AASHTO T 220-66 (2018)

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