What is the effect of stabilised subbase to crushed stone base?

[defg]

Curently I'm working with the Contractor to construct a road to bitumen standards-surface dressing.According to the design and drawings indicate that the subbase shall be of stabilised 200mm thick,and the base ccourse shall be ofstabilised(C2)of 150mm thick.Traffic class in that area is TCL10(3-10)E80millions.Due to unavailability of suitable materials in this area for C2.The Contractor has requested to use crushed stone(CRR)materials are the area is full of granite rocks.The Consultant issue his comments that if the Contractor wants to use crushed stone(CRR)he should use 200mm thick of crushed stone to be compacted into two layers say 100mmthick and inturn 100mmthick to make a total of 200mm thick.Is it a practical way of constructing a road?Because a road constructed of crushed stones(CRR)is more stronger than stabilised base course.On my opinion the thickness will remain same 150mm thick.

 

[teeman]

You might want to post this question in the Civil/Environmental Engineering forum.

 

[VersaK]

asphalt roadway design reveolves around structural number; once you have the design structural number, any combination of asphalt, base, and stabilized subgrade (each having a unique Sn coefficient) thicknesses can be used to get that Sn, subject to the limits of material availability and cost.