This Standard sets out the method for determining the transmissivity of geotextiles by measuring the rate of flow of water in the plane of the fabric under a constant head using a radial flow apparatus.*

NOTES:

1 Transmissivity is the preferred measure of the in-plane water flow capacity of a geotextile.

2 This method may have limitations for materials where the transmissivity varies with direction of flow.

3 The transmissivity of the fabric varies with other contact surfaces, compressive stress and hydraulic gradient.

* This method is based on RILEM SM–10, Synthetic membranes—Geotextiles. Transmittivity.