Acoustic emission monitoring of reinforced concrete beams repaired with engineered cementitious composites
Notice bibliographique
Résumé
In this thesis, acoustic emission (AE) monitoring was employed to analyze, characterize, and quantify the cracking behavior of a total of thirteen large-scale reinforced concrete (RC) multi-layered beams under flexural testing. The experimental work performed in this thesis was divided into two studies. In the first study, four RC beams were repaired with engineering cementitious composites (ECC) in either the tension zone or the compression zone of the beam. Two types of fibers were used in the ECC repair material: polyvinyl alcohol fiber (PVA) and steel fiber (SF). Three control beams (reference beams used for comparison) were tested for comparison including one normal concrete beam and two fully cast ECC beams with PVA and SF. AE parameters such as number of hits, cumulative signal strength (CSS), signal amplitude, peak frequency, absolute energy, and b-value (defined as the log-linear slope of AE’s frequency-magnitude distributions) were considered and used to evaluate the cracking behavior of both the repaired and unrepaired beams. Furthermore, rise time/maximum amplitude (RA) vs. average frequency (AF) analysis was implemented to categorize different failure modes (flexural, shear, or debonding). Varying the fiber type as well as sensor location/repair location seemed to have a significant effect on the signal amplitude and number of hits. With the aid of analyzing AE parameters (number of hits, CSS, and b-value), the first crack for all tested beams was successfully determined in the seven tested beams. In the second study, the flexural testing of four ECC multi-layered beams incorporated either crumb rubber (CRECC) or powder rubber (PRECC). Four beams were repaired in either the tension zone or the compression zone of the beam. Three beams were fully cast in normal concrete, CRECC, and PRECC, and were used as control beams (reference beams used for comparison). A variety of AE parameters such as number of hits and CSS as well as b-value were used to analyze the crack propagation of the tested beams. Damage quantification charts pertaining to different cracking stages (first crack and ultimate load), based on historic index [H (t)] and severity [Sr], were created in this study to categorize and quantify damage severity in terms of crack growth in composite beams. Alternating the rubber particle size, repair location or sensor location resulted in noticeable variations in the AE parameters (signal amplitude, CSS, and number of hits). For both studies, the addition of a new concrete layer (ECC incorporating fiber and/or rubber particles) seemed to result in a noticeable effect on AE parameters such as signal amplitude. In addition, varying the strengthening location, sensor location, and fiber type/ rubber particle size showed an impact on several AE parameters including number of hits, CSS, and b-value. By carrying out the AE analyses mentioned, the first crack identification for both the repaired and unrepaired beams was possible. Damage quantification and failure mode classification charts were successfully obtained by intensity analysis and rise time/amplitude analysis.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».