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Brick, gypsum, slag material, paints, glass, roofing material and others are also used for constructing different technical and civil road buildings and partially for road-bridge construction.

The cost of material, mainly its haulage makes the principal part of expenditure for the road building (about 60% or even more). Hence it becomes clear how important the rational using of the materials and reduction of haulage expenditure are and how necessary it is to utilize the local materials wherever possible.

Maximum mechanization of getting materials, their transportation, mechanization of building jobs, application of perfect road constructions, advanced methods of work with utilization of local building materials on large scale are the main ways of reducing the road building cost.

As to the origin and method of getting road building materials are divided into natural and artificial.

Natural materials are got in places of their natural formation, they possess the necessary technical characteristics while being in natural state and may be used for building purposes without additional complex treating.

The representatives of such group are sand, clay, gravel, crushed and chopped rock, peat, wood. Simple mechanical treatment has the purpose to give material the necessary size and shape, and sometimes only some definite state.

Artificial materials are such materials which are specially made of raw staff having the natural origin or of factory waste by mechanical or chemical influence. According to the origin, methods of obtaining, characteristics and application road building materials may be divided into the following groups:

1)ground materials: clays, loamу soils, sandy soils, etc.;

2)natural stone materials: a) massive granite, sandstone, limestone and others; crushed materials – broken natural stone; grinded material - stone powder; b) loose material – sand, gravel;

3)artificial stone materials: a) ceramic materials (articles of burnt clays) paving brick, tiles, agricultural pipes etc; b) silicate articles: brick, blocks, c) slag materials and clay articles – stones, broken stone, blocks, d) stone casting;

4)mineral binders: cements, lime, gypsum etc;

5)concretes using mineral binding materials – cement-concrete, concrete articles (slabs, blocks, etc.);

6)organic binders – bitumen, tar, etc;

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7) concretes, using organic binding materials – asphalt concrete, tar concrete and concrete articles;

8) materials and articles of wood;

9) metals and metal alloys: a) metallic materials: cast iron, steel, nonferrous metals, b) metal articles – beams, U-bars or channel iron, angle iron, cast iron pipes, rivets etc;

10) different materials and articles: a) roofing and insulating materials, b) glass, c) paints, varnish, d) rubber etc.

Building materials to be found in the place of construction and obtained to satisfy construction needs are called local building materials.

Application of local materials makes road and bridge construction cheaper, economizes centralized materials, frees the railway and water transport from haulage and ensures the wide front of road work for the construction.

13. In what meaning are the following words used in the text? Why do you think so?

14. Translate these words depending on their part of speech. Which of them were used in the text?

A cost – to cost; free – to free; the ground – to ground; a state – to state.

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Make up your own word-combinations and sentences with these words.

15. Complete the sentences using the text.

1.The grounds serve as … of the road to be built.

2.Bitumen with using … is generally used for making road surfacing.

3.The cost of material, mainly its … makes the principal part of expenditure for the road building.

4.As to the origin and method of getting road building materials are divided into … and … .

5.Natural materials may be used for building purposes without … .

6.Building materials to be found in the place of construction and obtained to satisfy construction needs are called … .

16. Answer the questions.

1.What are the most principal road materials?

2.Where are sands used?

3.What advantage does utilizing the local materials give?

4.What are the main ways of reducing the road building cost?

5.How may road building materials be divided?

6.What natural and artificial stone materials are used in road construction?

17. Make up a dialogue on the topic. One of the partners is a highway engineer. He answers the questions of the other dialogue participant, who is a student trying to get as much information as possible. Use the following conversational formulas:

a) For a student:

Good morning! (Good afternoon! Hello!) Let me introduce myself. My name is ______. I am a ______. I study at the________.

I am interested in __________.

I would like to ask you about ________. And what about ___________.

Could you describe me _________. Could you tell me about __________.

What are the main characteristics of ____________. Thank you for your help.

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It was nice to meet you.

See you.

Good-bye.

b) For a highway engineer:

Good morning! (Good afternoon! Hello!) How can I help you?

What can I do for you?

Do you know that ___________________? Let me tell you about ________________. I would like to mention that ___________. The point is that ____________________. Thank you for your coming.

It was nice to meet you. Hope to see you soon. Good-bye.

See you.

18. Read the texts and complete the table below:

Mineral Binding Materials

Mineral binding materials are mainly used for binding separate stones into a monolith, for decorating purposes and for making monolith parts of constructions (in concrete).

Representatives of mineral binders, known to the mankind from the ancient times, are clay, gypsum and lime.

Mineral binders are such materials which while mixing with water are capable of hardening, turning from liquid or paste state into hard stone-like state, most of them increasing their durability in the course of time.

Binding materials in most cases are manufactured at plants and are being turned out in the form of powder.

Depending on the conditions of the hardening all the binding materials may be divided into two large groups:

1)such binding materials which after mixing with water are capable of hardening only in the air are called air binders; the characteristic representatives of this group are air lime and gypsum;

2)such binding materials which after mixing with water are capable of hardening not only in the air but underneath water as well are called hydraulic binders.

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Typical representatives of this group are silicate cement and other cements.

For road surfacing in Russia we use ordinary silicate cement «400» and «500» trade mark cement, but in this case the silicate cement must have minimum slump while hardening and minimum expansion while being moistened (swelling), it must have sufficient mechanical durability not only when in compression but when in tension and bending as well.

Except this, such cement must resist rubbing out to a definite extent and possess little permeability to water.

It must also be capable of changing the volume evenly while drying. Satisfying these requests is achieved by regulating mineralogical

composition while manufacturing silicate cement.

Organic Binders

The principal representatives of organic binders are natural and petroleum bitumens and tars.

These materials represent black viscous liquid and plastic-hard substances, consisting of the mixture of various hydrocarbon combinations.

The function of organic binding material in the road surfacing is to envelop and bind separate stone or ground particles to make monolith of them.

Bitumen and tar materials impart to the road-surfacing plasticity and great resistibility to different atmospheric and mechanical influences side by side with the properties of solidity and impermeability to water which are generally characteristic to road surfacing treated with binders.

Thus organic binders differ from other materials by some important technical properties, and that is the reason of the organic materials being widely used in road construction.

Road surfacing plasticity conditioned by bitumen and tar material reduce surfacing wear caused by the influence of transport and thus raises the term of surface service. Besides this the availability of such materials in road surface softens the surface vibration and reduces the communication of the oscillatory movements resulting from the dynamic stresses to the adjacent structures.

The general drawback of organic binding materials lies in the fact that they change their binding properties depending on temperature which makes the mechanical properties of the road surfacing unstable.

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representatives

function

original state

conditioned road properties

19.State the function of –ing forms in the text “Mineral binding materials”.

20.In the text “Organic binders” find the nouns made from adjectives by means of the suffix -(i)ty. Translate them. What is their common meaning?

For example:

Plastic – plasticity (пластичность, гибкость).

21.Are the sentences below true or false? Correct wrong statements. Begin your answers with these expressions:

That’s right. Exactly so. Precisely so. I agree with it. I’m afraid that/s not correct. Nothing of the kind. No, that’s not right.

1.Mineral binders are such materials which while mixing with water turn into liquid or paste state.

2.Depending on the conditions of the hardening all the binding materials may be divided into three large groups.

3.Hydraulic binders are capable of hardening underneath water.

4.The difference of organic binders from other materials by some important technical properties is the reason of their limited using.

5.The general drawback of organic binding materials lies in the fact that they are unable to change their binding properties depending on temperature.

6.Road surfacing plasticity conditioned by bitumen and tar material reduces the term of surface service.

22.Read and study the following words, make up your sentences with them.

aggregate – заполнитель, инертный материал; совокупность beam – балка

fluctuation – колебание

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freeze – замерзать humidity – влажность impact – толчок, удар

reinforced concrete – армированный железобетон resist – сопротивляться

settle – усаживаться, уменьшаться в объеме slab – плита

stress – напряжение, усилие thaw – таять, оттаивать

23.In each line find the word with the most general meaning.

1.Foundation, girder, floor, construction, arch, pillar.

2.Sand, aggregate, cement, water, gravel.

3.Bending, force, settling, tension, friction.

24.Find nouns with suffixes -tion, -sion, -ion in the text.

25.Learn to recognize international words. Give Russian equivalents to the following words without a dictionary. Make up your own wordcombinations or sentences with them.

Specially, rationally, construction, silicate, temperature, general, dispersion, atmospheric, factor, service, stress, compact, deformation.

26. Read the text and answer the questions after it.

Cement Concrete

The specially and rationally selected, consolidated and hardened mixture of broken stone (or gravel), sand and cement paste is called concrete.

Before consolidating and hardening the aggregate of broken stone, sand, cement and water bears the name of concrete mixture.

Concrete is widely used in building for making foundation, reinforced concrete constructions, columns (pillars), girders (beams), floors, arches and bearing constructions.

The concrete for road surfacing is made with application of silicate concrete only.

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In contradiction to ordinary concrete and reinforced concrete constructions, the concrete of the road surfacing is in the most difficult conditions of work: it feels the repeated impact influence from vehicle movement, suffers wear because of friction etc.

The concrete in the road surfacing undergoes also the bending force. In case of settling or changing the temperature and humidity the concrete undergoes the tension force too.

Uneven humidity of the concrete slab as far as the thickness is concerned, drying out on top and moistening from below, create the additional stresses within the concrete.

The general peculiarity of the concrete work in the road surfacing is the dispersion of action of forces in the great number of places. At last the direct influence of atmospheric factors (moistening and drying out, the repeated freezing and thawing out, fluctuation of temperature etc.) create the most unfavourable conditions of service for the road concrete.

To be capable of resisting the forces arising in the road surfacing at the time of speedy movement of automobiles and when heavy loads are carried along the road, cement concrete must possess high compression, tensile and bending strength, it must be significantly hard to resist wear, must possess toughness to resist influence of impacts and at last it must be as compact as possible to ensure its frost resistance; besides this the concrete must possess properties ensuring the least degree of settling and temperature deformations.

1.What does concrete consist of?

2.What concrete is used in road surfacing?

3.Why is the concrete of the road surfacing in the most difficult conditions of work?

4.What forces does the concrete of the road surfacing undergo?

5.What properties must the cement concrete possess?

27.Study the following words.

cast – литой, отлитый curb – бордюр

float – гладилка, мастерок fluctuation – колебание hydroinsulating – гидроизоляционный levelling – выравнивание

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petroleum – нефть putty – замазка

slipperiness – скользкость solution – раствор

tenacious – вязкий, прочный, крепкий viscous – вязкий, липкий waterproofness – водонепроницаемость

28. Learn to recognize international words. Give Russian equivalents to the following words without a dictionary. Make up your own wordcombinations or sentences with them.

Limits, mastic, stability, elastic, bitumen, asphalt, special, character, plastic, absorb, amplitude, compactness, consistence, organization, mechanization, classify, cylinder.

29.Find the antonyms of these words in the text.

Liquid, artificial, hot, low, produced.

30.In what meaning are the following words used in the text?

Composition:

-a piece of writing undertaken as an academic exercise in grammatically acceptable writing; an essay;

-the parts of which something is composed or made up; constitution.

Powder:

-a solid substance in the form of tiny loose particles;

-fresh loose snow, esp. when considered as skiing terrain.

Property:

-a piece of land or real estate, esp used for agricultural purposes;

-a quality, attribute, or distinctive feature of anything, esp. a characteristic attribute such as the density or strength of a material.

31. Find the adverbs made from adjectives by means of the suffix -ly in the text. Translate them.

For example:

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