Question

9.                        and                              are two mechanisms that cause rutting.

10. In a typical conventional asphalt concrete pavement, keeping all other factors constant,

1. Increasing the HMA thickness typically ________ the surface deflections.

2. Increasing the HMA modulus typically ____   ___ the surface deflections.

3. Increasing the subgrade modulus typically _ _      the surface deflections.

11. The best way to characterize traffic for pavement design using a mechanistic-empirical design procedure is to use

12. List six of the factors used by the AASHTOWare ME Pavement Design in calculation of axle counts in the design lane.

Answer 1

i) Decrease

If HMA thickeness is increased deflection will decrease.

ii) Decrease

Increase in HMA modulus will increase stiffness which will further reduce surface deflection.

iii) Decrease

Increase in the subgrade modulus typically decrease the surface deflection.

iv) Full Axle load

The best way to characterize traffic for pavement design using a mechanistic-empirical design procedure is to use Full Axle load traffic spectrum.

v) Six factors are

• Base year truck traffic volume
• Traffic Volume adjustment
• Axle load distribution factor
• Number of axles per truck
• Wheel base
• Axle load configuration