Soil

Optimum moisture content for compaction (range in %)

Clay sands, sand-clay mix

10-11

Sand-silt-clay mix with plastic, silt + clay fraction

11-15

Inorganic silt, clayey silt

12-24

Inorganic clay

12-24

Organic silt

21-33

Inorganic clay, highly plastic

19-36

Organic

21-45