СОВРЕМЕННЫЕ ПРОБЛЕМЫ ПРОМЫШЛЕННОГО И...
TRANSCRIPT
Федеральное агентство по образованию Государственное образовательное учреждение высшего профессионального образования
«Ульяновский государственный технический университет»
СОВРЕМЕННЫЕ ПРОБЛЕМЫ ПРОМЫШЛЕННОГО
И ГРАЖДАНСКОГО СТРОИТЕЛЬСТВА
НА ЗАНЯТИЯХ АНГЛИЙСКОГО ЯЗЫКА
Учебное пособие
для студентов 2 курса дневного отделения
по специальности 270102.65
«Промышленное и гражданское строительство»
Составитель Е. В. Кузьмина
Ульяновск
2010
УДК 626/627(075) ББК 38.5я7 С56
Рецензенты: Кафедра иностранного языка Ульяновского высшего военно-технического училища (Военный институт); Кандидат филологических наук, доцент кафедры английского языка Ульяновского государственного педагогического университета Лобина Ю.А.
Утверждено редакционно-издательским советом университета
в качестве учебного пособия. Современные проблемы промышленного и гражданского строительства на занятиях английского языка : учебное пособие / сост. Е. В. Кузьмина. – Ульяновск УлГТУ, 2010. – 63 с. ISBN 978-5-9795-0555-8
Учебное пособие предназначено для студентов 2 курса дневного отделения по специальности 270102.65 «Промышленное и гражданское строительство», составленное в соответствии с программой курса английского языка для технических вузов ГОС ВПО (ГСЭ.Ф. 01).
Цель пособия – развитие навыков чтения и перевода специальной научно-технической литературы для извлечения информации, ознакомление с узкоспециализированной строительной терминологией на английском языке, а также развитие навыков устной речи по специальности.
Работа подготовлена на кафедре иностранных языков УлГТУ. Печатается в авторской редакции.
УДК 626/627 (075) ББК 38.5я7
© Кузьмина Е. В., составление, 2010. ISBN 978-5-9795-0555-8 © Оформление. УлГТУ, 2010.
С56
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Contents
Введение…………………………………………………………………….. 4
UNIT 1……………………………………………………………………….. 5
UNIT 2……………………………………………………………………….. 13
UNIT 3……………………………………………………………………….. 19
UNIT 4……………………………………………………………………….. 24
UNIT 5……………………………………………………………………….. 28
UNIT 6……………………………………………………………………….. 34
UNIT 7……………………………………………………………………….. 40
UNIT 8……………………………………………………………………….. 46
GLOSSARY………………………………………………………………….. 53
SUPPLYMENTARY READING……………………………………………. 55
Заключение. Библиографический список… …….………………………... 63
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Введение Учебное пособие «Современные проблемы промышленного и гражданского строительства на занятиях английского языка» предназначено для студентов 2 курса дневного отделения по специальности 270102.65 «Промышленное и гражданское строительство», составлено в соответствии с программой курса английского языка для технических вузов ГОС ВПО (ГСЭ.Ф.01).
Цель пособия – развитие навыков чтения и перевода специальной научно-технической литературы для извлечения информации, ознакомление с узкоспециализированной строительной терминологией на английском языке, а также развитие навыков устной речи по специальности.
Учебное пособие состоит из уроков-тем, каждый из которых содержит тексты, объединенные общей тематикой, предназначенные для обучения различным видам чтения. Подобные тексты будут способствовать формированию у студентов технического вуза умений и навыков так называемого «гибкого» чтения, при котором стратегия чтения изменяется в соответствии с изменениями задач чтения. В словаре поурочно представлена активная лексика на английском языке. После текстов предложены разнообразные упражнения для проверки понимания текстов, а так же для закрепления пройденной лексики. Во второй части пособия подобраны тексты по домашнему чтению, при подборе которых учитывались их познавательная ценность, последовательность и логичность изложения.
Данное учебное пособие позволит студентам изучить и обобщить специализированную лексику, необходимую для профессионального общения на английском языке. Тематика и сложность текстов определяется объемом общетехнических знаний, которыми владеют студенты после одного года обучения в техническом вузе. Тексты пособия отобраны с учетом их информативности и соответствия научно-техническим достижениям.
Учебное пособие «Современные проблемы промышленного и гражданского строительства на занятиях английского языка» поможет в решении одной из основных задач преподавания иностранного языка в технических университетах – развитие у студентов навыков понимания и перевода технического текста, что возможно осуществить как под руководством преподавателя, так и при самостоятельной работе студентов.
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UNIT 1
Table 1. Building materials.
Material Availability Use Properties Problems/ Durability
Came, leaves vine, bamboo, palm-fronds
Warm-humid zones
Roofs Light; does not store heat; allows free passage of air
Relatively short life span; deteriorates rapidly due to termite attack; highly combustible
Grass Intermediate and subtropical zones
Roofs Light; does not store heat; allows free passage of air
Relatively short life span; deteriorates rapidly due to termite attack; highly combustible
Hardwoods and softwoods
Tropical and subtropical zones (not hot-dry zones)
External woodwork
Extremes of climatic conditions cause dimensional changes, producing cracks, splits and warping; wind-blown sand and grit gradually erode timber; liable to wet and dry rot; attacked by termites and beetles
Earth Hot-dry lands Walls; roofs
Low thermal conductivity; brittle; does not withstand tension well
Termite damage may require frequent repair work
Concrete Hot-temperate Structure; foundation; floor slabs
Low resistance to passage of heat
Salts cause corrosion of reinforcement and spelling of cover; rapid evaporation and shortage of water can result in low strength cracking and high permeability
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TEXT A. THE PROPERTIES OF BUILDING MATERIALS
Materials that are used for structural purposes should meet several
requirements. In 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 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 labor.
Plastics combine all the fine characteristics of a building material with
good insulating properties. It is no wondered that the architects and engineers
have turned to them to add beauty to modern 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 building.
We use main 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.
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1. 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 building material? 9. What artificial building materials do you
know? 10. What natural building materials do you know?
2. Find the meaning of the following words and give the translation:
1. reinforced concrete
2. aggregate
3. raw materials
4. precast concrete
5. timber
6. crushed stone
7. equipment
8. binding materials
9. masonry
10. durability
1. оборудование
2. сырье
3. лесоматериал
4. каменная кладка
5. щебень
6. связывающие вещества
7. железобетон
8. заполнитель
9. долговечность, прочность
10. сборный бетон
Here are some examples of basic forms:
a cube a hemisphere a triangular prism
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a pyramid a rectangular prism a cone a cylinder
Now look at these drawings of buildings and building components:
a hotel a minaret an Egyptian house a mosque
a brick an Arabic arch a Roman arch the structure of a factory
a church a power station building a steel beam a steel channel
dome
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3. Look at these examples:
A man can easily lift a large roll of glass wool but not a concrete beam
Glass wool is light but concrete is heavy.
A man can bend a rubber tile but not a concrete tile.
Rubber is flexible but concrete is rigid.
Wood is combustible but concrete is non-combustible.
Water vapor can pass through stone but not through bitumen.
Stone is permeable but bitumen is impermeable.
You can see through glass but not through wood.
Glass is transparent but wood is opaque.
Stainless steel can resist corrosion but mild steel cannot.
Stainless steel is corrosion resistant but mild steel is not corrosion resistant.
Heat can be easily transferred through copper but not through wood.
Copper is a good conductor of heat but wood is a poor conductor of heat.
Rubber can be stretched or compressed and will then return to its original shape
but clay cannot.
Rubber is elastic but clay is plastic.
Bitumen can be dented or scratched easily but glass cannot.
Bitumen is soft but glass is hard.
Now complete these sentences with properties:
a) The polythene membrane can prevent moisture from rising into the concrete
floor. This means that polythene is ____________.
b) The T-shaped aluminium section can resist chemical action, i.e. aluminium
____________.
c) The stone block cannot be lifted without using a crane. This means that
stone is ____________.
d) The corrugated iron roof cannot prevent the sun from heating up the house,
i.e. iron is ____________.
e) Glass wool can help to keep a house warm in the winter and cool in the
summer, i.e. glass wool is ____________.
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f) The ceramic tiles on the floor cannot be scratched easily by people walking
on them. This means that ceramic tiles are ____________.
g) Asbestos sheeting can be used to fireproof doors. In other words asbestos is
____________.
h) Black cloth blinds can be used to keep the light out of a room, i.e. cloth is
____________.
4. Now look at this table:
Materials Density,
kg/m3
Melting point 0є
C
Typical tensile
strength
N/mm2
Relative cost
Glass
Concrete
Softwood (pine)
Hardwood(oak)
Mild steel
Aluminum
Copper
Zinc
2520
2300
5500
8800
7850
2640
8950
7100
1500
-
-
-
1900
660
1083
420
60
4
40
100
450
90
340
110
12
1
6
15
9
35
25
20
Identify these materials form the table:
a) This material has a slightly lower density than aluminum.
b) This material has a much higher melting point than glass.
c) This material has a tensile strength much higher than concrete, but
slightly lower than zinc.
d) This material is slightly lighter than oak but is much stronger in tension.
e) This material has a considerably higher melting point than copper, but a
much lower tensile strength.
f) This material has a tensile strength approximately twice that of pine.
g) The melting point of this material is approximately 1 Ѕ times as high as
that of copper.
h) The density of this material is approximately half that of pine.
i) This material is ten times as strong as concrete in tension.
j) These two materials have very nearly the same tensile strength.
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5. Look at these sentences:
The tensile strength of copper is approximately three times that of zinc.
Copper has a much higher tensile strength than zinc.
Now make similar sentences to compare the following:
a) Copper and aluminum with regard to their densities.
b) Zinc and oak with regard to their tensile strength.
c) Mild steel and aluminum with regard to their tensile strength.
d) Glass and concrete with regard to their densities.
e) Mild steel and copper with regard to their melting points.
Read this:
Oak is considerably heavier that pine, has a much higher tensile strength and
costs 2 Ѕ times more per kilogram.
Now compare the following in a similar way:
a) glass and concrete
b) aluminum and mild steel
c) copper and zinc
d) pine and mild steel
6. Read and learn the dialog:
Instructor: Right. Today, I’d like you to answer some questions about the
different types of components used in buildings. Now then, who can tell me the
names of the three different types of components?
Student 1: Umm… I think they are units, compound units and tubes.
Instructor: No, that’s not quite right – who can tell me which one of those
three is not correct?
Student 2: Er… Well, a tube is only an example of sectional component. The
three types of components are sections, units and compound units.
Instructor: Yes, that’s right. Now can you describe a section for me?
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Student 2: Yes, umm… A section is a component with a cross-section of a
definite shape – for example I-shaped of square-shaped. Sections are made in
long pieces and then cut to the required lengths.
Instructor: Good. Now who can describe a unit and a compound unit?
Student 1: Umm… I know this. A unit is formed as a simple three-dimensional
shape – such as, for example, a rectangular prism – whereas a compound unit is
made from combinations of sections and units.
Instructor: Very good. Now to make this clear, could you describe an example
of a compound unit please?
Student 1: Umm… Let me think. Well, a timber wall panel is made from solid
rectangular-shaped sections and flat boards. The rectangular sections support
the wooden boards and the boards act as space dividers. Because it is made
from a combination of sectional components, it is an example of a compound
unit.
Instructor: Yes. That’s very good. Thank you.
7. Discussion: Your ideas about the material.
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UNIT 2
TEXT A. RESIDENTIAL AND INDUSTRIAL BUILDINGS
In technically developed countries the building industry, comprising
skilled and unskilled workers in many trades building engineers and architects,
managerial staff and designers employs a considerable proportion, of the
available labour force.
Building industry including residential (public) and industrial
constructiones holds a considerable place in the National Economy and is being
carried on a large scale. It is the largest single industry in the country. The
problems of construction have grown into major, political issues in most
countries.
Housing is prominent, among the factors affecting the level of living. The
improvement of the housing represents a concrete and visible rise in the general
level of living. In many countries residential construction has constituted at
least 12 percent and frequently more than 25 per cent of all capital formation.
The ever growing housing demands have brought to life new methods of
construction with great emphasis upon standardization, new levels of
technological advance utilizing such techniques as offsite prefabrication,
precutting, use of reinforced concrete panels and large-scale site planning. At
present, prefabricated structures and precast elements may be classified into
two principal groups – for residential houses and industrial buildings.
Present-day designs for residential constructions envisage all modern
amenities for a dwelling, they advocate larger, better built and better equipped
flats and houses. There is a marked improvement in the heating and ventilating
systems as well as in hot-water supply, kitchen and sanitary fittings. Many
tenants now can afford better furnishings, refrigerators, washing, machines, etc.
A house which is a physical environment where a family develops is acquiring
a new and modern look.
Industrial buildings comprise another significant type of construction.
This type of construction involves factories, laboratories, food processing
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plants, mines, office buildings, stores, garages, hangars and other storage
facilities exhibitions halls, etc.
Each of these functions demands its own structural solution and
techniques. But in general they may be divided into classes according to
whether the plan must give greater attention to the size and movement of
machinery or of persons. The building techniques (by techniques we mean
building materials and methods) depend upon the types of buildings.
Modern industrial buildings have demonstrated the advantages of
reinforced concrete arches, metal frames, glass walls and prefabricated
standardized mass produce parts. Steel was gradually substituted for iron and
permitted wider rooms and larger windows. Windows can be enlarged to the
extent that they constitute a large fraction of the wall area.
1. Complete the sentences:
1. Modern industrial buildings have demonstrated the advantage of…
a) hot-water supply and panel heating
b) reinforced concrete arches, metal frame, glass walls and prefabricated
parts.
c) all modern conveniences for a dwelling
d) heating and ventilation systems
2. Industrial type of construction involves…
a) better built and equipped flats and houses.
b) theatres, cinemas, museums, etc.
c) factories, mines, office buildings, etc.
d) housing.
3. Present-day designs for residential construction envisage…
a) movement of machinery and persons.
b) application of metal frames and glass walls.
c) all modern conveniences.
d) windows as large as the wall area.
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2. Укажите, какие из данных предложений относятся к описанию
жилых зданий и какие – к промышленным. Сгруппируйте
предложения по этим темам.
1. In many countries residential construction has constituted at least 12 per cent
of all capital formation. 2. The problem of housing has grown into a major,
political issue in most countries. 3. Industrial buildings comprise another
significant type of construction. 4. Modern buildings have demonstrated the
advantages of reinforced concrete arches, metal frames, glass walls. 5. The
differing functions of industrial buildings require their own structural solutions
and techniques. 6. Present-day designs for housing envisage all modern
conveniences and sanitary fittings. 7. Buildings may be divided into two classes
according to whether the plan must give greater attention to the size and
movement of machinery or of persons. 8. Windows can be enlarged to the
extent that they constitute a large fraction of the wall area. 9. A house which is
a physical environment where a family develops is acquiring a new and modern
look.
3. Look and read:
When designing a building for a group of people, an architect considers
the maximum, minimum and average dimensions of their bodies. For each
design situation shown below say which dimension an architect should base his
calculations on:
Design situation: Dimension
Example: floor-to-ceiling height maximum height in the group (tallest
person)
a) width of doorway …
b) height of seat above floor …
c) height of notices …
d) length of seat surface from backrest to …
front edge
e) width of sink unit …
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4. Complete the paragraph:
When deciding on the floor-to-ceiling height of a building, an architect
should base his calculations on the tallest person in a group of people. The
tallest person in our group us _____ mm. Therefore the floor-to-ceiling height
of our building should be greater than ____ mm.
Explain the following facts:
a) The tables used in infant schools are lower than the ones used in
universities.
b) More people can be carried on a train during rush hour in summer than in
winter.
c) An African will be uncomfortable sitting in a chair designed for a
Japanese.
d) The doorway height in Britain is usually 2 100 mm although some
Britons are taller than 2 100 mm.
5. Look and read:
A room has three spatial dimensions: length, height and width. These
dimensions are measured in millimeters or metres. The volume of a room
equals length times height times width. Volume is measured in cubic metres
(m3). The area of a surface in the room is measured in square metres (m2).
Estimate the internal measurements of your classroom and make a table
like this:
Name Dimension Quantity Unit
Classroom
window
etc.
Width
area
4
2
Metre
square metres
Now from your table sentences like the following:
The classroom has a width of approximately 4 metres.
The classroom is approximately 4 metres wide.
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The window has an area of approximately 2 square metres.
The window is approximately 2 square metres in area.
6. Translate the text with a dictionary:
The single-store structure consists of three frames which are made up of
steel stanchions and beams. The frames are placed between and walls and
spaced at 3 meter centers. The stanchions carry the beams which support the
roof. The roof beams cantilever a short distance beyond the stanchions. This
means that they extend over the profiled sheet steel cladding which can then be
placed outside the line of the stanchions.
The beams are bolted to steel stanchions caps which are welded to the top
of each stanchion. The load on each beam is transmitted through these plates to
the stanchions.
The upper face of the steel base plates and the ends of the stanchions are
machined flat. The bottom of each stanchion is welded to a base plate which is
fixed to a concrete column base by two holding-down bolts.
Steel angles are fixed across the ends of the beams and built into the brick
walls. These angles tie the frames together and also provide a place to fix the
top of the cladding.
7. Translate the text without a dictionary:
When an architect receives a commission for a building, he meets the
client and discusses his requirements. After visiting the site, the architect draws
up preliminary plans and, together with a rough estimate of the cost, submits
them to the client for his approval. If the client suggests changes, the architect
incorporates them into the final design which shows the exact dimension of
every part of the building. At this stage, several building contractors are invited
to bid for the job of constructing the building. When they submit their tenders
or prices, the architect assists his client in selecting the best one and helps him
to draw up a contract between the client and the contractor.
Work now starts on the building. As construction proceeds, the architect
makes periodic inspections to make sure that the building is being constructed
18
according to his plans and that the materials specified in the contract are being
used. During the building period, the client pays the bills from the contractor.
Subsequently, the contractor completes the building and the client occupies it.
For six months after completion there is a period known as the ‘defects liability
period’. During this period, the contractor must correct any defects that appear
in the fabric of the building. Finally, when all the defects have been corrected,
the client takes full possession of the building.
Now find a word or an expression in the passage which means:
a) to be given the job of designing a building
b) to offer to a client for his consideration
c) to combine into a whole
d) to offer to do some work at a certain price
e) to look at the building work in detail at regular intervals
f) named or described exactly
g) an interval of time after the building has been finished during which the
contractor is responsible for correcting any faults in it
h) to have complete ownership of the building
8. Discussion: Your ideas about the material.
19
UNIT 3
CEMENTITIOUS MATERIALS
Cementations materials include the many products that are mixed with
either water or some other liquid or both to form a cementing paste that may be
formed or molded while plastic but will set into a rigid shape. When sand is
added to the paste, mortar is formed. A combination of coarse and fine
aggregate (sand) added to the paste forms concrete.
TYPES OF CEMENTITIOUS MATERIALS
There are many varieties of cements and numerous ways of classification.
One of the simplest classifications is by the chemical constituent that is
responsible for the setting or hardening of the cement. On this basis, the silicate
and aluminate cements, wherein the setting agents are calcium silicates and
aluminates, constitute the most important group of modern cements. Included in
this group are the portland, aluminous, and natural cements. Limes, wherein the
hardening is due to the conversion of hydroxides to carbonates, were formerly
widely used as the sole cementitious material, but their slow setting and
hardening are not compatible with modern requirements. Hence, their principal
function today is to plasticize the otherwise harsh cements and add resilience to
mortars and stuccoes. Use of limes is beneficial in that their slow setting
promotes healing, the recementing of hairline cracks. Another class of cements
is composed of calcined gypsum and its related products. The gypsum cements
are widely used in interior plaster and for fabrication of boards and blocks; but
the solubility of gypsum prevents its use in construction exposed to any but
extremely dry climates. Oxychloride cements constitute a class of specialty
cements of unusual properties. Their cost prohibits their general use in
competition with the cheaper cements; but for special uses, such as the
production of spark proof floors, they cannot be equaled. Masonry cements or
mortar cements are widely used because of their convenience. While they are,
in general, mixtures of one of more of the above-mentioned cements with some
admixtures, they deserve special consideration because of their economies.
Other cementitious materials, such as polymers, fly ash, and silica fume, may
20
be used as a cement replacement in concrete. Polymers are plastics with long-
chain molecules. Concretes made with them have many qualities much superior
to those of ordinary concrete. Silica fume, also known as microsilica, is a waste
product of electric-arc furnaces. The silica reacts with limes in concrete to form
a cementitious material. A fume particle has a diameter only 1% of that of a
cement particle.
Properties of cement.
All types of cement shrink during setting. In a normal concrete the
amount of this shrinkage will depend both on the proportion of cement in the
mix and the quantity of mixing water employed. Provided enough water is
present to enable the chemical action of setting to take place, then the smaller t
amount of water the less shrinkage there will be. The type of aggregate used has
an appreciable effect upon both the amount of water and the amount off
aggregate that can be mixed with given quantity of cement. Strength and
durability of concrete are linked properties in that they are both associated with
the low water-cement ration. In addition to the proportion of cement and the
water cement ratio of a cement product, the method of curing will also affect
the amount of shrinkage. Normally, the slower the drying the less shrinkage
there will be. All cement products are able to a considerable shrinkage during
setting and hardening.
PORTLAND CEMENTS
Portland cement, the most common of the modern cements, is made by
carefully blending selected raw materials to produce a finished material meeting
the requirements of ASTM C150 for one of eight specific cement types. Four
major compounds and two minor compounds constitute the raw materials. The
calcareous materials typically come from limestone, calcite, marl, or shale. The
argillaceous materials are derived from clay, shale, and sand. The materials
used for the manufacture of any specific cement are dependent on the
manufacturing plant’s location and availability of raw materials. Portland
cement can be made of a wide variety of industrial by-products. In the
manufacture of cement, the raw materials are first mined and then ground to a
powder before blending in predetermined proportions. The blend is fed into the
21
upper end of a rotary kiln heated to 2600 to 3000F by burning oil, gas, or
powdered coal. Because cement production is an energy-intensive process,
reheaters and the use of alternative fuel sources, such as old tires, are used to
reduce the fuel cost. (Burning tires provide heat to produce the clinker and the
steel belts provide the iron constituent.) Exposure to the elevated temperature
chemically fuses the raw materials together into hard nodules called cement
clinker. After cooling, the clinker is passed through a ball mill and ground to a
fineness where essentially all of it will pass a No. 200 sieve (75 m). During the
grinding, gypsum is added in small amounts to control the temperature and
regulate the cement setting time. The material that exits the ball mill is portland
cement. It is normally sold in bags containing 94 lb of cement. Concrete, the
most common use for Portland cement, is a complex material consisting of
Portland cement, aggregates, water, and possibly chemical and mineral
admixtures. Only rarely is Portland cement used alone, such as for a cement
slurry for filling well holes or for a fine grout. Therefore, it is important to
examine the relationship between the various Portland cement properties and
their potential effect upon the finished concrete. Portland cement concrete is
generally selected for structural use because of its strength and durability.
Strength is easily measured and can be used as a general directly proportional
indicator of overall durability. Specific durability cannot be easily measured but
can be specified by controlling the cement chemistry and aggregate properties.
ALUMINOUS CEMENTS
These are prepared by fusing a mixture of aluminous and calcareous
materials (usually bauxite and limestone) and grinding the resultant product to a
fine powder. These cements are characterized by their rapid-hardening
properties and the high strength developed at early ages. Table 4.3 shows the
relative strengths of 4-in cubes of 1:2:4 concrete made with normal Portland,
high-early-strength Portland, and aluminous cements. Since a large amount of
heat is liberated with rapidly by aluminous cement during hydration, care must
be taken not to use the cement in places where this heat cannot be dissipated. It
is usually not desirable to place aluminous-cement concretes in lifts of over 12
in; otherwise the temperature rise may cause serious weakening of the concrete.
22
Aluminous cements are much more resistant to the action of sulfate waters than
are Portland cements. They also appear to be much more resistant to attack by
water containing aggressive carbon dioxide or weak mineral acids than the
silicate cements. Their principal use is in concretes where advantage may be
taken of their very high early strength or of their sulfate resistance, and where
the extra cost of the cement is not an important factor. Another use of
aluminous cements is in combination with firebrick to make refractory
concrete. As temperatures are increased, dehydration of the hydration products
occurs. Ultimately, these compounds create a ceramic bond with the aggregates.
NATURAL CEMENTS
Natural cements are formed by calcining a naturally occurring mixture of
calcareous and argillaceous substances at a temperature below that at which
sintering takes place. The ‘‘Specification for Natural Cement’’ requires that the
temperature be no higher than necessary to drive off the carbonic acid gas.
Since natural cements are derived from naturally occurring materials and no
particular effort is made to adjust the composition, both the composition and
properties vary rather widely. Some natural cement may be almost the
equivalent of Portland cement in properties; others are much weaker. Natural
cements are principally used in masonry mortars and as an admixture in
Portland-cement concretes.
LIMES
These are made principally of calcium oxide (CaO), occurring naturally in
limestone, marble, chalk, coral, and shell. For building purposes, they are used
chiefly in mortars.
Hydraulic Limes
These are made by calcining a limestone containing silica and alumina to
a temperature short of incipient fusion so as to form sufficient free lime to
permit hydration and at the same time leave unhydrated sufficient calcium
silicates to give the dry powder its hydraulic properties.
Because of the low silicate and high lime contents, hydraulic limes are
relatively weak. They find their principal use in masonry mortars. A hydraulic
lime with more than 10% silica will set under water.
23
1. Put questions the words given on bold type
1. The water used for mixing cements, limes and plasters must be reasonably
clean.2. Pond, river and canal waters often contain vegetable and other organic
impurities and should not be used without examination. 3. Water fit for drinking
can be assumed to be free from harmful ingredients. 4. Only sufficient water
should be used to enable the hydration to take place and to make the mixture
easily workable; any access is detrimental to the ultimate strength of the
concrete.
2. Ask and answer the questions about building materials used:
The sand should be clean and free from clay and vegetable matter because
when it is mixed with water and cement a chemical action takes place.
Therefore, if impurities are present, the binding or adhesion is affected.
3. Give a written translation of the following:
1.Портландцемент в основном употребляется для изготовления наземных
и подземных бетонных и железобетонных конструкций. 2. Бетон
применяется в строительстве с глубокой древности. 3. В качестве
вяжущих в древности использовали известь, глину, гипс и асфальт. 4. Егор
Челиев впервые приготовил цемент в начале XIX в. 5. Изготовление
цементов в Англии и Германии началось на несколько лет позже.
4. Insert the needed words and groups of words:
Portland cement is a … product. It is made of …, … or … . They are … and …
with water to form a paste. The mixture is then … in a kiln. The clinker is
ground to … .
5. Discussion: Your ideas about the material.
24
UNIT 4
TEXT A. MORTARS
Mortars are composed of a cementitious material, fine aggregate, sand,
and water. They are used for bedding unit masonry, for plasters and stuccoes,
and with the addition of coarse aggregate, for concrete. Here consideration is
given primarily to those mortars used for unit masonry and plasters. Properties
of mortars vary greatly, being dependent on the properties of the cementitious
material used, ratio of cementitious material to sand, characteristics and grading
of the sand, and ratio of water to solids.
Mortar is the matrix used in the beds and side joints of brickwork and for
plastering walls and floors. Its functions are as follows:
1) to distribute the pressure throughout the brickwork,
2) to adhere and bind together the bricks,
3) to act as a non-conductor and prevent the transmission of heat, sound, and
moisture from one side of wall to the other. The factors governing the choice of
mortars for various purposes are:
a) strength as being a main factor determining the strength of the wall
b) porosity and capillary characteristics as affecting the rain-excluding
properties and durability of the wall,
c) content of soluble safts which determines the possibility to destruction
of the masonry or brickwork.
Mortar consists of an inert aggregate bound by a cementing material. The
cementing material is most important in determining the characteristics of the
mortar. The usual cementing materials used for constructional work are
hydraulic limes or Portland cement.
Clean, sharp pit sand is the best aggregate. Old bricks, burnt ballast or
stories ground in a mortar mill may be used as substitutes for sand.
Mortars may be classified as follows:
1. Cement mortars
2. Cement-lime mortars
3. Lime mortars
25
Lime Mortar – This is a mixture of quick lime and sand, in the proportion
of a part lime to 2 or 3 parts sand in addition to water. It is the principal
material used for bedding and jointing bricks, stones, etc. The slaked lime is
mixed with the sand and water either by hand or in a mortar mill. The period of
slaking, composition and strength of mortar depends upon the class of lime
used.
Non-hydraulic Lime Mortars must be well slaked before use. This type
can be stored in a heap for several days after mixing, provided the surface is
smoothed over with a shovel to, minimize carbonation by the exclusion of as
much air as possible. As such mortars can only harden when exposed to the
atmosphere, a relatively large proportion of sand must be added to the lime to
assist in the penetration of air for this reason the proportion of sand may be as
high as 4 parts by volume of sand to 1 part lime. These mortars are not suitable
for work below ground level, especially if the ground is water-logged.
Hydraulic Lime Mortars should be used within an hour after being mixed.
Any mortar which has stiffened and cannot be knocked up by means of a trowel
to a sufficiently plastic condition should never be used. The proportion of lime
to aggregate ranges from 1 part lime to from 2 to 3.5 parts sand, and common
mixture being 1:3. These are excellent mortars for all purposes and are
particularly suited for work below the ground level and in exposed positions.
Magnesian and Dolomitic Lime Mortars have a slow-setting an action and
should therefore be slaked for several hours before use. Their properties and
uses are somewhat similar those of hydraulic lime mortars.
Black Mortars. - Ashes or clinkers from furnaces are crushed finely and
ground with the lime in a mortar mill to produce a cheap and strong mortar,
known as black mortar. The ashes should be free from unburnt coal and dust. A
common proportion is 1 part lime to 3 parts ashes or clinker. They are hard-
setting mortars and are suitable for internal walls and for brickwork and
masonry where the color is not objected to.
Cement Mortars. - It is stronger than lime mortar and is used in the
construction for external walls. Cement mortar is now extensively used during
winter, owing to as relatively quick-setting property. It must be used
26
immediately after mixing. The usual, composition is 1 part cement to 3 parts
sand. A dense cement mortar should not be used for bedding and jointing low-
strength bricks.
Lime-Cement or Compo Mortars. - Compo is a mixture of lime, cement
and sand. It is usual to mix the lime mortar and then to gauge this mixture with
the necessary proportion of Portland cement immediately before the mortar is
required for use. Only non-hydraulic lime should be used for this class of
mortar. The addition of cement increases the hydraulicity of the mortar, besides,
increasing its strength and the rate of hardening is therefore accelerated. The
gauging also increases the workability of the mortars. The proportions vary
from 1 part cement: 2 to 3 part lime: 9 to 12 parts sand. Eminently hydraulicand
magnesian limes should not be ganged with cement.
Strength of Mortar. - Cement mortar produces the strongest brickwork,
non-hydraulic lime mortar is approximately half the strength of that in cement
mortar, and the strength of eminently hydraulic mortars is intermediate between
that of cement and non-hydraulic lime mortars. The strength of compo mortars
depends upon the cement content and may be very little less than that of cement
mortar.
Properties of Mortars
Workability is an important property of mortars, particularly of those
used in conjunction with unit masonry of high absorption. Workability is
controlled by the character of the cement and amount of sand. For example, a
mortar made from 3 parts sand and 1 part slaked lime putty will be more
workable than one made from 2 parts sand and 1 part Portland cement. But the
3:1 mortar has lower strength. By proper selection or mixing of cementitious
materials, a satisfactory compromise may usually be obtained, producing a
mortar of adequate strength and workability.
Water retention — the ratio of the flow after 1-min standard suction to
the flow before suction — is used as an index of the workability of mortars. A
high value of water retention is considered desirable for most purposes. There
is, however, a wide variation in water retention of mortars made with varying
27
proportions of cement and lime and with varying limes. The ‘‘Standard
Specification for Mortar for Unit Masonry’’ requires mortar mixed to an initial
flow of 100 to 115, as determined by the test method, to have a flow after
suction of at least 75%.
Strength of mortar is frequently used as a specification requirement, even
though it has little relation to the strength of masonry. The strength of mortar is
affected primarily by the amount of cement in the matrix. Other factors of
importance are the ratio of sand to cementing material, curing conditions, and
age when tested.
Volume change of mortars constitutes another important property.
Normal volume change (as distinguished from unsoundness) may be considered
as the shrinkage during early hardening, shrinkage on drying, expansion on
wetting, and changes due to temperature. After drying, mortars expand again
when wetted. Alternate wetting and drying produces alternate expansion and
contraction, which apparently continues indefinitely with Portland-cement
mortars.
PORTLAND-CEMENT CONCRETE
Portland-cement concrete is a mixture of Portland cement, water, coarse
and fine aggregates, and admixtures proportioned to form a plastic mass
capable of being cast, placed, or molded into forms that will harden to a solid
mass. The desirable properties of plastic concrete are that it is workable,
placeable and no segregating, and that it set in the desired time. The hardened
concrete should provide the desired service properties:
1. Strength (compressive and flexural)
2. Durability (lack of cracks, resistance to freezing and thawing and to chemical
attacks, abrasion resistance, and air content)
3. Appearance (color, lack of surface imperfections)
Each of these properties affects the final cost of the mix design and the
cost of the in-place concrete. These properties are available from normal-
weight, lightweight, and heavyweight concretes.
1. Discussion: Your ideas about the material.
28
UNIT 5
TEXT A. FROM THE HISTORY OF CONCRETE.
Mass or plain concrete dates from very early days. It was employed by
the Egyptians, Romans and Greeks in the construction of aqueducts and
bridges, in the construction of roads and town walls. Romans used it even in
under-water structures some of which have survived till our time. A large part
of the Great Chinese Wall (the 3rd century before our era) was also built of
concrete.
The concrete remains of the foundations of buildings built several
thousand years ago have been found in Mexico. As cement was not known in
those times, concrete was made of clay and later of gypsum and lime.
Nowadays concrete is made, in up-to date machinery with very careful
regulation of the proportion of the mix.
The idea of strengthening concrete by a network of small iron rods was
developed on the 19th century, and ferro-concrete was introduced into
engineering practice.
Text B. Concrete.
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 is 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
29
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 (ferro-concrete) where it is necessary to
introduce steel. Plain of mass concrete can be used for almost all building
purposes. Ferro-concrete us used in buildings bridges and arches, dams and
dock-walls, for structured 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 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 of 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.
30
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.
1. 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?
2. Read the following and then describe the behavior of concrete:
1. Curing. Concrete becomes hard by the chemical combination of cement and
water, during which process it is necessary to prevent as far as possible
evaporation of the water from the surface of the concrete; this is called
“curing”, and is accomplished by covering the concrete, as soon as it can be
done without damaging the surface, with damp cloths, wet straw, wet sand, etc.,
kept wet by sprinkling, or by immersing in water.
2. Hardening. The strength of concrete under favorable curing conditions
increases with age. Hardening is very rapid in the early stages, but continues
more slowly for an indefinite period amounting to years.
3. Insert the needed words and groups of words:
Portland cement is a … product. It is made of …, … or … . They are … and …
with water to form a paste. The mixture is then … in a kiln. The clinker is
ground to … .
31
4. Study the following text and then give it a title:
Concrete – unlike many buildings materials – is equally a framing and an
enclosing material. It can be used to construct a skeleton; it can also be used to
construct a complete weather tight shell of floor, walls and roof. In this respect
it is one of the few total building materials.
It is hardly surprising that for a long time reinforced concrete was treated
in a similar manner to a steel frame, clad in some other material.
Steel needs protection from the external elements and from internal fire;
concrete need neither of these. Steel was a construction material of parts
connected together; concrete could be handled to produce a monolithic structure
including enclosing surfaces.
The present stage of evolution shows and appreciation of concrete as a
total material.
5. Render the text in Russian:
Concrete. Concrete is and artificial stone. It is made by mixing a paste of
cement and water with sand and crushed stone, gravel, or other inert material.
After this plastic mixture is placed in forms, a chemical action takes place and
the mass hardens. Concrete, although strong in compression, is relatively weak
in resisting tensile and shearing stress which develop in structural members. To
overcome this lack of resistance, steel bars are placed in the concrete at the
proper positions, and the result is reinforced concrete. In beams and slabs the
principal function of the concrete is to resist compressive stresses, whereas the
steel bars resist tensile stresses.
6. Render the following in English:
1. Лёгкие бетоны изготовляют на пористых естественных или
искусственных заполнителях. 2. Лёгкие бетоны на пористых заполнителях
применяют для изготовления панелей для стен, плит перекрытий и
конструкций каркаса. 3. Конструкции из легких бетонов следует
применять при отсутствии агрессивных воздействий. 4. Когда
конструкции находятся в агрессивной среде (наличие агрессивных газов,
32
паров, кислот и т. д.), мелкие трещины растянутой зоны бетона
способствуют активному развитию коррозии арматуры. 5. Это приводит к
снижению несущей способности конструкций. 6. Для борьбы с коррозией
бетонных и железобетонных конструкций применяют плотные бетоны,
кислотостойкие бетоны, полимербетоны.
7. Complete the sentences:
1. Prefabrication means...
a) … reinforcement of brickwork with steel. b) … preassembly in a workshop,
so that the building can be more quickly erected on the site. c)... craft operation
at the building site.
2. Reinforced concrete is a building material in which...
a) ...such properties as small volume weight and high thermal conductivity are
combined. b) ...physical and mechanical properties at a normal temperature of
20°C make it semi-rigid and soft. c)...the joint functions of concrete and steel
are advantageously utilized.
3. Like any other stone material, concrete offers...
a) …the ability of binding together masonry units such as stone, brick and
plaster. b) … a good resistance to compressive loads. c) ...a lower volume
weight and it is manufactured from a mixture of unslaked lime and quartz sand.
8. Read this passage:
Concrete is made from cement, coarse aggregate (stones), fine aggregate
(sand or crushed stone) and water. Coarse aggregate ranging from 5 mm to 4
mm may be used for normal work. The maximum size of the aggregate should
not be greater than one quarter of the minimum thickness of the finished
concrete. The normal maximum sizes are 20 mm and 40 mm (20 mm being
more common. The maximum size of aggregate which should be used in small
concrete sections, or where reinforcement is close together, is 10 mm.
In concrete with widely spaced reinforcement, such as solid slabs, the size
of the coarse aggregate should not be greater than the minimum cover to the
33
reinforcement otherwise spalling will occur, i.e. the breaking off of pieces of
concrete below the reinforcement. For heavily reinforced sections, e.g. the ribs
of main beams, the maximum size of the coarse aggregate should be either:
(I) 5 mm less than the minimum horizontal distance between the reinforcing
rods, or,
(II) 5 mm less than the minimum cover to the reinforcement, whichever is
the smaller.
Now say whether these statements are true or false. Correct the false statements.
a) Concrete is made from three different materials.
b) Coarse aggregate ranges in size from 20 mm to 40 mm.
c) Then the minimum thickness of the finished concrete is 100 mm, the
maximum size of aggregate should not be greater than 25 mm.
d) When the reinforcing rods are close together, the maximum size of aggregate
used should be 10 mm.
e) Cover is the thickness of concrete between the reinforcing rods.
f) The reinforcing rods are placed near the bottom of the rib of a concrete beam.
g) Spalling can occur in a solid concrete slab when the cover to the
reinforcement is greater than the maximum size of the coarse aggregate.
h) Then the minimum horizontal distance between reinforcing rods is 15 mm,
the maximum size of aggregate should be less than 12 mm.
9. Discussion: Your ideas about the material.
34
UNIT 6
TEXT A. Gas concrete.
Lime and silica are ground together to very fine limits. The siliceous
material can vary considerably in its composition. Much use is made of such
waste materials as fly ash from power-stations, blast furnace slag, as well as
natural pozzolanas, pumice, etc. The degree of foaming in the gas concrete, and
thus its specific gravity, is determined by the amount of aluminium powder or
other agent added. The practical limits of the final density are between 13 and
90 Ib. Per cu. ft. If he gas concrete is allowed to harden on its own, it usually
takes about three weeks before, the final strength is achieved. It is more
customary to accelerate the setting of the gas concrete by steam hardening it in
autoclaves with superheated steam at about 140 Ib. per sq. in. The steam
hardening process takes about 15-20 hr. Air-cured gas concrete can be used for
the manufacture of special components for the refrigeration industry. Such
blocks are cast to special dimensions.
Gas concrete can be cast horizontally to form roomsized outer wall units.
It is possible to incorporate electric conduit pipes, piping for the cold and
hot water systems and also drainage pipes. The units usually include windows
and doors, and are reinforced by embedding steel mesh in the mix.
Gas concrete can be used as thermally insulating floor screeds or as an
additional thermally insulating layer a top of concrete roof.
Cast gas concrete is often used as the thermally insulating layer in
“sandwich wall” units.
Gas concrete is often used as a thermally insulating layer when casting
buildings by a continuous easting technique.
Text B. Steam treatment process to produce thermoplastic materials and
hydraulic cements
This invention relates to the manufacture of thermoplastic materials and
hydraulic cements from certain glass compositions. More particularly, this
invention relates to the manufacture of such products through the steam
treatment of glass powders in the alkali metal silicate composition field.
35
A thermoplastic material is one having the property of softening when
heated and of hardening and becoming rigid again when cooled. Hence, such a
material is normally hard at room temperature but will soften and become
moldable, adhesive, and cohesive when heated to some higher temperature.
This property of thermoplasticity is well-recognized in such organic materials
as cellulose acetate, polyethylene, and vinyl polymers and in glasses at
temperatures around and somewhat above the softening points thereof. The
value of this property is apparent in the forming of articles through molding,
pressing, extrusion, rolling, etc., and in forming composite structures,
laminates, and the like.
Hydraulic cement is one that is capable of hardening under the influence
of water. Hence, such a material, when mixed with water and allowed to stand,
gradually sets up as a hard, massive solid structure. Portland cement is probably
the best known material commercially of this type.
Text C. New types of concrete
Not long ago a new building material was born. Called alkali-slag
concrete, most of its components come literally from under foot. Cement is
replaced by a mixture of granulated blast-furnace slags and sodium and
potassium compounds. The filler 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
roads, pavements, irrigation systems and other structured. Specialists estimate
that the use of alkali-slag concrete will help save hundreds of millions of rubles
on the country's construction projects.
Chemically resistant concrete (кислотоупорный) may be sometimes used
in the construction of structures attacked by chemically active media (среда),
i.e. industrial, hydraulic and underground structures. It has been proposed to
prepare a chemically resistant concrete using a binder (вяжущее), a vitreous
sodium silicate (стекловидный силикат натрия). Then such a vitreous silicate
is dissolved in water, liquid (жидкий) glass is obtained. In order to assist in the
solidification (затвердение) of a liquid glass and increase its water resistance
36
certain elements are added to the concrete composition. They serve to neutralize
the alkali (щелочь) in the liquid glass and convert it into a water-insoluble
(нерастворимый) compound. Thus, during the course of the neutralization of
the alkali, free silica is evolved (выделяется кварц) from the liquid glass in the
form of a gel which serves as a binder.
Chemically resistant concrete has not found wide application because it is
completely permeable to aggressive, corrosive solutions. The Soviet scientist
V. P. Kirilishin decided to provide and improved alkali-metal-silicate based
concrete. In accordance with his invention high-silica-alkaline glasses are
practically insoluble in water even at elevated temperatures and are not suitable
for the production of liquid glass. However, when subjected to heat in the
presence of finely divided quartz sand, the high silica alkaline glass on the
finely divided particles of the quartz sand.
In the present invention the silica binding agent is not present in the form
of a gel that has the more thermodynamically and chemically stable crystalline
form of free silica, namely quartz. This leads to good chemical, physical,
thermal and mechanical characteristics for the binder and the chemically
resistant concrete.
Text D. Concrete structures
The world has suddenly become aware of the great resources of ocean
and their potential for providing many of man's most pressing needs: energy,
food, transport, minerals and waste-disposal. However the seas present an
extremely hostile environment, requiring cooperative efforts by many
engineering disciplines in order to achieve the necessary structures.
These structures must be strong, save, durable and economical.
Reinforced prestressed concrete meets these criteria extremely well for many of
the proposed structures, both fixed and floating. These include drilling,
breakwaters, ocean pipelines, offshore nuclear power plants; ocean bridges and
tunnels; offshore airports and terminals; Arctic Ocean structures; Barges, ships
and floating stable platforms; offshore expositions and even cities; sea floor
chambers etc.
37
The first reinforced concrete skyscraper in the world was built in 1902-03
in Cincinatti, Ohio. The 16-storey structure demonstrated for the first time the
safety and economy of reinforced concrete frames for high-rise construction,
and was a vital stimulus for using reinforced concrete in fireproof construction.
Concrete was chosen as the structural material chiefly for economics; it
offered the equivalent of steel frames in load bearing capacity and other
physical properties, yet was somewhat lower in cost. Engineers all over the
world watched with great interest as construction proceeded smoothly along its
16-storey route. Today this building is recognized by engineers as having
revolutionized the building industry.
Text E. Sand concrete
For many, many years nature has been destroying stone, changing it into
sand. Now man is learning to do the opposite: he is using sand and cement to
create materials which could compete with stone in strength and beauty.
At first the idea of making concrete by using sand was completely
rejected. It is common knowledge that concrete is made from gravel and
cement, while a mixture of sand and cement is considered useful only to bind
bricks. This idea has gripped the attention and minds of scientists and engineers
to such an extent that it is no easy task to cast doubt upon this universally
accepted truth.
“Sand” concrete is made by putting the matrix under vibration which
almost completely eliminates its weak points. Sand concrete has now become
almost twice as strong as ordinary concrete with a course aggregate, and much
cheaper as well. At present several varieties of sand concrete have been
developed.
1. Render it in Russian:
Gas concrete containing fly ash and blast furnace slag is often used as
structural. The method of substituting heavy aggregates by light ones is a rather
common practice today. There are several chemical reactions taking place
38
during the air entrainment. Portland cement is widely used in building. Various
concrete and reinforced concrete constructions are made from it. White
Portland cement is used in exterior and interior architectural and decorative
finishing ornamental works.
2. Fill up the blanks with English equivalents:
1. (Самым важным качеством) of concrete is its property to be formed into
large and strong monolithic units. 2. Concrete is made by mixing cement, sand,
gravel and water (в нужных количествах). 3. The characteristics of concrete
depend (от качества используемых материалов). 4. (Бетон применялся
египтянами, римлянами) in the construction of aqueducts and bridges. 5. (Так
как цемент не был известен в то время) concrete was made of clay and later
of gypsum and lime.
3. Read and translate the following word-combinations:
To put in position, to pour concrete, to lose strength, to come into
practical application, to cause tensile strength, to undergo shrinkage, at the turn
of the century.
4. What is the English for:
1. применять термин; 2. заливать бетон; 3. набирать прочность; 4. быть
опубликованным; 5. увеличивать, уменьшать прочность; 6. подвергаться
усадке; 7. вызывать растягивающие усилия; 8. использовать железобетон.
5. Complete the sentences using the English equivalents for the
Russian words in brackets.
1. The resulting material gains great strength when (он затвердевает). 2. At the
turn of the 19th century new structural concrete (стал применяться). 3. Steel
has great tensional, compressive and elastic properties but (со временем она
теряет прочность). 4. Steel does not undergo shrinkage and therefore it acts
(как сдерживающая среда). 5. Shrinkage causes tensile stresses in concrete
which are balanced (сжимающими усилиями в стали).
39
6.Translate into English:
1. Железобетон - это вид бетона, полученного в результате сочетания
бетона и стали. 2.Стальные стержни и стальная арматура укладываются в
нужном положении и заливаются бетоном. 3. Бетон затвердевает,
схватывается и приобретает большую прочность. 4. Сталь не подвергается
усадке, она действует как сдерживающая среда в железобетонном
элементе.
6. Render the following in English:
Проблема снабжения строительными материалами в пустыне
чрезвычайно остра. Даже обычный гравий приходится везти сюда за сотни
километров.
Ячеистый бетон представляет собой разновидность легкого бетона с
равномерно распределенными по всей массе материала замкнутыми
воздушными порами (85%).
Пористая структура ячеистых бетонов достигается применением
пено- или газообразователей.
По способу образования пористой структуры ячеистые бетоны
подразделяются на пенобетоны и газобетоны.
Газобетон почти в два раза легче железобетона, из него удобно
монтировать дома. Технология изготовления различных деталей проста и
хорошо освоена. Уже действует первый завод по выпуску газобетона
7. Discussion: Your ideas about the material.
40
UNIT 7
TEXT A. PILE FOUNDATIONS
The durability of a structure depends on how the foundation is built and
on the property of the ground.
Prior to the beginning of the last century buildings were put up mostly on
stable ground. Bands of stone and baked bricks bound together by lime mortar
served as foundations.
Our ancestors could not even imagine on what kind of ground we would
build. Towns and cities have appeared in places where there had recently been
swamps, on the permafrost ground of the northern regions of the country. Pile
foundations are widely used there. They cut through the unstable thickness of
the ground and rest upon firm layers.
Piles were also used in ancient times. Peter I widely used piles in building
the city. Interestingly, Ivan the Great’s bell tower in the Kremlin (about 500
years old) also stands on a peculiar pile foundation. The base is comprised of
round, closely bound upright logs from 120 to 180 cm high. In those days there
were no mechanisms to drive in piles – that accounts for their being so short.
Upon the piles rests a massive stone slab. The piles are submerged in water to
protect the wood from destruction.
Ferro-concrete was discovered about 200 years ago. Wooden piles
gradually became a thing of the past. The have been replaced by ferro-concrete
and metal piles.
During the last few decades pile boring has found wide application. A
bore hole is first filled with steel framework, then with concrete, and the pile is
ready
A group of specialists has developed piles without using building
materials for the purpose. At the depth of 16-18 m a hole is drilled. A special
burner is then inserted. At 1,400 o C the earth fuses. It then hardens and
becomes a bearing pillar. Several buildings have already been erected on such
“piles”.
The foundation of the Alma-Ata TV tower is quite original. The tower
was built on a small site in the mountains, where force 10 earthquakes can
41
occur. The foundation is a reinforced casing. On it there stands a three-storey
building together with a metal tower 360 m high.
TEXT B. THE USE OF PYRAMIDAL PILES IN BUILDING
Pyramidal piles are a progressive design of piles used in building. These
piles have the shape of an enlarged pyramid; they are rammed into the ground,
acute end first. Unlike prismatic piles, pyramidal piles pack the soil along the
sides while sinking into it, thus enhancing the mechanical quality of the soil,
and subsequently conveying the load of the whole side surface upon the packed
basis.
Such distinctive feature of the work of prismatic and pyramidal piles in
the basis soils ensures the possibility to enhance the bearing capacity of
pyramidal piles with respect to prismatic piles by 1.5-2 times.
Pyramidal piles are used in the basis of buildings and constructions for
various purposes and designs. They are especially effective when packed soil
lies on the upper part of the basis from 3 to 5 deep, while loose soil can lie
underneath.
In this case pyramidal piles must work as single piles. When pyramidal
piles are arranged in groups and joined by a low foundation raft, the depth of
the loose soil should be taken into consideration as well as the number of piles
in the group. If the basis is made up of cocked soil along the whole depth, the
number of piles in the group is not limited.
The structural design of pyramidal piles is carried out in accordance with
the deformations, proceeding from the equality of the work of external and
internal forces with due regard for obligatory requirements. The volume of the
stabilization zone should not exceed the volume of the consolidation zone while
conveying the load to the pile.
TEXT C. GRILLAGE FOUNDATION
Grillage, foundation bed, reinforced concrete footing, as a means of
protection, tier, to be encased, to resist, bending, shearing, bond, stress.
42
In order to distribute a column load over the foundation bed, steel grillage
is occasionally used instead of a reinforced concrete footing. This usually
consists of two layers of beams. The beams are encased in concrete not less
than 4 in thick as a means of protection, and the lower tier rests upon a bed of
concrete to distribute the column load to the foundation bed. Since the grillage
beams must be completely encased in concrete, the bearing areas of the grillage
foundation and a reinforced concrete footing are practically the same.
Therefore, it is usually expedient to use the reinforced concrete footing. In this
case the concrete resists lending, shearing, and bond stresses instead of merely
being a protecting material for the steel grillage beams.
TEXT D. THE FOUNDATION OF THE OSTANKINO TV TOWER
The reinforced concrete tower of the TV center in Moscow was built
latter the design of Nokolai Nikitin. The tower is 535 m high. The 32-thousand-
ton tower rests upon a monolithic hoped reinforced concrete foundation 9.5 m
wide, 3 m high and 74 m in diameter. In the 10-angled reinforced concrete band
of the foundation prestressing was created by means of a system of stressed
hooping.
The depth of the foundation is 4.65. It is assumed that it will settle from 3
to 3.5 cm. The stability of the tower has a six fold margin of safety.
The 8th International Soil Mechanics and Foundations Congress
recognized N. Nikitin’s idea of building the foundation at the depth of 4.65
m to be a brilliant one.
While the foundation was being built, specialists expressed their concern
that the depth was insufficient for such a high tower. Relying on the experience
of putting up high-rise structures, specialists suggested a hypothesis stressing
the necessity to plant the base of the TV tower on supports resting upon a rock.
Scientists were of the opinion that because of the insignificant depth of
the foundation, ground work in its vicinity (the building of collectors, tunnels,
metro lines etc.) could result in the loss of earth from under the foundation. The
43
specialists who shared this opinion recommended a 40-metre foundation. But
N. Nikitin turned down that opinion and proved that his designed tower could
stand even without having a foundation. Nikitin’s calculations have been
confirmed by life.
The reinforced concrete support of the whole structure is a conical casing
which rests upon bankets of the foundation with 10 reinforced concrete “legs”.
The diameter of the lower base of the casing is 60.0 m, being 18 m at the
height of 63 m. The upper part of the reinforced concrete bole, beginning at the
height of 321 m, is made in the form of a cylinder with an exterior diameter of
8.1 m. The base walls of the tower are 500 mm thick.
In the center of the conical base, resting upon an independent foundation
(a round reinforced concrete slab 12 m in diameter and 1 m thick), a reinforced
concrete “pocket” 63 m high and 7.5 m in diameter was erected through which
run means of communication”. The beam ends of 15 interstorey floors rest upon
the “pockets”. The construction (a separate foundations for the two independent
structures – the tower and the “pockets” – allows to exert upon the ground
different pressure when uneven setting occurs.
Notes
1. monolithic hooped reinforced concrete foundation – монолитный
кольцевой железобетонный фундамент.
2. a 10-angled reinforced concrete band of the foundation – десятиугольная
железобетонная лента фундамента.
3. a system of stressed hooping – система кольцевой напряженной
арматуры.
4. a sixfold margin of safety – шестикратный запас на опрокидывание.
5. to rest upon a rock – опираться на скалу.
6. to result in the loss of earth from under the foundation – приводить к
выводу грунта из-под фундамента.
7. to turn down an opinion – отвергать мнение.
8. to be confirmed by life – быть подтвержденным жизнью.
9. a conical casing – коническая оболочка
10. banket (banquette) – насыпь, берма
44
11. a leg – опора, стойка
12. a reinforced concrete bole – железобетонный ствол
13. pocket – гнездо, «стакан»
14. to run – зд.: проходить
15. means of communication – средства коммуникации
16. interstorey floors – междуэтажные перекрытия
17. uneven settling – неравномерная осадка
18. to occur – происходить, иметь место
1. Find answers in the text to the following questions:
1. What does the durability of a structure depend on? 2. How were foundations
built prior to the beginning of the last century? 3. Can you tell us what kind of
foundations is used in the northern regions of our country? 4. Were piles used
in ancient times? 5. Do you know anything about the foundation on which Ivan
the Great’s bell tower in the Kremlin stands? 6. When was ferro-concrete
discovered? 7. Pile boring has found wide application, right? 8. Can piles be
made without using building materials? 9. Why is the foundation of the Alma-
Ata TV tower considered to be quite original?
2. Find in the text nouns corresponding to the following words and
translate them into Russian:
to apply, to destroy, durable , to burn, wooden, to begin, to bake, stability,
firmness, peculiarity, to shorten, widely, dependent, service, appearance, useful,
binding, protection, discovery, filling, development, drill, hard, erection.
3. a) Find in the text the antonyms of the following words and translate
them into Russian: the end, to disappear, stable, young, long, the present,
down.
b) Find in the text the English equivalents of the following words and
word-combinations:
прочность сооружения; до начала прошлого века; устойчивый грунт;
ленты из камня и обожженного кирпича; известковый раствор; наши
45
предки; топи; свайные фундаменты; в давние времена; круглые бревна;
забивать сваи; огромная каменная плита; погружать; оберегать от
разрушения; уйти в прошлое; без применения строительных материалов;
горелка; затвердевать; землетрясение; железобетонная коробка;
буронабивная свая.
4. Render the following sentences in English:
1. Пирамидальные сваи имеют форму усеченной пирамиды, забиваемые в
грунт острым концом. 2. Пирамидальные сваи при погружении в грунт
производят уплотнение грунта вдоль боковой поверхности, повышая тем
самым механические свойства грунта. 3. Отличительные особенности
работы пирамидальных свай в грунтах основания обеспечивают
возможность повышения несущей способности пирамидальных свай по
отношению к призматическим в 1,5-2 раза. 4. Пирамидальные сваи
применяются в основании зданий и сооружений различного назначения и
конструкции. 5. Особенно эффективно их применять в том случае, когда в
верхней части основания на глубине 3-5 м залегают плотные грунты.
6. При кустовом расположении пирамидальных свай, объединенных
низким ростверком, учитывается глубина расположения слабого слоя и
количество свай в кусте. 7. Если же основание сложено на всю глубину
плотными грунтами, то количество свай в кусте не ограничивается.
5. Discussion: Your ideas about the material.
46
UNIT 8
TEXT A. FROM THE HISTORY OF WATER SUPPLY.
Water is power not only in the hydraulic sense, but in relation to progress
and culture; campaigns as well as fortresses have been lost, projects rendered
impracticable and communities have decayed for want of water.
Nature has provided prototypes for most of man’s devices and, just as the
streams and rivers anticipated water distribution systems, so tanks, cisterns and
reservoirs have their natural counterparts in water-holes and natural pools.
Long after man had found ways and means to organize water supplies,
find them where they were hidden and lead them to where he wanted them,
streams and pools in their natural state have served as communal water
supplies, even in more or less civilized Europe.
Many of the so-called “wells” of medieval Britain, for example, were
untouched pools or gushing springs. The same applies of course to a great many
“wells of the East” and in old writings the term “well” may not mean a dug well
at all but a surface pool adopted as a communal or regular water supply.
The history of conduits or public fountains as communal water supplies
starts at least as far back as the 13th century. In the “conduit age” – the centuries
immediately following the Middle Ages a water carrier was a common sight.
The 17th century marks the beginning of the new order in communal
organization and in relation to water supply, the beginning of large-scale
schemes.
All through London’s history until modem times, the question of water
supply continued to be a problem. In the 18th century even with the appearance
of larger water companies the water supply was far from being satisfactory. It
was a usual practice at the time to lay on water for two hours every second day.
At York, before the formation of the present water company in 1846 one
half of the city was supplied for 2 hours on Mondays, Wednesdays and Fridays
and the other half on Tuesdays, Thursday s and Saturday s, no supply being
given on Sundays.
Water drawn from the river Thames was in a state that was offensive to
the sight as the intake was found to be only three yards from the outlet of a
47
great sewer. As a matter of fact it took 2 outbreaks of cholera to pass a Bill for
an improved water supply in the middle of the 19th century.
In spite of the progress made in the field of water supply in many
countries, there is much to be done yet. In Asia, Africa, Central and South
America outside the great cities, methods are primitive as ever they were;
village ponds are still used in Africa and Asia for drinking, washing and bathing
and as watering places for cattle, in Madagascar in recent years people have had
to carry their water bottles several miles and, as some of them can only do the
journey twice a week, they have trained themselves to do with the minimum of
water, drinking only on alternate days and never washing during a drought.
In Japan, running water is still a luxury, even in the great cities: the
average household has to carry water from a central source, while the villages
rely on springs and streams.
The speedy industrialization of our country has also made the problem of
water very acute.
TEXT B. PURIFICATION OF WATER SUPPLY.
Water taken from its natural source – the ground lakes of rivers – contains
many objectionable elements. It may possess gases of an obnoxious nature,
bacteria, mineral elements, mud, and suspended vegetable growths which
render it unpalatable. Some of these objectionable materials may be eliminated
readily, others require complex treatment.
The obnoxious gases are removed by aerating the water. Some of the
mineral elements, such as certain forms of iron, also are removed by this means.
The suspended materials require coagulation and settling process, and bacteria
are eliminated with the addition of chemicals and sand filtration. The mineral
elements which render the water hard must be separated by a chemical process
in which the objectionable element is replaced by one that is favorable. A
filtration plant may use one or a combination of all of these processes, the water
undergoing a complete change as it passes through the plant.
The processes generally employed in making water safe for water supply
include coagulation, filtration, and disinfection. Water from some sources must
48
be treated also for the removal of color, taste, and odor. Coagulation is
commonly effected by adding to the water a salt of aluminum (usually
aluminum sulphate) or ferric iron. A precipitate forms and causes a clumping of
the bacteria and other foreign particles which then settle out during the several
hours of sedimentation; in this way 85% or more of the bacteria and suspended
particles can be removed. Activated carbon is sometimes added before
sedimentation to remove tastes and odors. In the process of filtration the water
is allowed to pass through layers of fine sand to remove remaining germs and
particles. Chlorine is commonly used to destroy harmful bacteria persisting in a
municipal water supply after the other treatments? Chlorine dioxide has more
recently been found effective as a destroyer of bacteria as well as means of
removing unwanted tastes and odors. Other means of destroying germs include
the use of ozone and of ultraviolet light. Some water supplies are aerated, i.e.,
exposed to the action of air and sunlight either through sprays or by running
over coarse gravel; taste and odor are improved and some germs are destroyed.
TEXT C. WATER SUPPLY.
Water is an important part of nature which surrounds us and of those
natural conditions we are changing constantly and ever more intensively: the
flora, the soil, the mountains, mineral resources, the deserts, the marshes, the
steppes and the taiga.
Water passes through a very interesting natural cycle. The atmosphere
which surrounds the earth’s surface contains water which varies in amount in
direct proportion to the temperature of its gases.. Water is also evaporated into
atmosphere. Atmosphere which has become saturated with water precipitates its
moisture when the temperature lowers. This phenomenon is termed rainfall.
The moisture falls to the earth and finds its way into a number of reservoirs
provided by nature.
Vast depressions in the earth are filled with water through the medium of
natural water sources such as rivers, lakes, etc. over the earth’s surface. These
bodies of water are classified as inland lakes and are excellent sources of water.
49
Sometimes the rainfall finds its way into the soil and forms water bodies
at various levels because of the impervious nature of the under soil. Often a
water body deep in the soil consists of a sand or gravel stratum which connects
or empties into the basin of an inland lake and provides a splendid source of
water supply through the medium of a drilled well.
Man uses water for domestic and sanitary purposes and returns it to the
source through sewage disposal system. Industry likewise replaces water
diverted to its use. Hence the cycle is completed but it is of prime importance
that the supply be protected against pollution, for if it fouls no one can predict
how disastrous may be the results.
An adequate supply of pure, wholesome and palatable water is essential
to the maintenance of high standards of health and to provide the convenience
modern society demands. In some localities water is available in unlimited
quantities and converting it to use is not a difficult problem. This is especially
true of towns situated on large inland lakes or rivers. On the other hand there
are cities where geographical location requires elaborate systems of water
supply, and to provide a satisfactory supply of water in these localities becomes
a large engineering task.
The importance of a sufficient supply of water for domestic and industrial
purpose has long been a deciding factor in the location cities. The earliest
settlers realized this need and took advantage of natural water sources by
establishing colonies in close proximity to them
Water may be taken from any sources of water for human consumption
after it has undergone a preliminary treatment to assure its purity. As man’s
communities grew in population, the demand for water increased and the need
for protection of the source of water supply against the possibility of
contamination became evident. Progress and civilization have called for
elaborate and various systems and methods of water treatment.
50
TEXT D. THE CONTINUOUS COUNTERCURRENT FILTRATION
SYSTEM
The continuous countercurrent filtration system includes chemical
precipitation and coagulation directly followed by filtration through a filter bed.
The basic principle involved is continuous countercurrent filtration through a
moving sand bed.
Chemicals are added directly to the influent wastewater line. Precipitation
and coagulation occur in the head tank. The dosage of chemicals can be varied
depending on the nature of the waste to be treated and the quality of effluent
desired.
The filter medium, which could be other than sand, is contained in a
tubular shell (called a bed) and is driven in one direction while the wastewater
being treated passes through the filter bed in the opposite direction. The
filtering action occurs through the depth of the bed as well as at its face.
Filtered water flows out of the bed through discharge screens located on the
side of the bed. The sand and solids filtered out of the water are pushed by a
hydraulic diaphragm toward the head tank countercurrent to the flow of water.
The solids are removed from the face of the filter bed by a mechanical face
cutter. After the diaphragm pushes the bed forward, it relaxes, thus allowing
clean sand to fall into the space vacated by the relaxing diaphragm. The
frequency with which the sand push-face cutting cycle occurs is varied to
optimize flow rate and effluent quality and is controlled automatically by the
level in the head tank.
The sludge-sand mixture mechanically removed from the filtering face
falls down into the hopper bottom of the head tank. This mixture is transferred
to a washing column for cleaning. The clean sand is then returned by gravity to
the hopper. The removal and washing of the sand may be intermittent or
continuous. Final washing of the sand is accomplished by means of filtered
effluent. Because the sand is removed, cleaned, and then returned to the system,
the filtration process is not interrupted for backwashing as it is in conventional
practice. The waste wash water flows into a settling tank where the sludge is
51
concentrated before dewatering. The settler overflow, or supernatant, is
recycled to the influent line of the filtration process.
TEXT E. SEWERAGE
The problem of protecting natural water resources has grown very
pressing for many countries since the beginning of the second half of the 20th
century. The development of human society, the growth of civilization and
social and technical progress has resulted in the changing of the composition of
natural water resources. The rivers, lakes and groundwaters contain today a
considerable amount of the products of mechanical, chemical and biological
pollution.
The waste products that result from the daily activities in a community
are of two general types: namely, the liquid waste, known as sewage and the
solid wastes, known as refuse. The different wastes of which sewage is
composed are the following: the wastes from lavatories, baths, sinks, and
laundry tanks in residences, institutions, and business buildings; certain liquid
wastes from various types of manufacturing or industrial plants, and, in many
communities, the surface run-off that results from storms or street-flushing
operations.
Sewage may also be divided according to its source into the following
three classes. The sewage from residences, institutions and business buildings is
called domestic sewage, sanitary sewage or house sewage; that resulting from
manufacturing or industrial processes is known as industrial waste; and that
from run-off during or immediately following storms is called storm sewage. A
combination of domestic sewage, industrial waste and storm water is called
combined sewage.
Both sewage and refuse must be removed promptly in order to avoid
endangering the health of the community and also prevent decomposition of the
materials of animal or vegetable origin and the subsequent production of
nuisances and odours.
The removal of all kinds of sewage is usually accomplished by means of
sewers. The sewers are placed in the streets at several feet below the ground
52
surface. The general process of removing sewage is designated as sewerage and
the entire systems of sewers including a sewage treatment plant is known as a
sewerage system.
The method of sewage treatment to be adopted in a particular case will
depend almost entirely on local conditions. It may consist only of the discharge
of the raw sewage into a stream or a large body of water. The usual methods of
sewage treatment consist either of preliminary treatment alone or of primary
treatment followed by secondary treatment.
During primary treatment the larger and heavier solid particles settle out
from the liquid. These solid particles that settle out form a slimy paste which is
known as sludge.
The partly clarified sewage that has been given primary treatment
generally contains much decomposable materials. Therefore, further treatment
which is known as secondary treatment is usually required.
An auxiliary treatment which may be used with either primary or
secondary treatment is disinfection or the killing of the most of the bacteria in
the sewage by means of chemicals.
53
Glossary
Unit 1
to meet requirements
fire-resistant
structural material
to burn
to decay
steel
concrete
stone wood
brick
sound and heat insulation
artificial
bearing structures
Unit 2
skilled and unskilled workers
managerial staff
labour force
considerable proportion
on a large scale
level of living
offsite prefabrication
precutting
modern amenities
dwelling
heating and ventilating systems
sanitary fitting
Unit 3
cementations materials
liquid
mold
rigid shape
coarse and fine aggregate
chemical constituent
setting
portland cement
aluminous cement
natural cement
lime
fly ash
silica fume
shring
raw materials
Unit 4
mortar
sand
ratio of water to solid
matrix
prevent the transmission of moisture
54
Unit 5
concrete
plain concrete
mass concrete
ferro-concrete
iron rod
blast cement
to pour into forms
alkali-slag concrete
silica concrete
dense material
void space
Unit 6
lime
silica
autoclave
drainage pipes
floor screed
sandwich wall
hydraulic
hence
moldable
adhesive
cohesive
sodium
potassium
conventional
chemically resistant
corrosive solutions
Unit 7
pile
bands of stone
to be submerged
to protect wood from destruction
to find wide application
a bore hole
framework
bearing pillar
pyramidal piles
to be rammed into the ground
enhance
grillage foundation
Unit 8
communal water supply
purification
obnoxious nature
coagulation
filtration
disinfection
sedimentation
to be evaporated into atmosphere
moisture
sewage disposal system
pollution
sewerage
55
SUPPLYMENTARY READING
FOUNDATIONS
Introduction
Foundation design could be thought of as analogous to a beam design.
The designer of the beam will need to know the load to be carried, the load-
carrying capacity of the beam, how much it will deflect and whether there are
any long-term effects such as creep, moisture movement, etc. If the calculated
beam section is, for some reason, not strong enough to support the load or is
likely to deflect unduly, then the beam section is changed. Alternatively, the
beam can either be substituted for another type of structural element or a
stronger material be chosen for the beam.
Similarly the soil supporting the structure must have adequate load-
carrying capacity (bearing capacity) and not deflect (settle) unduly. The long-
term effect of the soil’s bearing capacity and settlement must be considered. If
the ground is not strong enough to bear the proposed initial design load then the
structural contact load (bearing pressure) can be reduced by spreading the load
over a greater area – by increasing the foundation size or other means – or by
transferring the load to a lower stratum. For example, rafts could replace
isolated pad bases – or the load can be transferred to stronger soil at a lower
depth beneath the surface by means of piles. Alternatively, the ground can be
strengthened by compaction, stabilization, preconsolidation or other means. The
structural materials in the superstructure are subject to stress, strain, movement,
etc., and it can be helpful to consider the soil supporting the superstructure as a
structural material, also subject to stress, strain and movement.
Structural design has been described as using materials not fully
understood, to make frames which cannot be accurately analyzed, to resist
forces which can only be estimated. Foundation design is, at best, no better.
‘Accuracy’ is a chimera and the designer must exercise judgment.
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Foundation safety criteria
It is a statement of the obvious that the function of a foundation is to
transfer the load from the structure to the ground (i.e. soil) supporting it – and it
must do this safely, for if it does not then the foundation will fail in bearing
and/or settlement, and seriously affect the structure which may also fail. The
history of foundation failure is as old as the history of building itself and our
language abounds in such idioms as ‘the god with feet of clay’, ‘build not thy
house on sand’, ‘and build on a firm foundation ’,‘ the bedrock of our policy’.
The foundation must also be economical in construction costs, materials
and time. There are a number of reasons for foundation failure, the two major
causes being:
(1) Bearing capacity. When the shear stress within the soil, due to the
structure’s loading, exceeds the shear strength of the soil, catastrophic collapse
of the supporting soil can occur. Before ultimate collapse of the soil occurs
there can be large deformations within it which may lead to unacceptable
differential movement or settlement of, and damage to, the structure. (In some
situations however, collapse can occur with little or no advance warning!)
(2) Settlement. Practically all materials contract under compressive
loading and distort under shear loading – soils are no exception. Provided that
the settlement is either acceptable (i.e. will not cause structural damage or
undue cracking, will not damage services, and will be visually acceptable and
free from practical problems of door sticking, etc.) or can be catered for in the
structural design (e.g. by using three-pinned arches which can accommodate
settlement, in lieu of fixed portal frames), there is not necessarily a foundation
design problem.
Problems will occur when the settlement is significantly excessive or
differential.
Settlement is the combination of two phenomena:
(i) Contraction of the soil due to compressive and shear stresses resulting
from the structure’s loading. This contraction, partly elastic and partly plastic, is
relatively rapid. Since soils exhibit non-linear stress/strain behavior and the soil
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under stress is of complex geometry, it is not possible to predict accurately the
magnitude of settlement.
(ii) Consolidation of the soil due to volume changes. Under applied load
the moisture is ‘squeezed’ from the soil and the soil compacts to partly fill the
voids left by the retreating moisture. In soils of low permeability, such as clays,
the consolidation process is slow and can even continue throughout the life of
the structure (for example, the leaning tower of Pisa). Clays of relatively high
moisture content will consolidate by greater amounts than clays with lower
moisture contents. (Clays are susceptible to volume change with change in
moisture content – they can shrink on drying out and heave, i.e. expand, with
increase in moisture content.) Sands tend to have higher permeability and lower
moisture content than clays. Therefore the consolidation of sand is faster but
less than that of clay.
City Architecture
Any community consists of examples of architecture but in another sense
the community itself is the form of architectural planning. A true community
grows and changes, and its change is a symptom of its life.
In Europe and in the original settlements of North and South America the
modern city grew up around an older core, and down to our days these cores
have continued to have a powerful influence on new plans. Certain urban lay-
outs which have been repeated automatically are still looked upon as standard
forms.
The medieval town was a combination of camp, market, and sanctuary.
The necessity for protection colored all its institutions, dictated the use of a
defensive site on hillside or waterside. It led to the erection of walls separating
the town from the country and allowing access only through guarded gates. The
social functions of the medieval town were concentrated in a square. Medieval
builders, in their handling of space and their bold contrasting of horizontal
and vertical, still have something to teach the twentieth-century architect who
knows no way of achieving height except by erecting skyscrapers.
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The Baroque (or so-called Renaissance) city was formulated in the
fifteenth and sixteenth centuries and was actually built in the seventeenth and
eighteenth centuries. In the Baroque plan the old medieval market square is
transformed into the traffic circle which the pedestrian crosses at a great risk.
The focus of this plan is no longer the church but the palace, the seat of a one-
sided, despotic power. In contrast with the medieval town, the Baroque city
demands flat sites, straight continuous streets, and uniform building and roof
lines. It was built for armies and wheeled vehicles. The typical Baroque form
might be called the parade city: not only its soldiers but also its citizens and its
buildings are on parade. Whatever is visible must submit to this geometry; the
city is organized for show.
The Baroque plan, unlike the medieval, left a deep imprint on later
generations; it became standard throughout Western civilization. This style
preferred straight streets to curved ones ignoring the topography.
Building Construction
The construction of the homes and buildings in which people live and
work has been a major industry ever since early human beings first made huts
of sticks, mud, or rocks. Methods of building construction have been constantly
improved since those first crude structures. Modern skyscrapers can be built
within a year or two. Prefabricated buildings, with their various parts made in
factories by assembly-line methods, can be built in a day or two, but are rarely
as durable as traditionally made buildings.
A building has two main parts, the substructure (the part below ground)
and the superstructure (the part above ground). The substructure is usually
called the foundation. It includes the basement walls, even though these may
extend above the ground.
Both the substructure and the superstructure help to support the load
(weight) of the building. The dead load of a building is the total weight of all
its parts. The live load is the weight of the furniture, equipment, stored
material, and occupants of a building. In some regions, the wind load of a
59
building is important if the structure is to withstand storms. The snow load may
also be an important factor. In some areas, buildings have to be constructed to
withstand earthquake shocks.
Foundations are the chief means of supporting a building. They carry
both the dead and live loads. There are three main types of foundations: spread,
pier, and pile.
Spread foundations are long slabs of reinforced concrete that extend
beyond the outer edges of the building. Such foundations are not as firm as
those based on solid rock. The footing areas in contact with the soil must be of
sufficient size to spread the load safely over the soil and to avoid excessive or
uneven settlement. Any such settlement would cause walls to crack or doors to
bind.
Pier foundations are heavy columns of concrete that go down through
the loose topsoil to a bed of firm rock. This bed may also be sand, gravel, or
firm clay. If the bed consists of firm clay, the pier is usually enlarged at the
base, to increase the bearing area.
Pile foundations are long, slender columns of steel, concrete, or wood.
Machines, called pile drivers hammer them down as deep as 60 meters to a
layer of solid soil or rock. Workers can tell when the columns reach their proper
depth by the number of blows the pile driver needs to drive the columns a few
centimeters deeper. These columns transmit the building load to the supporting
soil. Most skyscrapers are supported by rock foundations.
Types of construction
In load-bearing-wall construction. The walls transmit the load to the
foundation. In skeleton construction, all loads are transmitted to the
foundation by a rigidly constructed framework made up of beans, girders and
columns. This skeleton carries the roof, walls, and floors, together with their
loads. Load-bearing-wall construction is usually most economical for buildings
less than four storeys high, but skeleton construction is better for taller
buildings. All buildings in the skyscraper class are of skeleton construction.
60
The first building to have skeleton construction was the 10-storey Home
Insurance Building in Chicago. Completed in 1885, this building was the
world's first skyscraper.
Many parts of a building have no structural function. Partition walls and
curtain walls carry only their own weight and serve to divide the interior of a
building or to keep out the elements. Other nonload-bearing parts include
windows, doors, stairs, and lifts.
In one method of construction, called tilt-up construction, concrete wall
panels are formed at ground level. Cranes or derricks then lift them into
position. Lift-slab construction may be used for positioning roof and floor
slabs. These slabs are formed with concrete at ground level, within the
framework of the building. They are then lifted into place using hydraulic jacks.
Beams, girders, and columns support a building much like bones
support the body. They form the skeleton of the superstructure, and bear the
weight of the walls and each floor of the building. Beams and girders run
horizontally. Girders are usually larger than beams. Closely spaced beams are
called joists, especially in wooden buildings. Purlins are small beams that
brace rafters or girders and help provide the structure to support roofs. Beams
above window and door openings are called lintels. Slabs are beams whose
width is greater than their depth.
Columns are heavy vertical supports that carry the load of beams and
girders. Trusses consist of many wood or steel supports that are connected in
triangular patterns. They provide the strength and rigidity to span large
distances with relatively small amounts of material. Arches are curved supports
that usually extend over openings.
Prefabricated Construction
Prefabrication has become an important part of most types of building
construction. Prefabricated sections of a building are produced in large
quantities in a factory and then shipped to various construction sites. This
procedure may allow work to continue despite poor weather conditions and
61
should reduce any waste in time and material at the site. As a result, costs are
lowered and construction time decreases.
Many types of building sections can be prefabricated. For example, entire
walls may be prefabricated for a wooden-frame house. Huge wooden arches are
prefabricated for use as supports in churches, gymnasiums, and other buildings.
Concrete beams, floors, roofs, and wall panels may be precast for many types
of structures. Entire buildings may be constructed in a factory and then
transported to the desired location.
Prefabricated structures are sometimes made by a process called modular
construction, first used in Japan. Modular construction refers to the use of a
standard measurement as the basis for all building materials. The size of the
module may vary considerably from country to country. In the United States,
the basic module is 10 centimeters. All building parts are designed so that each
dimension equals this measurement. Modular parts are also used in buildings
that are not prefabricated.
Site Improvement Methods
If the expected settlement for a proposed structure is too large, then
different foundation support or soil stabilization options must be evaluated. One
alternative is a deep foundation system that can transfer structural loads to
adequate bearing material in order to bypass a compressible soil layer. Another
option is to construct a floating foundation, which is a special type of deep
foundation where the weight of the structure is balanced by the removal of soil
and construction of an underground basement. Other alternatives include site
improvement methods, such as the following:
Soil Replacement. There are basically two types of soil replacement
methods: removal and replacement, and displacement.
The first is the most common approach and consists of the removal of the
compressible soil layer and replacement with structural fill during the grading
operations.
Usually the remove and replace grading option is economical only if the
compressible soil layer is near the ground surface and the groundwater table is
62
below the compressible soil layer or the groundwater table can be economically
lowered.
Water Removal. If the site contains an underlying compressible cohesive
soil layer, the site can be surcharged with a fill layer placed at ground surface.
Vertical drains (such as wick drains or sand drains) can be installed in the
compressible soil layer to reduce the drainage path and speed up the
consolidation process. Once the compressible cohesive soil layer has had
sufficient consolidation, the fill surcharge layer is removed and the building is
constructed.
Site Strengthening. Many different methods can be used to strengthen the
onsite soil. For example, deep vibratory techniques are often used to increase
the density of loose sand deposits.
Grouting. In order to stabilize the ground, fluid grout can be injected into
the ground to fill in joints, fractures, or underground voids. For the releveling of
existing structures, one option is mudjacking, which has been defined as a
process whereby a water and soil-cement or soil-lime cement grout is pumped
beneath the slab, under pressure, to produce a lifting force that literally floats
the slab to the desired position. Another commonly used site improvement
technique is compaction grouting, which consists of intruding a mass of very
thick consistency grout into the soil, which both displaces and compacts the
loose soil. Compaction grouting has proved successful in increasing the density
of poorly compacted fill, alluvium, and compressible or collapsible soil. The
advantages of compaction grouting are less expense and disturbance to the
structure than foundation underpinning, and it can be used to relevel the
structure. The disadvantages are that analyzing the results is difficult; it is
usually ineffective near slopes or for near-surface soils because of the lack of
confining pressure, and the danger exists of filling underground pipes with
grout.
Thermal. The thermal site improvement method consists of either heating
or freezing the soil in order to improve its shear strength and reduce its
permeability.
63
Заключение
Учебное пособие «Современные проблемы промышленного и
гражданского строительства на занятиях английского языка»
представляется своевременным и актуальным в связи с отсутствием
достаточного количества подобных учебных изданий для студентов
строительной специальности. Материалы, содержащиеся в учебном
пособии, будут способствовать овладению умениями и навыками чтения
технической литературы.
Библиографический список
1. Агабекян, И. П. Английский для инженеров / И. П. Агабекян,
П. И. Коваленко. – Ростов-на-Дону : Феникс, 2004.
2. Английский язык для студентов архитектурных и строительных
специальностей / Дж. Камминг ; предисл. к рус. изданию и англо-
рус. словарь проф. В. Н. Бгашева. – М. Астрель: АСТ, 2005. – 270 с.
3. Английский язык методические указания для студентов II курса
дневного отделения строительных специальностей вузов / сост.:
Н. В. Трубникова, О. Г. Гусева. – Ульяновск УлГТУ, 2003. – 120 с.
4. Дубровская, С. Г. Английский для технических вузов /
С. Г. Дубровская, Д. Б. Дубина. – М. : АСВ, 2007.
5. Building design and construction handbook / Frederick S. Merritt,
editor, Jonathan T. Ricketts, editor.—6th ed. http://www.knovel.com/web/portal/browse/display?_EXT_KNOVEL_DISPLAY_booki
d=608 Дата обращения 20.02.2010
6. The architects’ handbook I edited by Quentin Pickard.
http://books.google.ru/books?id=6QAKfIFPhLYC Дата обращения 20.02.2010
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Учебное издание
СОВРЕМЕННЫЕ ПРОБЛЕМЫ ПРОМЫШЛЕННОГО И ГРАЖДАНСКОГО СТРОИТЕЛЬСТВА НА ЗАНЯТИЯХ
АНГЛИЙСКОГО ЯЗЫКА
Учебное пособие
Составитель КУЗЬМИНА Елена Валерьевна
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