Temperature effects on volume change of bentonite sand liner

Ahmad Niaz Sinha and Osamu Kusakabe

Bentonite-sand (B:S) mixture is used as soil liner to protect seepage against contaminant migration. Experiments were conducted to study the volume change of bentonite-sand mix due to high temperature effects. Bentonite-sand (B:S) mix with dry weight ratio of 10% to 90% (10:90) was used as an ideal mixture in this experimental program. Volume change of bentonite-sand mix in normally consolidated (NC) stress condition was investigated at high temperatures (45˚ and 75˚C). Volume changes were measured by measuring the void ratio change at high temperatures using a modified consolidation cell. Experimental results show that volume change was more affected by high temperature and the initial hours of heating play the most significant role. It was found that pore water pressure change due to temperature change is affected by high temperature, which in turn causes the void ratio change. Such studies could be helpful to incorporate design modifications to improve the liner behaviour.