Experimental Investigation of Thermal Volumetric Changes in Clays: Unveiling Hidden Controls

Experimental Investigation of Thermal Volumetric Changes in Clays: Unveiling Hidden Controls | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Experimental Investigation of Thermal Volumetric Changes in Clays: Unveiling Hidden Controls Hamed Hoseini Mighani, Saeed Tourchi, Arash Alimardani Lavasan, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8699124/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 12 You are reading this latest preprint version Abstract Understanding the thermally induced volumetric behavior of fine-grained soils is central to designing resilient geo-energy infrastructures, including geothermal systems, underground storage facilities, and deep repositories for radioactive waste. In this study, we investigate the coupled thermal-mechanical response of silty clays from Budapest, Hungary, characterized by contrasting plasticity and stress histories. Drained heating and heating–cooling cycle tests were performed in a custom-built, temperature controlled oedometer on both low-plasticity (LP) and high-plasticity (HP) samples. Temperatures ranged from 20°C to 90°C under variable over-consolidation ratios (OCR = 1 to 22). Results confirm that normally consolidated clays exhibit consistent plastic contraction during thermal loading, whereas highly over-consolidated clays reveal a more nuanced response, largely governed by recent stress history. Significantly, reloading events led to contraction in samples where a small elastic expansion might otherwise be expected. High-plasticity samples consistently showed greater thermal strain magnitudes, underscoring the importance of the plasticity index in controlling volume change. Repeated heating–cooling cycles induced mostly plastic strain during the first cycle, transitioning toward elastic behavior and stabilizing volumetric changes by the fourth. These findings offer deeper insight into the mechanics of thermally affected clay deposits, with direct relevance to geological risk assessments for geothermal fields and to the engineered barriers of nuclear waste repositories. By highlighting the pivotal roles of OCR, plasticity index, and stress history, this research contributes to more accurate predictive models and more robust designs for thermally active subsurface infrastructures. Physical sciences/Engineering Earth and environmental sciences/Solid earth sciences Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 13 Mar, 2026 Reviews received at journal 13 Mar, 2026 Reviews received at journal 11 Mar, 2026 Reviews received at journal 20 Feb, 2026 Reviewers agreed at journal 09 Feb, 2026 Reviewers agreed at journal 04 Feb, 2026 Reviewers agreed at journal 03 Feb, 2026 Reviewers invited by journal 03 Feb, 2026 Editor assigned by journal 03 Feb, 2026 Editor invited by journal 02 Feb, 2026 Submission checks completed at journal 30 Jan, 2026 First submitted to journal 30 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8699124","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":585773343,"identity":"b4cda947-177b-4740-8578-bb6cbb5e78fd","order_by":0,"name":"Hamed Hoseini Mighani","email":"","orcid":"","institution":"Budapest University of Technology and Economics","correspondingAuthor":false,"prefix":"","firstName":"Hamed","middleName":"Hoseini","lastName":"Mighani","suffix":""},{"id":585773344,"identity":"d8dc384d-6ea3-4d22-b71f-ff6f20cd19ec","order_by":1,"name":"Saeed Tourchi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxklEQVRIiWNgGAWjYLACHgjFxpBQASKZG4jRYgDVcgZEMpKihbENRBPQIt9++OCDNwx/5AxuH3724OG8w3l8QI0S+LQYnElLNpzDYGBscC7N3CBx2+FiNoJaGHLMpIEOS9xwhodNAqglsY2QFvn+999/I7TMIUILw40cNmaElgYitBjceGYsOcfA2FjyDJuZRMKx9MQ2ZsZmC/wOS3744U2FnBzfGeZnkj9qrBPntzcfvIHXYRC7kDnMhNWPglEwCkbBKCAAACruQoNuyGWwAAAAAElFTkSuQmCC","orcid":"","institution":"University of Luxembourg","correspondingAuthor":true,"prefix":"","firstName":"Saeed","middleName":"","lastName":"Tourchi","suffix":""},{"id":585773345,"identity":"4c2d77ed-4e4f-430a-b6da-2f0b18181027","order_by":2,"name":"Arash Alimardani Lavasan","email":"","orcid":"","institution":"University of Luxembourg","correspondingAuthor":false,"prefix":"","firstName":"Arash","middleName":"Alimardani","lastName":"Lavasan","suffix":""},{"id":585773346,"identity":"328eb06f-c6dc-4903-af28-2e51393cb8d9","order_by":3,"name":"Fatemehsadat Hosseini","email":"","orcid":"","institution":"University of Debrecen","correspondingAuthor":false,"prefix":"","firstName":"Fatemehsadat","middleName":"","lastName":"Hosseini","suffix":""},{"id":585773347,"identity":"90df65c2-91e3-4de3-80c5-195c6a6da1fd","order_by":4,"name":"Janos Szendefy","email":"","orcid":"","institution":"University of Luxembourg","correspondingAuthor":false,"prefix":"","firstName":"Janos","middleName":"","lastName":"Szendefy","suffix":""}],"badges":[],"createdAt":"2026-01-26 10:23:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8699124/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8699124/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101918512,"identity":"260773fb-3bf1-4a54-80e9-927965a48e09","added_by":"auto","created_at":"2026-02-05 03:41:19","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":606100,"visible":true,"origin":"","legend":"","description":"","filename":"TOURCHIetall2026ExperimentalInvestigationofThermalVolumetricChangesinClaysUnveilingHiddenControls.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8699124/v1_covered_6e40e9fa-58c2-4f34-9b98-a134dc8e3493.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Experimental Investigation of Thermal Volumetric Changes in Clays: Unveiling Hidden Controls","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8699124/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8699124/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Understanding the thermally induced volumetric behavior of fine-grained soils is central to designing resilient geo-energy infrastructures, including geothermal systems, underground storage facilities, and deep repositories for radioactive waste. 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