Analysis of Strains in Baked Clay Based Materials During Freezing and Thawing Cycles

Abstract

In order to better understand the freezing mechanisms of baked clay materials, the strains of two types of tiles were observed during freezing and thawing cycles. The saturated medium began to contract, at first practically linearly, then water froze progressively between 0 and -10°C, and finally contraction became linear again for lower temperatures. Calorimetric measurements showed that the heterogeneous nucleation phenomenon was dominant. With the help of a hypothesis, the variation of the volumetric fraction of ice with temperature was determined. In the strains observed during the freezing period, the part due to temperature effects was separated from the part due to internal pressures produced by water and ice. Biot’s model then allowed the internal pressure generated by water and ice to be calculated as a function of temperature. The difference in behavior of the two materials was thus proved.