Abstract:

To study the effect of freeze-thaw cycles on the lining of the change of the coefficient of thermal conductivity, this paper simplifies concrete to a porous media model, by using Hamilton and Crosser theoretical calculation model and simulation software COMSOL concrete specimen coefficient of thermal conductivity of different porosity was calculated and analyzed. The research results show that by inverse calculation of the effective thermal conductivity of the concrete random distribution model, the effective thermal conductivity of the concrete model with different porosity under different freeze-thaw cycles is obtained, and the effective thermal conductivity of the concrete specimens and the freeze-thaw cycle are determined, and there is a non-linear function relationship between the times; the lining of coefficient of thermal conductivity under the effect of freeze-thaw cycles, the initial coefficient of thermal conductivity with the increase of freeze-thaw cycles decreases, with the increase of freeze-thaw cycles and mid stabilise the coefficient of thermal conductivity.

Key words: seasonally frozen tunnel, thermal conductivity, porous medium model; the porosity, freeze-thaw cycle