PERMITTIVITY

Cross Permeability Test Apparatus

EKE 248:

Permeability of a geotextile must be substantially greater then that of the protected soil, so that water can pass freely from the soil through the fabric without build-up of hydrostatic pressure, A high value of the permeability  of the geotextile also infers that partial clogging will not reduce the permeability. Both constant and falling head parameters  are generally used for  measuring normal permeability know as permittivity. Permeability is defined as the volumetric rate of flow of water per unit cross sectional area under unit hydraulic head across the plain of the geotextile ATM D4491 specifies permeability test using constant head and falling head permeameters, the constant head test is carried out using a head of 50 mm of water.

Specimen diameter is 100 mm

Essential Accessories
EKE 13111: Overhead Tank
EKE 24801: Loading Unit, Dead Weight Type, 300 kPa capacity

In-plane  Permeability Test Apparatus

EKE 249:

This test is necessary for drainage applications, the permeameters can be of parallel flow or radial flow type.  In either case, flow occurs along the plane of the permeameters, in the apparatus. Flow occurs radialy outwards, form a central hole to the periphery of a circular specimen, the in plane permeability as know as transmissivity which is defined as the volumetric rate of flow per unit width of geotextile and unit hydraulic head.

Specimen diameter is 100 mm 110 its capacity

Essential Accessories
EKE 13111: Overhead Tank
EKE 24801: Loading Unit, Dead Weight Type, 300 kPa capacity

Long Term Flow Test Apparatus

EKE 250:

The test for permissivity  and transmissivity help in comparing one fabric to another, but gives no indication of the hydraulic behavior of the composite soil – fabric system. Under steady  state and reversing flow conditions, fabric clogging or binding causes a decrease in water flow rate and corresponding increase in hydraulic  head loss through the geotextile . When the potential for fabric clogging is significant clogging resistance of  filter fabrics should be evaluated to ensure adequate long term filter performance. As the clogging is highly soil dependent, soil fabric permeability test is suggested to determine the long term flow capability of a geotextile

Specimen Diameter : 100 mm
Mould for Compaction of Soil : 10 cm dia. x 11.2 cm high
Head of water : Upto 37.5 cm

Essential Accessory 
EKE 13111: Overhead Tank

Gradient Ratio Test Apparatus
 
EKE 251:

The US Army of Engineers established a direct measure of geotextile clogging potential. They defined it as gradient ratio which is the ratio of hydraulic gradient through the geotextile plus 25.4 mm of the soil to that of hydraulic gradient through the adjacent 50.8 mm of the soil.

It is determined after 24 hours of flow.
Specimen Diameter : 100 mm
Mould for Compaction of Soil : 10 cm dia. x 11.2 cm high
Head of water : Upto 37.5 cm

Essential Accessory 
EKE 13111: Overhead Tank