Reactive transport and damage induced
by crystallisation/precipitation in porous geomaterials
Geomaterials are porous, discrete and heterogeneous media exposed to environmental interactions. These materials host multiple fluids with which they establish physico-chemical feedbacks. During the last decades, major shifts in climate and the continued exploration of remote environments encouraged the study of phase transitions within the pores of soils and rocks, which include salt crystallization, mineral precipitation, freeze/thaw dynamics, and methane hydrate dissociation, among others. Phase transitions are a key source of weathering, as they cause unprecedented alterations in the strength and deformation properties of natural deposits. Two major sources of weathering process are envisioned within these projects: haloclasty and freezing/melting cycling.
Current people in the group:
Crystallisation-induced damage under confined reservoir conditions
Crystallisation-induced damage in heterogeneous porous media in the context of the erosion of the French Basque coast and the damage of its protection buildings
(PhD defense in 2022)
Crystallization of water in nanoporous materials and its induced impact on the solid matrix
Cast3m modelling of crystallisation-induced damage in heterogeneous porous media
Martín P. Rodríguez
Molecular simulation of fluid confinement and crystallisation effects
Lattice discrete particle modelling of crystallisation-induced damage in heterogeneous porous media
Crystallisation-induced damage in heterogeneous rocks -Application to haloclasty
Newpores - New Frontiers in Porous Materials
Granted by E2S UPPA, NewPores is an international hub dedicated to the mechanics and physics of porous materials, which intends to answer to new Energy and Environment challenges. This is a joint effort of the group on Geomechanics and Porous Materials (G2MP) of the Laboratoire des Fluides Complexes et leurs Réservoirs at E2S UPPA (France), the Centre for Sustainable Engineering of Geological and Infrastructure Materials (SEGIM) at Northwestern University (USA), the University of Vigo (Spain), the Technical University of Madrid (Spain) and University of Liège (Belgium).
Ezponda - Étude des paramètres mécaniques et chimiques à l'origine de l'altération des falaises rocheuses de la côte basque et des ouvrages de défense
Granted by the European Union and the Nouvelle Aquitaine region, Ezponda intends to predict the evolution of the impact and the velocity of coastal erosion under current climate changes and forthcoming sea level rises. In particular, the Ezponda project aims at studying and hierarchizing the different key parameters (haloclasty, rain, storms), which drives coastal erosion and coastal protection building damage. Haloclasty is a natural rock failure process driven by salt crystallisation and salt weathering. It is particularly at sight on coastal areas because it is a key parameter for their natural erosion, which is a crucial social-economic challenge for local authorities in charge of coast management.
ConfCryst - Crystallisation-induced damage under confined reservoir conditions
Although crystallisation-induced damage under environmental conditions has been studied for years, motivated by the interest of the local authorities and restoration companies in salt weathering of historic monuments1-7, few research works have been performed in the geomechanical context of confined reservoir conditions, although fractures correspond to the main damaging process in the upper crustal levels. Granted by E2S UPPA and Total, this project aims at obtaining a better understanding of the mechanism of crystallisation-induced damage under confined reservoir conditions, which is of utmost importance to explain and predict the localisation of cracks and veins in heterogeneous unconventional reservoirs and therefore enhances their characterisation, their stimulation and their production of both conventional georessources as well as sustainable georessources.
CRYSTAL - Combined neutRon and x-raY imaging for the characterization of in Situ crysTallisation-induced crAcking in the context of cuLtural heritage preservation
Crystallization-induced damage contributes majorly to the degradation or weathering of natural building stones, construction materials and our cultural heritage. When saline fluids are present in the pore space of the material, salt crystals might precipitate upon changes in temperature or humidity conditions, leading to salt precipitation on the surface, efflorescence, or to salt crystals precipitating in the pores, subflorescence. The confined crystal growth within the pores might lead to a buildup of crystallization-induced stresses, which can eventually induce fractures in the porous medium. The fracturing results from the interplay of saline flow, salt precipitation reactions and crystallization-induced stresses. The CRYSTAL project, funded by the Communauté d'Agglomération Pau Pyréenées aims at understanding the coupling between those phenomena in order to develop models for advising the building and stone conservation industry.