Dolomit k?kenli agregalar?n alkali-karbonat reaktivitesinin ara?t?r?lmas?
Notice bibliographique
Résumé
Son y?llarda ?lkemizdeki baz? betonarme k?pr? ayaklar?, alkali-silika reaksiyonu sonucu hasar g?rm??t?r. Oysaki alkali reaktif agregalar?n kullan?m?n?n betonda hasara yol a?abilece?i 1940'l? y?llardan beri bilinen bir olgudur. Bu konuda gerek yurti?inde gerekse yurtd???nda geni? ?apl? ara?t?rmalar yap?lm??t?r ve yap?lmaya devam etmektedir. Alkali silika reaksiyonu (ASR) gibi alkali karbonat reaksiyonu (ACR) da bir alkali agrega reaksiyonu t?r?d?r. ACR'nin betonda hasara yol a?abildi?i 1950'li y?llardan beri bilinmektedir. ?lkemizde bu konuda yayg?n ?al??malar yap?lmad??? gibi, hen?z hasar da rapor edilmemi?tir. Ancak beton ?retiminde dolomit k?kenli agregalar?n kullan?m?n?n yayg?nla?mas? ile konunun ?nem kazand??? d???n?lmektedir. Dolomitlerde ACR ile dolomit ve kire?ta??, kendilerinden daha b?y?k hacimli olan kalsite ve brusite d?n???r (dedolomitizasyon). Olu?an genle?me betonda harita ?eklinde ?atlaklara yol a?ar. Reaksiyonun ?nlenebilirli?i konusunda farkl? g?r??ler mevcuttur. Kimi ara?t?rmac?lar mineral katk?lar?n ve lityum tuzlar?n?n reaksiyonu ?nleme konusunda ASR'de oldu?u gibi etkili oldu?unu iddia ederken, kimi ara?t?rmac?lar ise bu t?r ?nlemlerin reaksiyonu durduramad??? kan?s?ndad?r. Tez kapsam?nda ilk olarak reaktivite g?steren bir agrega se?ilmi?tir. Se?ilen agrega kullan?larak mineral ve kimyasal katk?lar?n reaksiyonu ?nlemedeki etkinli?i, iki farkl? h?zland?r?lm?? deney y?ntemi (AAR2 ve AAR5) ile ara?t?r?lm??t?r. Sonu?lar? k?yaslamak amac?yla, literat?rde Alkali-Karbonat Reaksiyonu i?in referans agregas? olarak kabul edilen Kanada agregas? da temin edilmi? ve ayn? deneyler y?r?t?lm??t?r. Reaksiyonun geli?imi petrografik incelemelerle ve SEM analizleri ile izlenmi?tir. Her iki agregada da ASR ve ACR'nin birlikte geli?ti?i g?r?lm??t?r. Mineral ve kimyasal katk?lar, reaksiyonu engellemede belli mertebelerde etkili olmaktad?r. Some reinforced concrete bridges have been deteriorated by alkali-silica reaction (ASR) in our country during the last decades. However, deleterious effects of ASR for concrete structures have been known since 1940. There are a lot of experimental studies denoted on ASR in Turkey and in abroad. Alkali carbonate reaction (ACR) in concrete is a kind of alkali aggregate reactions and detrimental effect of it has been known since 1950. However, the detailed investigations have not been conducted on ACR and damage has not been reported yet due to ACR in our country. Dolomites are now used in the production of concrete and it is expected that this phenomenon will be important for the construction industry in near future. Dolomite and limestone convert to the brucite and calcite due to alkali carbonate reaction which causes expansion in concrete and map cracking. Different investigators suggested different preventing measurements in the literature. According to some resources mineral admixtures and lithium salts are effective for preventing the ACR. However, contradictory test results have also been reported. Firstly, a reactive aggregate from Turkey was chosen. Then, influence of mineral and chemical admixtures on controlling the reaction was investigated by conducting two accelerated test methods (AAR2 and AAR5). In order to compare those test results, Canada aggregate, which is considered as reference Alkali-Carbonate reactive aggregate, was supplied and the same tests were also conducted on this aggregate. Development of the reaction was observed by petrographic examinations and SEM analysis. It was seen that both ASR and ACR are available in both of the aggregates. Mineral and chemical admixtures are effective on certain degrees on controlling the reaction.
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 | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,003 | 0,002 |
| Science ouverte | 0,001 | 0,002 |
| Intégrité de la recherche | 0,001 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,023 | 0,007 |
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 ».