What is a standard proctor used in?

• A. Embankment and structure back fill materials.
• B. Subgrade preparation only.
• C. Riprap selection.
• D. Asphalt mix design.

Answer: (A)

The standard Proctor test is a lab step used to determine how a soil densifies with moisture and compaction energy, giving the maximum dry density and the optimum moisture content for a soil’s compaction. This information is essential for fills used in embankments and around structures, because it tells you how wet the soil should be and how much compaction effort to expect to reach the required density in the field. It’s not the method you’d use for selecting riprap sizes, designing asphalt mixes, or solely for subgrade preparation, which involve different tests or criteria.