Journal of Natural Disaster Science

EXPERIMENTAL STUDY ON UNFROZEN WATER MIGRATION IN POROUS MATERIALS DURING FREEZING

Takeshi ISHIZAKI
Assistant Professor, The Institute of Low Temperature Science, Hokkaido University

(Received 14 December, 1995 and in revised form 18 March, 1996)

Abstract

In cold regions, stone remains and building materials deteriorate due to repeated freezing and thawing cycles. This rock weathering process sometimes causes abrupt failure of rock slopes and walls. The reason for this deterioration is considered to be the ice segregation of frost heave phenomena in these porous materials. To clarify the frost heave mechanism, we performed frost heave experiments on porous material (Oya tuff). The unfrozen water flow rate in a partially frozen zone was calculated using the growth rate of the ice lens. The relationship between this growth rate and the temperature of the ice segregation front was obtained. The unfrozen water flow in a partially frozen zone was modeled by slit flow between clay particle planes composed of porous materials and the results compared with experimental ones. The calculated flow rates coincided well with the experimental results.

Key words

frost damage, ice segregation, unfrozen water, porous rock