This standard covers laboratory and field methods for determining the water (moisture) content of soils. It establishes the oven-drying method as the standard reference test while detailing rapid alternative methods like the sand-bath and alcohol methods for field applications.
Specifies methods for determining the water content of soil samples, essential for various geotechnical calculations.
Quick Reference Values
standard oven drying temperature105 to 110 °C
oven temperature for organic or gypsum soils60 to 80 °C
minimum specimen quantity fine grained30 g
typical oven drying time16 to 24 hours
Key Formulas
w = ((W2 - W3) / (W3 - W1)) × 100 — Water content percentage (w), where W1=container, W2=container+wet soil, W3=container+dry soil
Practical Notes
For soils containing organic matter or gypsum, oven temperature must be strictly restricted to 60°C - 80°C to prevent decomposition or loss of water of crystallization.
Samples must be cooled in a desiccator before final weighing to prevent the dry soil from absorbing atmospheric moisture.
The sand-bath and alcohol methods are meant for rapid field checks and should not be used as official reference tests or applied to highly organic, calcareous, or clayey soils.