Polycrystalline rock salt’s compression is a function of applied stresses, exposure duration to the applied stresses, ambient temperature, and water content. Rock  salt’s compressional behavior under different conditions and its  effects on the specimens’  mechanical properties have been investigated in  the liter- ature. However,  the one-dimensional (1D)  compression behavior of polycrystalline rock salt at various water contents and how the specimen’s  compression at different water  contents further affects its physical and mechanical properties are not fully  understood yet.  In this study, polycrystalline rock salt specimens were prepared under nominally dry and wet conditions and some of the dry and wet spec- imens were annealed after the preparation. The  relationship between the porosity of the specimens and the logarithm of  the applied axial stresses during the 1D  compression was found to follow a  linear relationship after reaching unique critical porosities of  32%  and 37% for  the dry and wet specimens, respectively. Unloading and reloading the specimens did  not result in any major changes in the porosity of the specimens. The  specimens compressed under wet condition showed an average final porosity of

2.6% compared to 6.9% for  the dry specimens. The  dry and wet specimens that were annealed after the compression exhibited a  lower porosity in  comparison to the dry and wet specimens, respectively. Unconfined compression experiments on  the specimens showed dry and wet specimens possess aver- aged unconfined compressive strengths (su ) of 64.3 and 16.2 MPa,  respectively. Annealing decreased su

of the dry specimens to 39.6 MPa  and increased su  of the wet specimens to 41  MPa.

  2021 Institute of Rock  and Soil  Mechanics, Chinese Academy of Sciences. Production and hosting by

Elsevier B.V. This  is an  open access article under the CC BY-NC-ND license (http://creativecommons.org/