Test itemsTest methodTechnical indicatorSwell indexASTM D 5890≥ 24mL/2gFluid lossASTM D 5891≤ 18mLBentonite quality per unit areaASTM D 5993≥3.6kg/m2Tensile strengthASTM D 4632≥400NPeeling strengthASTM D 4632≥65NIndex flowASTM D 5887≤1 × 10-8m3/m2/secPermeabilityASTM D 5887≤5 × 10-9cm/secGCL hydrated intemal shear strengthASTM D 5321≥24kPa typicalGCL is made of 3layers,upper is PET non-woven geotextile,in the middle is bentonite,the carrier is PP woven geotextile,then needle punched together. they are used in landfill caps and for above ground tank farms,as well as within various other containment structure. such as dams,canals ,ponds, rivers and lakes . they are also used for waterproofing of building and other similar structure.