WATER RETENTION CHARACTERISTICS OF HIGHLY COMPACTED SAND-GMZ01 BENTONITE MIXTURES AT FIXED TEMPERATURES

Pure bentonite mixes with quartz sand can effectively improve the thermo conductivity, mechanical strength and long-term stability of the mixture. It also can reduce the construction cost of the engineering barrier system. Meanwhile, it may make changes of the water retention property of the mixture. This paper uses osmotic technique and vapor equilibrium technique and tests water retention characteristics of highly compacted GMZ01 bentonite-quartz sand mixtures at different temperatures(20℃, 40℃ and 60℃)under confined conditions. Results show that, for given suction and constant volume, water content of GMZ01 bentonite-sand mixtures decreases as temperature increases. But the changing rate depends on suction level. For low suctions, degree of saturation is higher than 1,which may result from the higher density of the absorbed water. Water retention characteristics of GMZ01 bentonite-sand mixtures fitted by the revised Wan Min model are consistent with the measured ones.