AASHTO T 220-66 (2018)

This method provides for the determination of the unconfined compressive strength of soil-lime stabilization mixtures.

Note 1 - Generally, an unconfined compressive strength of 690 kPa (100 psi) is satisfactory for the final course of base construction, and it is desirable that materials for such courses contain a minimum of 50 percent plus 0.425-mm (No. 40) material before treatment. Various soil materials may be treated for subbase, and, in such cases, the minimum suggested unconfined compressive strength is 345 kPa (50 psi).