We conduct a variety of hydraulic related tests.
These tests are used to determine specific properties of geotextiles that could be considered critical in certain applications.
More detail on tests:
Transmissivity
Scope
This test method covers the procedure for determining the flow rate per unit width within the manufactured plane of geosynthetics under varying normal compressive stresses and a constant head. The test is intended primarily as an index test but can be used also as a performance test when the hydraulic gradients and specimen contact surfaces are selected by the user to model anticipated field conditions.
Test Method
The flow rate per unit width is determined by measuring the quantity of water that passes through a test specimen in a specific time interval under a specific normal stress and a specific hydraulic gradient. The hydraulic gradient(s) and specimen contact surfaces are selected by the user either as an index test or as a performance test to model a given set of field parameters as closely as possible. Measurements may be repeated under increasing normal stresses selected by the user.
Test Standards
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Permeability
Scope
There are two test methods for determining the water permeability characteristics of a single layer of geotextile or geotextile-related product normal to the plane: the constant head method and the falling head method.
Test Method
A geotextile specimen is clamped within a cylindrical permeameter. A selected differential head of water is applied across the geotextile. Flow is initiated normal to the plane of the geotextile and the quantity discharged recorded. Permeability = Q / iAT
Test Standards
SANS 10221
ISO 11058
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View this test in action below.
LTGR
Scope
This test method covers a performance test applicable for determining the soil-geotextile system permeability and clogging behaviour for cohesion-less soils under unidirectional flow conditions.
Test Method
A soil sample is reconstituted over a geotextile filter in a clear cylindrical permeameter. Various head differentials are applied across the soil / geotextile system. Manometer ports at fixed positions along the profile of the system allow for measurement of flow rates and differential heads. This information can be used to determine the Hydraulic Gradient across a soil / geotextile system.
Test Standards
Generally in accordance with ASTM D 5101
Throughflow
Scope
There are two test methods for determining the water permeability characteristics of a single layer of geotextile or geotextile-related product normal to the plane: the constant head method and the falling head method.
Test Method
Flow rate = ℓ/m²/sec
Test Standards
SANS 10221
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View this test in action below.
Flow Velocity
Scope
There are two test methods for determining the water permeability characteristics of a single layer of geotextile or geotextile-related product normal to the plane: the constant head method and the falling head method.
Test Method
Flow Velocity = VR/AT
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This test is performed in the same way as the Permeability Test. View the test in action below.
Test Standards
Pore Size
Scope
This standard sets out the method for determining the pore-size distribution and apparent opening size (AOS) of a geotextile using the dry sieving method and, in consequences, the equivalent opening size (EOS).
Test Method
A sample of geotextile is clamped at the bottom of a steel panier using a stainless steel mesh as a support. A selection of glass beads of various designations is placed on top of the geotextile. The panier is repeatedly dunked in a trough of water and withdrawn allowing for the panier to drain. The test is conducted for a minimum of 1000 cycles. The glass beads that pass through the geotextile are collected and the particle size distribution recorded.
Test Standards:
AS 3706-07
CAN / CGSB 148.1 No 10