20.2.1. Contact Pressure

Try these first

1. 1.

   What is contact pressure?

   Hint

   Think about pressure and the connection between the tire and pavement.

2. 2.

   Why is wheel load important in pavement design?

   Hint

   Consider the weight that the pavement must support.

3. 3.

   What is the main influence of contact pressure on pavement design?

   • It affects asphalt viscosity.
   • It determines the stress distribution of the pavement.
   • It has no effect on design.

   Hint

   Consider the relationship between weight and pavement longevity.

4. 4.

   True or False: Moving loads at higher speeds cause more pavement damage than at lower speeds.

   • True
   • False

   Hint

   Think about stress distribution related to speed.

5. 5.

   A vehicle with a single axle carrying a weight of 40 kN has a tire pressure of 200 kPa. Calculate the contact area and discuss how this could impact pavement design preferences.

   Hint

   Use the contact pressure formula to find the area.

6. 6.

   Consider a road designed for heavy truck traffic with regular speeds of 20 km/hr. Discuss how this design might change if the trucks were moving at just 5 km/hr.

   Hint

   Reflect on how speed changes affect load impacts.