Time-of-Flight Acoustic Tomography for Rebar Localization and Dimensional Evaluation in Concrete Utility Poles

Time-of-Flight Acoustic Tomography for Rebar Localization and Dimensional Evaluation in Concrete Utility Poles | 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 Time-of-Flight Acoustic Tomography for Rebar Localization and Dimensional Evaluation in Concrete Utility Poles Ju Ma, Zhenghao Luo, Hankuo Zhang, Longjun Dong This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9665392/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 The structural integrity of reinforced concrete utility poles relies heavily on the distribution of their internal rebars. However, existing non-destructive testing techniques struggle to precisely locate and quantify the dimensions of these slender reinforcements. To address this limitation, we propose an evaluation method based on time-of-flight acoustic tomography. By integrating the fast marching method with a quasi-Newton optimization algorithm, this approach accurately models wave propagation in complex media and performs nonlinear inversion of the velocity field. Extensive numerical simulations under both homogeneous and complex radial gradient backgrounds confirm the algorithm's robustness. To objectively assess imaging quality, we introduce novel quantitative metrics: intersection over union (IoU), relative diameter error (RDE), amplitude recovery (AR), and separability index (SI). The results demonstrate that increasing external excitation sources significantly enhances ray coverage density. Under optimal configurations, the IoU exceeds 70 % , and the RDE drops to approximately 5 % . Furthermore, resolution limit tests reveal that the algorithm can distinctly resolve independent rebars spaced more than 4.0 cm apart and successfully image those with a minimum radius of 1.0 cm . The evaluation framework established through these local physical metrics accurately quantifies the resolution limits of acoustic tomography, providing a reliable methodological basis for the high-precision inspection of utility poles and similar infrastructure. Non-destructive testing Rebar detection Wave velocity inversion Full Text Additional Declarations No competing interests reported. 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. 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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-9665392","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":637447062,"identity":"2ec5e56f-b63a-4bae-bc53-d7ea2242ce8e","order_by":0,"name":"Ju Ma","email":"","orcid":"","institution":"Central South University","correspondingAuthor":false,"prefix":"","firstName":"Ju","middleName":"","lastName":"Ma","suffix":""},{"id":637447063,"identity":"8b9d90cb-3849-4258-ac01-56ab95759c41","order_by":1,"name":"Zhenghao Luo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2UlEQVRIiWNgGAWjYBACfmaG9B8SFTb185mZDxCnRbK94YGExZk0xo3tbAnEaTE4c/CBRGXLYcaG8zwGRLrsRnKCwc0GZmbGZp6PN94w2MnpNhDQwTgjLSFx5g42NnZm3s2WcxiSjc0OENDCLJGTcFjyDA8PYzPvNmkehgOJ2whpYZPI/9j8t01CguEwzzPitPDwHEhmkGwzMABqYSNOiwR7QxqDxJmEBMNmNmPLOQZE+MX+MANQS8X/BHn+ww9vvKmwkyOoBdVKoqMGSQupOkbBKBgFo2BEAABww0D6Z30vqwAAAABJRU5ErkJggg==","orcid":"","institution":"Central South University","correspondingAuthor":true,"prefix":"","firstName":"Zhenghao","middleName":"","lastName":"Luo","suffix":""},{"id":637447064,"identity":"95db3d88-c798-4588-a1d8-81ae31b7e9cd","order_by":2,"name":"Hankuo Zhang","email":"","orcid":"","institution":"Shandong Jinzhou Mining Group Co., Ltd","correspondingAuthor":false,"prefix":"","firstName":"Hankuo","middleName":"","lastName":"Zhang","suffix":""},{"id":637447065,"identity":"0ffaf808-969a-47cd-8a89-eef9da327bfc","order_by":3,"name":"Longjun Dong","email":"","orcid":"","institution":"Central South University","correspondingAuthor":false,"prefix":"","firstName":"Longjun","middleName":"","lastName":"Dong","suffix":""}],"badges":[],"createdAt":"2026-05-09 16:53:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9665392/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9665392/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109068089,"identity":"c867cb12-9edd-481e-8f0e-a9dc709ea260","added_by":"auto","created_at":"2026-05-12 10:03:32","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1871825,"visible":true,"origin":"","legend":"","description":"","filename":"TimeofFlightAcousticTomographyforRebarLocalizationandDimensionalEvaluationinConcreteUtilityPoles.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9665392/v1_covered_d68baac9-7032-4abd-a222-8a073609a0a2.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Time-of-Flight Acoustic Tomography for Rebar Localization and Dimensional Evaluation in Concrete Utility Poles","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":"Non-destructive testing, Rebar detection, Wave velocity inversion","lastPublishedDoi":"10.21203/rs.3.rs-9665392/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9665392/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe structural integrity of reinforced concrete utility poles relies heavily on the distribution of their internal rebars. However, existing non-destructive testing techniques struggle to precisely locate and quantify the dimensions of these slender reinforcements. To address this limitation, we propose an evaluation method based on time-of-flight acoustic tomography. By integrating the fast marching method with a quasi-Newton optimization algorithm, this approach accurately models wave propagation in complex media and performs nonlinear inversion of the velocity field. Extensive numerical simulations under both homogeneous and complex radial gradient backgrounds confirm the algorithm's robustness. To objectively assess imaging quality, we introduce novel quantitative metrics: intersection over union (IoU), relative diameter error (RDE), amplitude recovery (AR), and separability index (SI). The results demonstrate that increasing external excitation sources significantly enhances ray coverage density. Under optimal configurations, the IoU \u0026nbsp;exceeds 70 % , and the RDE \u0026nbsp;drops to approximately 5 % . Furthermore, resolution limit tests reveal that the algorithm can distinctly resolve independent rebars spaced more than 4.0 cm \u0026nbsp;apart and successfully image those with a minimum radius of 1.0 cm . The evaluation framework established through these local physical metrics accurately quantifies the resolution limits of acoustic tomography, providing a reliable methodological basis for the high-precision inspection of utility poles and similar infrastructure.\u003c/p\u003e","manuscriptTitle":"Time-of-Flight Acoustic Tomography for Rebar Localization and Dimensional Evaluation in Concrete Utility Poles","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-12 06:52:01","doi":"10.21203/rs.3.rs-9665392/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":"4c136195-e018-42f3-a400-a5f762c10f9a","owner":[],"postedDate":"May 12th, 2026","published":true,"recentEditorialEvents":[{"type":"submitted","content":"Journal of Nondestructive Evaluation","date":"2026-05-09T16:40:50+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-12T06:52:01+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-12 06:52:01","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9665392","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9665392","identity":"rs-9665392","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}