This standard specifies the laboratory method for determining the water content, porosity, and density (bulk, dry, and saturated) of rock material. It provides detailed procedures for specimen preparation, testing using equipment like ovens and pycnometers, and the formulas required for calculating these fundamental physical properties.
Method of test for laboratory determination of water content, porosity, density and related properties of rock material
Quick Reference Values
Oven drying temperature105 ± 5 °C
Minimum specimen mass for density test50 g
Balance sensitivity0.01 percent of the specimen mass
Specimen saturation period24 to 48 hours
Weighing accuracy for mass0.01 g
Volume measurement accuracy0.1 cm³
Key Formulas
Water Content (w) = [(Ms - Md) / Md] * 100
Bulk Density (ρ) = Md / V
Porosity (n) = [ (Vv / V) ] * 100 = [ (1 - ρ / ρs) ] * 100
Void Ratio (e) = Vv / Vs = n / (1-n)
Practical Notes
Ensuring complete saturation (24-48 hr soaking) and complete drying (to a constant mass at 105°C) is critical for accuracy.
When using the water displacement method for volume, ensure the sample is surface-dried (SSD condition) without losing internal moisture before weighing.
The accuracy of the weighing balance is paramount, especially for low-porosity rocks where the mass difference between saturated and dry states is minimal.