ABSTRACT
In this study, triaxial permeability and free swell tests were performed on a geosynthetic clay liner (GCL) that had Ca bentonite and was enhanced with the biopolymer, sodium carboxymethyl cellulose (Na CMC) with a concentration of 0.25, 0.5, 1, 2, 5 and 10% by dry mass respectively. The GCL specimens were permeated with a simulated acidic leachate at a temperature of 20, 40, 60 and 80°C. Test results indicated that the temperature increase leaded to an increase in both the permeability and the swell index. As the temperature was increased from 20 to 80°C, the permeability increased by up to 1.5 orders of magnitude. Furthermore, 2% Na CMC was found to be the optimum concentration in the bentonite component of the GCL. 2% Na CMC addition caused the permeability to decrease from 9.81 × 10−7 to 2.24 × 10−8 m/s and the swell index to increase from 8.5 to 13.5 ml/2g at 80°C.
