Compressive Strength of Nigerian Gmelina Arborea Cross-laminated Timber: A combined experimental and probabilistic approach for polyurethane and epoxy resin adhesive bonding

Compressive Strength of Nigerian Gmelina Arborea Cross-laminated Timber: A combined experimental and probabilistic approach for polyurethane and epoxy resin adhesive bonding | 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 Research Article Compressive Strength of Nigerian Gmelina Arborea Cross-laminated Timber: A combined experimental and probabilistic approach for polyurethane and epoxy resin adhesive bonding Yusuf Yau, Amana Ocholi, Jibrin Mohammed Kaura, Adamu Lawan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6000757/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Cross-laminated timber (CLT) is gaining recognition as a sustainable alternative to traditional building materials like steel and concrete, offering enhanced structural rigidity and dimensional stability. However, its performance depends heavily on the wood species used. This study explores the potential of Gmelina arborea , a fast-growing hardwood widely cultivated in Nigeria but underexplored for CLT applications. The research evaluates the compressive strength of CLT panels made from Nigerian-grown Gmelina arborea under in-plane and out-of-plane loading conditions. Panels were fabricated using visually graded planks bonded with one-component polyurethane (PUR) and two-component epoxy resin (ER) adhesives. Compressive strength tests were conducted following the BS EN 408:2010 + A1:2012 standard, and reliability analysis was performed using Python and MATLAB to compute reliability indices (β) and probabilities of failure (P f ) via the first-order reliability method (FORM). Results revealed that compressive strength perpendicular to the grain ranged from 11.37 to 13.38 N/mm², while parallel strength ranged from 14.30 to 30.26 N/mm², with PUR-bonded panels exhibiting slightly higher values. PUR-bonded panels achieved a mean perpendicular strength of 12.47 N/mm² compared to 12.24 N/mm² for ER-bonded panels. Parallel strength in the minor direction was higher than perpendicular strength, with PUR and ER panels averaging 18.19 N/mm² and 15.80 N/mm², respectively. The major strength direction showed the highest values, with PUR at 27.86 N/mm² and ER at 26.79 N/mm². Reliability analysis indicated that PUR adhesives outperformed ER, with higher reliability indices (β = 3.6637, P f = 0.0243%) compared to ER (β = 3.1646, P f = 0.077641%). These findings highlight the superior structural reliability of PUR-bonded CLT panels. Cross-laminated timber (CLT) In-plane and Out-of-plane compression Major and Minor strength direction Reliability analysis Gmelina arborea Timber PUR and ER Adhesives. Full Text Additional Declarations No competing interests reported. Appendix XXIV Appendix XXIV is not available with this version. Cite Share Download PDF Status: Posted Version 1 posted 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-6000757","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":420231767,"identity":"6f6ff1ea-2dbd-4262-9d06-a47ca1dcbd13","order_by":0,"name":"Yusuf Yau","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYFACxsYDQFIOxDzwgEgtDSAtxmAtCcTaA9KS2ABiEaXF4EZyw2Gemrr0+WGHHwJtsZPTbSCoJRGo5djh3I230wyAWpKNzQ4QpYXtQO7G2QkgLQcStxGn5V9duuHs9A8kaOFtY06Ql84h0hbJMw8bDs7tO2y4QTqn4ECCARF+4Tue/vDBm2918vKz0zd/+FBhJ0dQi8KFBAYmHpALwSoNCCgHAfn+AwyMP0CMBiJUj4JRMApGwcgEAM8GUDhDMnOWAAAAAElFTkSuQmCC","orcid":"","institution":"Ahmadu Bello University","correspondingAuthor":true,"prefix":"","firstName":"Yusuf","middleName":"","lastName":"Yau","suffix":""},{"id":420231768,"identity":"90b23031-da52-445a-8cca-66d02736d36f","order_by":1,"name":"Amana Ocholi","email":"","orcid":"","institution":"Ahmadu Bello University","correspondingAuthor":false,"prefix":"","firstName":"Amana","middleName":"","lastName":"Ocholi","suffix":""},{"id":420231769,"identity":"529ad41c-7748-446c-92a2-26a22aa285f9","order_by":2,"name":"Jibrin Mohammed Kaura","email":"","orcid":"","institution":"Ahmadu Bello University","correspondingAuthor":false,"prefix":"","firstName":"Jibrin","middleName":"Mohammed","lastName":"Kaura","suffix":""},{"id":420231770,"identity":"50f64dce-c7b6-41a2-89ce-9fe9e3a24e64","order_by":3,"name":"Adamu Lawan","email":"","orcid":"","institution":"Ahmadu Bello University","correspondingAuthor":false,"prefix":"","firstName":"Adamu","middleName":"","lastName":"Lawan","suffix":""}],"badges":[],"createdAt":"2025-02-10 16:11:45","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6000757/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6000757/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":77275008,"identity":"e9cbf178-36ee-411c-ba8a-d0d05c98773d","added_by":"auto","created_at":"2025-02-27 02:36:59","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":640039,"visible":true,"origin":"","legend":"","description":"","filename":"MyManuscripttoEJWWP.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6000757/v1_covered_60bb6f46-6edc-45cb-bb04-876aceb25aaf.pdf"}],"financialInterests":"\u003cp\u003eNo competing interests reported.\u003c/p\u003e\n\u003cp\u003eAppendix XXIV\u003c/p\u003e\n\u003cp\u003eAppendix XXIV is not available with this version.\u003c/p\u003e","formattedTitle":"Compressive Strength of Nigerian Gmelina Arborea Cross-laminated Timber: A combined experimental and probabilistic approach for polyurethane and epoxy resin adhesive bonding","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Cross-laminated timber (CLT), In-plane and Out-of-plane compression, Major and Minor strength direction, Reliability analysis, Gmelina arborea Timber, PUR and ER Adhesives.","lastPublishedDoi":"10.21203/rs.3.rs-6000757/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6000757/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCross-laminated timber (CLT) is gaining recognition as a sustainable alternative to traditional building materials like steel and concrete, offering enhanced structural rigidity and dimensional stability. However, its performance depends heavily on the wood species used. This study explores the potential of \u003cem\u003eGmelina arborea\u003c/em\u003e, a fast-growing hardwood widely cultivated in Nigeria but underexplored for CLT applications. The research evaluates the compressive strength of CLT panels made from Nigerian-grown \u003cem\u003eGmelina arborea\u003c/em\u003e under in-plane and out-of-plane loading conditions. Panels were fabricated using visually graded planks bonded with one-component polyurethane (PUR) and two-component epoxy resin (ER) adhesives. Compressive strength tests were conducted following the BS EN 408:2010\u0026thinsp;+\u0026thinsp;A1:2012 standard, and reliability analysis was performed using Python and MATLAB to compute reliability indices (β) and probabilities of failure (P\u003csub\u003e\u003cem\u003ef\u003c/em\u003e\u003c/sub\u003e) via the first-order reliability method (FORM). Results revealed that compressive strength perpendicular to the grain ranged from 11.37 to 13.38 N/mm\u0026sup2;, while parallel strength ranged from 14.30 to 30.26 N/mm\u0026sup2;, with PUR-bonded panels exhibiting slightly higher values. PUR-bonded panels achieved a mean perpendicular strength of 12.47 N/mm\u0026sup2; compared to 12.24 N/mm\u0026sup2; for ER-bonded panels. Parallel strength in the minor direction was higher than perpendicular strength, with PUR and ER panels averaging 18.19 N/mm\u0026sup2; and 15.80 N/mm\u0026sup2;, respectively. The major strength direction showed the highest values, with PUR at 27.86 N/mm\u0026sup2; and ER at 26.79 N/mm\u0026sup2;. Reliability analysis indicated that PUR adhesives outperformed ER, with higher reliability indices (β\u0026thinsp;=\u0026thinsp;3.6637, P\u003csub\u003e\u003cem\u003ef\u003c/em\u003e\u003c/sub\u003e = 0.0243%) compared to ER (β\u0026thinsp;=\u0026thinsp;3.1646, P\u003csub\u003e\u003cem\u003ef\u003c/em\u003e\u003c/sub\u003e = 0.077641%). These findings highlight the superior structural reliability of PUR-bonded CLT panels.\u003c/p\u003e","manuscriptTitle":"Compressive Strength of Nigerian Gmelina Arborea Cross-laminated Timber: A combined experimental and probabilistic approach for polyurethane and epoxy resin adhesive bonding","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-27 02:12:54","doi":"10.21203/rs.3.rs-6000757/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c393b61e-7e5b-45a2-91ae-862436a31c2a","owner":[],"postedDate":"February 27th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-27T02:12:54+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-27 02:12:54","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6000757","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6000757","identity":"rs-6000757","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}