Which option is NOT a standard method for verifying field density after compaction?

• A. Nuclear density gauge
• B. Sand cone test
• C. Core sampling for density
• D. Visual inspection of surface uniformity

Answer: (D)

Determining field density after compaction relies on objective measurements that quantify how compacted the soil is in place. The nuclear density gauge provides a quick, in-situ density reading along with moisture content, making it a standard method. The sand cone test uses a calibrated volume of sand to replace a portion of soil, allowing calculation of dry density directly in the field. Core sampling for density involves extracting a cylindrical core from the compacted lift and calculating its density from mass and volume, another accepted approach. Visual inspection of surface uniformity looks at appearance or roughness but cannot quantify density or reveal density variations beneath the surface; it’s subjective and not a reliable method for verification. Hence visual inspection is not a standard method for verifying field density after compaction.