{"title":"二元膨润土基混合物的可压缩性,特别强调球团取向","authors":"Arisleidy Mesa-Alcantara , Enrique Romero , Joel Torres-Serra , Nadia Mokni","doi":"10.1016/j.clay.2024.107575","DOIUrl":null,"url":null,"abstract":"<div><div>Binary mixtures of Wyoming-type bentonite, consisting of 80 % mass high-density pellets and 20 % granular bentonite, are currently considered candidate materials for the French concept of vertical sealing systems for deep and long-term disposal of radioactive wastes. At low emplacement water contents, the hydro-mechanical behaviour is primarily controlled by contact forces between pellets, forming a coarse grain-supported structure over which granular bentonite is poured. These pellets were uniaxially compacted at elevated stresses to reach high dry densities. Subsequent pellet unloading resulted in anisotropic features due to fissuring and delamination, followed by water absorption. This study investigated compressibility changes upon loading under laterally confined conditions of a well-oriented pellet-supported structure, mimicking the setup of the <em>in situ</em> VSEAL 1 experiment at Tournemire (France). Two pellet orientations at the same dry density and coordination number of pellet contacts were examined in a pure pellet skeleton and a mixture to account for potential heterogeneity during pouring. A discrete element method was used to simulate the compression results with pellets represented as a clump with a heterogeneous void ratio distribution due to fissuring. These simulations were instrumental in understanding the important anisotropic deformation properties of pellet-supported structures under two distinct orientations.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"261 ","pages":"Article 107575"},"PeriodicalIF":5.3000,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Compressibility of a binary bentonite-based mixture with particular emphasis on pellet orientation\",\"authors\":\"Arisleidy Mesa-Alcantara , Enrique Romero , Joel Torres-Serra , Nadia Mokni\",\"doi\":\"10.1016/j.clay.2024.107575\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Binary mixtures of Wyoming-type bentonite, consisting of 80 % mass high-density pellets and 20 % granular bentonite, are currently considered candidate materials for the French concept of vertical sealing systems for deep and long-term disposal of radioactive wastes. At low emplacement water contents, the hydro-mechanical behaviour is primarily controlled by contact forces between pellets, forming a coarse grain-supported structure over which granular bentonite is poured. These pellets were uniaxially compacted at elevated stresses to reach high dry densities. Subsequent pellet unloading resulted in anisotropic features due to fissuring and delamination, followed by water absorption. This study investigated compressibility changes upon loading under laterally confined conditions of a well-oriented pellet-supported structure, mimicking the setup of the <em>in situ</em> VSEAL 1 experiment at Tournemire (France). Two pellet orientations at the same dry density and coordination number of pellet contacts were examined in a pure pellet skeleton and a mixture to account for potential heterogeneity during pouring. A discrete element method was used to simulate the compression results with pellets represented as a clump with a heterogeneous void ratio distribution due to fissuring. These simulations were instrumental in understanding the important anisotropic deformation properties of pellet-supported structures under two distinct orientations.</div></div>\",\"PeriodicalId\":245,\"journal\":{\"name\":\"Applied Clay Science\",\"volume\":\"261 \",\"pages\":\"Article 107575\"},\"PeriodicalIF\":5.3000,\"publicationDate\":\"2024-09-27\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Clay Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0169131724003235\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Clay Science","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0169131724003235","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Compressibility of a binary bentonite-based mixture with particular emphasis on pellet orientation
Binary mixtures of Wyoming-type bentonite, consisting of 80 % mass high-density pellets and 20 % granular bentonite, are currently considered candidate materials for the French concept of vertical sealing systems for deep and long-term disposal of radioactive wastes. At low emplacement water contents, the hydro-mechanical behaviour is primarily controlled by contact forces between pellets, forming a coarse grain-supported structure over which granular bentonite is poured. These pellets were uniaxially compacted at elevated stresses to reach high dry densities. Subsequent pellet unloading resulted in anisotropic features due to fissuring and delamination, followed by water absorption. This study investigated compressibility changes upon loading under laterally confined conditions of a well-oriented pellet-supported structure, mimicking the setup of the in situ VSEAL 1 experiment at Tournemire (France). Two pellet orientations at the same dry density and coordination number of pellet contacts were examined in a pure pellet skeleton and a mixture to account for potential heterogeneity during pouring. A discrete element method was used to simulate the compression results with pellets represented as a clump with a heterogeneous void ratio distribution due to fissuring. These simulations were instrumental in understanding the important anisotropic deformation properties of pellet-supported structures under two distinct orientations.
期刊介绍:
Applied Clay Science aims to be an international journal attracting high quality scientific papers on clays and clay minerals, including research papers, reviews, and technical notes. The journal covers typical subjects of Fundamental and Applied Clay Science such as:
• Synthesis and purification
• Structural, crystallographic and mineralogical properties of clays and clay minerals
• Thermal properties of clays and clay minerals
• Physico-chemical properties including i) surface and interface properties; ii) thermodynamic properties; iii) mechanical properties
• Interaction with water, with polar and apolar molecules
• Colloidal properties and rheology
• Adsorption, Intercalation, Ionic exchange
• Genesis and deposits of clay minerals
• Geology and geochemistry of clays
• Modification of clays and clay minerals properties by thermal and physical treatments
• Modification by chemical treatments with organic and inorganic molecules(organoclays, pillared clays)
• Modification by biological microorganisms. etc...