Flexible Pavement

Two main types of pavements are used — bituminous, or flexible, pavement and concrete, or rigid, pavement. Bituminous pavement is cheaper and easier to construct, but it requires more maintenance. Concrete pavement lasts for a very long time with minimal upkeep but is much more expensive and time-consuming to build.

Flexible and rigid pavements each contain several different layers of materials. The layers below combine to support the traffic moving along on the surface layer, which is known as the wearing course. Asphalt makes up the wearing course of flexible pavement and is often found on residential streets in cities. Rigid pavement made of concrete is more durable and is a popular choice for highway construction.

Bituminous pavements are made with by-products of petroleum, such as asphalt. Weather and seasonal changes can cause roadways and the earth below them to rise or fall slightly. As these natural shifts occur, bituminous pavements allow the road surface to bend or flex slightly without breaking.

Bituminous material softens when heated and can be prepared and applied in a wide range of concentrations. Thin layers of bituminous material are sometimes applied with a pressure sprayer to the base course or the top course. The bituminous material seeps into the crushed rock and penetrates the tiny spaces between the compacted rockfill, binding the aggregate together. To provide traction for moving traffic, a thin layer of aggregate may then be spread over the bituminous material and compacted.

Asphalt, a thick bituminous material, can be used directly as a pavement. Asphalt can be applied in thin overlays less than 2 cm (0.75 inch) deep or in layers several centimeters deep, depending on the type of surface and its purpose. Asphalt is commonly mixed with aggregates for added strength and traction. The asphalt and aggregates are first mixed and heated, and the material is then transported to the construction site, where it is spread directly over the base course or top course and compacted. Asphalt surfaces are fairly easy to construct and repair.

Task 6

Restore the sentences. Consult the text above.

1. Bituminous pavements are made with....

2. The bituminous material serves to….

3. A thick bituminous material is called….

4. Asphalt can be used directly as….

5. Asphalt is usually mixed with aggregates for….

6. The stability of bituminous pavements depends on.…

7. Asphalt surfaces are relatively easy to….

8. But flexible pavements require more….

Task 7

Answer the following questions using the information from the text above.

1. What main types of pavements are used in present-day road construction?

2. Which type of the pavement is more durable, bituminous or concrete?

3. What happens to bituminous material when it is heated?

4. What do road-builders do to achieve better strength and traction of pavement?

5. Where are the asphalt and aggregates mixed and heated before being transported to the construction site?

6. What factors may affect roads conditions?

7. What are the main advantages of asphalt surfaces?

8.What are the main disadvantages of concrete pavements?

10. What is aggregate used for?

Task 8

Fill in the gaps with prepositions if necessary. Consult the text above.

1. Flexible pavement is often found .… residential streets …. cities.

2. Bituminous pavements allow the road surface to bend or flex slightly .… breaking.

3. Asphalt is usually mixed .… aggregates …. added strength and traction.

4. A thin layer …. aggregate is spread .… the bituminous material and then compacted.

5. The bituminous material seeps .… the crushed rock and penetrates …. the spaces …. the compacted rocks.

6. Weather can cause roadways and the earth .… them to rise or fall slightly.

Task 9

Transform the following sentences according to the model. Translate the sentences into Ukrainian (Russian).

Model

Concrete pavement lasts for a very long time with minimal upkeep.  Concrete pavement can last for a very long time with minimal upkeep.

1. Weather and seasonal changes cause roadways to rise or fall slightly.

2. Bituminous material is prepared in a wide range of concentrations.

3. Thin layers of bituminous material are applied with a pressure sprayer to the top course.

4. Asphalt is used directly as a pavement.

5. Asphalt is applied in thin overlays less than 2 cm deep or in layers several centimeters deep.

6. Asphalt is mixed with aggregates for added strength and traction.

Task 10

Translate into English the following word-combinations.

1. Дорожнє покриття, асфальтове покриття, бітумне покриття, тверде покриття, пружне покриття, зміцнення покриття.

2. Нафтопродукти, побічні нафтопродукти, виготовляти з побічних нафтопродуктів.

3. Кам’яне засипання, утрамбоване кам’яне засипання.

4. Зчеплення, сила зчеплення, додаткова сила зчеплення, збільшення сили зчеплення покриття.

5. Бітумний матеріал, розподіляти бітумний матеріал на поверхні дороги.

6. Розпилювач, використовувати розпилювач.

7. Трудомісткий процес.

8. Заповнювач, застосовувати заповнювачі, застосовувати заповнювачі для зміцнення покриття, змішувати із заповнювачами.

9. Робочий стан, підтримувати у робочому стані.

Task 11

Translate the sentences into English using the active vocabulary and the text above.

1. Тверде і пружне дорожнє покриття може складатися з декількох шарів.

2. Ремонтувати асфальтове покриття досить нескладно.

3. Бітумне покриття виготовляють з побічних нафтопродуктів.

4. Покриття з бетону може зберігатися протягом тривалого часу.

5. Покриття з асфальту дешевше, але воно менш зносостійке, ніж бетонне покриття.

6. Бітум служить сполучним матеріалом для утрамбованого кам’яного засипання.

7. Асфальт можна змішувати із заповнювачами для збільшення міцності та сили зчеплення покриття.

Task 12

Speak on characteristic features of flexible and rigid pavements using the information in the text above.