Freezing-Thawing Cycles of Saturated Sand Sample

Freezing and thawing cycles in laboratory were studied. Freezing-thawing cycles were carried out in the laboratory on fully saturated packed sand sample (15 cm in diameter and 20 cm in height). Series of freezing-thawing cycles were conducted with newly designed experimental setup. The setup consisted of inner plastic tube covered on its sides and outer plastic tube. The column sample was placed into the precisely controlled freezer chamber. The top of the sample was covered by an aluminum lid. Initially the sample was equilibrated at +10 °C then the temperature inside the chamber was changed to -10 °C. The inner temperature of the sample was monitored in three depths by thin temperature sensors (109 SS, Campbell Scientific, USA) horizontally inserted into the sample. The experiment aims to provide information on freezing dynamics and thermo-mechanical changes during the freezing and thawing cycles. Horizontal gradient within freezing cycle was monitored. The data were compared with simulations obtained by a numerical model (Žák et al., 2013). The model is based on the heat balance within the sample assembly and a modified heat equation for the porous medium temperature allowing for the phase transition below the freezing point depression.