Xiv. Natural building materials
| abilityспособность abrasion стирание, снашивание absorbпоглощать, впитывать abutmentопора, береговой устой aggregate заполнитель ambientокружающий as compared with по сравнению bring about осуществлять, вызывать cementцементировать chalk мел conductivityпроводимость constituent компонент, составная часть crackтрещина, трескаться crustземная кора dailyежедневно disintegrationразложение evaporate испаряться extract извлекать facing облицовка favourableблагоприятный for instance например front фасад, лицевая сторона gravel гравий homogeneousоднородный howeverоднако, тем не менее humidityвлажность impact['impækt] удар in comparison withпо сравнению indicateпоказывать texture текстура, строение, структура thermal conductivityтеплопроводность varyingразличный | intact [in'tækt] нетронутый, неповрeжденный internalвнутренний lowнизкий mainlyглавным образом make use of использовать marlмергель moistureвлага nailгвоздь nearly почти negativeотрицательный offer resistance оказывать сопротивление on the one hand с одной стороны on the other hand с другой стороны owing to благодаря paving material материал для покрытия дороги pier бык, пилон, свая Portland cement портланд цемент positiveположительный reason причина screw шуруп shortcomingнедостаток shrink - shrank - shrunk давать усадку step ступенька stormбуря, шторм, ливень stress напряжение swell вспучивать viscous ['viskəs] вязкий volumeобъем warp[wɔ:p] коробиться |
Wood. Wood is the most ancient structural material which was used by the primitive man for building a hut protecting him from stormy weather and wild animals. It is daily growing in importance. In comparison with steel wood is lighter, easy to work and its mechanical properties are good. For some purposes it has certain advantages over steel. Wood possesses a comparatively high strength combined with a small volume weight, elasticity and low heat conductivity. Under favourable service conditions wood remains intact during long periods of time (several hundred years).
Wood is very widely used in the building field, owing to the above indicated qualities and a comparatively low cost. The ease with which wood can be shaped and fastened together, especially with nails and screws is the chief reason why it has been the leading structural material since man used tools.
On the other hand, wood has certain disadvantages as compared with other structural materials. Wood is non-homogeneous in texture and it results in a difference in strength and thermal conductivity. Wood has the ability to absorb and evaporate moisture with varying humidity and temperature of ambient air. It swells and shrinks that brings about the appearance of internal stresses resulting in cracking and warping. Wood burns and is therefore unsuitable for fire-proof buildings. It decays and is not considered so durable as steel and concrete. Builders must be familiar with the positive and negative building properties of wood to be able to make the best use of the positive properties.
Natural stone. Stone belongs to one of the oldest building materials used by man. Primitive stone structures imitating caves where the primitive man found shelter were the earliest types of human dwellings.
Stone is characteristic of many properties owing to which it is still widely used for building purposes. These properties are mechanical strength, compactness, porosity, sound and heat insulation and fire-resistance.
Rock is defined as a mineral mass consisting essentially of one mineral (mono-mineral rock) or several minerals (compound or poly-mineral rock). A mineral is a substance characterized by the following features. It is a chemical element, chemical compound or a mixture of such compounds. Rocks, such as granite, limestone, marble and others, form the hard constituent of the earth's crust - the lithosphere. Rocks are extracted mainly to be utilized in the building field as natural stone and also for the fabrication of different artificial building materials.
Stone goes into nearly every structure. Owing to its high building qualities (durability, strength and frost resistance) and great abundance, natural stone is widely employed in modern building for foundations, walls and steps of buildings. Stone is mostly used for ordinary or decorative facing of fronts and interiors of buildings, for the facing of engineering, hydro-technical and sanitary structures: bridge abutments, piers, railway, hydro-technical and sanitary installations, etc. Strong and viscous rocks offering high resistance to impact and abrasion are utilized as paving materials. Natural stone materials which are the product of rock disintegration (gravel and sand) are widely employed as aggregates in the production of artificial building materials which are cemented by some binding substances (mortars), in the construction of highways and also in a number of other applications.
Rocks are employed in the production of building materials, for instance, Portland cement (limestone, marl, clay, chalk), lime (limestone), building gypsum (natural gypsum stone), brick and artificial stone (clay, sand), etc.
XV. METALS AND NON-METALS
| affectвоздействовать на allowразрешать, позволять althoughхотя amaze изумлять, поражать appearanceвнешний вид applicableприменимый, пригодный, подходящий assortmentассортимент brittleхрупкий buckleсгибаться carbonуглерод castingлитье, отливка ceramicsкерамика chromiumхром complex сложный component составная часть compositionсостав compressive strength прочность на сжатие conductпроводить conductor проводник coolохлаждать copperмедь crackingрастрескивание denseплотный, густой densityплотность, удельный вес describeописывать displaceвытеснять, замещать doubtful сомнительный, неясный edgeкрай, кромка, острие, лезвие exceptисключая, кроме ferrousсодержащий железо plasticпластичный pleasing приятный pliantгибкий, податливый porousпористый pressureдавление provocation раздражение pullтянуться, растягивать pureчистый resinсмола rigid жесткий sawdustопилки sectionчасть, отрезок, деталь semi-dry полусухой semi-rigid полужесткий seriousсерьезный shearсдвиг, срез significantзначительный | ferrous metal черный металл forgeковать former прежний, бывший; первый из названных i. e. = that is то есть in general вообще in respect to что касается justify оправдывать keenострый latterнедавний; последний из двух названных lb = poundфунт lead [led] свинец liquidжидкий, жидкость lithiumлитий lustre блеск magnesiaокись магния maintain поддерживать, обслуживать man-madeискусственный mercuryртуть mixtureсмесь mould = mold форма, опалубка; формовать, отливать в форму non-ferrous цветной (о металле) non-metal неметалл, металлоид ordinaryобычный other than а не, кроме paviour brick дорожный кирпич, камень для мощения, клинкер percentageпроцент, процентное отношение permit позволять, разрешать slightнезначительный, слабый snapломаться softмягкий special steel сталь специального назначения specificспецифический stateсостояние subsequentlyвпоследствии, потом, позже supple гибкий, податливый temperingотпуск стали tensionрастяжение tin олово toughness['tÙfnis] жесткость tungstenвольфрам weak слабый withstandвыдерживать, противостоять |
There are two kinds of materials used in engineering - metals and non-metals. We can divide metals into ferrous and non-ferrous metals. The former contain iron and the latter do not contain iron. Metals possess the following properties. They have specific metallic lustre. All metals except mercury are hard substances. They can be forged, pulled and melted. In general, they are good conductors of electricity.
The heavy metals include iron, copper, lead, tin and some others. Some metals are light (aluminium), some are hard (iron) and others are soft (tin, lead). The lightest is lithium and the heaviest is osmium. The most useful metals are iron, copper and aluminium. However, only small quantities of the above metals are used in their pure form. Metals vary in density, hardness, heat and electrical conductivity and weight.
The uses of metals are based upon their physical and chemical properties. Non-ferrous metals have the following characteristics: high electric and heat conductivity, high corrosion resistance, non-magnetic qualities, light weight, etc.
An alloy is a mixture of two or more metals melted together. Each constituent of an alloy is called a component. Cast iron and steel are ferrous metals. Cast iron and steel are both alloys, or mixtures of iron and carbon. Cast iron is weak in tension and shear, strong in compression and has low resistance to impact.
As a structural material steel has come into general use with the development of industry, its manufacture requiring special equipment and skilled labour. Steel has largely displaced wood and bricks as basic materials in construction. Speaking of steel we should realize how many different properties it can possess. It is doubtful whether many of us realize the amazing range of the properties of steel. We get it sometimes so brittle that it will snap at the slightest provocation; at others so supple that it buckles under its own weight. It may be so pliant that it can be bent about in wire, or so keen that it will form a cutting edge. These varying properties depend on the nature of the tempering – that is, on the way in which the steel has been allowed to cool, and partly on the substances with which the iron has been combined, such for instances, as carbon, magnesia, tungsten, chromium and nickel.
A steel containing some metallic element other than iron and carbon is generally known as "special steel". It is corrosion-resistant and is widely used in building. Various metals when added to steel in certain percentages, increase hardness and toughness of steel. Cast steel is used to replace cast iron when castings of considerable strength are required.
Plastics and ceramics are non-metals. Plastics have appeared comparatively recently but, owing to their inherent valuable and diverse properties, have found a wide application in many industrial fields (machine-building, aviation, textile industry, etc.). Application of plastics in the building field widens from year to year.
In respect to physical and mechanical properties all plastics are divided into rigid, semi-rigid, soft and plastic. In respect to the number of constituents plastics may be classified as simple and complex. Plastics consisting of one polymer are referred to as simple. Thus, organic glass (plexiglass) consists of one synthetic resin. But in the building field we usually deal with complex plastics, e.g. plastics consisting of a polymer and other components.
Synthetic plastics are man-made substances which not only change their shape when moulded under great heat and pressure, but change their chemical state as well. They are light and hard, being produced by mixing together a number of gases and liquids. A synthetic product must be both better and cheaper in order to justify its manufacture at all.
Plastics combine all the fine characteristics of a building material together with good insulating properties, and are fireproof as well. Plastic products offer many advantages over the materials they replace, such as ease of handling, lower maintenance costs and rapidity of assembly.
Ceramics are used when materials which can withstand high temperatures are needed. Ceramic products are manufactured from different kinds of clay, sometimes with additions of non-plastic materials (sand, sawdust, etc.) by moulding and subsequent burning. The manufacture of ceramic products originated back in the ancient times, many thousand years before our time.
The wide assortment, high strength and durability of ceramic products make them applicable in all sections of constructed buildings, from the foundation to the roof. All ceramic building materials are divided into two groups - porous and dense. Porous materials include clay brick, porous brick, hollow brick, tile, etc. Floor tile and paviour brick are considered to be dense ceramic materials.
A brick is best described as "a building unit". In shape it is a rectangular solid and its weight is from 6.5 to 9 lb. It is an artificial stone made from clay by moulding and burning. It may be made of concrete, of mortar or of a composition of sawdust and other materials. Building bricks are manufactured by two processes: plastic and semi-dry brickmaking.
In many cases bricks are very satisfactory for use in the construction. Bricks generally present a pleasing appearance and can be obtained with various qualities, colours and textures. Being of high volume weight and high thermal conductivity, ordinary bricks are not always satisfactory in building practice. There are other kinds of bricks which are more effective. They are hollow or porous bricks. Light-weight bricks differ from ordinary clay bricks in a lower volume weight and thermal conductivity, and are therefore more economical than ordinary bricks. The use of light weight bricks permits a reduction in thickness of walls. Lightweight bricks are utilized for laying upper stories of multi-storeyed buildings.
C O N T E N T S
КОНТРОЛЬНОЕ ЗАДАНИЕ 3…………………………………………………...3
ВАРИАНТ 1…………………………………………………………………………….....3
ВАРИАНТ 2…………………………………………………………………………….....4
ВАРИАНТ 3…………………………………………………………………………….....6
ВАРИАНТ 4……………………………………………………………………………....7
ВАРИАНТ 5……………………………………………………………………………...8
Грамматика: КОНТРОЛЬНОЕ ЗАДАНИЕ 3………………………………….11
Функции глагола to be (37)...............................................................................................11
Функции слова after (38)...................................................................................................11
Функции слова before (39).................................................................…………………...11
Придаточные предложения времени (40).......................................................................12
Придаточные предложения условия (41).......................................................................12
Дополнительные придаточные предложения (42)........................................................12
Определительные придаточные предложения (43)......................................................12
Бессоюзное подчинение (44)...........................................................................................13
Modal verbs + Infinitive Indefinite Passive.(45).................................................................13
Функции герундия (46)....................................................................................................14
Тексты для чтения для 2 курса (3 семестр)…………………………………….......16
XI. BUILDINGS……………………………………………………………………….....16
XII. STRUCTURAL ELEMENTS……………………………………..............................17
XIII. BUILDING MATERIALS …………………………………………………………18
XIV. NATURAL BUILDING MATERIALS…………………………………………….21
XV. METALS AND NON-METALS…………………………………………………….23