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Types of floor with steel beams
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The shorter the route taken by a load to its foundations and the fewer the elements involved in the process, the greater the economy of the structure. Nevertheless, the space required for services is significant in the selection of the arrangement of the main and secondary beams, their interrelationship and their depth.
Floor without steel beams The flat concrete slab, supported at its four corners,transmits the loads directly to the columns. With long spans the slab is very heavy. Therefore, this form of construction can be used only in combination with closely spaced columns.
Floors with one-way beam systems The floor beams are supported directly by thecolumns. The force transmission routes being short, this is an economical solution. The planning grid consists of elongated rectangles with columns widely spaced in one direction, closely spaced in the other.
Floors with beams in two directions If the columns are widely spaced in both griddirections, the loads from the secondary beams are transmitted to main beams which, in turn, transmit them to the columns. The forces thus have to pass farther than in the
| examples given above. In general, it is better to keep the span of the main beams shorter | Упражнение3.Напишите предложения с каждым из перечисленных ниже слов: | |
| than that of the secondary beams. | ||
| For very long spans it may be necessary to support the main beams on a third set | characteristic n. - characteristic adj. | |
| of members, such as lattice girders, which finally transmit the loads to the columns. | space n. - space v. | |
| Notes: interrelationship n. взаимоотношение, взаимосвязь | thick adj. - thickness n. | |
| rectangle n. прямоугольник |
Ответьте на вопросы к тексту.
1. What does the economy of the structure depend on?
2. What does the space required for services influence?
3. What are the features of floor without steel beams?
4. What are the features of floors with one-way beam systems?
5. What are the features of floors with beams in two directions?
6. When is a third set of members used?
Грамматические упражнения
Упражнение 1. Найдите в тексте инфинитивы и переведите их на русский
язык.
Упражнение 2. Найдите в тексте причастия и переведите их на русский язык.
Лексические упражнения
Упражнение 1. Переведите на русский язык приведённые ниже слова. Если Вы не знаете слово, найдите его в словаре. Выпишите из словаря то значение слова, в котором оно использовано в тексте.
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grid (n.), lattice girder, route (n.), corner (n.), in turn, secondary beam.
Упражнение 2. Найдите перевод слов списка А в списке В.
| A | B | A | B |
| однако | above | зависимость | therefore |
| комплект | combination | пролёт | flat |
| над | directly | далекорасположенный | closely spaced |
| плоский | span | сила | relationship |
| поэтому | such as | такой как | force |
| инженерные сети | height | сочетание | set |
| близкорасположенный | widely spaced | непосредственно | nevertheless |
| высота | depth | толщина | services |
Урок 2.7
Фонетическое задание
Прочитайте транскрипцию в списке A, соотнесите её с соответствующим словом из списка B и переведите слово на русский язык. Учтите, что не все слова списка В даны в списке А.
A
[q'GeIsqnt]; ['sentq]; [graVt]; ['sJkwqns]; [Im'bed]; ['dxmIG]; ["Intq'fIq];
[q'pIq]; [prq'sJGq]; [I'fISqnt]; [prI'saIslI]; [q'kAmplIS]; [tek'nJk]; ['daVql]
| B | ||||
| procedure | sentence | damage | embed | efficient |
| drainage | accomplish | precisely | techniques | proceed |
| adjacent | technique | dowel | interfere | appear |
| grout | sequence | growl | centre | amber |
Текст A
SETTING THE FLOOR SLABS
With any construction technique, problems often appear and procedures have to be developed which can overcome these in a practical and efficient way. This has been the same in the case of high-rise buildings. Often, different methods are adaptable to the same situation.
Several techniques have been developed for placing the reinforcement as well as grouting. One sequence involves laying walls to storey height and placing the slabs on the ungrouted masonry. Then the vertical reinforcement is placed into the block cells, ensuring that it projects above the finished floor slab to serve as dowels for the next storey walls. This is a very efficient method, but the unreinforced wall possesses relatively little stability and can be easily damaged when the floor slabs are being placed on it. A safer method involves building the masonry walls to full height with the reinforcement located in the walls as the masonry units (brick or block) are laid up. Grouting is then accomplished in full-storey height lifts. The dowels projecting above the slab must be precisely centred in the wall so that when the slabs are lowered into position, the projecting dowels do not interfere with them.
In another procedure, the grouting is stopped a short distance below the floor line, dowels are placed in the grout space, and this space is solid grouted after the slabs have been positioned. Thus, the slabs can be placed without dowels positioned earlier
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interfering. This method also possesses the advantage that it is easier to place the bond beam steel at the top of the wall. The steel extending along the wall at the floor slab level serves to tie all the slabs together. Another method of tying the slabs together lies through the use of weld plates embedded in the slabs so that the weld plates can be used as splices to adjacent panels, tying them together directly.
Notes:
bond beam steel крепёжная арматура железобетонной балки cell n.1 секция, камера
grout n. жидкий строительный раствор grouting n. заливка строительного раствора interfere v. мешать, сталкиваться
ungrouted masonry колодцевая кладка без заполнения пустот строительным раствором weld plate сварная пластина
Ответьте на вопросы к тексту.
1. What is typical with any constructional technique?
2. What is the first construction technique described?
3. What is its drawback?
4. Is there a safer method?
5. What is it?
6. What is the second method described?
7. What is the advantage of this method?
8. What other method of tying the slabs together is there?
Лексические упражнения
Упражнение 1. Переведите на русский язык приведённые ниже слова. Какие из перечисленных слов могут быть другими частями речи? Какими именно? Как они в этом случае переводятся на русский язык?
lift (n.), grout (v.), centre (v.), sequence (n.), adjacent (adj.), position (v.), embed (v.), splice (n.).
Упражнение 2. Переведите следующие слова на английский язык:
класть, устанавливать, в качестве, другой, разрушать, элемент каменной кладки, полезный, эффективный, относительно, устойчивость, размещать, преодолевать, сваривать, скреплять, тянуться, так же как и, опускать, надёжный, высотой в этаж.
Упражнение 3. Найдите в тексте термины, связанные с установкой перекры - тий. Перечислите их и дайте перевод на русский язык.
Упражнение 4. Какие из указанных переводов слов являются ошибочными. Укажите правильный перевод.
| project v | выступать | technique | технология |
| precisely | точно | use n | использование |
| accomplish | добиваться | along | длинный |
| grouting | заливка раствором | settlement | осадка |
| slab | плита | superstructure | большое здание |
| finished | готовый | pier | вертикальная опора |
| ensure | обеспечивать | footing | основание |
| develop | разрабатывать | shaft | ствол |
| way | способ | possess | процесс |
| procedure | процесс | strip | полоса |
Упражнение 5. Заполните пропуски в тексте, используя слова из приведённого ниже списка:
loads space types used ways
Building materials are used in two basic (1)…. In the first way they are used to support the (2)… on a building and in the second way they are used to divide the (3)… in a building. Building components are made from building materials and the form of a component is related to the way in which it is (4)…. We can see how this works by considering three different (5)… of construction.
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(продолжение текста в упражнении 5 урока 2.8 стр. 48)
Грамматические упражнения
Упражнение 1. Переведите следующие предложения, определите функции герундия.
1. A property particularly with concrete is shrinkage caused by loss of water after hardening.
2. Summer is good for building.
3. Because of the low tensile strength of concrete, shrinkage when restrained leads to cracking.
4. The wet concrete can be transported to its final position on site by pumping.
5. More fluid concrete mixes are required for pumping.
6. No wet concrete, after being placed in its final position, should be at a temperature less than 5°C or 40°F.
7. The concrete must be prevented from drying out too fast because this may cause cracking.
8. A concrete structure may be constructed by casting the concrete in place on the site, by building it of elements cast in some other place or by a combination of the two.
9. With some types of precast concrete construction no time is lost in waiting for concrete to gain strength at one level of a structure before the next level can be placed.
10. Special admixtures make hardening faster.
Упражнение 2. Переведите следующие предложения, определите время и залог глаголов.
1. Several techniques have been developed for placing the reinforcement as well as grouting.
2. Grouting is accomplished in full-storey height lifts.
3. The unreinforced wall possesses relatively little stability and therefore can be easily knocked over when the floor slabs are being placed on it.
4. The grouting is stopped a short distance below the floor line, dowels are placed in the grout space, and this space is solid grouted after the slabs have been positioned.
5. This procedure will provide for a continuous uniform bearing.
6. Other schemes involved the use of steel.
7. Such slabs do not require a topping.
8. A topping slab will be poured on top of the filler block to form the finished wearing surface of the tee shape and the floor diaphragm.
Упражнение 3. Переведите следующие предложения, определите функцию инфинитива.
1. To construct a grillage for equal load transmission in both directions involves considerable effort.
2. The structural steel floor comprises the floor slab and the beams to support it.
3. To achieve this, the supporting beams must be quite closely spaced.
4. Low temperatures decrease stretch of the fabric but make it easier for tears to develop.
5. Insulation, which is material with a very low U, is used to make the rate of heat flow as low as possible.
6. Steels which have higher carbon contents are more brittle at low temperatures and more difficult to weld.
7. To reduce the weight of the slab is the task of an engineer.
8. The type of concrete mix and the properties of the hardened concrete may be altered. To do that the proportions of the ingredients may be varied, the type of cement and aggregates may be altered and admixtures may be used.
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Упражнение 4. Задайте пять разделительных и пять альтернативных вопросов к тексту А.
Текст B
TYPES OF FLOOR SYSTEMS
Floor systems not only support the vertical loads but they also serve as the horizontal diaphragms which distribute the lateral forces to the shear walls. There are several different types of floor systems:
Cast-in-place slabs
The simple cast-in-place slab floor system is sometimes used where there are irregular floor designs that would make it difficult to form similar precast units. It provides a good structural tie without requiring any specific type of a joint.
Prestressed elements
Precast prestressed tees are a different type of system. They provide economical long spans giving open space below that can be easily divided with partitions. A topping slab provides both a finished floor surface and a tie, so that the system functions as a diaphragm. This cast-in-place topping slab must be thick enough so that the reinforcement within it can achieve adequate bond to the concrete.
Steel bar joists
The system uses steel bar joists which support a concrete floor slab or a metal deck with a concrete topping surface. It is useful where some space between the ceiling and floor deck above for different kinds of services is required.
Lift-on slab
A lift-on slab, usually of full room size, has proven to be economical and efficient. Such slabs do not require a topping or finish since the floor surface and ceiling finish are part of the slab.
Notes:
lift-on precast slab сборное железобетонное перекрытие, монтируемое методом “lift slab”
steel bar joist решётчатая вспомогательная стальная балка
Ответьте на вопросы к тексту.
1. Which functions do floor systems perform?
2. When is cast-in-place slab floor system used?
3. When are precast prestressed tees used?
4. Why must cast-in-place topping slab be thick?
5. What is the reason for the use of steel bar joists?
6. What are the advantages of a lift-on slab?
Грамматическое упражнение
Упражнение 1. Найдите в тексте неличные формы глагола, определите, какими частями речи они являются, какую функцию выполняют в предложении, и переведите их на русский язык.
Лексические упражнения
Упражнение 1. Переведите на русский язык приведённые ниже слова. Если Вы не знаете слово, найдите его в словаре. Выпишите из словаря то значение слова, в котором оно использовано в тексте.
irregular (adj.), tee (n.), floor deck, diaphragm (n.), topping (n.), deck (n.), shear wall, finish (n.).
Упражнение 2. Найдите перевод слов списка А в списке В.
| A | B | A | B |
| обеспечивать | prove | стяжка | bar |
| иногда | since | потолок | cast-in-place |
| вспомогательная балка | joint | так как | several |
| перегородка | tie | брус | partition |
| несколько | sometimes | оказываться | provide |
| соединение | distribute | монолитный | useful |
| распределять | achieve | полезный | joist |
| стык | ceiling | достичь | bond |
Упражнение 3. Напишите предложения с каждым из перечисленных ниже
слов:
stable adj. - stability n. finish n. - finish v.
Урок 2.8
Фонетическое задание
Прочитайте транскрипцию в списке A, соотнесите её с соответствующим словом из списка B и переведите слово на русский язык. Учтите, что не все слова списка В даны в списке А.
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A
[kqm'pxkt]; ['tPlqrqns]; [skrJd]; [rI'kwaIqmqnt]; ['wLtqtaIt]; [In'hIqrqnt];
[mqVld]; [pq'mIsIbql]; [trPf]; ['kAvqrIN]; ['speIsIN]; [prI'lImInqrI]; [qb'teIn];
| ['stxndqdaIzd] | ||||
| B | ||||
| screed | spacious | tolerance | mould | spacing |
| ordain | inherent | permissible | waterfront | compact v. |
| trough | standardised | obtain | covering | watertight |
| requirement | contact | recruitment | traffic | preliminary |
Текст A
FLOOR REQUIREMENTS
The floor must be designed considering all the functions it will be required to perform. The following factors are important in determining the span to be adopted for the floor slab:
• The span of the slab should fit in with the dimensions of the planning grid for the building.
• The thickness of the concrete slab depends not only on structural factors, but also on such requirements as sound insulation and fire protection.
• The spacing of the floor beams is determined by the maximum permissible width necessary for transportation of the precast concrete units, the main joints of which are parallel to these floor beams.
Lightweight concrete used either as a filler material or as a structural material, reduces the weight of the floor. However, it may involve some loss of sound insulation and fire protection. Furthermore, with long spans and heavy loads, the weight advantage of lightweight concrete may be reduced because deeper sections are necessary.
The degree of evenness of the surface of the structural floor depends on the method of construction. The dimensional tolerances in herent in the construction of an in-situ concrete floor require the application of a screed as a preliminary finishing layer over the slab. Smaller tolerances are obtained when in-situ concrete is placed on permanent
formwork, such as precast concrete units or steel troughs. A floor composed of precast concrete units generally requires only a very thin screed. If these units are precast in standardised steel moulds, a surface of such evenness can be obtained that the floor covering may be laid directly upon the structural floor.
Normally, a steel floor cannot be considered as watertight. To make it watertight an in-situ concrete floor should be laid in one continuous operation, without construction joints, and the concrete itself should be of good quality and well compacted.
Notes:
evenness n. ровность (поверхности) preliminary adj. предварительный
Ответьте на вопросы к тексту.
1. What are the factors important in determining the span for the floor slab?
2. What are the advantages and disadvantages of the use of lightweight concrete for floor slabs?
3. What does the degree of evenness of the structural floor depend on?
4. Why is the application of a screed required?
5. How are smaller tolerances obtained?
6. What should be done to achieve very high evenness of the structural floor?
7. How can watertightness of the structural floor be obtained?
Лексические упражнения
Упражнение 1. Переведите на русский язык приведённые ниже слова. Какие из перечисленных слов могут быть другими частями речи? Какими именно? Как они в этом случае переводятся на русский язык?
screed (n.), tolerance (n.), watertight (adj.), covering (n.), dimensional tolerance, permissible (adj.), in herent (adj.), compact (v.), trough (n.), construction joint, structural floor, mould (n.), finishing (n.), spacing (n.), requirement (n.).
Упражнение 2. Переведите следующие слова на английский язык:
соответствовать, операция, сокращать, легкий бетон, нагрузка, более того, огнезащита, как, балка перекрытия, уплотнять, водонепроницаемый, ширина, постоянная опалубка, получать, главный, сборный бетон.
Упражнение 3. Найдите в тексте термины, связанные с проектированием и возведением перекрытий. Перечислите их и дайте перевод на русский язык.
Упражнение 4. Какие из указанных переводов слов являются ошибочными. Укажите правильный перевод.
| deck | настил | bracing | система связей |
| finish | отделка | arrangement | размещение |
| prove | оказываться | subsequent | последующий |
| equalize | уравновешивать | slender | тонкий |
| topping | верхний | primary | основной |
| irregular | неправильной формы | perform | выполнение |
| grid | решётка | capability | возможность |
| expose | обнажать | row | ряд |
Упражнение 5. Заполните пропуски в тексте, используя слова из приведённого ниже списка:
| as | fixed together |
| building | form |
| can be | plastics |
| compressive | solid |
| concrete | strength |
(Продолжение. Начало в упражнении 5 урока 2.7, стр. 42)
1. In one kind of construction, blocks of materials such as brick, stone, or (1)… are joined together to form (2)… walls. These materials are heavy, however they have high (3)… strength. Walls made up of blocks support the building and divide the space in the (4)….
2. In another type of construction, sheet materials ( листовой материал) are used to
(5)… walls which act as both space-dividers and structural support. Timber, concrete and some (6)… can be made into large rigid sheets and (7)… to form a building.
3. Rod materials (8)… used for structural sup port but not for dividing spaces. Timber, steel and concrete can be formed into rods and used (9)… columns. Rod materials with high tensile and compressive (10)… can be fixed together to form framed structures.
Грамматические упражнения
Упражнение 1. Переведите следующие предложения, обращая внимание на герундий в функции подлежащего.
1. The spacing of the floor beams is determined by the maximum permissible transportable width of the precast concrete units.
2. Welding or bolting of steel components produces high strength connections.
3. Altering the internal layout involves dismantling and re-erecting the partitions.
4. Applying long term loads may cause sagging of timber beams due to creep.
5. Stiffening with the help of lattice bracing or solid diaphragm walls results in fixed points in the building.
6. The spacing of the supports determines the spans of the floor structure and therefore its construction depth.
7. Mixing aggregates, cement and water followed by curing produces the hardened concrete.
8. Although bulk costs of metal are higher than those of most other materials building of steel is still reasonable.
| Упражнение2.Переведите следующие глаголы. | ||
| arrange | design | produce |
| build | erect | start |
| construct | form | use |
Образуйте от них глаголы с помощью приставки re-, означающей повторное действие. Переведите полученные производные слова.
Упражнение 3. Переведите следующие предложения. Определите, от каких слов и с помощью каких суффиксов образованы подчеркнутые существительные.
1. The thickness of the concrete slab depends on such requirements as sound insulation and fire protection.
2. The dimensional tolerances inherent in the construction of an in-situ concrete floor require the application of a screed as a preliminary finishing layer over the slab.
3. The most popular thermosetting plastic in use in the construction industry, due to its cost, strength, relative hardness and toughness, is fibreglass reinforced polyester.
4. It can be easily adapted to changing requirements.
5. Folding screens can be moved by the users of the building themselves.
6. Steel loses strength and stiffness at high temperatures.
Упражнение 4. Переведите следующие предложения. Определите функции неличных форм глагола.
1. Admixtures are available to retard the setting of the wet concrete and this can be used in hot weather to prevent a premature set.
2. The material may fail by breaking or by excessive deformation.
3. A structural member made this way is called a glu-lam member.
4. A building used by people must be kept warmer than the surrounding air in cold climates and cooler than the surrounding air in hot climates.
5. Since the structures designed by civil engineers are intended to be stationary or stable, these forces must be kept in balance.
6. Longitudinal reinforcing has been selected on the basis of providing minimal shrinkage.
7. To reduce weight the slab may be formed with internal cavities or composed of ribs joined together by a thin top layer of concrete, the latter being described as a waffle slab.
8. All buildings have to be stiffened to resist wind loading.
9. The load transmission conditions being approximately the same in both directions, a planning grid is adopted this being typical of in-situ-concrete construction.
10. The joints may be sealed by binding the precast concrete floor units together with a special adhesive mortar.
Упражнение 5. Задайте три вопроса к подлежащему, три – к определению подлежащего и три разделительных вопроса к тексту А.
Текст B
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