Unsaturated poroelasticity for crystallization in pores

Abstract This paper shows how poroelasticity provides a quantitative explanation of the role of the pore size distribution in the deformation of porous materials subjected to the frost action. Unsaturated poroelasticity is the natural extension of saturated poroelasticity, once recognized that any crystallization process within a porous material results from two distinct physical processes: (i) an invasion process by the forming crystal, which is driven by surface energy effects; (ii) a deformation process under the crystallization pressure, whose intensity is governed by the poroelastic properties of the porous solid and by the current liquid saturation. The analysis reveals that the origin of the expansion is twofold: (i) the pressure build up of the unfrozen part of the porous network, that originates from the action of the excess of liquid expelled from the freezing sites; (ii) the cryo-suction process that constantly drives the liquid back towards the frozen sites as the cooling further increases. This explains the long known efficiency of air-voids against the frost action. These voids act both as expansion reservoirs and as cryo-pumps. The analysis finally provides an assessment for the recommended spacing factor between adjacent air-voids.

[1]  Olivier Coussy,et al.  A general theory of thermoporoelastoplasticity for saturated porous materials , 1989 .

[2]  J. Rice,et al.  Some basic stress diffusion solutions for fluid‐saturated elastic porous media with compressible constituents , 1976 .

[3]  D. H. Everett.  The thermodynamics of frost damage to porous solids , 1961 .

[4]  T C Powers,et al.  "A tribute to Theory of Volume Changes in Hardened Portland-Cement Paste during Freezing""""" , 2008, SP-249: Selected Landmark Paper Collection on Concrete Materials Research.

[5]  J. Beaudoin,et al.  The mechanism of frost damage in hardened cement paste , 1974 .

[6]  M. Biot.  General Theory of Three‐Dimensional Consolidation , 1941 .

[7]  Olivier Coussy,et al.  Thermomechanics of saturated porous solids in finite deformation , 1989 .

[8]  Karen Scrivener,et al.  Delayed ettringite formation , 2001 .

[9]  Vesa Penttala,et al.  Freezing-Induced Strains and Pressures in Wet Porous Materials and Especially in Concrete Mortars , 1998 .

[10]  J. Hallett.  The Temperature Dependence of the Viscosity of Supercooled Water , 1963 .

[11]  Ivan V. Markov,et al.  Crystal growth for beginners , 1995 .

[12]  Fernando M.A. Henriques,et al.  Proceedings of the 7th International Congress on Deterioration and Conservation of Stone , 1992 .

[13]  Olivier Coussy,et al.  Poromechanics of freezing materials , 2005 .

[14]  R. J. Speedy.  Thermodynamic properties of supercooled water at 1 atm , 1987 .

[15]  M. Pigeon,et al.  Durability of Concrete in Cold Climates , 1995 .

[16]  Jean-Pierre Guilbaud,et al.  Determination of liquid water content and dielectric constant in porous media by the capacitive method , 2004 .

[17]  John A. Hudson,et al.  Comprehensive rock engineering , 1993 .

[18]  P. K. Mehta.  Concrete: Structure, Properties, and Materials , 1992 .

[19]  Maurice A. Biot,et al.  VARIATIONAL LAGRANGIAN-THERMODYNAMICS OF NONISOTHERMAL FINITE STRAIN MECHANICS OF POROUS SOLIDS AND THERMOMOLECULAR DIFFUSION , 1977 .

[20]  Antonia Moropoulou,et al.  Patterns of damage in igneous and sedimentary rocks under conditions simulating sea‐salt weathering , 2003 .

[21]  Robert Eymard,et al.  Constitutive modeling of unsaturated drying deformable materials , 1998 .

[22]  A. Cheng,et al.  Fundamentals of Poroelasticity , 1993 .

[23]  O. Coussy,et al.  Dielectric capacity, liquid water content, and pore structure of thawing-freezing materials , 2006 .

[24]  Olivier Coussy,et al.  Deformation and stress from in-pore drying-induced crystallization of salt , 2006 .

[25]  Olivier Coussy,et al.  Acoustics of Porous Media , 1988 .

[26]  I. Evans.  Salt crystallization and rock weathering: a review , 1970 .

[27]  T. Powers,et al.  THE AIR REQUIREMENT OF FROST RESISTANT CONCRETE , 1950 .

[28]  Jacques Marchand,et al.  Predicting the volume instability of hydrated cement systems upon freezing using poro-mechanics and local phase equilibria , 2004 .

[29]  Charles Eyraud,et al.  A new method for the simultaneous determination of the size and shape of pores: the thermoporometry , 1977 .

[30]  Franz-Josef Ulm,et al.  Is concrete a poromechanics materials?—A multiscale investigation of poroelastic properties , 2004 .

[31]  Luc Dormieux,et al.  Micromechanics of saturated and unsaturated porous media , 2002 .

[32]  V. F. Petrenko,et al.  Physics of Ice , 1999 .

[33]  George W. Scherer,et al.  Crystallization in pores , 1999 .

[34]  O. Coussy.  Revisiting the constitutive equations of unsaturated porous solids using a Lagrangian saturation concept , 2007 .

[35]  Carl W. Correns,et al.  Growth and dissolution of crystals under linear pressure , 1949 .

[36]  Paulo J.M. Monteiro,et al.  Stress analysis of expansive reactions in concrete , 2000 .