Effect of temperature on soil-water characteristics and hysteresis of compacted Gaomiaozi bentonite

Abstract

Laboratory tests under different constraint conditions were carried out to obtain the soil-water retention curves (SWRCs) of highly-compacted confined/unconfined Gaomiaozi (GMZ) bentonite at 20, 40 and 80 °C, respectively. The effect of temperature on the soil-water characteristics of the highly-compacted GMZ bentonite was analyzed. The results show that the water retention capacity of the highly-compacted GMZ bentonite decreases as the temperature increases under unconfined and confined conditions. At a certain temperature, the constraint conditions have little influence on the water retention capacity of the compacted bentonite at high suction, but the water retention capacity of the confined specimen is lower than that of the unconfined specimen at low suction. Under unconfined conditions, the hysteretic behaviour of the compacted bentonite decreases with increasing temperature. At high suction (>4 MPa), the hysteretic behaviour of the unconfined bentonite tends to increase with the decrease of the suction. In summary, the hysteretic behaviour of the compacted bentonite is not significant.

Keywords

Gaomiaoz / bentonite / soil-water characteristic / hysteretic behavior / nuclear waste repository / water retention capacity / temperature

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