MODELING FREEZING OF CEMENTITIOUS MATERIALS BY CONSIDERING PROCESS KINETICS

Author: Francesco Pesavento, Dariusz Gawin
Paper category: Proceedings
Book title: Proceedings of the International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference Segment on Frost Action in Concrete
Editor(s): Marianne Tange Hasholt, Katja Fridh and R. Doug Hooton
ISBN:978-2-35158-182-7
e-ISBN:978-2-35158-183-4
Publisher:RILEM Publications SARL
Publication year:2016
Pages:112-121
Total Pages:10
Language:English

Abstract: In this work we present a new numerical model for the simulation of the behaviour of partially saturated porous materials, exposed to temperatures below the freezing point.Usually in modelling such a kind of phenomenon, the assumption that there exists thermodynamic equilibrium between the ice and liquid water, is applied. In this way, one can use the equilibrium curve, which describes liquid water content in the pores being in equilibrium with ice at a given temperature T. Here the water freezing / melting process in the material pores is modelled as a non-equilibrium process, the kinetics of which is governed by an evolution law, obtained from the second law of Thermodynamics. As far as the effective stress principle is concerned, during freezing of water at thermodynamic equilibrium, the pressure difference on the interface between ice and liquid water in the pores can be calculated by means of the Gibbs-Thomson law. With these measures of pressure it is possible to evaluate the effective stress on the solid skeleton of the porous medium due to the simultaneous presence of gas, water and ice. Some relevant numerical cases will be presented to show the effectiveness of the formulated model.

Online publication:2016
Publication type:full_text
Public price (Euros):0.00