Swelling of MX-80 bentonite in a narrow tube

This dataset consists of the results of 16 bentonite swelling experiments. The samples (d = 1.0 cm, h = 2.0 cm) were made by compacting MX-80 bentonite into vertical aluminum tubes. The bottom end of the samples was fixed while the top end was able to move. The experiments were started by pouring simulated groundwater (0.1 M NaCl) onto the samples. The swelling process of each sample was monitored four days using a developed X-ray imaging method. Eight different combinations of initial dry density (1.40–1.80 g/cm3) and water content (12–24%) values with two repetitions for each case were used in the experiments. The method yields the partial density profiles of bentonite and water, and the deformation of the samples in the axial direction as a function of time. The method was validated by slicing the samples at the end of the experiments and measuring the partial densities of bentonite and water in the slices by oven drying. In addition, a separate sedimentation test was performed to ensure that the added tracer particles, needed in the deformation measurement, follow the solid material also in the most dilute parts of the samples. The experimental setup in this study mimics a scenario where bentonite, planned to be used as a buffer material in a nuclear waste repository, swells into a rock fracture filled by groundwater.  For more information see:   Harjupatana, T., Miettinen, A., & Kataja, M. (2022). A method for measuring wetting and swelling of bentonite using X-ray imaging. Applied Clay Science, 221, 106485. https://doi.org/10.1016/j.clay.2022.106485