Why is the capillary water transmission rate important?

It indicates the stone's vulnerability to rising dampness, freeze-thaw damage, and efflorescence caused by salt crystallization.

What is the standard oven-drying temperature for the stone specimens?

The specimens must be dried at a temperature of 105 ± 5 °C until they achieve a constant mass.

How deep should the stone be placed in the water tray?

Only the base of the specimen is immersed to a shallow depth (typically 3 to 5 mm) to allow pure capillary action without applying hydrostatic pressure.

IS 4121

: 1967

Method of test for determination of water transmission rate by capillary action through natural building stones

CurrentSpecializedTesting MethodMaterials Science · Stones

Download PDF BIS Portal Google

This standard lays down the procedure to determine the rate of water transmission through natural building stones via capillary action. It is essential for evaluating a stone's susceptibility to rising dampness, porosity, and long-term weathering resistance.

Method of test for determination of water transmission rate by capillary action through natural building stones

Quick Reference Values

Drying temperature105 ± 5 °C

Accuracy of weighing balance0.01 g

Immersion depth of specimen base3 to 5 mm

Key Formulas

Water transmission rate = (M2 - M1) / (A * t) — Rate of water absorbed per unit area over time

Practical Notes

Testing should be performed relative to the natural bedding plane of the stone, as capillary absorption is often highly anisotropic.

Ensure the test environment is free from drafts and direct sunlight to prevent premature evaporation from the stone's upper surfaces.

The stone must reach a constant mass during the oven-drying phase to ensure all residual moisture is eliminated before the test begins.