Temperature Effects on the Swelling and Bentonite Extrusion Characteristics of GCLs

摘要

This investigation was conducted to evaluate effects of temperature on swelling and bentonite extrusion properties of GCLs. The swelling characteristics were determined using standardized test procedures and extrusion characteristics were determined using a new test method developed by the authors. Tests were conducted on a conventional medium-weight woven/nonwoven GCL. The range of test temperatures was 2 to 98°C (swelling tests) and -5 to 100°C (extrusion tests). The extrusion tests were conducted under stresses between 100 and 400 kPa and moisture contents between 50 and 150%. Temperature had significant effects on both swell and extrusion. The swell index ranged from 21 mL/2g at 2°C to 36.5 mL/2g at 98°C, with the largest increase occurring from 20 to 40°C. The amount of extrusion ranged from nearly 0 to 40.5 g/m2 with generally decreasing extrusion with temperature from 2 to 100°C. At a given temperature, extrusion increased with increasing stress and moisture content.