The standard is divided into three specific procedures, each tailored to different soil types and engineering needs:
When performing these tests, lab technicians typically report several critical metrics used in foundation design: astm d454621 pdf
: This procedure uses "undisturbed" or intact samples taken directly from natural deposits or existing fill. It measures how a specific point in the soil profile will react to wetting while under its in-situ vertical stress. The standard is divided into three specific procedures,
: Unlike the first two methods, Method C focuses on what happens after the soil has already swelled or collapsed. It measures how much more the soil will compress when additional structural loads (like a new building) are applied to the already-wetted ground. Key Parameters Measured astm d454621 pdf