This standard details the laboratory method to determine the relationship between moisture content and dry density of soils using light compaction (Standard Proctor test). It is used to identify the Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) crucial for field compaction control.
Describes the standard Proctor test for determining the moisture-density relationship of soils.
Quick Reference Values
Weight of Rammer2.6 kg
Height of Drop310 mm
Number of compacted layers3
Blows per layer (1000 cc mould)25
Blows per layer (2250 cc mould)56
Standard mould volume1000 cc
Key Formulas
Bulk Density (γ_b) = (Mass of compacted soil) / (Volume of mould)
Dry Density (γ_d) = (100 * γ_b) / (100 + w), where w is moisture content in %
Practical Notes
Ensure soil is thoroughly mixed with water and allowed to cure in airtight containers before testing to ensure uniform moisture distribution.
Reusing soil for consecutive tests is not recommended if the soil contains fragile grains that break down and alter gradation during compaction.
The standard 1000 cc mould is used for fine/medium soils, while the 2250 cc mould is required for coarser soils containing gravels.