Rigid Pavement

Rigid (concrete) pavements are made from a mix of portland cement and aggregate. They have a long life and require little maintenance. Concrete is generally laid as a single thick layer directly over a base course. For heavily traveled roads concrete layers can range in thickness from 20 to 36 cm (8 to 14 inches). Concrete is usually laid in long sections or slabs of varying length. Metal bars or dowels inserted into the slabs help connect the joints where one slab ends and another begins.

Concrete is a strong material and can withstand compression, but it has poor tensile strength. When the ground underneath expands and contracts from seasonal or weather changes, the concrete becomes prone to cracking. Cracks can occur at or near the joints where concrete slabs meet or on the slabs themselves. Deep cracks can allow the broken concrete slabs to move upward or downward, creating an uneven road surface.

Reinforced concrete contains steel bars or mesh imbedded within the concrete layer. The steel helps hold concrete together over time, even if cracks occur.

Unreinforced concrete may be used when cost is a factor, or where weather conditions are milder. Unreinforced slabs have several shallow grooves cut into them, allowing the concrete to crack at defined points. The cracked slabs are kept in place by pressure and by the grainy texture of the concrete itself.

Task 5

Restore the sentences. Consult the text above.

1. Rigid pavements are made from.…

2. The thickness of concrete layers ranges….

3. Reinforced concrete contains.…

4. …/holds concrete together over time.

5. Сoncrete is prone to.…

6. Deep cracks in concrete slabs result in ….

7. Cracked unreinforced slabs are kept in place owing to.…

8. …. require little maintenance.

Task 6

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

1. What are rigid pavements made from?

2. How do concrete layers usually range in thickness?

3. When do concrete pavements become prone to cracking?

4. What makes road surface uneven?

5. What does reinforced concrete contain?

6. What holds reinforced concrete together?

7. What keeps unreinforced slabs in place when they go cracking?

Task 7

Find in the text opposites of the following words and word-combinations. Give their Ukrainian (Russian) equivalents.

1. Upward;

2. reinforced concrete;

3. flexible pavement;

4. even surface;

5. thin;

6. under;

7. outside;

8. to expand.

Task 8

Fill in prepositions if necessary. Consult the text above.

1. Metal dowels inserted .…the slabs hold them together.

2. Concrete layers range .… thickness .…20 …36 cm.

3. Cracks often occur …. the joints where concrete slabs meet or …. the slabs themselves.

4. Concrete becomes prone …. cracking due to seasonal or weather changes.

5. Shallow grooves cut …. unreinforced slabs, allow the concrete to crack .… defined points.

6. Steel bars are imbedded …. the concrete layer.

7. The cracked slabs are kept .… place .… pressure and .… the grainy texture .… the concrete itself.

Task 9

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

Model

Concrete becomes cracked due to seasonal or weather changes.  Concrete became cracked due to seasonal or weather changes.

1. Metal bars between the concrete slabs hold them together.

2. Concrete is laid as a single thick layer directly over a base course.

3. Concrete pavements don’t require much maintenance.

4. Cracked slabs remain in place because of pressure and due to the grainy texture of the concrete.

5. Cracks occur at the joints where concrete slabs meet or on the slabs themselves.

Task 10

Translate into English the following word-combinations.

1. Бетон, армований бетон, неармований бетон, структура бетону, зерниста структура бетону.

2. Розтріскування, піддаватися розтріскуванню.

3. Тиск, витримувати тиск.

4. Стикування, пази для стикування, мати пази для стикування.

5. Розрив, міцність на розрив, низька міцність на розрив.

6. Межа, варіюватися у межах.

7. Довжина, перемінна довжина, мати перемінну довжину.

8. Товщина, товщина бетонного покриття.

9. Плита, бетонна плита, структура бетонної плити.

10. Стикувати, стикувати бетонні плити.

11. Прут, металевий прут, установлювати металеві прути.

12. Зносостійкість, висока зносостійкість, мати високу зносостійкість.

13. Тріщина, глибока тріщина, глибокі тріщини у бетонних плитах.

Task 11

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

1. Бетонні покриття характеризуються високою зносостійкістю.

2. Товщина бетонного покриття варіюється у межах від 20 до 36 сантиметрів.

3. Стрижні арматури збільшують міцність бетонної плити.

4. Бетон витримує тиск, але має низьку міцність на розрив.

5. Бетон може розтріскуватися, оскільки грунт розширюється і стискується при різних температурах навколишнього середовища.

6. Глибокі тріщини руйнують структуру бетонних плит.

7. Бетонні плити, що мають глибокі тріщини, піднімаються і опускаються, створюючи нерівності на дорогах.

Task 12

Speak on the properties of reinforced and unreinforced concrete.