Investigation of the hydro-mechanical behaviour of GMZ bentonite pellet mixtures

Properties of Granulated Bentonite Mixtures for Radioactive Waste Disposal: A Review

“…Recently, Kunigel GBM was used to fill the voids between the prefabricated engineered barrier system module (PEM) and tunnel wall at Horonobe Underground Research Laboratory (URL), in Hokkaido, Japan [14]. The pellets and pellet/powder mixtures of two other bentonite materials, FoCa (France) and GMZ (China), have been used as either buffer or gap-filling materials in the RESEAL project [4] and mock-up tests in China [15], respectively. The basic properties of these materials are presented in Table 1 [16].…”

“…The water retention characteristics and hydraulic conductivity of GBM and pellet mixtures were examined in the laboratory by various researchers [8,9,12,13,15,26,[36][37][38][39]. The tested materials, methodology, and the experimental conditions are summarized in Table 3.…”

“…The water retention curves of Serrata and GMZ pellet mixtures under constant volume conditions 3 [15,36]. At high suction, both materials have comparable water retention properties.…”

“…On the other hand, the water contents of tested materials varied depending on the packed void ratio at lower suction rates. A possible explanation is that the water retention curve is independent of the void ratio [36] and initial conditions such as DD and fabrics at high suction [15]. Water is stored within the pellets as intrapellet water, and the water content of the sample is conditioned by material characteristics, including specific surface of clay and the soil microstructure as well as the pore fluid chemistry.…”

“…The hydraulic conductivity of a porous medium is affected by various factors including grain size distribution, particle structure, water content (or degree of saturation), density, and void ratio [40]. Figure 4 [8,9,12,13,15,26,37,38] presents the effects of DD on the saturated hydraulic conductivities of GBM and pellet mixtures. The plots show that hydraulic conductivities decreased with increasing DD.…”