AASHTO R 74-16 (2020)

This method describes the wet preparation of soil samples, as received from the field, for mechanical analysis and the determination of soil constants.

Method A provides for drying the field samples at a temperature not exceeding 60°C (140°F), making a wet separation on the 0.425-mm (No. 40) sieve and drying to a temperature not exceeding 60°C (140°F). Method B provides that the field sample shall be kept at a moisture content equal to or greater than the natural moisture content. Samples of such soil should be shipped to the laboratory in sealed containers and not allowed to dry out before testing. If no procedure is specified, Method A shall govern.

This standard was formerly designated as test method T 146.