A study of freezing behavior of cementitious materials by poromechanical approach

The freezing behavior of cementitious materials is investigated in this paper through poromechanical approach after the Biot-Coussy theory. The material is taken as a porous medium saturated with water and subject to freezing. The involved thermodynamic laws are recalled to establish the constitutive equations for the phase change, mass transport and heat transfer processes. As a result, the pore pressure arising from freezing is converted to macroscopic effective stress through homogenization scheme. The established model is applied to predict the macroscopic freezing strain of a saturated cement paste and the theoretical prediction is compared to observed experimental results in (Powers and Helmuth, 1953). The results show that the poromechanical model can reasonably capture the freezing behaviors from pore pressure accumulation, pore pressure relaxation as well as the thermal shrinkage associated with the freezing process. (C) 2011 Elsevier Ltd. All rights reserved.