Effect of Weathering Tests on Wood Properties

Öz

The knowledge on the aging of wood and changes on wood properties due to aging is very important in terms of preserving historical wood buildings and wood cultural heritage such as wood objects. Furthermore, againg studies can help to predict the service life of wood. For this purpose, wood can be directly exposed to degrading factors in outdoor conditions, or degradation can be artificially simulated in laboratory conditions. Although natural weathering tests gives the most accurate and reliable results, it is not commonly preferred due to long test periods and high safety requirements. For this reason, artificial aging, which is mostly controlled under laboratory conditions, is commonly preferred by the reseachers. In this review study, the effects of the degrading factors of wood in outdoor conditions were investigated. In the study, abiotic and biotic factors, wood degradation, photodegradation of wood, and its effects on wood properties have been reported. Besides, different artificial and natural aging test methods and modelling between the aging methods are examined.

Anahtar Kelimeler

• Accelerated weathering
• natural weathering
• photodegradation
• modelling

Yaşlandırma Testlerinin Ahşap Malzemenin Özelliklerine Etkisi

Öz

Ahşap malzemenin yaşlandırılması ve yaşlandırılan ahşabın özelliklerindeki değişimin bilinmesi tarihi ahşap binalar ve ahşaptan yapılmış nesneler, objeler gibi ahşap kültürel mirasların korunması açısından çok önemlidir. Yaşlandırmayı konu alan çalışmalar, malzemenin kullanım ömrünün belirlenmesini de sağlamaktadır. Bunun için malzeme doğal dış ortam koşullarının bozundurucu faktörlerine direkt olarak maruz bırakılabileceği gibi laboratuvar koşullarında da dış ortam bozunması yapay olarak simüle edilebilmektedir. Doğal dış ortam koşullarına maruz bırakma en doğru ve güvenilir sonuçlar verse de testlerin uzun yıllar sürmesi ve yüksek güvenlik ihtiyacı sebeplerinden dolayı çoğunlukla laboratuvar koşullarında kontrollü gerçekleştirilen yapay yaşlandırmalar tercih edilmektedir. Bu derleme çalışmasında, ahşap malzemenin dış ortam koşullarında kullanımı sırasında maruz kalabileceği bozundurucu faktörlerin ahşap özelliklerine etkisi araştırılmıştır. Çalışmada ahşabı bozunduran abiyotik ve biyotik faktörler, ahşap malzemenin fotodegradasyonu ve bunun sonucu olarak ahşapta meydana gelen değişimler incelenmiş, farklı yapay ve doğal yaşlandırma test yöntemleri irdelenmiştir. Ayrıca yapay ve doğal yaşlandırma arasında modelleme çalışmalarına da değinilmiştir.

Anahtar Kelimeler

• Yapay yaşlandırma
• doğal yaşlandırma
• fotodegradasyon
• modelleme

Teşekkür

Bu çalışmada derlenen bilgilerin bir kısmı Şebnem S. Arpacı’nın Bursa Teknik Üniversitesi Fen Bilimleri Enstitüsü bünyesinde 2020 yılında tamamladığı ‘Çeşitli Odun Türlerinin Dış Ortam Koşullarında Ultraviyole Işınlarına Karşı Dayanımlarının Belirlenmesi’ başlıklı yüksek lisans tezinde sunulmuştur.

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