Question 1
Assess the importance of the thickness of the bituminous layer and road base on the pavement fatigue life.
Clarification:
You can use Sensitivity analysis
Question 2
For the pavement structure considered, develop an overlay design chart based on the following assumptions:
- The minimum overlay thickness is 5 cm and the maximum is 20 cm.
- The effective modulus of the surface layer (existing bituminous layer + overlay) may vary with regard to the existing condition and the materials to be used with typical values of 1000, 2000, 3000 and 5000 MPa.
- The subgrade strength is considered equal to the average value found in question 3 above.
- The performance of the overlaid pavement is described in terms of fatigue only.
- The expected traffic will not exceed 50 msa.
Clarifications:
Question 3
Compare the results found under Question 2 with those from RN31 and the AASHTO method. For any data that is not given you should make your own justifiable assumptions.