Unit 5

Question 1

Provide the functions of paved roadways (6).

Answer 1

1. Carries vehicle loads that unpaved roads cannot.
2. Provides drainage away from driving surface.
3. Add smoothness to allow higher vehicle speeds and greater “drivability”
4. Provide skid resistance for vehicles
5. Provides a relatively dust-free surface.
6. High-speed surface

Question 2

Define the following:
1. Aggregate
2. Bitumen
3. Asphalt pavement
4. Concrete pavement

Answer 2

1. Aggregate - natural sand, gravel & stone
2. Bitumen - petroleum residue (naturally occurring or from distillation of crude oil)
3. Asphalt pavement = aggregate + asphalt + air. It has less construction cost but needs greater maintenance i.e. has a shorter lifespan. Common type is Hot mix asphalt.
4. Concrete pavement = aggregate + cement + water + air

Question 3

Draw and label the following:
1. Single seal
2. Double seal
3. 1 1/2 seal
4. Cape seal
5. Slurry seal
6. Sand and grit seal
7. Geotextile seal
8. Split seal
9. Choked seal
10. Inverted double seal
11. Graded aggregate seals

Answer 3

See notes