{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/105090"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/105090","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"NDT to characterize 3D printed concrete interlayer bonds","abstract":"3D printing in the construction industry involves extruding layer upon layer of concrete to create a desired structure. Layer interfaces can form cold joints, or bond weaknesses, that could compromise structural integrity. Furthermore, the unique characteristics and geometric constraints associated with 3D printed concrete render traditional inspection methods to characterize material quality useless. This research examines nondestructive testing (NDT) techniques that characterize the interlayer bond quality (bond strength) of 3D printed concrete in situ. An experimental study applied four NDT methods (x-ray radiography, ultrasonic pulse velocity (UPV), vibration resonance, and multi-element array ultrasonics) to idealized, layered concrete specimens that simulate layers of a 3D printed structure. The bond interfaces in the samples were characterized into well bonded, weakly bonded, and disbonded categories based on mechanical tests applied to the samples to measure bond strength. Two of those NDT methods, x-ray radiography and multi-element array ultrasonics, showed promise in characterizing bond strength, and threshold values for data from both methods were established to characterize interlayer bonds into one of the three defined bond quality categories. Multi-element array ultrasonics and UPV were then adapted and applied to full-scale 3D printed concrete walls. UPV was not sensitive to the bond condition. However, multi-element array ultrasonics successfully located and categorized cracks, expansion joints, and layer debonding on the full-scale 3D printed structures.","abstract_html":"3D printing in the construction industry involves extruding layer upon layer of concrete to create a desired structure. Layer interfaces can form cold joints, or bond weaknesses, that could compromise structural integrity. Furthermore, the unique characteristics and geometric constraints associated with 3D printed concrete render traditional inspection methods to characterize material quality useless. This research examines nondestructive testing (NDT) techniques that characterize the interlayer bond quality (bond strength) of 3D printed concrete in situ. An experimental study applied four NDT methods (x-ray radiography, ultrasonic pulse velocity (UPV), vibration resonance, and multi-element array ultrasonics) to idealized, layered concrete specimens that simulate layers of a 3D printed structure. The bond interfaces in the samples were characterized into well bonded, weakly bonded, and disbonded categories based on mechanical tests applied to the samples to measure bond strength. Two of those NDT methods, x-ray radiography and multi-element array ultrasonics, showed promise in characterizing bond strength, and threshold values for data from both methods were established to characterize interlayer bonds into one of the three defined bond quality categories. Multi-element array ultrasonics and UPV were then adapted and applied to full-scale 3D printed concrete walls. UPV was not sensitive to the bond condition. However, multi-element array ultrasonics successfully located and categorized cracks, expansion joints, and layer debonding on the full-scale 3D printed structures.","abstract_has_math":false,"creators":["Helsel, Michelle Annette"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Civil Engineering","degree_department":null,"school":null,"contributors":["Popovics, John S."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-08-23T20:36:10Z","date_published":"2019-08-23T20:36:10Z","updated_at":"2026-07-22T22:24:44Z","subjects":["3D printed concrete","interlayer bonds","bond condition","characterization","NDT","non-destructive testing","non-destructive evaluation","additive manufacturing"],"languages":["en"],"rights":["Copyright 2019 Michelle Annette Helsel"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/105090","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Popovics, John S."]},{"key":"dc:creator","label":"Author","values":["Helsel, Michelle Annette"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2019-08-23T20:36:10Z","2021-08-24T09:15:28Z","2019-04-25","2019-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["3D printed concrete","interlayer bonds","bond condition","characterization","NDT","non-destructive testing","non-destructive evaluation","additive manufacturing"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2019 Michelle Annette Helsel"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/105090"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["3D printing in the construction industry involves extruding layer upon layer of concrete to create a desired structure. Layer interfaces can form cold joints, or bond weaknesses, that could compromise structural integrity. Furthermore, the unique characteristics and geometric constraints associated with 3D printed concrete render traditional inspection methods to characterize material quality useless. This research examines nondestructive testing (NDT) techniques that characterize the interlayer bond quality (bond strength) of 3D printed concrete in situ. An experimental study applied four NDT methods (x-ray radiography, ultrasonic pulse velocity (UPV), vibration resonance, and multi-element array ultrasonics) to idealized, layered concrete specimens that simulate layers of a 3D printed structure. The bond interfaces in the samples were characterized into well bonded, weakly bonded, and disbonded categories based on mechanical tests applied to the samples to measure bond strength. Two of those NDT methods, x-ray radiography and multi-element array ultrasonics, showed promise in characterizing bond strength, and threshold values for data from both methods were established to characterize interlayer bonds into one of the three defined bond quality categories. Multi-element array ultrasonics and UPV were then adapted and applied to full-scale 3D printed concrete walls. UPV was not sensitive to the bond condition. However, multi-element array ultrasonics successfully located and categorized cracks, expansion joints, and layer debonding on the full-scale 3D printed structures.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-05-01","The student, Michelle Helsel, accepted the attached license on 2019-04-24 at 16:26.","The student, Michelle Helsel, submitted this Thesis for approval on 2019-04-24 at 16:38.","This Thesis was approved for publication on 2019-04-25 at 11:02.","DSpace SAF Submission Ingestion Package generated from Vireo submission #13891 on 2019-08-22 at 15:08:32","Made available in DSpace on 2019-08-23T20:36:10Z (GMT). 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Layer interfaces can form cold joints, or bond weaknesses, that could compromise structural integrity. Furthermore, the unique characteristics and geometric constraints associated with 3D printed concrete render traditional inspection methods to characterize material quality useless. This research examines nondestructive testing (NDT) techniques that characterize the interlayer bond quality (bond strength) of 3D printed concrete in situ. An experimental study applied four NDT methods (x-ray radiography, ultrasonic pulse velocity (UPV), vibration resonance, and multi-element array ultrasonics) to idealized, layered concrete specimens that simulate layers of a 3D printed structure. The bond interfaces in the samples were characterized into well bonded, weakly bonded, and disbonded categories based on mechanical tests applied to the samples to measure bond strength. Two of those NDT methods, x-ray radiography and multi-element array ultrasonics, showed promise in characterizing bond strength, and threshold values for data from both methods were established to characterize interlayer bonds into one of the three defined bond quality categories. Multi-element array ultrasonics and UPV were then adapted and applied to full-scale 3D printed concrete walls. UPV was not sensitive to the bond condition. However, multi-element array ultrasonics successfully located and categorized cracks, expansion joints, and layer debonding on the full-scale 3D printed structures.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-05-01","The student, Michelle Helsel, accepted the attached license on 2019-04-24 at 16:26.","The student, Michelle Helsel, submitted this Thesis for approval on 2019-04-24 at 16:38.","This Thesis was approved for publication on 2019-04-25 at 11:02.","DSpace SAF Submission Ingestion Package generated from Vireo submission #13891 on 2019-08-22 at 15:08:32","Made available in DSpace on 2019-08-23T20:36:10Z (GMT). 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