{"created":"2023-06-19T10:30:29.275477+00:00","id":10927,"links":{},"metadata":{"_buckets":{"deposit":"415180d5-e421-45da-b859-f75f3b9a0c39"},"_deposit":{"created_by":18,"id":"10927","owners":[18],"pid":{"revision_id":0,"type":"depid","value":"10927"},"status":"published"},"_oai":{"id":"oai:muroran-it.repo.nii.ac.jp:00010927","sets":["41:227"]},"author_link":["59403"],"item_81_date_granted_17":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2022-03-23"}]},"item_81_degree_grantor_10":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_language":"ja","subitem_degreegrantor_name":"室蘭工業大学"},{"subitem_degreegrantor_language":"en","subitem_degreegrantor_name":"Muroran Institute of Technology"}],"subitem_degreegrantor_identifier":[{"subitem_degreegrantor_identifier_name":"10103","subitem_degreegrantor_identifier_scheme":"kakenhi"}]}]},"item_81_degree_name_11":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士（工学）","subitem_degreename_language":"ja"}]},"item_81_description_25":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_81_description_7":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"コンクリートの凍害は，寒冷地において生じる劣化現象であり，強度の低下や美観の悪化を伴う重大な劣化の一つであるため，凍害危険度などの凍害環境の地域性の評価手法が提案・活用されている。また，コンクリートの長寿命化の観点から，ASTM相当サイクル数などの様々な凍害劣化予測手法が提案されている。一方で，乾燥を受けることにより直径40～2000nm細孔量が増加，耐凍害性が低下することが明らかとなっており，乾燥条件から直径40～2000nm細孔量の予測手法として温湿度時間積が確立されている。しかし，既往の凍害地域性評価や劣化予測手法では乾燥による影響を考慮することができない。そのため，本研究では，ASTM相当サイクル数と温湿度時間積を組み合わせることにより，乾燥による耐凍害性低下を考慮した凍害環境評価および凍害劣化予測手法の確立とその活用方法の提案を目的とした。年間の凍結融解回数であるASTM相当サイクル数と組み合わせて相対動弾性係数を予測するために，温湿度条件から劣化の兆候が現れる過程と明確な劣化が現れる過程における凍結融解1サイクルあたりの相対動弾性係数低下量を導出する式を誘導した。それにより，気象条件と環境条件，材料条件から任意の経過年数における相対動弾性係数や，相対動弾性係数が90％，85％，60％になるまでの年数である安全管理年数，維持管理限界年数，設計限界年数の予測が可能である。本予測手法を用いて凍害環境の地域性を評価するために，気象データの時間間隔や統計処理手法ごとに適した計算手法を検討し，その検討結果を踏まえ，気候変動による凍害環境の地域性の変化として比較的温暖な地域でのみ凍害リスクが減少したことを明らかにした。また，日本国内における凍害環境の地域性分布図の作成し，北海道と本州・九州の山岳部においてはほぼ同等の凍害環境であることを示した。さらに，世界の凍害環境に対する気候帯ごとの整理を行い，亜寒帯が厳しい凍害環境であることを示し，他の気候帯では条件によって凍害環境になる場合があることを明らかにした。本予測手法を用いる際にJIS A 1148 A法の試験結果が必須であるという問題を解決するために，LightGBMを用いた機械学習によって調合条件などからJIS A 1148 A法試験結果予測モデルの作成を試みた。その結果，学習データの偏りによって汎用性は乏しいものの特定条件下であれば十分な精度での試験結果の予測が可能なモデルの作成が行えた。これらの結果を踏まえたうえで，凍害劣化予測システムの提案とそれを利用した維持管理，調合選定への本予測手法の活用方法について提案した。","subitem_description_language":"ja","subitem_description_type":"Abstract"},{"subitem_description":"Frost damage of concrete occurs in cold regions, and is one of the serious deteriorations. Therefore, a method for evaluating the regional characteristics of the frost damage environment, such as the Frost Damage Degree, has been proposed and utilized. In addition, various frost damage prediction methods such as Equivalent Cycles to ASTM Test (CyASTM) have been proposed. On the other hand, it has been clarified that the pore volume of 40 to 2000 nm in diameter increases and the frost resistance decreases due to drying. Based on this, the Maturity of Temperature and Humidity has been established as a method for predicting the pore volume of 40 to 2000 nm in diameter from the drying conditions. However, the effects of drying cannot be taken into consideration by the existing methods for evaluating or predicting frost damage. Therefore, in this study, I aimed to establish a frost damage environment evaluation and frost damage prediction method considering the decrease in frost resistance due to drying by combining CyASTM and Maturity of Temperature and Humidity, and to propose a method of utilizing. In order to predict the relative dynamic modulus of elasticity (RDM) in combination with the CyASTM, an equation to derive the amount of decrease in the RDM per freeze-thaw cycle from the temperature and humidity conditions has created. As a result, it is possible to predict the RDM over arbitrary number of years from climate data, environmental conditions, and material conditions. In order to evaluate the regional characteristics of frost damage environment using this prediction method, a calculation method suitable for each time interval of climate data and statistical processing method has examined. Based on the results of the study, regional distribution map of the frost damage environment in Japan has created, and the frost damage environment is almost the same in Hokkaido and mountainous areas of Honshu / Kyushu has shown. Furthermore, I organized the world’s frost damage environment by climatic zone, showed that the subarctic zone is severe frost damage environment. In order to solve the problem that the test results of the JIS A 1148 A method are indispensable when using this prediction method, a test results prediction model was created from the mix proportions by machine learning using LightGBM. As a result, a model that can predict test results with sufficient accuracy under specific conditions has created, although it is not versatile due to the bias of training data. Based on these results, a frost damage prediction system has proposed.","subitem_description_language":"en","subitem_description_type":"Abstract"}]},"item_81_dissertation_number_13":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"甲第495号"}]},"item_81_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15118/00010864","subitem_identifier_reg_type":"JaLC"}]},"item_81_subject_9":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"511","subitem_subject_scheme":"NDC"}]},"item_81_text_12":{"attribute_name":"学位の種別","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"課程博士"}]},"item_81_text_14":{"attribute_name":"報告番号","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"甲第495号"}]},"item_81_text_15":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"博甲第495号"}]},"item_81_text_16":{"attribute_name":"研究科・専攻","attribute_value_mlt":[{"subitem_text_language":"ja","subitem_text_value":"工学専攻"}]},"item_81_version_type_24":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"open access","subitem_access_right_uri":"http://purl.org/coar/access_right/c_abf2"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorAffiliations":[{"affiliationNameIdentifiers":[],"affiliationNames":[{"affiliationName":""}]}],"creatorNames":[{"creatorName":"野口, 巧巳","creatorNameLang":"ja"},{"creatorName":"ノグチ, タクミ","creatorNameLang":"ja-Kana"},{"creatorName":"NOGUCHI, Takumi","creatorNameLang":"en"}],"familyNames":[{},{},{}],"givenNames":[{},{},{}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2022-06-30"}],"displaytype":"detail","filename":"A495.pdf","filesize":[{"value":"5.9 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"A495","objectType":"fulltext","url":"https://muroran-it.repo.nii.ac.jp/record/10927/files/A495.pdf"},"version_id":"3940ca0a-5469-4394-a164-6e5507f8cc2b"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2022-06-30"}],"displaytype":"detail","filename":"A495_summary.pdf","filesize":[{"value":"381.7 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"A495_summary","objectType":"abstract","url":"https://muroran-it.repo.nii.ac.jp/record/10927/files/A495_summary.pdf"},"version_id":"a02d4b3a-285e-492f-b214-918f2be64e0d"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"doctoral thesis","resourceuri":"http://purl.org/coar/resource_type/c_db06"}]},"item_title":"乾燥を考慮したコンクリートの凍害劣化予測手法と利用に関する研究","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"乾燥を考慮したコンクリートの凍害劣化予測手法と利用に関する研究","subitem_title_language":"en"}]},"item_type_id":"81","owner":"18","path":["227"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2022-06-30"},"publish_date":"2022-06-30","publish_status":"0","recid":"10927","relation_version_is_last":true,"title":["乾燥を考慮したコンクリートの凍害劣化予測手法と利用に関する研究"],"weko_creator_id":"18","weko_shared_id":-1},"updated":"2024-01-05T10:05:23.139159+00:00"}