What is the method number for the Standard Proctor?

• A. AASHTO T-99
• B. FM 1 T-180
• C. ASTM D698
• D. AASHTO T-121

Answer: (A)

The key idea is recognizing which test method defines the Standard Proctor, i.e., the procedure that uses the standard (lower-energy) compaction to chart moisture versus dry density.

The standard method used for the Standard Proctor in this context is the AASHTO T-99 procedure. It specifies the test setup and energy: a 5.5-pound rammer dropped from 12 inches into a mold to compact soil samples at several moisture contents, so you can determine the maximum dry density and the corresponding optimum moisture content. This is the baseline energy level for Proctor testing, distinguishing it from the higher-energy Modified Proctor.

The other options relate to different standards or higher-energy procedures. AASHTO T-180 refers to the Modified Proctor with greater compaction energy, while ASTM D698 is the ASTM designation for a standard Proctor test in ASTM terminology. AASHTO T-121 is a different test procedure not used for the Standard Proctor.