IS 3085

: 1965

Method of Test for Permeability of Cement Mortar and Concrete

CurrentSpecializedTesting MethodMaterials Science · Cement, Concrete, Aggregates and RCC
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This standard outlines the testing method to determine the coefficient of permeability for cement mortar and concrete. It details the preparation of cylindrical specimens, the setup of the permeability cell under applied water pressure, and the calculations based on Darcy's Law once a steady flow state is achieved.

Method of Test for Permeability of Cement Mortar and Concrete

Quick Reference Values
Concrete specimen size (max aggregate 38mm)150 mm diameter x 150 mm height
Mortar specimen size100 mm diameter x 50 mm height
Test pressure appliedUsually up to 15 kg/cm2 depending on design head
Standard age for testing28 days
Key Formulas
K = Q / (A * t * (H/L)) — Coefficient of permeability (Darcy's Law)
Practical Notes
Proper sealing of the specimen using a beeswax and rosin mixture is strictly required to prevent water from bypassing the concrete through the edges (edge leakage).
Do not record measurements until a steady state of flow is achieved; initial water intake is primarily due to capillary absorption rather than actual permeability.
Micro-cracks induced during demolding or curing can drastically alter flow results. Specimens must be handled with extreme care.