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constriction equipment. In permafrost areas, cuts in untrained frozen materials are commonly made by first removing trained materials, excavation may be carried down to the elevation required. Thaw in fine-grained frozen soils may be as much as 6 in. per day following exposure. Frozen materials may also be thawed by use of cold-water or broken up by explosives. Care must be taken to avoid permitting too a depth of fine-grained soil to become thawed at one time, as it may become impossible for the construction equipment it cope effectively with the soft, liquefied material.

Establishment of grades when the ground is freezing or thawing is difficult in areas of frost-susceptible because of the rise and fall of temporary beach marks and of the pavements themselves. In borderline permafrost areas, where freezing does not reach the permafrost surface until late in the winter, the pavement may be continuously rising and falling throughout the year.

Notes to the text:

The notes cover definitions of some specialized terms used in connection with frost and permafrost road and highway engineering:

Permafrost – perennially frozen ground.

Annual frost zone – the top layer of ground subject to annual freezing and thawing.

Frost heave – the raising of a surface due to the formation of ice in the underlying soil.

Frost-susceptible soil – soils in which significant ice segregation will occur when the requisite moisture and freezing conditions are present.

Non-frost-susceptible materials – cohesionless materials such as crushed rock, gravel, sand, slag, and cinders in which significant ice segregation does not occur.

143. Read and study the following words:

to proceed – происходить, действовать

field investigations – исследования местности non-frost region – район незамерзания precipitation – осадки (метеор.)

emergency – крайний случай, критическое положение, авария undrained materials – водонепроницаемый материал

thawed material – талый, оттаявший материал thaw – таяние

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exposure – метеорологическая сводка to cope with – справиться, совладать

liquefied material – материал в жидком состоянии susceptible – восприимчивый, поддающийся perennially – всегда, вечно, постоянно

frost heave – пучина (на дорогах) heave – подъём, вздувание почвы

cohesionless material – несвязанный материал

144. State the Tense of verbs in Passive Voice in the following sentences:

1. Design of highway in cold regions should be preceded by field investigation. 2. Field investigation in cold regions must be carried farther then in nonfrost regions. 3. In cold regions to the usual data topography, hydrology, etc. special information is needed on the climatic factors of temperature. 4. In seasonal frost and permafrost areas highway construction is limited to the period during which air at or above freezing. 5. Well-drained granular materials and hot-mix bituminous surfacing are occasionally placed in below-freezing temperatures for emergency purposes. 6. Constructions of highways is also limited by the spring “mud time”. 7. Frozen materials may also be thawed by use of cold-water.

145. State the -ing forms, their functions and translate into Russian.

1. Frost effect and the occurrence of low temperatures very seriously affect the scheduling of construction operations in cold regions. 2. Effective highway construction is usually limited to the period during which air temperatures are at or above freezing, though well-drained granular materials and hot-mix bituminous surfacing are occasionally placed in bellow- freezing temperatures. 3. In permafrost areas, cuts in undrained frozen materials are commonly made by first removing thawed materials. 4. Care must be taken to avoid permitting too great a depth of fine-grained soil. 5. Establishment of grades when the ground is freezing or thawing is difficult in areas of frost-susceptible materials. 6. In permafrost regions this problem extends through the summer thawing season. 7. In borderline permafrost areas, where freezing does not reach the permafrost surface until late in the winter, the pavement may be continuously rising and falling throughout the year. 8. Annual frost zone is the top layer of ground subject

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to annual freezing and thawing. 9. Frost heave is the raising of a surface due to the formation of ice in the underling soil. 10. When the requisite moisture and freezing condition are present frost-susceptible soils are formed.

146. Answer the question to the text.

1. Does the design of a highway in cold regions need any investigation? 2. What investigation are required? 3. What are the peculiarities of cold regions highway engineering? 4. What is the main difficulty in highway construction in cold regions? 5. What is the period of construction operation in cold regions? 6. What are the ways of handling of thawed materials? 7. What are the characteristics of soil in frost permafrost areas?

147. Read and retell.

Considering the frost action in design is much need. Frost action to highways and airfield pavement results in the following damaging effects:

1.Seasonal frost heave and settlement

2.Surface roughness

3.Loss of compaction

4.Deterioration of the pavement surfacing

5.Loss of strength during that

6.Degradation through melting of permafrost

7.Restriction of subsurface drainage

148. Give the short summary of the text “Construction of Highways in cold regions”.

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ROAD BUILDING MATERIALS

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

Mechanical, physical, technological, chemical, compression, constant, process, correct, laboratory, experimental, industrial, real, initial, result, specific, form, accumulation.

3. Find the synonyms of these words in the text below:

The capability, intended, to be implemented, proper, use, deep, to gain, to condition, an aim.

4. Translate the following words keeping in mind their suffixes and prefixes. Define their part of speech.

Conduct, conductance, conducting, conduction, conductive, conductivity, conductor.

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Utilize, utilizable, utilization, utilize, utilitarian, utility, utilized, utilizing, reutilize.

Character, characteristic, characterization, characterize, characterizer, characterless, uncharacteristic.

5. Analyze the models of word formation. Read and translate the words generated by these models.

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

General properties of materials

The quality of any road-building material is determined by its technical properties which include mechanical, physical, technological and chemical properties.

Mechanical properties of any material are characterized by the ability of this material to resist the action of outer mechanical forces. Under the influence of mechanical forces the material in road structures undergoes compression, shear, bending, tension and torsion.

Physical Properties of the material are determined by the physical constants. Physical properties include weight, compactness, water properties, weather resistance, heat conductivity, fire-resistance, sound conductivity etc.

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Technological properties are such properties which stipulate the attitude of the material towards the technological processes.

Chemical qualities of the material define the ability of the material to the chemical interaction with other substances.

The quality and durability of the road revetment depend to the considerable extent upon the correct choice of the road building materials.

To make a correct choice of the road-building material it is not only necessary to know its properties but also to have a notion of how these properties will remain for some time under a given traffic density of the road and in such natural conditions in which the structure will work.

Besides the durability in the true sense of this word it is necessary to have the judgment about the capability of the material to resist the influence of natural factors and alongside with this it is important to know about how this material can save money. Usually the defining of the technical properties of the road-building material destined for some or other structure is done by means of the corresponding tests, which may be fulfilled under field conditions, in a laboratory and on the experimental road.

Natural stone materials are the oldest representatives of the building materials, but the rational utilization of stone for different building purposes became possible only from the second half of the XIX century as a result of numerous scientific researches and the studying of the industrial experience of the utilizing of stone materials in different natural regions.

The works of N. A. Bolelyubsky on the research of frost resistance of stone materials, the works of professors I. H. Maluga, N. K. Lakhtin and others were of extremely great importance.

In tsarist Russia the knowledge of natural riches of the country was quite insignificant. This is proved at least by the fact that such material as granite was very often imported from Sweden, marble - from Italy and so on. Only later the prospecting of minerals and researching of stone materials began being developed.

Thanks to the works of academicians D.S. Belyankin, F.U. Levinson - Lessing, V. A. Obruchev and other scientists now we know and utilize our riches of stone materials.

Stone materials are characterized by comparatively great strength and durability. Stone materials are widely used in road and bridge building; they are also used for making stone elements of artificial structures, for constructing stone road surfacing, they serve as a stone frame for the majority of cement-concrete and asphalt-concrete mixtures; stone material is used for draining facilities and many other road structures.

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Natural stone material is nothing else as rocks, which are organic part of the crust from the upper layers of which they are obtained in the form of solid, massive boulders of unequal size and shape or in the form of loose accumulation of disintegrated rock formations of different size. In order to become the real building material the massive rocks undergo mechanical treatment.

Artificial rock materials are produced at the mills of the raw stuff of the natural origin or of the factory waste.

In the process of manufacturing artificial articles the initial raw stuff undergoes more or less profound changes and acquires some new technical properties.

Out of numerous artificial stone articles road paving brick, common building brick, ceramic pipes, silicate brick, slag broken stones etc. are used in road building.

The most widespread initial raw stuff for manufacturing the artificial stone articles are clay and sand and of the factory waste is slag.

Articles received as a result of working clays are called ceramic articles. Road paving brick belongs to the range of ceramic articles.

Paving brick represents such stone material which is obtained of clay by means of baking it.

Paving brick produces the specific metallic sound when hit.

Paving brick is used in different branches of building: for constructing pavement and sidewalk surfacing, floors, foundations, hydrotechnical, decorating and other jobs.

Depending upon the purpose the paving brick is made of different forms and technological properties.

1.What technical properties of road-building materials do you know?

2.What is necessary to make a correct choice of the road-building materials?

3.Where may the defining tests of the road-building material be ful-

filled?

4.What are the oldest representatives of the building materials?

5.Where are stone materials widely used?

6.What artificial stone articles are used in road building?

7.Complete the sentences using information from the text.

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1.Mechanical properties of any material are characterized by the ability of this material to resist … .

2.Physical properties include … .

3.Chemical qualities of the material define the ability of the material to… .

4.Stone materials are characterized by comparatively great … .

5.In order to become the real building material the massive rocks … .

6.Articles received as a result of working clays are called … .

7.Paving brick is obtained of clay by … .

8.Depending upon the purpose the paving brick is made of … .

8. Read and memorize the following words.

9. Learn to recognize international words. Give Russian equivalents to the following words without a dictionary.

Natural, ceramic, material, characteristic, gravel, mineral, massive, granite, technical, silicate, local, method, mechanization, economize, front, centralized, role, rational, transportation, utilize.

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