 . Of this huge amount of waste, only 1/6 is used in the construction materials industry (as well as in the pulp and paper industry). For the production of building materials, wood chips, shavings, and sawdust are used. Large sawmill waste (slab, for example) and wood from cutting sites are crushed and used as a filler in chipboard, fibreboard, fiberboard, wood concrete and other binder materials.

Listed here are just some of the types of waste used in the production of SM. The use of man-made waste is an integral feature of all resource-saving technologies. When using waste, as a rule, the environment improves due to the reduction of dumps, landfills, harmful emissions waste water and gases.

All subsequent lectures, except for metals, were adapted to the first course only during the reading process. Materials from the first chapter of our textbook (Andreev et al. Materials Science) are not repeated here.

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted on http://www.allbest.ru/

Wood as a building material

Wood as a building material has a number of positive properties: it has relatively high strength, low density, low thermal conductivity, and is easy to machine.

At the same time, wood also has a number of disadvantages: it is susceptible to rotting and is easily flammable; different indicators of strength and thermal conductivity along and across the fibers complicate its operation and application; The hygroscopicity of wood often leads to changes in its size. Among other things, wood is prone to warping and cracking. When manufacturing wooden products, significant waste is generated (sawdust and shavings account for up to 40%).

Depending on the degree of processing, they distinguish: forest materials obtained only by mechanical processing; finished products and structures manufactured in workshops and factories, as well as synthetic materials obtained through deep processing of wood.

The most widely used types of trees in construction are pine, spruce, larch, fir and cedar. Mostly load-bearing wooden structures are made from them. The most widely used wood is pine. Spruce wood contains less resinous substances than pine, and therefore rots more easily in conditions of high and variable humidity.

Hardwood wood has less durability and uniformity. The most valuable hardwood species is oak, the wood of which is very hard and durable.

Semi-finished products and construction products

Semi-finished products and construction products are made from coniferous and hardwood with a moisture content not exceeding 12% for the finished floor and 15% for other parts. wood construction semi-finished product plywood

Depending on the type of processing, this group of wood materials includes: planed bars, planed and tongue-and-groove boards for finished floors, parquet, plywood, profile materials - skirting boards, fillets, railings, platbands, etc.

Tongue boards Unlike conventional edged boards, they have a tongue (notch) on one side of the edges, and on the other - a ridge that fits into the tongue of the adjacent board. The tongue and groove, with the help of which the boards fit tightly, may have different shape- rectangular, triangular, trapezoidal and segmental. Tongue and groove boards are used for flooring, partitions and other work.

Profile materials- skirting boards and fillets - used for sealing corners between the wall and the floor, handrails - for stair railings and platbands - for covering window and door openings.

Parquet produced in the form of parquet boards, type-setting and piece parquet with a wood moisture content of 8±2%. Parquet boards consist of two layers: the top - a front covering of parquet strips 6-8 mm thick and the bottom - in the form of a slatted base 18-19 mm thick. Parquet planks are made from high-quality wood: oak, beech, ash, pine, larch, maple, elm and some other species.

The basis for parquet boards is wood of various types of wood, including cedar, pine, spruce, fir, as well as antiseptic-treated wood of birch, alder, aspen, etc. The planks of the front layer of parquet boards are glued to the base with waterproof synthetic adhesives. Parquet boards have an edge on one side - a groove, and on the other - a ridge for a tight connection when laying the boards into a parquet floor. They have the following advantages compared to piece parquet: less consumption of valuable wood, more durable sticking of parquet planks, higher degree of mechanization of production and higher speed of flooring.

Stacked parquet is a set of parquet strips (13 hardwoods: oak, beech, etc., glued face down onto paper in a certain order). After laying the type-setting parquet on the prepared floor base, the paper along with the glue is removed and the parquet floor is finished accordingly.

Block parquet consists of hardwood strips of a certain size and shape.

Plywood- sheets obtained by gluing three or more thin layers of wood veneer with mutually perpendicular arrangement of wood fibers. Plywood veneer is made on special peeling machines by cutting a layer of wood in the form of a continuous wide strip and then cutting it into format sheets. Plywood can be ordinary (glued), decorative and baked. Depending on the type of glue used, there is a distinction between plywood of the FSF brand, which has increased water resistance - glued with waterproof phenol-formaldehyde adhesives; medium water resistance grades FK and FBK - glued with urea or albumin casein adhesives; limited water resistance of the FB brand - glued with protein adhesives. To produce laminated plywood, pine, spruce, fir, alder, oak, birch and beech wood are widely used.

Decorative plywood is also made by hot pressing several layers of veneer impregnated with synthetic resin. During the hot pressing process, the wood texture of the surface layers becomes clearer, giving the plywood decorative look. Often to obtain the front surface of plywood one color. In different or varied colors, special textured papers, fabrics, or thin resin films impregnated with synthetic resins are used. Such colored papers, fabrics and films are firmly bonded to the wood during the hot pressing process, giving the plywood surface an original texture.

Posted on Allbest.ru

Similar documents

Natural and artificial building materials. Wood materials that have preserved its natural physical structure and chemical composition (timber), their division into processed and unprocessed. Basic properties and defects of wood.

course work, added 12/16/2010


Varieties and features tree species. Characteristics of the structure of a tree trunk. Description of the most common wood defects. Wood decay and fire, methods of protection. Scope of application of semi-finished products and structures made of wood.

abstract, added 06/07/2011


Characteristics of the properties of building materials. Mineral composition of igneous rocks. Gypsum binders, their properties. Rotting and antiseptic treatment of wood. Roll roofing materials. Technology for producing cement using the “wet” method.

test, added 07/25/2010


Properties of building materials. Area of ​​use of the building material. Metal roofing materials. Main characteristics of bitumen compositions. Structure of consumption of rolled roofing materials in Russia. Rolled roof coverings.

abstract, added 06/23/2013


Properties of road building materials. Methods for molding ceramic products. Natural stone materials. Raw materials, properties and application of low-burnt building gypsum. Basic processes required to produce Portland cement clinker.

test, added 05/18/2010


Positive and negative properties of wood, standards for types of forest products, permissible defects, humidity and hygroscopicity, the tendency of wood to rot and catch fire. Types of ceramic products by purpose, requirements for raw materials for production.

test, added 04/16/2010


Main types of wood. Physico-chemical processes during autoclave processing of lime-sand stones. Raw materials for the production of thermal insulation materials. Plastic processing methods. Production of reinforced concrete products using the flow-aggregate method.

test, added 03/30/2010


Characteristics of prestressed reinforced concrete and its advantages over conventional concrete. Definition and structure of wood. Mineral wool manufacturing process. Basic soundproofing materials. Purpose of mortars.

test, added 05/12/2009


Properties, composition, technology of basalt production. A device for producing continuous fiber from thermoplastic material. Description and claims, product characteristics. Types of building materials. Application of basalt in construction.

abstract, added 09.20.2013


general characteristics development of construction business in pre-revolutionary Russia. Standardization and personnel, basic building materials, structures: wooden, load-bearing, reinforced stone, mixed. Mechanization construction work. Residential and public buildings.

Costs for building materials, products and structures account for 50-70% of the construction cost. That's why it's so important to know how to minimize costs. This can be done through the use of modern resource and energy saving technologies, local raw materials, industrial waste. At the same time, materials, products and structures are required to ensure the required quality.

Construction Materials - natural and artificial materials and products used in the construction and repair of buildings and structures. There are building materials for general and special purposes.

The following classification criteria are chosen: the industrial purpose of building materials, the type of raw materials, the main quality indicator, for example their weight, strength, and others. Currently, the classification also takes into account functional purpose, for example, thermal insulation materials, acoustic materials and others, in addition to dividing into groups based on raw materials - ceramic, polymer, metal, etc. One part of the materials combined into groups is natural, and the other part is artificial.

Each group of materials or their individual representatives in industry correspond to certain industries, for example, the cement industry, glass industry, etc., and the systematic development of these industries ensures the implementation of construction plans.

Natural, or natural, building materials and products are obtained directly from the bowels of the earth or by processing forest areas into “industrial timber”. These materials are given a certain shape and rational dimensions, but their internal structure and composition, for example chemical, are not changed. More often than other natural materials, forest (wood) and stone materials and products are used. In addition to them, in finished form or with simple processing, you can obtain bitumen and asphalt, ozokerite, casein, kir, some products of plant origin, such as straw, reeds, brome, peat, husks, etc., or animal products, such as wool, collagen, Bonn blood, etc. All these natural products are also used in relatively small quantities in construction, although forest and natural stone materials and products remain the main ones.

Artificial building materials and products are produced mainly from natural raw materials, less often from industrial by-products, Agriculture or raw materials obtained artificially. The produced building materials differ from the original natural raw materials both in structure and in chemical composition, which is associated with the radical processing of raw materials in a factory using special equipment and energy costs for this purpose. Factory processing involves organic (wood, oil, gas, etc.) and inorganic (minerals, stone, ores, slag, etc.) raw materials, which makes it possible to obtain a diverse range of materials used in construction. There are large differences in composition, internal structure and quality between individual types of materials, but they are also interconnected as elements of a single material system.

Rice. 1. Types of lumber: 1 - sawing wood into boards; 2 - boards after drying; 3 - beam; 4 - trimming plates; 5 - trimmed quarters; 6 - sawing the trunk into bars; 7 - left - plate; on the right is a log chopped into firewood; 8 - sun lounger Fig. 1. Types of lumber: 1 - sawing wood into boards; 2 - boards after drying; 3 - beam; 4 - trimming plates; 5 - trimmed quarters; 6 - sawing the trunk into bars; 7 - left - plate; on the right is a log chopped into firewood; 8 - sun lounger

Wood is a material obtained from a tree trunk that has been cut down and cleared of bark and branches. It should be noted that this material is the most widely used and favorite in household work (and not only in them). Wood is a material obtained from a tree trunk that has been cut down and cleared of bark and branches. It should be noted that this material is the most widely used and favorite in household work (and not only in them). The properties of wood are determined by the type of tree, its structure and which part of the trunk it belongs to. The properties of wood are determined by the type of tree, its structure and which part of the trunk it belongs to. For carpentry and joinery work, it is best to use coniferous wood: it planes well, glues firmly, is painted, does not warp or dry out. For carpentry and joinery work, it is best to use coniferous wood: it is well planed, firmly glued, painted, does not warp or dry out.

Wood species used in construction Wood species used in construction All wood is divided into groups: coniferous and deciduous. The latter are hard-leaved and soft-leaved in terms of strength. All wood is divided into groups: coniferous and deciduous. The latter are hard-leaved and soft-leaved in terms of strength. Coniferous trees Coniferous trees Coniferous trees Coniferous trees Hardwood trees Hardwood trees Hardwood trees Hardwood trees Softwood trees Softwood trees Softwood trees Hardwood lumber Hardwood lumber Hardwood lumber Hardwood lumber Roundwood coniferous round timber coniferous round timber coniferous round timber softwood lumber softwood lumber softwood lumber softwood lumber

In each year of the tree's life, a one-year ring is formed. In each year of the tree's life, a one-year ring is formed. In spring, tree cells are less dense and durable (early wood) than in summer and autumn (late wood); in addition, the first ones are lighter in color. In spring, tree cells are less dense and durable (early wood) than in summer and autumn (late wood); in addition, the first ones are lighter in color. In the central part of the trunk there is a core of loose tissue surrounded by rings. In the central part of the trunk there is a core of loose tissue surrounded by rings. The heartwood is in the middle and has the greatest density, resistance to decay, and is also darker in color than the outer sapwood, which is less valuable than the heartwood. However, not all trees have this internal structure. Therefore they are classified as follows. The heartwood is in the middle and has the greatest density, resistance to decay, and is also darker in color than the outer sapwood, which is less valuable than the heartwood. However, not all trees have this internal structure. Therefore they are classified as follows.

Sound wood: pine, larch, oak, ash - having light sapwood and a dark core. Sound wood: pine, larch, oak, ash - having light sapwood and a dark core. Sapwood: white beech, maple, birch; these breeds do not have a dark core. Sapwood: white beech, maple, birch; these breeds do not have a dark core. Mature wood: spruce, fir, red beech, linden; in these trees the wood is not divided into heartwood and sapwood, but the inner layers are stronger and more mature, as in heartwood. Mature wood: spruce, fir, red beech, linden; in these trees the wood is not divided into heartwood and sapwood, but the inner layers are stronger and more mature, as in heartwood.

Wood has a number of positive properties. Wood has a number of positive properties. The advantages of this material, which explain the reasons for its widespread use in construction, include, firstly, a fairly high compressive strength, the strength limit is MPa, and the tensile and bending strength limit is MPa; secondly, lightness - the average density of wood is approximately kg/m3 (for the most common species of pine, spruce, larch, oak). The advantages of this material, which explain the reasons for its widespread use in construction, include, firstly, a fairly high compressive strength, the strength limit is MPa, and the tensile and bending strength limit is MPa; secondly, lightness - the average density of wood is approximately kg/m 3 (for the most common species of pine, spruce, larch, oak).

Wood of any species tends to warp and swell under the influence of heat and moist air; wood is said to breathe. This can happen in three directions: Wood of any species tends to warp and swell under the influence of heat and moist air; wood is said to breathe. This can happen in three directions: 1) in the longitudinal direction (i.e. along the trunk), the wood breathes very little, and the amount of deformation (shrinkage or swelling) is 0.1-0.3%, which is not significant for work; 1) in the longitudinal direction (i.e. along the trunk) the wood breathes very little, and the amount of deformation (shrinkage or swelling) is 0.1-0.3%, which is not significant for work; 2) in the radial direction about 5%; this is a noticeable amount; 2) in the radial direction about 5%; this is a noticeable amount; 3) in the direction of the annual rings, i.e. tangentially (tangently) to them, the shrinkage value can be 1012%, which is very important to take into account when working with wood. 3) in the direction of the annual rings, i.e. tangentially (tangently) to them, the shrinkage value can be 1012%, which is very important to take into account when working with wood.

Pine. Pine wood has medium density, very high strength and resistance to decay; relatively durable, moderately flexible and elastic; crackability is moderate. Relatively easy to process, it is one of the best ornamental materials; can be used for both internal and external structures; It is especially often used for the manufacture of wooden structures, floors and furniture. Pine. Pine wood has medium density, very high strength and resistance to decay; relatively durable, moderately flexible and elastic; crackability is moderate. Relatively easy to process, it is one of the best ornamental materials; can be used for both internal and external structures; It is especially often used for the manufacture of wooden structures, floors and furniture. Spruce. In terms of strength and resistance to decay, it is somewhat inferior to pine. The wood is light, soft, white; very flexible and elastic, withstands high loads, easily splits, and has high tensile strength. Due to the abundance of knots, it is more difficult to process and not as clean as pine wood. Low resistance to variable action of humid and dry atmosphere. It is used in construction, for various crafts and for the manufacture of musical instruments. Spruce. In terms of strength and resistance to decay, it is somewhat inferior to pine. The wood is light, soft, white; very flexible and elastic, withstands high loads, easily splits, and has high tensile strength. Due to the abundance of knots, it is more difficult to process and not as clean as pine wood. Low resistance to variable action of humid and dry atmosphere. It is used in construction, for various crafts and for the manufacture of musical instruments. Fir has a straight, slender trunk. It is a light and soft wood that is moderately durable, has high compressive and bending strength, and is easy to split. Due to the absence of resin passages through which the resin penetrates into the inner layers of the trunk, fir is less resistant to decay than spruce. It is used in the same way as pine, and, in addition, for the manufacture of musical instruments. Fir has a straight, slender trunk. It is a light and soft wood that is moderately durable, has high compressive and bending strength, and is easy to split. Due to the absence of resin passages through which the resin penetrates into the inner layers of the trunk, fir is less resistant to decay than spruce. It is used in the same way as pine, and, in addition, for the manufacture of musical instruments.

Larch. Its wood is light, it is harder and richer in resin than pine, it is distinguished by high strength and elasticity, and splits easily; breathes little. This is the hardest and most durable softwood. Difficult to process; good for construction work. Used for the same purposes as pine. Larch. Its wood is light, it is harder and richer in resin than pine, it is distinguished by high strength and elasticity, and splits easily; breathes little. This is the hardest and most durable softwood. Difficult to process; good for construction work. Used for the same purposes as pine. Cedar. More resistant to decay than pine. The wood is yellowish or reddish in color, light, easy to cut; used as a building material. Cedar. More resistant to decay than pine. The wood is yellowish or reddish in color, light, easy to cut; used as a building material. Oak. Its wood is hard, heavy, very strong and tough; resistant to decay, bends well; extremely durable, dries out and swells little. Resists weather well and wears little; remains indefinitely under water. An oak tree that has lain underwater for a long time turns black; it is called moraine. Often used to make tools, wood plugs, parquet and plank floors, thresholds and doors, furniture and waterworks. Oak. Its wood is hard, heavy, very strong and tough; resistant to decay, bends well; extremely durable, dries out and swells little. Resists weather well and wears little; remains indefinitely under water. An oak tree that has lain underwater for a long time turns black; it is called moraine. Often used to make tools, wood plugs, parquet and plank floors, thresholds and doors, furniture and waterworks.

Red beech has hard, heavy, durable and ductile wood. It splits easily and resists tearing and shearing deformations well. Not very resistant to alternating effects of humidity and dryness, does not withstand long-term loads; breathes heavily. It is mainly used for the manufacture of tools, wooden plugs, plank and parquet floors, door thresholds, stair steps, fittings, plywood and a number of carpentry works. Red beech has hard, heavy, durable and ductile wood. It splits easily and resists tearing and shearing deformations well. Not very resistant to alternating effects of humidity and dryness, does not withstand long-term loads; breathes heavily. It is mainly used for the manufacture of tools, wooden plugs, plank and parquet floors, door thresholds, stair steps, fittings, plywood and a number of carpentry works. White beech. It is a very hard, heavy and tough wood that does not split easily; persists only in a dry atmosphere; breathes heavily; low elasticity. Commonly used for making tools, planes, chisel handles and wooden hammers. White beech. It is a very hard, heavy and tough wood that does not split easily; persists only in a dry atmosphere; breathes heavily; low elasticity. Commonly used for making tools, planes, chisel handles and wooden hammers. Ash. Its wood is similar in properties and appearance to oak; relatively heavy and hard, very elastic and viscous; but, unlike him, short-lived; breathes little. Well processed; used for the manufacture of hammer handles and ax handles, sports equipment. Ash. Its wood is similar in properties and appearance to oak; relatively heavy and hard, very elastic and viscous; but, unlike him, short-lived; breathes little. Well processed; used for the manufacture of hammer handles and ax handles, sports equipment. Maple. The wood is dense, hard, and easy to process. Scope of application: parts of furniture, musical instruments, planes, etc. Maple. The wood is dense, hard, and easy to process. Scope of application: parts of furniture, musical instruments, planes, etc.

Birch has a homogeneous, medium-density wood. Used in furniture production as an ornamental material. Particularly valuable is Karelian birch wood, which is used for finishing furniture. Birch has a homogeneous, medium-density wood. Used in furniture production as an ornamental material. Particularly valuable is Karelian birch wood, which is used for finishing furniture. Linden. The wood of this tree is uniform and soft, easy to process with a knife, chisel, or cutters. It is used to make plywood, various crafts, wooden dishes, musical instruments. Linden. The wood of this tree is uniform and soft, easy to process with a knife, chisel, or cutters. It is used to make plywood, various crafts, wooden dishes, and musical instruments. Alder is a light-colored wood that turns red in the air and resists moisture well. Used for the manufacture of plywood, containers, furniture. Alder is a light-colored wood that turns red in the air and resists moisture well. Used for the manufacture of plywood, containers, furniture.

Wet wood quickly rots and does not glue well: objects made from it warp and crack. Therefore, it is most advisable to work with wood that contains no more than 18% moisture by weight of the wood. In freshly cut oak this value is 5070%. Wet wood quickly rots and does not glue well: objects made from it warp and crack. Therefore, it is most advisable to work with wood that contains no more than 18% moisture by weight of the wood. In freshly cut oak this value is 5070%. Therefore, to obtain wood suitable for carpentry, it is kept in the fresh air for 1 to 3 years. Dried wood is well processed, firmly glued, painted, does not warp or dry out. Edged and planed boards dry better. Therefore, to obtain wood suitable for carpentry, it is kept in the fresh air for 1 to 3 years. Dried wood is well processed, firmly glued, painted, does not warp or dry out. Edged and planed boards dry better.

Wood materials and products are divided into several groups: timber obtained by mechanical processing of wood; modified wood treated with synthetic resins, pressed, plasticized with ammonia, etc.; wood products plywood, wood panels, particle boards and wood fiber boards, wood-laminated plastics, etc. Materials and wood products are divided into several groups: timber obtained by mechanical processing of wood; modified wood treated with synthetic resins, pressed, plasticized with ammonia, etc.; wood products plywood, wood panels, particle boards and wood fiber boards, wood-laminated plastics, etc. Timber products are divided into round, sawn, peeled, milled (planed), chipped and by-products sawdust, shavings, chips, wood flour. Timber products are divided into round, sawn, peeled, milled (planed), chipped and sawdust by-products, shavings, wood chips, and wood flour. Round timber, i.e. trunks of a fallen tree, cleared of branches. They are divided into parts (bucking) of different lengths: logs, ridges, blocks. By thickness, round timber is divided into large with a diameter of more than 26 cm, medium from 14 to 24 cm, small from 6 to 13 cm. Even thinner timber from 3 to 7 cm is called poles. Round timber, i.e. trunks of a fallen tree, cleared of branches. They are divided into parts (bucking) of different lengths: logs, ridges, blocks. By thickness, round timber is divided into large with a diameter of more than 26 cm, medium from 14 to 24 cm, small from 6 to 13 cm. Even thinner timber from 3 to 7 cm is called poles.

Depending on the quality of the wood (presence of defects) and defects during processing, round timber is divided into four grades, of which the 2nd and 3rd are mainly used in construction. Depending on the quality of the wood (the presence of defects) and defects during processing, round timber is divided into four grades, of which the 2nd and 3rd are mainly used in construction.

Lumber is divided into beams, beams, plates, quarters, boards and slabs. The bars have a thickness of less than 100 mm and a width of no more than double the thickness. The beams have a thickness and width of more than 100 mm; the boards are less than 100mm thick and more than double the width. Beams and boards can be edged or unedged (the edges are not sawn or sawn less than half the length). Boards thinner than 32 mm are called thin or planks. The length of the boards is from 1 to 6.5 m. Lumber is divided into bars, beams, plates, quarters, boards and slabs. The bars have a thickness of less than 100 mm and a width of no more than double the thickness. The beams have a thickness and width of more than 100 mm; the boards are less than 100mm thick and more than double the width. Beams and boards can be edged or unedged (the edges are not sawn or sawn less than half the length). Boards thinner than 32 mm are called thin or planks. The length of the boards is from 1 to 6.5 m. Coniferous boards and beams are divided into five grades: selected, 1st, 2nd, 3rd and 4th. In carpentry production, only grades 1 and 2 are used. The maximum width of boards and beams is 250 mm, for beams 200 mm. Hardwood lumber is divided into three grades. Coniferous boards and beams are divided into five grades: selected, 1st, 2nd, 3rd and 4th. In carpentry production, only grades 1 and 2 are used. The maximum width of boards and beams is 250 mm, for beams 200 mm. Hardwood lumber is divided into three grades.

For the production of parts of finished products, so-called blanks of boards and beams are used, cut to specified dimensions and with allowances for machining and drying. They are used for glued structures, as well as for the manufacture of skirting boards, fillets, cornices, platbands, etc. For the production of parts of finished products, so-called blank boards and beams are used, cut to specified dimensions and with allowances for machining and drying. They are used for glued structures, as well as for the manufacture of skirting boards, fillets, cornices, platbands, etc. Wood products. Elements of small cross-section, wooden milled parts, called molded parts (they are measured in linear meters) - these are skirting boards, fillets, cornices, belts, platbands, handrails for stair railings, cladding, layouts, as well as boards and bars for flooring (they have a groove on one edge , to another ridge). Wood products. Elements of small cross-section, wooden milled parts, called molded parts (they are measured in linear meters) - these are skirting boards, fillets, cornices, belts, platbands, handrails for stair railings, cladding, layouts, as well as boards and bars for flooring (they have a groove on one edge , to another ridge).

Rice. 2. Bars: a - two-edged; b – three-edged; c - four-edged (or clean) Fig. 2. Bars: a - two-edged; b – three-edged; c - four-edged (or clean) lumber. The trunk can be sawed into beams, whetstones, planks, obapoles, plates and quarters. Lumber with sawn edges is called edged, with unsawn, unedged. Lumber. The trunk can be sawed into beams, whetstones, planks, obapoles, plates and quarters. Lumber with sawn edges is called edged, with unsawed unedged. The beams (Fig. 2) are manufactured with a thickness of more than 100 mm and up to 400 x 400 mm. They can have two, three or four sides sawn; in these cases they are called two-, three- and four-edged, respectively. The beams (Fig. 2) are manufactured with a thickness of more than 100 mm and up to 400 x 400 mm. They can have two, three or four sides sawn; in these cases they are called two-, three- and four-edged, respectively.

Rice. 3. Bars: a - purely edged; b - with blunt wane; c - with sharp wane Fig. 3. Bars: a - purely edged; b - with blunt wane; c - with sharp wane The bars (Fig. 3) have a thickness of mm, and a width of no more than double the thickness. They can be purely edged or have the side surface of the log remaining untouched, the so-called wane. A small-format block is called a lath. The bars (Fig. 3) have a thickness of mm, and a width of no more than double the thickness. They can be purely edged or have the side surface of the log remaining untouched, the so-called wane. A small-format block is called a lath.

Rice. 4. Boards: a - purely edged; b - unedged; c - one-sided edged; 1 - outer face; 2 - edge; 3 - end; 4 – wane Fig. 4. Boards: a - purely edged; b - unedged; c - one-sided edged; 1 - outer face; 2 - edge; 3 - end; 4 – wane Boards (Fig. 4) are edged, unedged and one-sided edged with a thickness of mm, a width of up to 275 mm and a length of up to 6.5 m. The wide part of the board is called the face, the narrow edge, the end edge the end. The face “looking” at the periphery of the log is called the outer (or right) one, and the inner (left) one at the core of the log. Boards (Fig. 4) are edged, unedged and one-sided edged with a thickness of mm, a width of up to 275 mm and a length of up to 6.5 m. The wide part of the board is called the face, the narrow edge is the end face. The face “looking” at the periphery of the log is called the outer (or right), and the face at the core of the log is called the inner (left).

Obapols are waste left over from sawing logs. They look like part of a cylinder, cut off by a plane parallel to the cylinder axis. Obapols are waste left over from sawing logs. They look like part of a cylinder, cut off by a plane parallel to the cylinder axis. Plates are obtained by sawing logs in half along the grain, and quarters by sawing the plates lengthwise into two equal parts. Plates are obtained by sawing logs in half along the grain, and quarters by sawing the plates lengthwise into two equal parts. Wood materials (WM). These are structural, insulating and ornamental materials produced on the basis of wood. The technology is hot pressing of sawdust, shavings, fibers that are mixed with a binder, or gluing sheets of peeled veneer into thin sheets of wood obtained by peeling short logs on special walls. In some cases, DM have advantages over natural wood, in particular, they surpass it in performance properties, as well as in size. DM includes the following materials: plywood, fibreboard (fibreboard), particle board (chipboard), wood plastics. Wood materials (WM). These are structural, insulating and ornamental materials produced on the basis of wood. The technology is hot pressing of sawdust, shavings, fibers that are mixed with a binder, or gluing sheets of peeled veneer into thin sheets of wood obtained by peeling short logs on special walls. In some cases, DM has advantages over natural wood, in particular, it surpasses it in performance properties, as well as in size. DM includes the following materials: plywood, fibreboard (fibreboard), particle board (chipboard), wood plastics. Plywood. This type of DM is glued together from sheets of peeled veneer, and in adjacent layers the wood fibers are located perpendicular to each other. In the production of plywood, the wood used is pine, spruce, larch, birch, beech, maple, and hornbeam. Types of plywood used for various purposes can be divided into several groups depending on the area of ​​application (table Plywood. This type of DM is glued together from sheets of peeled veneer, and in adjacent layers the wood fibers are located perpendicular to each other. In the production of plywood, pine wood is used, spruce, larch, birch, beech, maple, hornbeam. Types of plywood used for various purposes can be divided into several groups depending on the area of ​​application (table).

In recent years, glued structures, large-sized elements made by gluing relatively small wooden blanks to each other or to other materials, arches, I-beams, blocks, etc., have been increasingly used. They are made using waterproof and high-strength polymer adhesives. In recent years, glued structures, large-sized elements made by gluing relatively small wooden blanks to each other or to other materials, arches, I-beams, blocks, etc., have been increasingly used. They are made using waterproof and high-strength polymer adhesives. They are more durable, water-resistant, bio- and fire-resistant than conventional wood structures, and are not subject to shrinkage and warping. The use of laminated veneer lumber is one of the most cost-effective ways to use wood in construction. They are more durable, water-resistant, bio- and fire-resistant than conventional wood structures, and are not subject to shrinkage and warping. The use of laminated veneer lumber is one of the most cost-effective ways to use wood in construction.