Учебное пособие 1575

to govern – определять

ROOFS

A roof is the topmost part of a building. It is a covering constructed over the building to keep out rain and wind. Roofs also tie the walls and give strength and firmness to the structure.

The constructive design of a roof is to resist wind loads and to sustain snow loads. A roof consists of bearing members resisting dead and live loads and of waterproof covering (roofing). Since the main bearing elements are arranged at a relatively large distance and are themselves unable to carry the covering, some intermediate members are introduced for this purpose. They are called purlins. The purlins are usually made of timber and they rest on the bearing construction.

Roofing is the covering placed on the top of the structural part of the roof. It may be of wood, metal, tiling or fabricated units. Slates and tiles are largely used as coverings being fire and water resistant, non-conductors of heat, durable and economical.

Different kinds of felts are used for the lower layers of multiple layer roofs beneath tiles or slates. There are different kinds of felts:

Impregnated bitumen felts, sanded bitumen felts, which are surfaced with sands, tar felts and others. Roofs are built varying in inclination from nearly horizontal to the steeply pitched. The flat roofs are often used in buildings of cities not only as coverings but also for play-grounds, cafe and the like. The inclination of the roof is made as flat as possible for the purpose of economizing the timber and covering material. The pitch of the roof is governed first by climatic conditions, secondly by the covering material used and by architectural requirements. For any given covering the milder the climate the flatter the pitch that may be given to the roof.

II.Translate the sentences into English.

1.Крыша – самая верхняя часть здания.

2.Она предохраняет здание от внешних воздействий: дождя, ветра и снега.

3.Несущие элементы крыши воспринимают постоянную и переменную нагрузку.

4.На каком расстоянии расположены основные несущие элементы?

5.По расчету конструкции крыша должна воспринимать ветровые нагрузки и выдерживать нагрузку от снега.

6.Какой материал обычно используют для обрешетки?

7.Для экономии кровельных материалов уклон ската крыши делают как можно более плоским.

8.Для кровли используют древесину, металл, черепицу и другие материалы.

III. Write down the summary of the text.

IV. Give antonyms to the following words:

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1) strong; 2) light; 3) coarse; 4) precast; 5) construct; 6) part; 7) bearing; 8) problematic; 9) profit; 10) often; 11) unable; 12) form; 13) past; 14) inner; 15)possible; 16) rapidly; 17) monolithic; 18) rare.

V.Put 10-15 questions to the text.

LIST OF NON-STANDARD VERBS

Таблица нестандартных глаголов

TOPICS FOR SPEECH PRACTICE

Темы для речевой практики

1.Speak about students’ life at Cambridge.

2.Tell your partner about your first session and winter holidays.

3.Speak about cements, Portland cement, being the most important of them.

4.Brick was the first artificial building material made by man, wasn`t it?

5.Why are aggregates necessary for construction?

6.Concrete is one of the constructive building materials. What innovations has concrete led to?

-reinforced concrete (a combination of steel and concrete);

-prestressed concrete (an entirely new application of old materials).

7.Tell your group-mates

-how to mix concrete by hand;

-how to prepare a foundation for a brick wall.

8.Prove that stone is the oldest building material known to a man and successfully used by him.

9.Speak about cement and concrete as

-the basis of modern engineering practice;

-the great industrial importance of concrete;

-the interrelation of the cement and concrete production.

10.Why is glass one of the valuable building materials today? What makes glass unique?

11.Speak about timber as one of the most important natural building materials.

12.Compare glass and timber considering their similarity, their difference and future application.

13.Compare glass and plastics using the previous plan.

14.Do you agree that a great future is open for plastics? Why do / don`t you think so?

15.Read the information about glass and prove that glass is no longer a fragile substance.

16.Reinforced concrete is one of the main building materials in modern construction, isn`t it?

17.What are the main parts of a building? What part is the most important?

18.Structural steel is widely used in modern construction. Give your pros and cons.

19.Why do the future engineers study different building materials at the University?

20.Characterize building materials used in the world`s infrastructure.

ЗАКЛЮЧЕНИЕ

Сегодня знание иностранного языка – необходимое условие для успешной карьеры специалиста любого профиля.

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Поэтому важно развивать навыки чтения, адекватного перевода и обсуждения англоязычных публикаций для извлечения полезной информации и использование ее в профессионально-практической деятельности.

Учебный материал пособия связан с будущей профессией студентов и является источником специализированных знаний, которые помогут обучающим-

ся самостоятельно изучать литературу по специальности, заниматься науч- но-исследовательской деятельностью, расширят общий кругозор, позволят участвовать в совместных проектах с зарубежными партнерами и откроют новые горизонты для дальнейшего карьерного роста.

БИБЛИОГРАФИЧЕСКИЙ СПИСОК

1.Английский язык для инженеров: учеб. для вузов/ Т.Ю. Полякова, Е.В. Синявская, О.И. Тынкова и др. – 7-е издание. – М.: Высш. шк., 2009. – 463 с.

2.Восковская, А.С. Английский язык для вузов: учеб. пособие / А.С. Восковская, Т.А. Карпова – 2-е изд. – Ростов н/Д: Феникс, 2007. – 349 с.

3.Голицынский, Ю.Б. Грамматика: сборник упражнений / Ю.Б. Голицынский, Н.А. Голицынская – 6-е изд., - Каро, 2008 – 544 с.

4.Карпова, Л.В. В мире строительства: учеб. пособие по английскому языку для студентов-строителей / Л.В. Карпова, Е.В Терехова. – 2-е изд. –

Воронеж, 2007. – 138 с.

5.Английский язык для строительных вузов: учеб. пособие / под общей ред. З.Е. Фоминой; Воронеж. гос. арх.-строит. ун-т. – Воронеж, 2006 – ч.1. Unit 1. – 147 с.

6.Рубцова, М.Г. Чтение и перевод английской научной и технической литературы: лексико-грамматический справочник / М.Г. Рубцова – М.: Астрель:

АСТ, 2006. – 382 с.

7.Bonamy David. Technical English. 1 [Текст]: Course Book / Bonamy David. – Edinburgh Gate: Pearson Education Limited, 2008. – 127 p.

8.Bonamy David. Technical English. 2 [Текст]: Course Book / Bonamy David. – Edinburgh Gate: Pearson Education Limited, 2008. – 127 p.

9.Murphy, Raymond. English Grammar in Use. – Cambridge: Cambridge University Press, 2006. – 300 p.

10.MacMillan Exam Skills for Russia: Reading and Writing Teacher`s Guide. MacMillan Publishers Limited 2008. – 223 p.

11.MacMillan Exam Skills for Russia: Speaking and Listening Teacher`s Guide. MacMillan Publishers Limited 2008. – 167 p.

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DICTIONARIES

1.Поздняков, А.А. Англо-русский словарь по строительным и новым строительным технологиям / А.А. Поздняков, В.В. Быков – М.: Русский язык: Медиа, 2008. – 867 с.

2.Мюллер В.К. Новый англо-русский словарь / В.К. Мюллер – 15-е изд.: – М.: Русский язык: Медиа, 2008. – 945 с.

3.Macmillan English Dictionary – Second Edition B2-C2 Advanced. Michael Rundell, Gwyneth Fox. England: Macmillan, 2007. – 1674 pp.

4.Webster's New World College Dictionary. Fourth edition. – Webster's New World, the United States of America, 2004. – 1728 pp.

SPECIAL MAGAZINES

1.House Beautiful. USA, New York.

2.Engineering News-Record. USA, New York.

3.The Architectural Review. Great Britain, London.

4.Canadian Journal of Civil Engineering. Canada, Vancouver.

5.Building Materials, Great Britain, London.

6.New Civil International Magazine of the Institution of Civil Engineering, London.

7.Journal of Composites for Construction. American Society of Civil engineers. The Pennsylvania State University.

8.News Week. The International News Magazine, New York.

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Appendix 1

Приложение 1

SUPPLEMENTARY READING

Внеаудиторное чтение

TEXT 1

BASIC CEMENTING MATERIALS

A basic cementing material is classified as one that, without special additives for weight control or setting properties, when mixed with the proper amount of water, will have cementitious properties. This may be a single ingredient or a combination of two or more ingredients, but they are always used in this combination even when special additives are used with them. The following are of this class: Portland Cement, Pozmix Cement, High Early Cement Pozmix 140, Retarded Cement.

THE MANUFACTURE AND COMPOSITION OF CEMENT

Manufacture. Cements are made of limestone (or other materials high in calcium carbonate content), clay or shale, some iron and aluminum oxides if they are not present in sufficient quantity in the clay or shale. These dry materials are finely ground and mixed thoroughly in the correct proportions either in the dry condition (dry process) or mixed with water (wet process). This raw mixture is then fed into the upper end of a sloping, rotary kiln, at a uniform rate, and slowly travels to the lower end.

The kiln is fired with powdered coal, fuel oil, or gas to temperatures of 2,600 to

2,800°F. (1427°C. to 1530°C) These temperatures cause certain chemical reactions to occur between the ingredients of the raw mixture with the resulting material called clinker. The clinker is ground with a controlled amount of gypsum to form the product we know as Portland cement.

Composition. The following are the principal compounds formed in the burning process and their functions:

Tricalcium Aluminate (C3A) is the compound that promotes rapid hydration and is

the constituent which controls the initial set and thickening time of the cement. It is also responsible for the susceptibility of cement to sulfate attack and to be classified as a high-sulfate resistant cement, it must have three percent or less C3A.

Tetracalcium Aluminoferrite (C4AF) is the low-heat-of-hydration compound in cement. The addition of an excess of iron oxide will increase the amount of C4AF and decrease the amount of C3A in the cement.

Tri-Calcium Silicate (C3S) is the prevalent compound in most cement and the prin-

cipal strength producing material. It is responsible for the early strength (1 to 28 days). High early cements generally have higher percentages of this compound than do Portland or Retarded cements.

Dicalcium Silicate (C2S) is the slow hydrating compound and accounts for the small, gradual gain in strength which occurs over an extended period of time.

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All cements are manufactured in essentially the same way and are composed of the same ingredients, only in different proportions. The water requirement of each type of cement varies with the fineness of grind or surface area. High early strength cements have a high surface area (fine grind), the retarded cements have a low surface area, and the Portland cements have a surface area slightly higher than the retarded cements. The chemical retarder used in retarded cements may be added to the clinker during the secondary grinding stage to provide uniform distribution, or to the finished product.

Common Portland Cement

This cement is intended for use in oil wells from surface to 6,000 ft. depth (1830 m) when no special properties are required. The recommended water-cement ratio, according to API, is 0.46 by weight (5.2 gals./sk.) (19.7 L/sk.). It is more economical than premiumcements and should be used when no special properties are desired and well conditions permit.

High Early Cement

This cement is intended for use in oil wells from surface to 6,000 ft. depth (1830 m). It is ground finer than Portland and has a high C3S content, both of which contribute

to the higher strength. The API water requirement for this cement is 0.56 (6.3 gals./sk.) (24 L/sk.)

The compressive strength of this cement is greater than Portland cement at curing times up to 30 hours; and the pumping time slightly less under the same test conditions. This cement is more expensive than Portland and, unless its special properties are needed, should not be used. Generally, Portland with calcium chloride will give better strengths than this type of cement without accelerators.

Basic Cement

This cement is intended for use as manufactured from surface to 8,000 ft (2440 m) or can be modified with accelerators or retarders to meet a wide range of temperature conditions. It is chemically similar to API Class B cement but is manufactured to more rigorous chemical and physical specifications which result in a more uniform product. As manufactured it contains no accelerators, retarders or viscosity control agents other than gypsum normally ground with cement clinker. All necessary additives are blended by the service Company. The API water requirement for Class G is 0.44 (5.0 gals/sk.) (18.9 L/ sk.) and for Class H is 0.38 (4.3 gals/sk.) (16.3 L/sk.).

Retarded Cement

Most of these cements are retarded with an organic compound while some are retarded by chemical composition and grind. The most common retarders are of the lignin type, the most widely used being calcium lignosulfonates similar to HR-5. These cements are more expensive than Portland cement and, unless their special properties are needed, should not be used.

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This basic cementing composition consists of portland cement, a pozzolanic material (Pozmix), and 2 per cent bentonite based on the total weight of cement and Pozmix. By definition a pozzolan is a siliceous material which reacts with lime and water to form calcium silicates having cementitious properties. Advantages of this reaction are utilized with Pozmix Cement since portland cements release approximately 15 per cent free lime when they react with water, and the lime will subsequently react with the Pozmix to yield a more durable mass of calcium silicates. Because this type of composition is less expensive than the other basic materials and performs well with most additives, it has almost universal application in well cementing.

TEXT 2

THE REQUIREMENTS FOR A SUCCESSFUL CONCRETE STRUCTURE

In the words of the first Concrete Primer: “The concrete must have sufficient strength to carry the loads imposed. The concrete must be able to endure under the conditions of exposure to which it will be subjected. The concrete must be economically produced in comparison with other materials equally strong and durable, which might be used. Thus the requirements may be briefly stated as strength, resistance to degradation, and economy.” These words are equally applicable today.

Assuming that concrete is made from the correct ingredients and in the correct proportions, what other requirements must be met to ensure a durable structure, that is, a structure with long

life?

The important overall requirements are related to measuring, mixing, transporting, placing, curing, and inspection:

(1)All materials should comply with specifications.

(2)The methods of storing, handling, and measuring all ingredients should be such that the selected mixture can be accurately obtained at all times.

(3)The concrete should be adequately mixed, and it should be transported and placed by methods that will avoid segregation and loss of ingredients. The consolidated mass should be uniform without rock pockets or honeycombed areas.

(4)The arrangement of joints and methods for bonding successive lifts of concrete are important details that can vitally affect the performance of the structure even though the concrete itself is durable. Provisions should be made in the structural plans for drainage to avoid areas of constant saturation that would be more susceptible to damage by freezing than other portions of the structure.

(5)Curing of the concrete should not be neglected. This includes protection against extremes of temperature as well as provision for ensuring availability of moisture during the critical early period. No detail of concrete construction offers such possi-

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bilities for increased strength and durability at so low a cost as is offered by the possibilities of better curing.

(6) Careful inspection should be enforced in all of the above operations (ACI Manual of Concrete Inspection, SP-2). After a dissertation on correct practices in the maintenance of the Roman aqueduct in AD 97, Julius Frontinius noted that “all these the workmen know but few observe.”

TEXT 3

POST-TENSIONED CONCRETE

Designers use post-tensioning as a way to reinforce concrete by prestressing it. In prestressed members, compressive stresses are introduced into the concrete to reduce tensile stresses resulting from applied loads including the self weight of the member (dead load). Prestressing steel, such as strands, bars or wires, is used to impart compressive stresses to the concrete. Pre-tensioning is a method

of prestressing in which the tendons are tensioned before concrete is placed and the prestressing force is primarily transferred to the concrete through bond. Posttensioning is a method of prestressing in which the tendons are tensioned after the concrete has hardened and the prestressing force is primarily transferred to the concrete through the end anchorages.

POST-TENSIONING

Unlike pre-tensioning, which can only be done at a precast manufacturing facility, post-tensioning is performed on the jobsite in cast-in-place applications. The concrete component is cast with steel reinforcing strands installed in a way that protects them from bonding with the concrete. This practice gives designers the flexibility to further optimize material use by creating thinner concrete members.

The materials used to post-tension concrete members are ultra-high-strength steel strands and bars. Horizontal applications (like beams, slabs, bridges, and foundations) typically employ strands. Walls, columns, and other vertical applications usually utilize bars. Steel strands used for post-tensioning typically have a tensile strength of 270,000 psi, are about a half-inch in diameter, and are stressed to a force of 33,000 pounds.

BENEFITS

While concrete is strong in compression, it is weak in tension. Steel is strong under forces of tension, so combining the two elements results in the creation of very strong concrete components. Post-tensioning can help create innovative concrete components that are thinner, longer, and stronger than ever before.

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