Wood is one of the oldest building materials. Not only the various structural elements of buildings and structures are manufactured from it, but also build whole wooden buildings. Wood is a raw material for the manufacture of finishing materials, fibrolite, wood fiber and chipboard, for the production of furniture and parquet, such positive properties are promoted as high strength with small volumetric mass, low thermal conductivity and ease of mechanical processing. The disadvantages of wood include: the inhomogeneity of the structure that causes various indicators of strength and thermal conductivity along and across the fibers, exposure to rotting, combustibility and light margins, high hygroscopicity, the presence of various vices (bitch, cracks, blast, curvature of the trunk, etc.).
Considering the high physical and mechanical properties and a relatively small volumetric mass, for construction purposes, wood conifers are often used: pines, spruce, larch, cedar and less frequently wood hardwood: oak, beech, grab, maple, ash, birch- for temporary structures and auxiliary structures (formwork, canopies, doom) use soft hardwood wood: aspen, alder, poplar, linden,
Forest building materials used in construction are divided into round timber and lumber (Fig. 2.15).
Round timber The segments of wood trunks (different breeds) are purified from the crust and boring and, depending on the diameter in the upper end, are divided into log, Spacking and Pilia.
Breed have a diameter in the upper end at least 14 cm and the length of 4-6.5 m. Depending on the presence of wood vices, the logs used in the construction of the logs are divided into three categories, to the 1st and 2nd categories include logs without defects, Rotary and wormworms, to the 3rd - logs with many vices, except rot.
Podovarnik represents a part of the tree trunk with a diameter in
stammer end 8-13 cm and 3-9 m long.
Fig. 2.15. Types of sawn timber:
1 - log (sawmaker); 2 - Liezhalan; 3 - Lanta, edged from two sides; 4 - plate; 5 - a review bar; 6 ~ Bar; 7 - Gorny; 8 - board with a review; 9 - edged board; A - edge: 6 - Plast; V - edge.
Pole have a diameter in the upper end 3-7 cm and a length of 3-9 m. Round timber stored in stacks by breeds, variety and length
Lumber Get longitudinal sawing logs According to the nature of the timber treatment, there are edging and non-edged-shaped lumber lumber separated on a liter, plate, bars. Revollae, bars clean, porch, boards with a reconnaissance. Depending on the quality of wood and the presence of vices of lumber are divided into five grades: selected, 1, 2, 3 and 4 depending on the ratio of the width to the thickness of the sawn timber separated on boards, bars and bars.
Boards Made a thickness of from 13 to 100 mm and width from 80 to 250 mm, but always the ratio of the width to thickness is less than 2.
Brucki Present timber to 100 mm thick with a width ratio to a thickness of less 2. More often, the bars have a square cross section.
Brussia have a thickness and width of more than 100 mm.
Ways to enhance the durability of timber. To increase the durability of timber subjected drying, processing with antiseptics, And to protect against moisture and fire their surfaces cover special protective compositions.
Drying Woods can be natural and artificial with natural dryer lumber laid in a stack with gaskets and protect them with canopies. Artificial drying of wood is carried out in drying chambers with hot air, gas, steam or high frequency current, as well as by immersing lumber into heated petrolatum. When drying wood, its quality is improved, fungal infection and insect pests are destroyed - the humidity of the dried wood is 6-8%.
Amtiseptation - the impregnation of wood with solutions of fluoride and molding sodium, ammonium, creoshot or anthracene oil in order to protect it from rotting,
To protect wood from injury injury Use coal oil with solvents, shale oil, chlorofos in the form of healing, suspensions, emulsions and gaseous condition
To protect wood from moisture, fire Its surfaces are coated with oil and synthetic paint flame retardant compositions, fire-based compositions are prepared on the basis of liquid glass at elevated temperatures, these compositions are fused and form a glass-like layer, which prevents access to oxygen. To increase fire resistance, wood is also impregnated with chemical compositions - antipirens, for example solutions of ammonium phosphate, boos, boric acid.
Natural stone materials and products on them.
The main properties of natural stone materials are: a bulk mass, density, porosity, compressive strength, frost resistance and softening coefficient in terms of the magnitude of these properties estimate the qualities of stone materials and determine their brands.
In bulk mass Stone materials are divided into severe-clearer over 1800 kg / m 3 and light - less than 1800 kg / m 3
On the limit of strengthin compression, brands are installed: for heavy stone materials - 100, 125. 150, 200, 300. 400, 500, 600. 800 and 1000; For the lungs - 4. 7, 10, 15, 25, 35. 50, 75, 100, 125, 150 and 200, the number indicates the strength of the material in N / m 2
By the degree of frost resistance The brands from 10 to 200 are installed. The digital of the frost resistance indicates the number of cycles of "freezing - defrost", under which the strength is stored.
By the coefficient of softening, the stone materials are divided into four groups with K \u003d 0.6; 0.75; 0.9 and 1.
Depending on the purpose of the stone materials, additional requirements are imposed: abrasion resistance, wear, color, texture, etc. Natural ordinary stones and small blocks are made of limestone, volcanic tuffs and other rocks with a bulk mass of 2200 kg / m 3, limit compressive strength of at least 2.5 MPa, frost resistance of at least 15 and the softening coefficient of 0.6 and more
Depending on the method of manufacturing, the accuracy of processing and shape, the native stones are separated by the smashed and clean, efficient and coarse tesse, heavy. Planny panel and stone ribbon.
Stone butt It is mainly produced from sedimentary rocks (dense limestone, dolomite, sandstone) and less often from the erupted rocks. The boulder strength of the butt stone is not lower than 10 MPa, the softening coefficient is not lower than 0.75, the mass of separate stones from 15 to 40 kg. Waste in the manufacture of boob stone and ripped ripped stone processed on crushed stone,
Large blocks from natural stone. The greatest propagation was obtained large blocks of limestone with a strength limit of 2.5-10 MPa and a bulk mass of 1500-1800 kg / m 3. The size of the blocks and the nomenclature is set to GOST 15884-70. Blocks are released for two-, three- and four-row cuts for walls of residential and public buildings and multi-row - for industrial construction.
Facing plates from natural stoneit is made of gravel 9480-77 with abrasive (polished, rugged, polished, sawn) and rock (relief, thermal-beam, point, furred) texture of facial surfaces. Facing plates are made of granite, shenieta, diorita, gabbro, labrodite, quartzite, limestone, tuff, sandstone, marble. From natural stone In addition to facing plates, profile details are manufactured: plinth, cartel, capitals, steps, submool boards, etc.
Natural sands Used in construction in a natural state, as well as as a placeholder for construction solutions and concrete. Sands are separated into heavy with a bulk mass of more than 1200 kg / m 3 and light (porous) - less than 1200 kg / m 3.
Heavy natural sand (GOST 8736-77) - the product of the natural destruction of rocks and the grain composition is divided into large with grains of 2.5-5 mm, the middle - 2.5-2 mm, small - 2-1.5 mm and Very small - 1.5-1 mm.
Natural porous sands (GOST 22263-76) are obtained by crushing and resaking pumice, volcanic slag, tuff, porous limestone and shell.
Gravel - the product of natural destruction of rocks and is a mixture of stone grains of a rounded shape with a size of 5 to 70 mm.
Forest materials
Wood - a highly porous product of wildlife, characterized by a specific fibrous structure, which predetermining the originality of its physicomechanical properties, wide and diverse use in various sectors of the national economy.
Thanks to these properties, forest materials, as well as products and structures based on them can work long enough in various operating conditions.
TO positive, properties Woods include high mechanical strength and at the same time easily, which makes it possible to attribute it to effective materials with a fairly high coefficient of constructive quality.
Wood is capable of absorbing shock loads and extinguishing vibrations, it is distinguished by high heat, sound and electrical insulation properties, chemical resistance to acids and alkalis, is easily processed by centered instruments, well holds metal and other fasteners, it is safely glued and finally possesses natural decorativeness, What makes it popular finishing material.
To negative properties Woods include anisotropy, i.e. The heterogeneity of the structure and properties in various directions relative to the location of wood fibers; increased hydroscopicity and water absorption, predetermining the change in the most important physico-mechanical characteristics due to uneven swelling; Boxing and cracking.
Building and composition
A growing tree consists of a root system, barrel and crown. The trunk has an industrial significance, since it turns out from 60% to 90% of wood. Macrofructure call the structure of the tree trunk, visible to the naked eye or through a magnifying glass, Microstructure - visible under the microscope. Typically, three main cuts of the barrel are studied: transverse (end), radial passing through the barrel axis, and the tangential, passing along the chord along the barrel (Fig. LM-1A).
Fig. LM-1 Truck of the tree trunk:
a) The main cuts of the barrel: 1 - transverse (end); 2 - radial; 3 -Tancial; b) the structure of the trunk of the tree on the cross section: 1 -Kor; 2 - Cambier; 3 - Louba; 4 - swamp; 5 - core; 6 - core rays.
Macrotructure
When considering the cuts of the tree trunk with a naked eye or through a magnifying glass, it is possible to distinguish the following main parts: core, bark, cambium and wood (Fig. LM-2).
Core Consists of cells with thin walls, weakly connected with each other. The core jointly with the wood fabric of the first year of wood development forms a core tube. This part of the tree trunk easily boosts and has low strength.
Bark It consists of a peel or crust, cork tissue and a loob. Cork or Skin and Cork Fabric Protect the tree from harmful effects of the medium and mechanical damage. Lub conducts nutrients from the crown in the barrel and roots.
Under the lubyan layer in the growing tree there is a thin ring layer of living cells - Cambier. Every year, in the vegetative period, Cambius deposits in the direction of the cortex of the Luba cell and inside the trunk, in a significantly larger volume - wood cells. The division of the cells of the cambial layer begins in the spring and ends in autumn, so the wood wood (part of the barrel from the bottom to the core) in the transverse section consists of a number of concentric, so-called annual Rings located around the core. Each annual ring consists of their two layers: (spring) wood, resulting in spring or early summer, and late (summer) wood, which is formed by the end of summer. Early wood bright and consists of large but thin-walled cells; Late wood is darker, less porous and has greater durability, as it consists of fine-grained cells with thick walls.
In the process of growth in the wood of the wall of the cells of the inner part of the trunk, adjacent to the core, gradually change their composition and are impregnated in coniferous rocks, and in deciduous - tanning substances. The moisture movement in the wood of this part of the trunk is terminated and it becomes more transparent, solid and less capable of reinforcing. This part of the barrel consisting of dead cells is called some rocks in some breeds, in others - ripe wood. Piece of two more trunk wood closer to the cortex in which live cells are still changing, providing the movement of nutrients from the roots to Krone, called Zabolov. This part of the wood has a large moisture, relatively easily replete, low-strength, has a greater drying and a tendency to the charge.
Breeds from which the core differs from the chloride with a darker color and smaller humidity, called Sound (Pine, larch, oak, cedar, etc.). Breeds, in which the central part of the trunk differs from the chloride only by smaller humidity, is called spellers (spruce, fir, beech, linden, etc.). Wood breeds that can not be distinguished by a significant difference between the central and outer parts of the wood of the trunk, are called Breed breeds (Birch, Maple, Alder, Osina, etc.).
In the wood of all breeds are located core rays which serve to move moisture and nutrients in the transverse direction and create the reserve of these substances at winter. In coniferous breeds, they are usually very narrow and visible only under the microscope. The wood is easily split through the core rays, it is cracking on them while drying.
Forests of Russia are not only rich in wood. They grow plants giving various food, frightening, dosage and technical raw materials. There are many plant-honey plants in the forest and fodder herbs. On huge forest areas, the fruits of walnut walnut, pistachios, flavory, cherries, apple trees, pears, and mulberries are ripening annually.
Each year there are millions of tons of lingers, raspberries, blueberries, currants, blueberries, cranberries and many other valuable products. Collecting mushrooms and berries in our forests-constant fishing. The average consumption of mushrooms per capita is approximately 6-7 kg per year. Enterprises annually harvest thousands of tons of mushrooms, hundreds of tons of honey, thousands of tons of fruits and berries, including cranberries, lingonberries. In the forests of the country, technical raw materials are produced (tannilic products, dyeing raw materials, gilita, resin, essential oils, guttaperchens and rubberos, etc.), medicinal raw materials (medicinal and vitamin plants, housing for the manufacture of caroten paste, animal medicinal raw materials, etc.).
Forests serve as a source of many medicines. Vitaminonosos (Kalina, rosehip, black currant, pine, fir, etc.) are especially appreciated. About 40% of all medical drugs receive from forest medicinal plants. According to the variety and number of medicinal plants, the forest of Russia occupies the first place in the world. For the manufacture of drugs, not only leaves, havoy, flowers, fruits and bark of woody breeds, but also many types of grassy plants, mushrooms, moss growing under the wood canopy, on forest glades and edges, on forest swamps. For the manufacture of drugs, the kidneys of birch, fern, ginseng, linden flowers, chamomile, lily of the lily and others are used. Flowers of many shrubs and trees are used by bees. For example, the flowers of one tree linden can give as much honey as buckwheat flowers with 1 hectare.
Hunting for forest animals and birds is one of the important fisheries of the population. More than 100 types of animals and more than 200 species of birds live in the forests of our country. For the mining of Pushnin Russia in 1970 ranked first in the world. From wood produces up to 20 thousand types of products. Thanks to the chemical impact and other methods of processing, wood raw materials becomes material for industrial and economic products and consumer items.
Wood is primarily lumber, plywood, paper, cardboard, wood-fibrous and chipboard. In the future, an increase in forest production is envisaged, including wood-fibrous and chipboard. The increase in the volume of forest products will be carried out mainly due to the use and processing of wood left on the forest-shops, as well as due to the disposal of waste industrial sawmills. Houses and furniture, sleepers and mine rack, paper and sugar are made from wood.
More durable and durable materials displacing wood from construction. Increasingly, furniture made of polymeric materials are manufactured, and wooden sleepers are replaced with concrete. However, 5 million m 3 of high-quality wood annually spend the furniture industry. And although the share of wood use in capital construction decreases, the volumes and capacity of woodworking enterprises increase, as well as their number, and in general, the demand for wood increases.
The costs of building materials, products and structures are 50-70% of the cost of construction. Therefore, it is so important to know how to minimize the costs of them. This can be done through the use of modern resource and energy-saving technologies, local raw materials, industrial waste. At the same time, the materials, products and structures require the provision of 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 of general and special purposes.
As classification features, the production appointment of building materials, the type of raw material, the main quality indicator, such as their mass, strength, and others are chosen. Currently, the classification also takes into account the functional purpose, for example, thermal insulation materials, acoustic materials and others in addition to division into groups on the basis of raw materials - ceramic, polymer, metallic, etc. One part of the materials united in the Group belongs to natural , and the other part of them - to artificial.
Each group of materials or individual representatives in industry correspond to certain industries, such as the cement industry, glass industry, etc., and the systematic development of these industries ensures the implementation of plans for the construction of objects.
Natural, or natural, building materials and products are obtained directly from the depths of the Earth or through the processing of forests in the "Business Forest". These materials give a certain form and rational dimensions, but do not change their inner structure, composition, such as chemical. More often than other natural forests (wood) and stone materials and products are used. In addition to them, in the finished form or with simple processing, you can get bitumen and asphalt, ozokerite, casein, Cyrus, some products of plant origin, such as straw, reed, fire, peat, luzu, etc., or animal world, for example wool, collagen, Bonn Blood et al. All these natural products in relatively small quantities are also used in construction, although forest and natural stone materials and products remain the main and natural stoneware materials.
Artificial building materials and products are mainly made of natural raw materials, less often - from by-products of industry, agriculture or raw materials obtained by artificially. Generated building materials differ from the initial natural raw materials in both the structure and chemical composition, which is associated with the root processing of raw materials in the factory conditions with the involvement of special equipment and energy costs for this purpose. In factory processing, organic (wood, oil, gas, etc.) and inorganic (minerals, stone, ores, slags, etc.) are participating in the raw material, which allows to obtain a diverse range of materials used in construction. Between certain types of materials there are large differences in the compositions, internal structure and quality, but they are interrelated as elements of a single material system.
Building materials based onOrganic raw materials.
Wood materials Fig. 1. Types of sawn timber:
1 - sawing wood on the boards; 2 - boards after
sweeping; 3 - timber; 4 - edged plates; 5 edged quarters; 6 - sawing trunk on
bars; 7 - Left - plate; On the right - it is full
split on firewood; 8 - Lyryjak Wood - this material obtained from
cut and purified from the bark and branches
Tree trunk. It should be noted that this
The material is the most widely used and
favorite in homework (and not only in
them).
Wood properties are determined by the breed
Tree, its structure and to which part of the trunk
It applies.
For carpentry and carpentry work is best
Apply wood coniferous rocks: it is good
plasted, firmly gluits, paint, not
It brends and does not succumb. Wood breeds used in
Construction
All wood is divided into groups: coniferous and
Large breeds. Latest by strength
There are solid and soft.
Coniferous species of trees
Trees of hardwood
Trees of soft breeds
Lumber of hardwoods
Round forest coniferous breeds
Timber of coniferous wood In every year of the tree of wood forms
One-year ring.
Spring Tree Cells are less dense and durable
(Early Wood) than in the summer and autumn (late
wood); In addition, the first brightest color.
In the central part of the trunk is located
The core of loose fabric surrounded by rings.
The kernel is in the middle and is distinguished by the greatest.
density, resistance to posting, and
Dark color than the outer part -
Collot, which is less valuable than the kernel. However, N.
All trees have such an internal structure.
Therefore, they are classified as follows. Sound: Pine, larch, oak, ash having a bright swamp and a dark core.
Zabolov: white beech, maple, birch; W.
These breeds are not a dark core.
Spellers: spruce, fir, red beech,
Linden; these trees are not divided
on the core and the swamp, but internal layers
more durable and ripe, like the kernels
breed. Wood has a number of positive
Properties.
To the advantages of this material
explaining the reasons are wide
use of it in construction,
refer to first, high enough
Strength - with compression tensile strength
is 35 ... 70 MPa, with tension and
Begake limits of strength, equal to 80 ... 120
MPa; Secondly, ease - average
The density of wood is approximately
400 ... 600 kg / m3 (in the most common
Breed pines, spruce, larch, oak). Wood of any breed has a property
brew and swell under the influence of heat and
wet air; Wood, as they say
breathe. It can occur in three
Directions:
1) in the longitudinal direction (i.e. along the barrel)
Wood breathes very little, and the magnitude
deformation (dermole or swelling) is
0.1-0.3%, which is insignificant to work;
2) in the radial direction - about 5%; this is
a noticeable value;
3) in the direction of annual rings, i.e.
Tangential (on the tangent)
Experience can be 10-12%, which is very
It is important to consider when working with a tree. Pine. Pine wood has an average density, very high
Strength and resistance to posting; relatively durable,
moderately bending and elastic; Razeliness moderate. Relatively
Easily processed, it is one of the best diverse materials;
can be used for both internal and external
designs; Especially often used for manufacture
Wooden structures, floors and furniture.
Spruce. By strength and resistance to shuttering, somewhat inferior
pine. Wood light, soft, white; very flexible and elastic,
withstands high loads, easily splits, has a high
Tweight strength. Because of the abundance of the bitch is processed harder and
Not so pure as wood pine. Small resistant to variable
The action of a wet and dry atmosphere. Applied in construction,
For various crafts and making musical instruments.
Fir has a straight slender barrel. She has an easy and soft
Wood, which is moderately durable, has a high
Compressive strength and bending, easily split. Due to lack
Smith strokes for which resin penetrates internal layers
Barrel, fir is less than a rack to shut down than fir. Used like that
as pine, and, moreover, for the manufacture of musical
Tools. Larch. Her wood is light, she is harder and richer
resin than pine, distinguished by high strength and
elasticity, easily splits; breathe little. This is the most
Solid and durable wood coniferous rocks.
It is difficult to; Good for construction work.
It is used for the same goals as pine.
Cedar. More racks to boot than pine. Wood
yellowish or reddish color, lightweight, easily cut;
Used as a building material.
Oak. His wood is solid, heavy, very durable and viscous;
resistant against posting, well bend; exclusively
Durable, little dry and swells. Good opposed
bad weather and wears little; how old is long
Stored under water. Long underwater under water oak
becomes black; It is called moraine. Often
Used for making tools, wooden
plugs, parquet and board floors, thresholds and doors,
Furniture and hydraulic structures. Red beech has a solid, heavy, durable and viscous wood. She is
It is easily splitting, well opposed the deformations of the break and cut.
Not very resistant to the variable action of humidity and dryness, bad
withstands long-term loads; Bad breathing. Used in
Mainly for the manufacture of tools, wooden plugs, board and
parquet floors, door thresholds, staircases, accessories,
Plywood and for a number of joinery.
White beech It is a very solid, heavy and viscous tree that is bad
splits; stored only in a dry atmosphere; breathing greatly;
Maidoelastic. Usually applied to the manufacture of tools,
Rubankov, chisel arms and wooden hammers.
Ash. Its wood according to the properties and appearance is similar to Oak;
relatively heavy and solid, very elastic and viscous; But, in contrast
from him, short-lived; breathe little. Well processed;
It is used for the manufacture of handles of hammers and solid,
Sports inventory.
Maple. Wood is dense, firm, well processed. Region
Applications: details of furniture, musical instruments, plans, etc. Birch has a homogeneous, medium density
Wood. Used in furniture
Production as an amicing material. Especially
valuable is the wood of Karelian birch,
which goes to the furniture finish.
Linden. The wood of this tree is homogeneous and
soft, easily processed with a knife, chisel,
cutters. From it make Paneru, various
crafts, wooden dishes, musical
instruments.
Olha has a bright blossoming in the air
Wood, which is well opposed
Moisturizing. Applied to manufacture
Plywood, containers, furniture. Wet wood quickly boosts
Blooming badly: made of it
Items are boxed, cracking.
Therefore, it is more expedient to work with
wood that contain moisture not
More than 18% of the mass of wood. IN
Fresed oak this value
is 50-70%.
Therefore, to obtain wood suitable
for joinery, it is kept in the fresh
Air from 1 to 3 years. Dried wood
well processed, firmly gluits,
It is painted, it does not breed and does not succify. It is better
dried edged and planed boards. Materials and wood products are divided into
Several groups: timber produced by
mechanical tree processing; Modified
Wood treated with synthetic resins,
extruded, plasticized by ammonia et al.;
Wood products - plywood, joinery,
Wood-chip and wood-fibrous plates,
Wood-layered plastics, etc.
Timber are divided into round, sawn,
Lush, milled (planed), crushing and
By-products - sawdust, chips, chips,
Wood flour.
Round timber, i.e., trunks of the dyed tree,
Cleanted against busts. They are divided into parts (Disclocked)
Different log lengths, ridges, churaki. Thick
Round timber divided into large
with a diameter of more than 26 cm, the average one is 14 to 24 cm, small
- 6 to 13 cm. Even a thinner forest from 3 to 7 cm
Call jersey. Depending on the quality of wood
(presence of defects) and defects when processing
Round timber divide on four
varieties from which are used in construction
Mainly the 2nd and 3rd. Lumber is divided into bars, bars,
Plates, quarters, boards and porch. Brucki
have a thickness of less than 100 mm and no more width
Double thickness. Bars have a thickness and
width more than 100 mm; Boards have a thickness less
100 mm and width of more double thickness. Brussia I.
Boards are edged and unedged (edges not
propylene or propylene less than on
Half length). Boards thinner 32 mm called
Thin or tesome. Board length from 1 to 6.5 m.
Boards and bars of coniferous rocks are divided by five
Varieties - selected, 1st, 2nd, 3rd and 4th. In carpentry
Production use only the 1st and 2nd grade.
Maximum width of boards and bar 250 mm,
Brucks - 200 mm. Lumber deciduous
The rocks are divided into three varieties. For the production of details of finished products
Apply the so-called billets - boards and
bars, embedded in relation to the specified
sizes and with allowances for mechanical
Processing and drying. They are used for glued
structures as well as for making
Plinths, cartoons, eaves, platbands, etc.
Wood products. Elements of small
cross-section-wooden
Molded parts, called migratory
(they are measured by route) - it
Plinths, cartel, eaves, belts, platbands,
handrails for stair railings, trim,
layouts, as well as boards and bars for coating
floors (on one edge there are grooves, on another
crest). Fig. 2. Brux: A - twin; b - tripler; in - quadant (or pure)
Lumber. The trunk can be cut to
bars, bars, boards, cliffs, plates and
Quarter. Sawn timber
edges are called edged, with
Heaven - unedged.
Brux (Fig. 2) Made a thickness more
100 mm and up to 400x400 mm. They may have
Two, three or four sides are poured; In these
cases they are called two-, respectively,
Three- and quadructive. Fig. 3. Bruks:
a - purely edged; b - with a stupid oblave; in - with sharp
Ozol
Bruks (Fig. 3) have a thickness of 50-100 mm, and width -
no more double thickness. They can be pure
edged or have the remaining untouched side
The log surface is the so-called oblave.
Little-format bar is called a rail. Fig. 4. Boards: A - purely edged; b - unedged; in one-sided edged; 1 - the outer; 2 edge; 3 - end; 4 - Obzol.
Boards (Fig. 4) are edged, unedged and
one-sided edged thickness of 16-100 mm, width
up to 275 mm and up to 6.5 m long. wider board
Called the peeper, narrow - edge, end face -
Shoot. Ram, "looking" on the periphery of the log,
called outdoor (or right), and on the kernel of the log -
internal (left). Obapol - these are waste remaining from sawing logs. They have
View of a part of the cylinder cut off with a plane parallel to the axis
cylinder.
Plates are obtained by sawing logs in half along the fiber, and
Quaternar - sawing plates in length into two equal parts.
Wood materials (DM). It is structural, insulating and
DIRECTION MATERIALS PRODUCED ON WORLDS. Technology
- hot pressing of wood sawdust, chips, fibers that
mixed with a binder, or bonding sheets
Lush veneer - thin sheets of wood obtained by brush
Short logs on special walls. DM in some cases have
Advantages Compared to natural wood, in particular,
Superope its operational properties, as well as on dimensions. TO
DM includes the following materials: plywood, wood-fibrous
Plates (Fiberboard), chipboard (chipboard), wood plastics.
Plywood. This type of DM gloves from the sheets of peeled veneer, and in
adjacent layers of wood fiber are perpendicular to each other
Friend. In the production of plywood uses pine woods, ate,
larch, birch, beech, maple, grab. Types of plywood used for
different purposes can be divided into several groups - depending on
Application Areas (Table In recent years, glued are increasingly used
designs, large-sized elements,
produced by gluing relatively
small wooden blanks with each other
or with other materials - arches, beams
2-way, blocks, etc. them
manufactured on waterproof and high strength
Polymer glue.
They differ greater strength
water resistance, bioc and fire resistance than
ordinary wood structures, not
Surround and warp.
Use glued structures - one of
most cost-effective ways
Applications of wood in construction.
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