Unit i. The history of roads and highways
UNIT I. THE HISTORY OF ROADS AND HIGHWAYS
Pre-reading tasks
Before you read the text, look at the words in the box and tick the ones you know. Consult the others in the dictionary.
| to mean to throw solid to drain ditch to protect to manufacture to search to investigate to follow highway | ancient route to carry straight flat cobblestone vehicle wagon to slope condition pavement |
2. Match the equivalents:
1. wheeled vehicle а) грузовой автомобиль
2. urban area b) происхождение
3. origin c) твердое основание
4. truck d) городская территория
5. clearing e) сельская местность
6. rural area f) колесное транспортное средство
7. solid base g) участок земли, очищенный от деревьев и кустарника
Reading task
3. Read the text carefully and do the tasks that follow:
Road is a strip of land that provides routes for travel by automobiles and other wheeled vehicles. Roads usually connect urban areas with each other and rural areas with urban areas.
Roads and highways are vital lifelines. Farmers use them to ship their products to markets. Trucks can carry manufactured products from one area to another. Good roads carry millions of automobiles that travel on business and for pleasure.
Roads are so old that we are not sure of the origin of the word “road”. Most experts think it came from the Middle English word “rode” meaning “a mounted journey”. This may have come from the Old English “rad”, from the word “ridan”, meaning “to ride”.
In England, hundreds of years ago, certain main roads were higher than the surrounding ground. This was because earth was thrown from the side ditches towards the center. Because they were higher they were called highways. These roads were under protection of the king’s men and were opened to all travelers.
The first roads in the world probably followed trails and paths made by animals. People followed these trails to hunt for animals. People also made their own trails and paths in searching for water, food and fuel. Explorers followed these trails as they investigated new lands.
Early roads were built in the Near East soon after the wheel was invented. This was about 3000 B.C. As trade developed between villages, towns and cities, other paths or trade routes were made. One such early system of roads was the Old Silk Trade Route which ran over 6,000 miles (9,700 kilometers), connecting China with Rome and Europe. Merchants used this ancient route to carry Chinese silk across Turkistan, India and Persia.
The Egyptians, Carthaginians and Etruscans all built roads. But the first really great road builders were the Romans. They knew how to lay a solid base and how to make a pavement of flat stones. The Romans knew that the road must slope slightly from the center toward both sides to drain off water. The Roman road builders knew also that there must be ditches along the sides of the road to carry water away. Roman roads were built mainly to get soldiers from one part of the Empire to another. These roads ran inA cobblestone Roman
almost straight lines and passed over hills road in Pompeii
instead of cutting around them. The Romans built more than 50,000 miles (80,000 kilometers) of roads in there Empire and some of them are still in use.
From the 500’s to the 1800’s most roads in Europe were merely clearings in the forests. Cobblestone paving was used in some urban areas. There was little reason to built good roads, because most of the travel was on the horseback. The cleared way was sometimes quite wide so that robbers hiding in the woods could not leap out suddenly upon unsuspecting travelers. Later, when more wheeled vehicles, such as wagons, came into use, the roads of Europe still remained in poor condition.
Comprehension check
4. Answer the following questions.
1. What does this text deal with?
2. What do roads and highways serve for?
3. Did people use the paths made by animals in ancient times?
4. What really accelerated the building of good roads?
5. What was the most famous trade route?
6. Why do we consider the Romans the great road builders?
7. What purpose were Roman roads built for?
8. Asphalt paving was used in some urban areas, wasn’t it?
Vocabulary practice
5. Fill in the correct word from the box:
| hunting construction straight cobblestone ways ditches country |
Roadmaking originated in the period of early human settlements. People chose the most convenient and the shortest ________of approach to their ________and fishing grounds, making footpaths. The first artificially constructed tracks were made in mountainous and forested _______.
Road _________ was extensively developed during the Roman Empire. Their roads were ________. Materials used in the construction of Roman roads were gravel, _________and hewn (тесаный) stone. ________ helped roads to drain, even when roads were not elevated much.
6. Give the English equivalents to the Russian words:
1. Early roads were built in the Near East after the (изобретения) of the (колеса). 2. The Romans knew that the road (должна слегка наклоняться) from the centre towards both sides. 3. The centre of the highways was higher than (окружающая земля, чтобы отводить воду) from the surface. 4. The road pavement was made of (плоских камней) with (прочным основанием). 5. The Roman roads were (прямые) with (канавами вдоль сторон дороги).
Language focus
7. Match the words with their synonyms:
a) to ship, car, to manufacture, trip, main, to connect, path, towards
b) journey, to produce, vehicle, to carry, to, chief, way, to join
8. Match the words with their antonyms:
a) narrow, to build, curved, top, soft
b) to ruin, wide, solid, bottom, straight
9. Form the verbs from the following nouns and translate them:
Concrete (бетон) – to concrete (бетонировать)
slope, hunt, design, load, place, form, shape
10. Form the adverbs from the following adjectives and translate them:
Main (главный) – mainly (главным образом)
slight, complete, sudden, mere, recent, probable
Speak on:
a)the appearance of the first roads in the world;
b)the Roman road builders;
UNIT II. THE MASTER ROAD BUILDERS
Pre-reading tasks
1. Before you read the text, check the meaning of these words. Use a dictionary if necessary.
| demand scarcity to carry out thoroughly edgewise suitable formation cross-section to elevate | void to facilitate trench impermeable to compact surface course to remove layer |
2. Match the equivalents:
1. improvement а) подчёркивать
2. to pass b) дюйм
3. impassable c) непрерывное обслуживание
4. to support the load d) усовершенствование
5. uniform thickness e) относительно, сравнительно
6. inch f) идти; проходить, проезжать
7. relatively g) выдерживать нагрузку
8. to stress h) одинаковой толщины
9. continuous maintenance i) надлежащий дренаж
10. proper drainage j) непроходимый
Reading task
3. Read the text carefully and do the tasks that follow:
Gradual technological improvements in the 17-th and 18-th centuries increased commercial travel, improved vehicles and the breeding of better horses. Rural roads became impassable in wet weather. These factors created an increasing demand for better roads.
Up to this time roads similar to the Roman roads were built. However, owing to a scarcity of a suitable material and the high cost of labour, the amount of stone material used was progressively reduced and the work was carried out less thoroughly. Research was carried out to find out more rational methods of using stone for pavement construction which would reduce both the amount of labour and the cost. And in the last half of the 18-th century the farthers of modern road building and road maintenance appeared in France and Britain.
Tresaquet. In France in 1764, Pierre Tresaquet, became an engineer of bridges and roads in Limoges. He developed an entirely new type of relatively light road surface, based on theory that the underlying natural formation should support the load.
His standard cross-section, 18 feet wide, consisted of an eight-inch-thick course of uniform stones laid edgewise on the natural formation and covered by a two-inch layer of broken stone. The second layer was topped with one-inch layer of smaller broken stone. In order to maintain surface level Tresaquest's pavement was placed in an excavated trench — a technique that made drainage a difficult problem.
Figure 2
McAdam. The greatest advance came from John McAdam, born in 1756 in Scotland. He reached major heights in his road-building career after 1804 when he was appointed general surveyor for Bristol. The roads leading to Bristol were in poor condition. There he showed that traffic could be supported by a relatively thin layer of small, single-sized pieces of broken stone placed and compacted on a well-drained natural formation and covered by an impermeable surface of smaller stones.
Mc Adam is famous for the surface he developed for roads. This kind of surface, called macadam, is still used today. Mc Adam also stressed the importance of proper drainage to keep roads on a solid foundation. Drainage was essential to the success of Mc Adam’s method and he required the pavement to be elevated above the surrounding surface. The structural layer of broken stone was eight inches thick and used stone of two or three inches maximum size laid in layers and compacted by traffic. The top layer was 2 inches thick, using three-quarter-inch stone to fill surface voids between the large stones. Continuous maintenance was essential.
Russian engineers were the first ones to construct granular surfacing laid on sand base which are now widely used in other countries. The use of a sand base permitted the cost of construction to be reduced and the removal of water from the subgrade to be facilitated. It helped to increase subgrade stability.
Comprehension check
4. Answer the following questions:
1. When did a period of intensive road-building begin in Europe?
2. Why was there a great demand for better roads?
3. What problems did the first engineers try to solve?
4. When did the fathers of modern road building appear?
5. What was the main idea of Tresaquet’s method of road pavement construction?
6. What kind of surface did Mc Adam suggest?
7. What was essential in road pavement construction in Mc Adam’s opinion?
8. What method of road pavement construction was proposed by Russian engineers?
UNIT III. PAVING MATERIALS
Pre-reading tasks 1
1. Translate the following words and memorize them:
| failure to force tough to crush stiff strength recycled asphalt | application crack resistance tyre friction impetus behaviour to conduct |
Reading task 1
2. Read the text carefully and do the tasks that follow:
Roads at the turn of the 20th century were largely inadequate for the demands about to be placed on them by the automobile and bicycle. As vehicle speeds increased rapidly, the available friction between road and tyre became critical for accelerating, braking and cornering. In addition, numerous pavement failures made it obvious that much stronger and tougher materials were required. The result was an ongoing search for a better pavement. Asphalt and concrete both offered promise.
Asphalt is a mixture of bitumen and stone, and concrete is a mixture of cement and stone. The first road use of asphalt occurred in 1824 when asphalt blocks were placed on the Champs-Elysees in Paris. The first successful concrete pavement was built in Inverness, Scotland, in 1865. Both asphalt and concrete required the availability of powerful stone-crushing, mixing and spreading equipment.
The impetus for the development of modern road asphalt came from the United States which had few deposits of natural bitumen to draw upon and where engineers were therefore forced to study the behaviour of this material. The first steps came in the 1860s with the work of Belgian immigrant Edward de Smedt at Columbia University in New York. De Smedt conducted his first tests in New Jersey in 1870 and by 1872 was producing the equivalent of modern road asphalt. The first applications were in Battery Park and on Fifth Avenue in New York City in 1872.
In 1887 de Smedt was followed as inspector of asphalts and cements by Clifford Richardson. Richardson basically developed two forms of asphalt: asphaltic concrete, which was strong and stiff and thus provided structural strength; and hot-rolled asphalt, which contained more bitumen and thus produced a far smoother and better surface for the car and bicycle.
Richardson published a standard textbook on asphalt paving in 1905, and the practice did not change greatly thereafter. The biggest change was in the machinery available to produce, place and finish the material rather than in the product itself. Toward the end of the century, there were major movements towards the use of recycled asphalt, chemical modifiers for improving bitumen properties and small fibres for improving crack resistance.
The first modern concrete roads were produced by Joseph Mitchell who conducted three successful trails in England and Scotland in 1865-66. Like asphalt technology, concrete road Machine laying asphalt concrete
building was largely, fed from a dump truck
developed by the turn of the 20th century and was restricted more by the available machinery then by the material. For the following century the two materials remained in intense competition, both offering a similar product at a similar cost, and there was little evidence that one would far ahead of the other as they continued on their paths of gradual improvement.
- Champs-Elysées – главный бульвар в Париже (Елисейские поля).
- Battery Park Бэттери-парк Парк на берегу Нью-Йоркской гавани на южной оконечности Манхэттена. От парка начинается Бродвей.
Comprehension check 1
3. Answer the following questions:
1) The world entered the 20th century and roads didn’t satisfy the demands of the automobile, didn’t they? Why?
2) What kinds of materials were required for modern roads?
3) Why did the impetus for the development of modern road asphalt come from the United States?
4) What scientist produced the equivalent of modern road asphalt?
5) What kinds of asphalt did Clifford Richardson develop?
6) Who published standard textbook on asphalt paving?
7) Where were the first concrete roads built?
8) Why was concrete road building restricted?
9) Why did asphalt and concrete remain in intense competition for the following century?
4. Match the beginning with the ending:
1. Asphalt a) was strong and stiff and provided structural strength.
2. Concrete b) is a mixture of bitumen and stone.
3. Asphaltic concrete c) is a mixture of cement and stone.
4. Hot-rolled asphalt d) were restricted by available machinery.
5. Asphalt technology and e) contained more bitumen and produces concrete road building a far smoother and better surface for the
car and bicycle.
Language Focus 1
5. Match the following words with their synonyms:
a) to accelerate, to occur, rapidly, to contain, to restrict, similar, to apply, to modify.
b)to take place, to change, to limit, slowly, to speed up, to involve, the same, to use.
6. Give the derivatives of the following words (adjectives, adverbs, nouns, verbs) and translate them:
to pave, conductivity, to mix, to require, possible, to improve, to change, stiff, to continue, to produce, to move, to complete, to add, available.
Speaking 1
7. Try to recollect the achievements of the following people whose names were mentioned in the text:
Writing Practice 1
Comprehension check
4. Answer the following questions:
1. How was native asphalt obtained in ancient times?
2. Where were large sources of native asphalt found?
3. What was asphalt used for?
4. What does the amount of asphalt in a crude oil depend on?
5. How is the crude oil transported to the refineries?
6. What processes are used in the refining of asphalt?
7. What is done to form a stable waterproofed base course?
Language focus
5. Build derivatives from the words below and translate them:
To vary – adj.; to resist – n.; to stabilize – n.;
to continue – adj.; to crack – n.; to coat – n.;
to extract – n.; to refine – n.; to form – n.;
stable – n.; proper – adv.
6. Match the following words with their synonyms:
a) to contain, to obtain, amount, to remain, to bind, course, to separate, way, to apply, fraction, to aid.
b) quantity, to get, to involve, method, to connect, to divide, layer, to help, to stay, particle, to use.
7. Put the correct forms of the words into the sentences:
Nature works its wonders
| Sir Waller Raleigh ___________ on the island of Trinidad in 1595 and stayed there long enough to obtain a ____________ ofasphalt. The asphalt he used was a native asphalt ________ from an asphalt lake a short distance from the shore of the Gulf of Paria and was similar to that __________ by the ancienls. Hundreds of thousands of tons of asphalt have been _______ from the Trinidad lake without any sign of loss. As the material removed, pressure deep in the earth ________ more of the heavy residue to the surface, where nature continues its ____________ process. The natural asphalt ________ from the lake ________ many impurities and foreign matter such as water, fine sand and vegetation. To produce a _____________ paving material, these impurities have to be _________; therefore a refining process is necessary. | to land to supply to take to use to remove to force to refine to remove to contain to suit to remove |
8. Translate from Russian into English:
1. Асфальт является природным материалом, получаемым из нефтяных скважин.
2. Сырую нефть транспортируют на нефтеочистительные заводы, где её разделяют на различные составные элементы.
3. Количество асфальта в сырой нефти зависит от её плотности.
4. Чем выше плотность сырой нефти, тем выше содержание асфальта.
5. При очистке асфальта используется два метода: метод паровой и вакуумной дистилляции, а также метод экстракции селективным растворителем.
6.Укрепление грунта или заполнителя асфальтом широко используется при строительстве дорог и аэродромов.
7. Тонкое покрытие асфальтом вокруг частиц грунта обеспечивает высокую степень водонепроницаемости основания дорожной одежды.
9. Read the text and choose the right statement:
Some interesting facts
One of man's oldest building materials is finding its way into a lot of new places these days. Concrete, first discovered by the Romans, is now more widely used in construction than all other materials together.
The magic ingredient that makes concrete possible is cement, about which, according to one expert, more has been learnt in the past three decades than in the preceding 2,000 years. Concrete is a synthetic stone which can be formed while soft into practically any shape the builder wants. Portland cement mixed with water is the paste that binds sand, gravel, clinker (шлак) into an artificial rock that becomes harder as the years pass. Portland cement does not come from a place of that name; it was called Portland because Joseph Aspdin, the English builder who invented the first dependable, scientifically made cement about 1824, thought it resembled (напоминать) the rock excavated on the Isle of Portland on the Dorset Coast.
Portland cement is called …
1. after the name of the person invented it;
2. after the name of the place it had been formed;
3. after the name of the island where the mineral it is similar to was excavated.
Pre-reading tasks
1. Translate the following words and memorize them:
| structure to withstand subgrade moisture load distribution stability to vary to cause | subsoil content excessive disintegration site complete (adj.) maintenance to subject earthwork |
2. Match the equivalents:
1. engineering structure a. распределение влаги
2. road subgrade b. инженерное сооружение
3. moisture distribution c. дробление каменных материалов
4. gravel quarrying d. грунтовое основание дороги
5. subsoil moisture content e. эксплуатационные качества дорожной одежды
6. pavement performance f. содержание влаги в подстилающем слое
7. engineering solution g. вводить в эксплуатацию
8. put into service h. инженер, ответственный за
9. repair shops i. плотность движения
10. utmost importance j. вписывать в ландшафт
11. traffic density k. первостепенная важность
12. fit into landscape l. выдерживать нагрузки
13. withstand loads m. ремонтные мастерские
14. stone crushing n. разработка гравийного карьера
15. engineer in charge of o. техническое решение
Reading task
3. Read the text carefully and do the tasks that follow:
Modern highways are complex engineering structures. They are intended for high-speed motor traffic. The road pavement must continuously provide good riding qualities and be capable of withstanding the dynamic loads influenced by passage of vehicles. Pavements and road subgrades are subject to the influence of many natural factors such as heating by the sun, freezing, thawing, moistening by rain, etc. Complex physical processes develop in the subgrade caused by variations in moisture distribution and an increase in subsoil moisture content. An excessive moisture content quickly causes the subsoil to lose its strength and may lead to disintegration of the road foundation. The many and varied factors of pavement performance have to be taken into account by the designer and constructor who have to provide for the maximum stability of the subgrade and for the maximum strength of the pavement.
Roads are built in the most varied natural conditions - in broad plains and hills, sandy deserts and in mountains. In all these diverse and complex conditions the road engineer has to be able to find correct engineering and economic solutions. Because of this, A highway paved with concrete
when solving construction problems related to road he has to make use of natural and historical sciences, i.e. geology, climatology, hydraulics, hydrology, etc. He must be able to design highways so as to ensure comfort and safety of transportation.
The road-building operations become complicated because of the extensive length of the construction site – often tens and hundreds of kilometers. The task of the road engineer is to mechanize and technically develop the road-building operations and to provide for the most efficient and complete mechanization of the entire construction process. This is true to such operations as earthworks, sand and gravel quarrying, stone crushing and cement-concrete surfacing.
Finally, when the highway is put into service, its maintenance and the provision for uninterrupted traffic become of the utmost importance of the national economy. The engineer in charge of the highway operation must ensure the maintenance of the road quality under all traffic and weather conditions.
With the growth of traffic density a demand for greater amenities will come. It will be necessary to provide the national road system with hotels and restaurants, service stations and repair shops, where drivers and passengers may rest and vehicles be serviced and repaired. Attention should be given to such questions as fitting roads into the landscape in plan and in profile, planting trees, so as to improve their aesthetic value.
Comprehension check
3. Answer the following questions:
1. What is a highway?
2. What are modern highways intended for?
3. What is the main function of the road pavement?
4. What factors are pavements and road subgrades subject to?
5. Why do complex physical processes develop in the subgrade?
6. What can an excessive moisture content lead to?
7. What kinds of sciences must the road engineer know to ensure comfort and safety of transportation?
8. What do you know about the conditions in which road engineers have to build different kinds of roads?
9. In what way it is possible to make road-building operations easier?
10. What conveniences must the national road system be provided with?
Vocabulary practice
6. Choose the right translation of the word:
1. subsoila) почва b) гравий с) подстилающий слой грунта
2. to withstand a) различать b) выдержать с) обеспечить
3. distribution a) распределение b) расширение с) удаление
4. content a) ослабление b) уклон с) содержание
5. surfacing a) покрытие b) замерзание с) увлажнение
6. disintegration a) осушение b) расслоение с) преодоление
7. excessive a) чрезмерный b) полный с) разнообразный
8. to crush a) поднимать b) уничтожать с) дробить
9. to cause a) определять b) вызывать с) требовать
10. stability a) изменение b) влияние с) устойчивость
Language focus
5. Read the following words paying attention to the stress and translate them:
transport (n) – to transport; subject (n) – to subject;
increase (n) – to increase; import (n) – to import;
export (n) – to export. concrete (n) – to concrete
6. Complete the table. Try to remember what the following words mean:
| Verb | Noun |
| 1. to construct 2. … 3. to heat 4. … 5. to influence 6. … 7. to design 8. … 9. to vary 10. … 11. to solve 12. … 13. to provide | … load … passage … distribution … maintenance … provision … moisture … |
7. Give the initial forms of the words and translate them:
continuously, varied, qualities, withstanding, sandy, necessity, uninterrupted, excessive, safely.
8. Match the words with their synonyms:
a) to ensure, to vary, solution, operation, diverse, complete, amenities, to take into account.
b) decision, to pay attention to, work, various, conveniences, total, to change, to guarantee.
9. Fill in the correct prepositions:
to intend …; to be capable …; to subject …; to take … account; to give attention …; because …; to provide … .
10. Translate the following sentences into English:
1. Современные дороги предназначены для высокоскоростного автомобильного транспорта.
2. Покрытие дороги должно обеспечивать хорошее качество езды и выдерживать динамические нагрузки.
3. Покрытия и дорожные основания подвержены влиянию многих природных факторов таких как нагревание солнцем, замерзание, таяние, увлажнение и т.д.
4. Сложные физические процессы, вызванные изменением в распределении влаги, развиваются в грунтовом основании.
5. Чрезмерное содержание влаги в грунтовом основании может привести к его разложению.
6. Проектировщик и строитель должны обеспечивать максимальную устойчивость грунтового основания и максимальную прочность покрытия.
7. Задача инженера-дорожника заключается также в том, чтобы обеспечить механизацию таких процессов как земляные работы, разработка песчаных и гравийных карьеров, дробление камня и цементно-бетонных покрытий.
Speak on:
a)the road pavement of modern highways;
b)the role of a road engineer in the construction of modern highways.
UNIT V. HIGHWAY NETWORK PLANNING
Pre-reading tasks
UNIT VIII. PAVEMENT
Pre-reading tasks
Comprehension check
4. Answer the following questions:
1. What does this text discuss?
2. What is the pavement?
3. Why is it necessary to conduct subsurface explorations to design the pavement?
4. How are different properties of the local rock and soil determined?
5. What is the function of the base course?
6. Does the thickness of the base course range in a typical rural pavement?
7. Where is the subbase situated?
8. What kinds of pavements are described in the text?
9. What kinds of surfacings of a flexible pavement are used?
10. What are the advantages of bituminous surfacing?
11. Where is asphalt surfacing used?
12. What material is used for rigid pavements?
13. What property does concrete possess when it hardens?
14. What is usually done to control cracking?
15. What is necessary to take into account when making the final choice of pavement structure?
Vocabulary practice
5. Choose the right translation of the word:
1. to create a) соединять b) создавать с) дополнять
2. to spray a) напылять b) отражать с) укатывать
3. to enable a) требовать b) давать возможность с) допускать
4. embankment a) насыпь b) прочность с) пленка
5. treatment a) отражение b) обработка с) распределение
6. durability a) упругость b) долговечность с) гибкость
7. solidify a) защищать b) обеспечивать с) затвердевать, застывать
8. additive a) добавка b) обочина с) плотность
9. stabilize a) распределять b) включать с) укреплять (грунт)
10. reinforcement a) наклон b) арматура с) износ
6. Fill in the blanks using the words below and translate the sentences:
flexible, pavement, highway, rigid, cracking, resistance, properties, gravel, site
1. The substance ________ to be determined are of great importance for our research.
2. The ________ has storage for up to 50,000 tonnes of material.
3. The road ________ must be of adequate rigidity, uniformity and resistance to wear.
4. The asphalt concrete surfacing is ________ and should, therefore, be laid over a solid stone base.
5. Broken-stone surfacings have a low ________ to wear under automobile traffic.
6. The pavement is the most expensive part of a ________.
7. The ________ road is the cheapest form of road and the simplest from the construction point of view.
8. Two classifications of pavement have been developed: flexible and ________.
9. Rigid pavement, made of Portland cement concrete, generally has greater strength but is susceptible to ________.
Language focus
7. Arrange the words according to their part of speech:
typically, removal, solidify, supplement, durability, temporary, place, thoroughly, reflect, suitable, moisten, resist, relatively, coating, shrink, cast, prevent, reinforcement, distribute, joint, harden, workability, flexible, protective, cause, stabilizer, additive.
| verb | noun | adjective | adverb |
8. Translate the following words paying attention to the prefixes and suffixes:
impermeable, unsuitable, disadvantage, motionless, unprotected, untested, useless, invisible, irregular, inaccurate, disappear.
9. Form nouns from the following words:
to resist, stiff, to add, durable, to shrink, susceptible, to distribute, to stabilize, to supply.
10. Match the words with their synonyms:
a) to conduct, to range, to glue, commonly, to involve, to ensure, to stabilize, to enhance, to solidify, to identify, to protect.
b) to connect, to vary, to carry out, to contain, to specify, usually, to reinforce, to defend, to guarantee, to enlarge, to harden.
11. Match the words with their antonyms:
a) to heat, to expand, to repair, to appear, to enhance.
b) to damage, to cool, to contract, to reduce, to disappear.
12. Translate from Russian into English:
1. Дорожная одежда – это горизонтальная конструкция, поддерживаемая естественным материалом.
2. Для того чтобы спроектировать горизонтальную конструкцию, необходимо определить строительные свойства грунта.
3. Такие свойства горной породы и грунта как прочность, жёсткость, долговечность и чувствительность к влаге определяют различными путями.
4. Дорожная одежда – это многослойная (multilayer) конструкция, состоящая из нескольких слоёв: поверхностного слоя, основания дорожной одежды, подстилающего слоя и земляного полотна.
5. Существует 2 типа дорожной одежды: нежёсткая и жёсткая дорожная одежда.
6. Выбирая тип покрытия, инженер должен принимать во внимание многие факторы.
Speaking
13. Speak about:
a) flexible pavement
b) rigid pavement
Pre-reading tasks
1. Translate the following words and memorize them:
| stress roadbed to induce to attenuate surfacing abrasion to employ wear | binder smoothness roughness porous subbase subgrade to saturate to distribute |
2. Match the English words with their Russian equivalents:
1. pavement structural layers а) водонепроницаемый
2. semi-rigid structure b) илистый грунт
3. base course c) несущая способность
4. wearing course d) конструкционные слои дорожной одежды
5. impervious to water e) глинистый грунт
6. protective (sealing) coat f) полужесткая конструкция
7. polished surfacing g) морозозащитный слой
8. pavement base h) несущий слой
9. weak bed soil i) суглинистый грунт
10. silty soil j) слабый грунт земляного полотна (основание)
11. winter moisture accumulation k) скользкое покрытие
12. frost resistance l) многослойная конструкция
13. loamy soil m) защитный слой
14. bearing strength n) основание дорожной одежды
15. clayey soil o) слой износа
16. anti-frost heave course p) морозостойкость
17. multilayer structure q) зимнее влагонакопление
Reading task
3. Read the text carefully and do the tasks that follow:
To ensure all-year-round operation of traffic on a road independent of weather conditions, the carriageway is covered with a pavement which is a rigid or semi-rigid structure laid on the surface of the roadbed and resisting traffic stresses and climatic factors.
Traffic stress diagram for a multilayer pavement:
a) diagram of vertical stresses; b) diagram of horizontal stresses;
1 – wearing course; 2 – base course; 3 – subbase; 4 – subgrade;
5 – homogeneous soil; 6 - pavement
The stresses induced in the pavement by motor vehicle wheels attenuate with the depth. This enables the pavement to be designed in the form of a multilayer structure, employing materials whose strengths vary for each layer and are determined in accordance with the magnitude of the acting forces. The pavement consists of following layers:
1. Surfacing is the upper, and most rigid, layer of the pavement. It is comparatively thin, but resists well the abrasion and the impacts caused by the wheels, and also the effect of weather conditions. Usually, the surfacing is the most expensive part of the pavement and, therefore, is laid to the minimum admissible thickness. The surfacing provides the required road service qualities (surface smoothness, high coefficient of adhesion). Surfacing usually comprises two coats or courses - the base course, on which depend the basic qualities of the surfacing, and a wearing course, which is not regarded in calculations and which is periodically renewed as it wears out. When the surfacings are made of weak materials, which are subject to appreciable wear, a special wearing course made of strong stone material treated with organic binders is necessary, which may be periodically renewed in the course of road operation.
If the surfacing is not sufficiently impervious to water and may be destroyed during freezing or drying out in hot arid weather conditions, it is covered with a thin protective or sealing coat by surface treatment with a binder and a filling of fine sand. Surface treatment is also used for increasing the roughness of polished surfacings.
2. Below the surfacing base coat is the pavement base, a strong bearing layer of stony material or stone with a binder. This layer is designed to distribute the individual wheel-loads over the roadbed or sub-base.
The pavement base is not subject to the direct action of automobile wheels. Therefore, materials of less strength than those used for the surfacing or the wearing course can be employed in its construction.
When the base is protected from the action of surface water - in the case of an impervious surfacing - it may become saturated by water drawn upwards from the roadbed during winter frost penetration. For this reason, in the northern regions materials used for base construction have to satisfy certain requirements concerning frost resistance.
3. The sub-base is a layer of earth or stone materials, resistant to moisture, inserted when necessary between the pavement base and the roadbed to reduce the required thickness of the pavement base. The sub-base is made of gravel, slag, soil treated with binding agents, sand, etc.
On sections where the roadbed comprises silty, loamy and clayey soils, inside which winter moisture accumulation may occur, a sub-base of porous materials is introduced. This consists of a sand or gravel layer which drains away excess water from the upper layers of the roadbed, drains the pavement structure and increases the bearing strength of the roadbed. It is termed a drainage or anti-frost heave course.
If the roadbed is composed of stable, impervious sand, sandy loam or gravel soils, a sub-base is not necessary.
4. The subgrade comprises the thoroughly compacted upper layers of the roadbed, upon which are laid the layers of the pavement. The subgrade receives all the distributed pressure of traffic loads and, therefore, is a very important element of the pavement structure. The stability of road pavements can be ensured only on a heterogeneous, well compacted roadbed with adequate drainage. The increase of roadbed soil resistance to external loads, its drainage and the uniformity of water conditions are the best means for ensuring pavement stability and reducing its cost. No increase in the thickness of the pavement base can guarantee the strength of a pavement laid on a weak bed soil.
Comprehension check
4. Answer the following questions:
1. Is the pavement a multilayer structure?
2. What do you know about stresses in each layer?
3. Do the strengths of materials for each layer of the pavement vary?
4. What are the main layers of the pavement?
5. How many courses does the surfacing have? Characterize them.
6. What course of the surfacing is often renewed?
7. When is the surfacing covered by a sealing coat?
8. What is the function of the pavement base?
9. Why is the pavement base of less strength than surfacing?
10. How can the pavement base be saturated by water?
11. What materials are used for the sub-base?
12. Why is the sub-base course termed a drainage or anti-frost heave course?
13. What layer receives all the distributed pressure of traffic loads?
14. Subgrade is the thoroughly compacted upper layer of the roadbed, isn’t it?
5. Complete the following sentences:
1. The pavement structural layers are …
2. Surfacing is the most expensive part of the pavement and it is laid to the minimum …
3. Surfacing provides the required road serving qualities such as …
4. The pavement base is designed to distribute …
5. The pavement base can be saturated by water drawn upwards from the roadbed during…
6. The sub-base is made of …
7. The sub-base is termed …
8. The subgrade receives all the distributed pressure of …
Vocabulary practice
6. Fill in the blanks using the words below and translate the sentences:
Language focus
7. Match the words with their synonyms:
a). operation, to induce, to determine, rigid, impact, to comprise, to protect, section, to satisfy the requirements, agent, to term, thoroughly, to occur, to regard, to employ.
b). tough, substance, to decide, work, to consider, to cause, to meet the requirements, to use, to defend, stretch, to involve, carefully, influence, to take place, to call.
8. Match the words with their antonyms:
a). upwards, external, roughness, heterogeneous, reduce, fine.
b). internal, increase, smoothness, coarse, homogeneous, downwards.
9. Form nouns from the following words:
to treat-…..; rough-…..; to penetrate-…..; to resist-…..; to drain-…..; to compact-…..; to distribute-…..; smooth-…..; stable-……
10. Fill in the correct prepositions:
1. to consist … sth (something); 2. to subject … sth; 3. … accordance … sth; 4. to treat … sth; 5. to depend … sth; 6. … addition; 7. … the same time; 8. to be designed … sth.
11. Fill in the blanks with English equivalents:
1. The surfacing provides (гладкость поверхности и высокий коэффициент сцепления). 2. (Слой износа) is not taken into account in calculations. 3. The surfacing which is made of weak materials (обрабатываeтся) with organic (вяжущими). 4. To make the surfacing (водонепроницаемым) it is covered with a thin (защитным слоем). 5. (Основание дорожной одежды) is designed (чтобы распределить нагрузку колёс) over the sub-base. 6. The pavement base (может быть насыщено) by water drawn upwards from the roadbed. 7. (Подстилающий слой устойчив к влаге), it is designed of (пористых материалов). 8. The sub-base is also termed (дренажный или морозозащитный слой). It is done from (гравия, шлака или грунта) treated with binders. 9. (Грунтовое основание) comprises thoroughly compacted upper layers of the roadbed. It receives all (нагрузки транспорта) and therefore is considered to be a very important element of pavement structure.
Speaking
13. Comment on the pavement and its structural layers:
a). the surfacing c). the sub-base
b). the pavement base d). the subgrade
Writing
14. Write the summary to the text in English.
UNIT X. CONSTRUCTION
Pre-reading tasks
1. Translate the following words and memorize them:
| to blast removal alignment | seal to spread marking | settling to strip to stockpile |
2. Match the equivalents:
1. continuous right-of-way a) до некоторой степени
2. bearing ratio b) непрерывная (сплошная) полоса отвода
3. in-situ c) как только
4. motorized grader d) защитное покрытие
5. to some extent e) показатель плотности грунта
6. once f) напоминать выпуклость
7. to import g) начинать
8. commence h) световозвращающий отражатель
9. seal i) слегка выступать
10. retroreflector j) ограждение (установленное на раздел. полосе или на обочине)
11. to feature camber k) на месте
12. to protrude slightly l) вносить, вводить
13. crash barrier m) автогрейдер
Reading task
3. Read the text carefully and do the tasks that follow:
Road construction requires the creation of a continuous right-of-way, overcoming geographic obstacles and grades low enough to permit vehicle travel. Removal of earth and rock by digging or blasting, construction of embankments, bridges and tunnels, and removal of vegetation (this may involve deforestation) are often needed. A variety of road building equipment is employed in road building.
Once these activities are completed, construction of the pavement can begin.
Firstly the longitudinal and vertical alignment of the road is set out by a surveyor. The alignment of the road will be marked with control pegs. The pegs will have level markings as a control mechanism to ensure the road is constructed according to design levels.
Construction of the road commences with the stripping of the topsoil, within the road reserve. The topsoil is usually stockpiled nearby for the construction of embankments along the road. The in-situ ground will be removed, using a heavy motorised grader to a level specified by the civil engineer. This is considered as the roadbed level. It will be compacted using a heavy vibratory road roller. Once the roadbed has been compacted to the required density (as will be specified by the engineer), the pavement layers can now be imported.
The first layer to be imported is the selected subgrade. This is usually a gravel type material. Once placed the material is leveled off by a grader. It will be compacted to a required density, using a road roller.
The next layer to be imported is the sub-base. The subbase material is of a higher quality than the selected sub-grade. It is usually a gravel type
material with a high bearing ratio. While the material is worked Asphalt layer and roller
by a grader, it is mixed with water to aid compaction. Once the subbase layer has been compacted to its required density, the importation of the final layer can commence.
The final layer of a road is the base course consisting of gravel or crushed stone. The base course will be leveled of and compacted. Sometimes (usually for roads that will experience heavy loads) portland cement will be added to it, to ensure adequate strength of this layer. On top of the base course is placed a surface course which typically consists of asphalt concrete or a seal consisting of a mixture similar sized small stones, bitumen and portland cement. This surface course strengthens the pavement structure by spreading out the vehicle loads applied to the subgrade. It also provides a smooth and high-friction surface for vehicles to drive on.
Two important factors in road construction are ensuring adequate compaction of the pavement layers and ensuring quality control over the use of materials in the pavement layers.
Each layer should be compacted such that the density of the layer is relatively close the maximum dry density of that specific material. For road construction the density required is usually greater than 95% of the materials maximum dry density. This limits the possibility of the pavement layers from settling and therefore preventing any undulations and holes in the road surface.
Modern roads, and indeed many ancient ones, such as those built by the Romans, feature camber. This is designed to allow water to drain away from the road to its edges. Modern roads that carry motor traffic also employ camber in curves to aid traffic stability by allowing them to "bank into" the bend to some extent.
On the side of the road there may be retroreflectors on pegs, rocks or crash barriers, white toward the direction of the traffic on that side of the road, and red toward the other direction. In the road surface there may be cat's eyes: retroreflectors that protrude slightly, but which can be driven over without damage.
Road signs are often also made retroreflective. For greater visibility of road signs at daytime, sometimes fluorescence is applied to get very bright colors.
Comprehension check
4. Answer the following questions:
1. What does road construction require?
2. Who sets out the longitudinal & vertical alignment of the road?
3. What road building equipment is used during road construction?
4. What is the difference between the materials used in the subgrade & in the subbase?
5. What is the purpose of mixing the materials of the sub-base with water?
6. What does the final layer consist of?
7. Asphalt concrete or a seal is used in a surface course, isn’t it?
8. Can you name the important factors in road construction?
9. What does the low density of each layer lead to?
10. What is camber designed for?
11. Are there any special devices on the side of the road? What is their purpose?
12. What is added to road signs to make them brighter at daytime?
5. Decide whether these statements are true or false:
1. Removal of earth and rock by digging or blasting, building embankments, bridges and tunnels are often needed when the road is constructed.
2. The longitudinal and vertical alignment of the road is set out by road planners.
3. The removed topsoil is usually stockpiled nearby for rehabilitation of newly constructed embankments along the road.
4. A heavy motorized grader is used to remove the in-situ ground.
5. The first pavement layer to be imported is the selected sub-base.
6. The sub-based material is usually a gravel type material which is worked by a grader and mixed with water to aid compaction.
7. The base course is the final layer of a road.
8. The density of each layer shouldn’t be close the maximum dry density of the specific material to prevent any undulations and holes in the road surface.
9. Modern roads feature camber.
10. Road signs are not retroreflective.
Vocabulary practice
6. Choose the right translation of the word:
1. уклон a) level b) shoulder c) grade
2. взрывать a) to blast b) to penetrate c) to compact
3. удаление a) development b) removal c) reduction
4. колышек a) mark b) peg c) barrier
5. складировать a) to keep b) to remove c) to stockpile
6. плотность a) density b) location c) quality
7. грунтовое основание a) subsoil b) pavement base c) subgrade
8. слой износа a) surface course b) wearing course c) base course
9. распространение a) digging b) blasting c) spreading
10. оседание a) overcoming b) settling c) alignment
7. Match the words with their definitions:
1. right-of-way a) is a mixture of bitumen and stone
2. asphalt b) movements of people and vehicles along roads and streets
3. pavement c) is a mixture of cement and stone
4. traffic d ) central part of the road used by wheeled traffic
5. subbase e) the land needed for road pavement, shoulders, ditches, side slopes
6. carriageway f) is a rigid or semi-rigid upper layer of the surface of the road
7. concrete g) is a thoroughly compacted upper layer of the roadbed
8. gravel h) a self-propelled wheeled machine with a steel blade used to level roads, hills and cuts
9. road i) to put flat stones, bricks, etc. on a path, a road, etc.
10. motor grader j) specially prepared way between places for the use of pedestrians, riders, vehicles
11. to pave k) small stones with coarse sand
12. subgrade l) is a layer resistant to moisture, which is made of gravel, slag, soil treated with binders
8. Choose the right verb:
1. When constructing a road builders should carry away | exclude | overcome| overtake different obstacles.
2. Builders sometimes compact | add | place | level Portland cement to the base course to ensure adequate strength of this layer.
3. The surface course spreads out the vehicle loads and at the same time strengthens | involves | cuts | compacts the pavement structure.
4. A borrow pit (source for obtaining fill, gravel, and rock) and a water source should be divided | located | used | indicated near or in reasonable distance to the road construction site.
5. Old road surfaces, fences, and buildings may need to be blasted | removed | allocated | erased before construction can begin.
Language Focus
9. Match the words with their synonyms:
a) to commence, to employ, to strip, to permit, to introduce, to aid, to select, bend, to specify.
b) to remove, to import, turn, to choose, to begin, to determine, to apply, to help, to allow.
10. Arrange the words according to the parts of speech:
| Noun | Verb | Adjective |
Variety, creative, import, selection, remove, select, creation, vary, importation, survey, selective, continue, create, removable, continuous, surveyor, various, strengthen, removal, strength, spread, reflect.
Speak on:
11. Speak about road construction stages, using the following clichés:
First, the author discusses … .
Attention is drawn to the fact that … .
Further it should be noted that … .
A detailed description of … is given.
The author e