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DOI	10.1016/j.tecto.2021.228976
	Mechanical properties of quartz sand and gypsum powder (plaster) mixtures: Implications for laboratory model analogues for the Earth's upper crust
	Poppe S.; Holohan E.P.; Rudolf M.; Rosenau M.; Galland O.; Delcamp A.; Kervyn M.
发表日期	2021
ISSN	00401951
卷号	814
英文摘要	Granular materials are a useful analogue for the Earth's crust in laboratory models of deformation. Constraining their mechanical properties is critical for such model's scaling and interpretation. Much information exists about monomineralic granular materials, such as quartz sand, but the mechanical characteristics of bimineralic mixtures, such as commonly-used quartz sand mixed with gypsum powder (i.e. plaster), are largely unconstrained. We used several mechanical tests (density, tensile, extension, shear) to constrain the failure envelope of various sand-plaster mixtures. We then fitted linear Coulomb and parabolic Griffith failure criteria to obtain cohesions and friction coefficients. Tests of the effects of emplacement technique, compaction and humidity demonstrated that the most reproducible rheology is given by oven-drying, pouring and mechanically compacting sand-plaster mixtures into their experimentation container. As plaster content increases, the tensile strength of dry sand-plaster mixtures increases from near zero (pure quartz sand) to 166 ± 24 Pa (pure plaster). The cohesion increases from near zero to 250 ± 21 Pa. The friction coefficient varies from 0.54 ± 0.08 (sand) to 0.96 ± 0.08 (20 wt% plaster). The mechanical behaviour of the resulting mixtures shifts at 20–35 wt% plaster from brittle Coulomb failure along a linear failure criterion, to more complex brittle-plastic Coulomb-Griffith failure along a non-linear failure criterion. With increasing plaster content, the brittle-plastic transition occurs at decreasing depth within a pile of sand-plaster mixture. We infer that the identified transitions in mechanical behaviour with increasing plaster content relate to (1) increasing porosities, (2) increasing grain size distributions, and (3) a decrease in sand-sand grain contacts and corresponding increase in contacts of anisotropic gypsum-gypsum grains. The presented characterisation enables a more quantitative scaling of the mechanical behaviour of sand-plaster mixtures, including their tensile strength. Sand-plaster mixtures can thereby realistically simulate brittle-plastic properties of the Earth's crust in scaled laboratory models. © 2021 Elsevier B.V.
关键词	Analogue materials Cohesion Friction coefficient Gypsum powder Laboratory modelling Mechanical properties Quartz sand Shear strength Tensile strength
英文关键词	Failure (mechanical); Friction; Grain size and shape; Granular materials; Gypsum; Mixtures; Piles; Quartz; Sand; Structural geology; Tensile strength; Brittle-plastic transition; Friction coefficients; Grain size distribution; Laboratory models; Mechanical behaviour; Mechanical characteristics; Non-linear failure criteria; Scaled laboratories; Plaster; cohesion; deformation; failure mechanism; gypsum; laboratory method; mechanical property; quartz; upper crust
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/208053
作者单位	Physical Geography, Department of Geography, Vrije Universiteit Brussel, Brussels, Belgium; Now at Laboratoire G-Time, Department of Geoscience, the Environment and Society, Université libre de Bruxelles, Brussels, Belgium; UCD School of Earth Sciences, University College of Dublin, Dublin 4, Ireland; Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences, Potsdam, Germany; Physics of Geological Processes, The Njord Center, University of Oslo, Oslo, Norway
推荐引用方式 GB/T 7714	Poppe S.,Holohan E.P.,Rudolf M.,et al. Mechanical properties of quartz sand and gypsum powder (plaster) mixtures: Implications for laboratory model analogues for the Earth's upper crust[J],2021,814.
APA	Poppe S..,Holohan E.P..,Rudolf M..,Rosenau M..,Galland O..,...&Kervyn M..(2021).Mechanical properties of quartz sand and gypsum powder (plaster) mixtures: Implications for laboratory model analogues for the Earth's upper crust.Tectonophysics,814.
MLA	Poppe S.,et al."Mechanical properties of quartz sand and gypsum powder (plaster) mixtures: Implications for laboratory model analogues for the Earth's upper crust".Tectonophysics 814(2021).