| Autor: |
Paulo J.M. Monteiro, Olivier Coussy |
| Rok vydání: |
2007 |
| Předmět: |
|
| Zdroj: |
Computers and Geotechnics. 34:279-290 |
| ISSN: |
0266-352X |
| DOI: |
10.1016/j.compgeo.2007.02.007 |
| Popis: |
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. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect