Field Density Test (FDT)

Field Density Test (FDT)

Nattest's Field Density Test (FDT) is an important in-situ geotechnical method that assesses the level of compaction accomplished in the field during construction. It gives a direct measurement of soil density in its natural or compacted form, which is crucial for determining whether compacted soil layers meet technical criteria. The FDT is commonly used in earthworks, road construction, and infrastructure development to assure the stability, performance, and longevity of subgrade and backfill materials. The Sand Cone Method (ASTM D1556 / BS 1377-9) and the Nuclear Density Gauge Method (ASTM D6938) are two methods for taking precise, repeatable measurements on-site. Effective compaction handling with FDT helps to avoid future settlement, increases structural support, and lowers maintenance costs by ensuring that the foundation and pavement layers operate correctly.

Advantages of FDT:

• Immediate and accurate compaction evaluation
• Ensures conformity with engineering standards.
• It prevents settling and structural collapse.
• Supports quality assurance in road and foundation construction.
• Applicable to cohesive and compacted soils