BS EN ISO 11058:2010 Geotextiles and geotextile-related products. Determination of water permeability characteristics normal to the plane, without load
BS EN ISO 11058 specifies two test methods for determining the water permeability characteristics of a single layer of geotextile or geotextile-related product normal to the plane:
a) The constant head method;
b) The falling head method.
If the full permeability characteristics of the geotextile or geotextile-related product have previously been established, then for control purposes it can be sufficient to determine the velocity index at a head loss of 50 mm only.
Contents of BS EN ISO 11058:
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Test specimens
4.1 Handling
4.2 Selection
4.3 Number and dimensions
4.4 Condition of specimens
5 Constant head method
5.1 Principle
5.2 Apparatus
5.3 Procedure
5.4 Calculation and expression of results
6 Falling head method
6.1 Principle
6.2 Apparatus
6.3 Procedure
6.4 Calculation and expression of results
7 Test report
Annex A (informative) Determination of the correction factor, RT, to a water temperature of 20 °C
Annex B (informative) Relationship between head loss and flow velocity
Annex C (informative) Velocity index
Annex D (informative) Experimental data and calculations
