This standard prescribes the laboratory testing methods for determining the water absorption, apparent specific gravity, and porosity of natural building stones. These properties are critical for engineers to assess the durability, density, weathering resistance, and overall quality of stones used in masonry and monumental construction.
Method of test for determination of water absorption, apparent specific gravity and porosity of natural building stones
Quick Reference Values
Specimen dimensions50 mm cubes or cylinders of 50 mm diameter and 50 mm height
Oven drying temperature105 to 110 °C
Water immersion duration24 hours
Water temperature during immersion20 to 30 °C
Minimum number of test specimens3
Key Formulas
Water Absorption (%) = [(W2 - W1) / W1] × 100 (where W1: dry weight, W2: saturated weight)
Apparent Specific Gravity = W1 / (W2 - W3) (where W3: weight suspended in water)
Porosity (%) = [(W2 - W1) / (W2 - W3)] × 100
Practical Notes
Ensure test specimens are completely dry by heating in an oven to a constant mass before recording the initial dry weight (W1).
Carefully remove all trapped air bubbles from the specimen surface when recording its weight while suspended in water (W3).
Wipe off surface water with a damp cloth immediately before recording the saturated weight in air (W2) to ensure true saturated mass is measured without excess surface water.