CBR for base-course in roadworks

[Emilian]

I would like to find out if an unsoaked CBR value can exceed 100% for a base-course material: maximum size aggregate 37.5mmm and having a continuous grading curve, sourced from a borrow pit.
Thanks for your help.

 

[fattdad]

Yes, it's possible. After all CBR is a ratio (California Bearing Ratio) and is based on the subgrade response of a reference aggregate material. If your aggregate material has a greater strength then the reference aggregate material, then the subgrade support will be greater. One word of caution: What is your justification for using unsoaked CBR value? There is a potential for your subgrade strength to be affected by the dry strength of the compacted sample.

f-d