TEXT 4A. THE PROPERTIES OF BUILDING MATERIALS
Read and translate the text:
Materials that are used for structural purposes should meet several requirements, hi most cases it is important that they should be hard, durable, fire-resistant and easily fastened together.
The most commonly used materials are steel, concrete, stone, wood and brick. They differ in hardness, durability and fire-resistance.
Wood is the most ancient structural material. It is light, cheap and easy to work. But wood has certain disadvantages: it burns and decays.
Stone belongs to one of the oldest building materials used by man. It is characteristic of many properties. They are mechanical strength, compactness, porosity, sound and heat insulation and fire-resistance.
Bricks were known many thousands of years ago. They are the examples of artificial building materials.
Concrete is referred to as one of the most important building
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получили высокое распространение бетонные конструкции, внедрение которых было тесно связано с промышленным изготовлением портландцемента. 13. Железобетонные изделия и сооружения появились после успешного использования стальной арматуры. 14. Железобетон как строительный материал очень молод.
III. Read the text carefully and then translate it:
„ Concrete is made by binding together particles ofsand and gravel stone or broken brick. The binding agent used is a paste ofPortland cement and water, in suitable proportions. When water is added to the cement, hydration takes place. This causes the whole mixture to set and harden, forming a solid mass. The sand, gravel (or broken stone) arc termed "aggregate"; sand is known as "fine aggregate", and gravel as "coarse aggregate". Concrete can be made on a building site and poured into position as a wet mix, or it may be used as the material for making prefabricated units in a factory. That is why there is another classication into" in-situ" (or cast-in-place) concrete and "precast" concrete.
!V. Answer the following questions:
1. How is concrete made? 2. What takes place when water is added to the cement? 3. Does the whole mixture set and harden when hydration takes place? 4. A solid mass is formed, right? 5. Do you know what is termed "aggregate"? 6. Is sand known as "fine aggregate"? 7. And what is meant by "coarse aggregate"? 8. Can concrete be made on a building site and poured into position as a wet mix? 9. Are you able to explain what is meant by "in-situ" concrete?
V. Complete the sentences using the English equivalent for the Russian words in brackets:
1. All metals are divided into (черные и цветные). 2. Ferrous metals include (железо, сталь и их сплавы). 3. Copper, aluminium and some other metals are referred to as (цветные металлы). 4. Metals in general, and especially ferrous metals are of (большое значение в строительстве). All metals have specific metallic (блеск), 6. All metals, except mercury, are (твердые вещества). 7. All metals are good
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3. The basic materials for making concrete are cement, aggregate and water, aren't they? 4. What is the most essential material for making concrete? 5. Can we make cement if we take limestone and clay? 6. How is cement made? 7. What are Portland and blast furnace cement suitable for? 8. When does cement start hardening? 9. How long does the process of hardening last? 10. Can you tell us what process is called concrete hardening? 11. Are you able to say what the characteristics of concrete depend on? 12. Should concrete be hard, strong, durable fire-resistant and economical? 13. Into what two classes can concrete be divided? 14. Is Yes the use of concrete and ferro-concrete most universal? 15. Do builders now produce two or three types of new building materials? 16. Where is silica concrete widely used?
II. Render the following in English:
1. Прочность хорошего кирпича, стали, природных камней со временем не меняется. 2. Бетон в течение длительного времени способен становиться прочнее. 3. Бели применять прочность бетона за 100 процентов, то через 1 1/2 года она будет - 150, через 2 года - 200, а через 5 лет - 225%. 4. Плотный бетон морозостоек. 5. Прочность, водостойкость, плотность, морозостойкость делают бетон очень хорошим строительным материалом, пригодным для возведения гидротехнических сооружений. Бетон хорошо защищает от ударной волны и светового излучения. 6. Официальной датой появления железобетона считают 1867 год, когда французский садовник Ж.Монье получил первый патент на железобетон как строительный материал. 7. Ж.Монье делал из бетона цветочные горшки и кадки, небольшие бассейны для воды и другие изделия. 8.. Первый железобетонный мост был построен в 1875 году. 9. Русские инженеры оказали большое влияние на развитие железобетонного строительства. Русские инженеры использовали железобетон как прекрасный строительный материал в Ленинграде, Новороссийске и других городах. 10. Несколько промышленных и гражданских зданий, выполненных, частично из железобетона, сохранились и по сей день. 11. В 1904 году недалеко от Николаева был построен первый в мире железобетонный маяк. 12. С конца XIX века в строительстве
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materials. Concrete is a mixture of cement, sand, crushed stone and water.
Steel has come into general use with the development of industry. Its manufacture requires special equipment and skilled labour.
Plastics combine all the fine characteristics of a building material with good insulating properties. It is no wonder that the architects and engineers have turned to them to add beauty to modem homes and offices.
All building materials are divided into three main groups: 1) Main building materials such as rocks and artificial stones, timber and metals. 2) Binding materials such as lime, gypsum and cement. 3) Secondary or auxiliary materials which are used for the interior parts of the buildings.
We use many building materials for bearing structures. Binding materials are used for making artificial stone and for joining different planes. For the interior finish of the building we use secondary materials.
Natural building materials are: stone, sand, lime and timber. Cement, clay products and concrete are examples of artificial building materials.
Exercises
I. Answer the following questions:
1. What are the properties of the building materials?
2. What are the most commonly used building materials?
3. Do building materials differ from each other?
4. What can you say about the most ancient building materials?
5. What can you say about bricks?
6. Is concrete an artificial or natural building material?
7. Into what groups do we divide building materials?
8. Can you give an example of a binding material?
9. What artificial building materials do you know?
10. What natural building materials do you know?
II. Render the following in English:
Пластмассы как материал для строительных конструкций
Пластмассы - это материал, который состоит из полимеров или их сочетаний. Большая легкость, значительная прочность, водостойкость являются основными достоинствами большинства
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пластмасс. Эти свойства пластмасс позволяют издавать легкие, прочные, красивые, экономически выгодные конструкции.
Основными компонентами пластмасс являются синтетические смолы. Эти смолы представляют собой высокомолекулярные соединения, полученные путем синтеза из низкомолекулярных соединений. Уголь, торф, нефть, являются основным сырьем для смол. Смолы - это полимеры малых молекул - мономеров.
TEXT 4B. TIMBER
Study the text and then translate it orally using a dictionary:
Timber is the most ancient structural material. In comparison with steel timber is lighter, cheaper, easier to work and its mechanical properties are good. On the other hand, timber has certain disadvantages. First, it burns and is therefore unsuitable for fireproof buildings. Second, it decays.
At present an enormous amount of timber is employed for a vast lumber of purposes. In building timber is used too.
Timber is a name applied to the cut material derived from trees. Timber used for building purposes is divided into two groups: softwoods and hardwoods. Hardwoods are chiefly used for decorative purposes, as for panelling, veneering in furniture, and some of them are selected for structural use because of their high strength and durability. In modern construction timber is often used for window and door frames, flooring, fences and gates wallplates, for temporary buildings and unpainted internal woodwork.
Timber cannot be used for either carpenters' or joiners' work immediately it has been felled because of the large amount of sap which it contains. Most of this moisture must be removed, otherwise the timber will shrink excessively, causing defects in the work and a tendency to decay. Elimination of moisture increases the strength, durability and resilience of timber.
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(ferro-concrete) where it is necessary to introduce steel. Plain or mass concrete can be used for almost all building purposes. Ferro-concrete is used in building bridges and arches, dams and dock-walls, for structures under water, for foundations, columns, girders, beams. The use of concrete and ferro-concrete is almost universal.
Builders now produce two types of new building materials: alkali-slag concrete and silica concrete. In alkali-slag concrete cement is replaced by a mixture of granulated blast-furnace slags and sodium
\ and potassium compounds. The fillers can be sand or sandy loams containing various amounts of clay, which usually cannot be used with conventional cement. The new material has been tested successfully and is now being used for irrigation systems, roads, pavements and other structures. Silica concrete is light, fire-resistant and acid-proof. It contains no cement whatever. Silica concrete is widely used in aviation and in under water constructions.
The term "concrete" is used to describe a dense material composed of cement and aggregate mixed with water. The density of such a material, and therefore many of its properties, depend upon the density of the aggregate. Therefore 'there is a broad division of concrete types into:
a) Dense concretes - composed of heavy aggregates.
b) Light-weight concretes - composed of light aggregates.
The aggregates are graded in size from fine to coarse in order to reduce the amount of void space to be filled by cement.
There are "cellular" concretes made by using materials which foam or form gas during the mixing of the concrete. These give a product of very light weight, because after setting it contains a large number of small voids.
The reduction in weight is accompanied by a considerable decrease in strength Another type of light weight concrete is made by "entraining"air bubbles in the mix to which a substance has been added to keep the bubbles stable during setting.
Exercises.
I. Answer the following questions:
1. Is it possible to put up modern structures without using concrete?
2. Do you know what the most important quality of concrete is?
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Dialogue 4
A.: Do you agree that an aluminium domed roof makes it simple to provide lighting in the walls beneath?
В.: I do. Besides, the domes can be assembled at ground level and lifted into position.
A.: That's remarkable! Don't you think dome roofs pack economically for sea transport?
В.: It's exactly what I was going to tell you.
UNIT VI. CONCRETE.
TEXT 6A. CONCRETE
Read and translate the text:
It is difficult to imagine modern structure without concrete. Concrete is the very building material which led to great structural innovations. The most important quality of concrete is its property to be formed into large and strong monolithic units. The basic materials, for making concrete are cement, aggregate and water. Cement is the-most essential material and the most important one for making concrete of high quality. Cement is made of limestone and clay. It is burnt (calcined) at high temperature and ground up into powder. Depending on the kind and composition of the raw materials different types of cement are obtained. Portland cement, blast furnace cement are suitable for putting up marine structures.
Concrete is made by mixing cement, water, sand and gravel in the right amount. As soon as it is thoroughly mixed it is poured into forms that hold it in place until it hardens: The crystals forming in the process of making concrete stick together in a very hard artificial stone. Cement starts hardening one hour after the water has been added and the process of hardening lasts for about twenty-eight days. The process is called concrete curing.
The characteristics of concrete depend upon the quality of the materials used, grading of the aggregates, proportioning and amount of water. The most important requirements for concrete are: it should be hard, strong, durable, fire-resistant and economical. ) Concrete can be divided into two classes: mass or plain concrete and reinforced concrete
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STONE
Stone has been used as a structural material since the earliest days. Almost all famous buildings of classic times, of the medieval and Renaissance periods and of the eighteenth and early nineteenth centuries were erected of stone. The art of making any structure in stone is called stone masonry. In some places stone was used because of the scarcity of timber, but in other places stone was preferred because of its durability.
The stones which are usually used for masonry work are as follows:
1. Granite. Granite is very hard, strong and durable. It is used particularly for basements, base courses, columns and steps and for the entire facades. Its colour may be gray, yellow, pink or deep red.
2. Sandstone. Sandstone is composed of grains of sand or quarts cemented together. Sandstones form one of the most valuable materials. The durability of sandstones depends very largely upon the cementing material. Thus there are different kinds of sandstones. Many sandstones are exceptionally hard and are selected for steps, sills, etc. It is an excellent material for concrete aggregate.
3. Marble. Marble is a crystalline stone chiefly used for decorative purposes. White and black marbles are used for ornamental decoration where the beauty of the marble is shown to its best advantage.
Exercises
I. Answer the following questions:
1. Is timber a very ancient structural material?
2. What are the advantages of timber in comparison with steel?
3. What are the disadvantages of timber in comparison with steel?
4. Into what two groups is timber, used for building purposes, divided?
5. For what purposes are hardwoods chiefly used?
6. For what purposes is timber often used in modern construction?
7. Why cannot timber be used for either carpenters' or joiners' work immediately it has been felled?
8. What increases the strength, durability and resilience of timber?
II. Answer the following questions: - 19 -
1. Do you know that stone has been used as a structural material since the earliest days? 2. What is called stone masonry? 3. Why did people begin to use stone? 4. Can you name the stones used for masonry work? 5. Granite is usually used in construction, isn't it? 6. Does granite possess any special properties? 7. Can you say what these properties are? 8. What does the durability of sandstone depend upon? 9. Why are many sandstones selected for steps, sills, etc.? 10. Marble is chiefly used for decorative purposes, isn't it? 11. White and black marbles are widely used for ornamental decoration, aren't they?
III. Complete the following sentences using English equivalents instead of the Russian words and word-combinations.
1. Stone has been used as a structural material since древних времен. 2. The art of making any structure in stone is called каменная кладка. 3. Granite is used particularly for фундаментов, колонн, ступеней и т.д. 4. Sandstone is composed of зерен песка и кварца.5. Sandstone is an excellent material for заполнителя бетона. 6. Sandstones form one of the most ценных материалов. 7. Limestones are used extensively for строительных целей. 8. Marbles are chiefly used for декоративных целей.
4 С. DIALOGUES
Memorize these dialogues and perform them in pairs.
I. - What do you know about cement?
- It's a powder which, when mixed with water, becomes hard like stone.
- Suppose we mix cement with sand and stones?
- If we mix cement with sand and stones, we get concrete.
II - Do you know what a brick is?
- Yes, I do. It is a block of baked clay.
- What are bricks chiefly used for?
- They are chiefly used for building houses.
III.-What kind of a building is called a "skyscraper"?
- A skyscraper is a very, very tall building.
- How tall are some skyscrapers?
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10. Are the uses of aluminium almost illimitable? 11. How many building products are now made of aluminium? 12. Was there a time when aluminium was as valuable as silver?
5C. DIALOGUES
II. Read the dialogues and use the conversations in pairs.
Dialogue 1.
A: What can you say about aluminium as a structural material?
В.: You see, aluminium has many attractions as a structural material.
A.: Can it be readily obtained in various alloys?
В.: Yes, it can be readily obtained in various alloys.
A.: And can it be obtained in various conditions and shapes?
В.: It can - to suit specific uses.
A.: You haven't said anything about aluminium's reliability.
В.: Oh, there is sufficient experience now to have confidence in its reliability.
Dialogue2
A.: Aluminium alloys of very high strength are obtainable, aren't they?
В.: They are, but such alloys are not generally used in structural engineering.
A.: Is corrosion from sea air or industrial pollution a problem?
В.: No, corrosion from sea air or industrial pollution is no longer a problem.
A.: So that means that painting is not necessary?
В.: You are right. Painting is not necessary at all.
Dialogue 3
A.: I've heard that aluminium lends itself particularly well to
roofing. Is that so?
В.: Yes, that's so. Aluminium is a wonderful roofing material!
A.: But it must be very expensive. Don't you think so?
В.: It is rather expensive, but there are many instances were aluminium structures justify themselves. – 25 -
for energy conservation. 4. In direct contact with a heat source, aluminium is an excellent conductor. 5. World's lightweight champion in the long-distance transport of electricity, aluminium has virtually replaced heavier copper in high-voltage power lines. 6. Nearly indestructible aluminium can be remelted over and over. 7. Aluminium is alloyed with small amounts of other metals. 8. Copper adds strength; magnesium imparts additional marine-corrosion resistance. 9. Unlike copper or iron, aluminium does not occur naturally in metallic form. 10. Aluminium exists only in combination with other elements, primarily oxygen, with which it forms an extremely hard oxide known as alumina. When tinted by traces of other elements, alumina can take the form of gems such as rubies and sapphires. 11. Constituting 8 per cent of the earth's crust, aluminium is the most abundant of metals, as well as one of the hardest to produce. 12. Even fly ash from coalbuming furnaces could become a source of aluminium. 13. Subduing the waves, aluminium alloys not only combine lightness with strength but stoutly resist salt water's corroding effect. 14. When we recycle aluminium, we save 95 per cent of the energy needed to make new metal from bauxite. IS. Once you make aluminium it becomes an energy bank that you can tap over and over again. 16. The uses of aluminium are almost illimitable. 17. Aluminium panels sheathe the World Trade Center in New York. 18. Builders can use aluminium nails, and bolts to install aluminium storm doors, screens, flashing, gutters, downspouts, shingles, awnings, and Venetian blinds - some 200 building products in all. 19. In 1884, when aluminium was still as valuable as silver, a hundred-ounce tip of the metal was chosen by architects to finish the 555 ft high Washington Monument in Washington, D. C, USA.
II. Answer these questions:
1. Can aluminium alloys possess the strength of steel? 2. Is aluminium an excellent conductor when it is in direct contact with a heat source? 3. Has aluminium replaced copper- in high-voltage power lines? 4. Do you think aluminium can be remelted over and over? 5. Does copper add strength when it is alloyed wi th aluminium? 6. Is it true that aluminium exists only in combination with other elements? 7. When combined with oxygen, what does aluminium form? 8. Aluminium is not the most abundant of metals, is it? 9. Do aluminium alloys resist salt water's corroding effect?
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- Some are so tall that their tops are hidden by clouds when it rains.
IV.- Suppose you wanted to make some concrete, what would you take?
- I'd take some cement, gravel and sand. Then I'd mix them with water.
- Quite right! Now, what is concrete used for? • It's used for building, making roads, etc.
V-What is a lift?
- It's an apparatus for taking people up or down to another floor.
- Do the Americans call this apparatus a lift?
- No, they don't. They call it an elevator.
VI.- How long does it take to build such a house?
- It takes about ten or eleven months.
- How long did it take to build the house you live in?
-I suppose it took about a year and a half.
VI.- What do we call a number of rooms on one floor of a building?
- If the rooms are used as a home, then we call the rooms a flat.
- And what is an apartment?
- In England they use the word "flat", while in America they use the word "apartment".