Abstract:

Unfrozen water content is not only an important evaluation index of water migration in frozen soils, but also a common parameter in thermotechnical calculation. The principles of two unfrozen water measurement methods  are analyzed respectively, which are temperature measurement method and calorimetric method, and some problems on principle of temperature measurement method are put forward. Unfrozen water content at any temperature can be obtained by calorimetric method, while by temperature measurement method it can only get the initial water content at its initial freezing temperature, as the curve can not reflect the unfrozen water variation with temperature. The contrast test of the two methods are carried out using six samples which contains different water content. The results show that there is a uncertainty in the result obtained by temperature measurement method. Therefore the calorimetric method is suggested to use if the test condition permitted.

Key words: unfrozen water, temperature measurement method, calorimetric method, water content