Figure 5
Time evolution of a pre-cut (45°) gypsum sample during its partial dehydration while under triaxial conditions at the TOMCAT beamline (SLS). Couples (a, b), (c, d), (e, f) and (g, h) show the gradual dehydration with a view at the sample scale and local scale on the top [(a), (c), (e) and (g)] and bottom [(b), (d), (f) and (h)] rows, respectively. The scan interval is 6 min [30 min between (c), (e) and (g)]. The position of the cut plane at 45° is highlighted by the red arrows and dashed lines when poorly visible. Phases present are gypsum (dark grey), bassanite (light grey), pores (black) and celestite (white) and are indicated by the yellow arrows. Tomography volumes were acquired with a sample–detector distance of 500 mm. |