Investigation of Natural Aging by Colour Change in the Historical Wooden Structures of Istanbul

Öz

In this study, colour changes were examined in naturally aged wood samples taken from structural elements—such as roof trusses and main load-bearing components—of two significant historical industrial buildings in Istanbul: the Fabrika-ı Hümayun in Zeytinburnu, built in 1846, and structures within the Haliç Shipyard in Beyoğlu, constructed in the 1850s. Samples were selectively obtained from structural elements where biological deterioration was not visibly apparent, ensuring minimal interference from microbial or fungal decay. To identify the botanical origin of the samples, both macroscopic and microscopic wood anatomical assessments were conducted. Thin transverse, radial, and tangential sections were prepared and examined under a stereomicroscope and a polarizing research microscope. The wood was identified as pine spruce and fir species. As a result of the study, the colour parameters L* (lightness/brightness), a* (position on the red-green axis), and b* (position on the yellow-blue axis) were measured in the naturally aged wood samples. In the study, the L*, a*, and b* colour coordinate values of the spruce samples taken from both buildings exhibited variations throughout the aging process, depending on the specific location of the sample within the structure and the architectural element. An increase along the b* axis and a decrease in the a* values were observed. When compared with new wood samples, it was observed that the colour values of the aged wood had decreased. The calculated ΔE (colour difference) values for the aged wood samples indicated significant colour changes by aging effect.

Anahtar Kelimeler

• Naturally aged timber
• Historical timber building
• Colour parametres
• Colour measurement

İstanbul’un Tarihi Ahşap Yapılarında Doğal Yaşlanmanın Renk Değişimi ile İncelenmesi

Öz

Bu çalışmada İstanbul’daki önemli endüstri mirası yapılarından, 1846 yılında inşa edilen Zeytinburnu’ndaki Fabrika-ı Hümayun ve 1850’li yıllarda inşa edilen Beyoğlu, Haliç Tersanesi’ndeki yapıların çatı makasları, ana taşıyıcı gibi yapısal elemanlarından alınan doğal yaşlanmış ahşap örneklerinde; renk değişimi incelenmiş ve günümüz odun örnekleri renk değerleri ile karşılaştırılmıştır. Örnekler; biyolojik bozunmanın çıplak gözle görünmediği yapı elemanlarından alınmaya çalışılmıştır. Çalışma sonucunda doğal yaşlanmış ahşap örneklerinde L* (ışıklık/renk parlaklığı), a* (kırmızı-yeşil eksenindeki değer) ve b * (sarı- mavi eksenindeki değer) ölçülmüştür. Doğal yaşlanmış ahşap örnekleri; makroskopik ve mikroskopik ahşap cinsi teşhisi için hazırlanmıştır. Hazırlanan örneklerin ince kesitleri anatomik yapıları araştırma mikroskobu (tek nikol) ve stereo mikroskop altında incelenerek çam, ladin ve göknar cinsi olarak belirlenmiş ve günümüz örnekleri ile karşılaştırıldıklarında da renk değerlerinin azaldığı tespit edilmiştir. Araştırmada her iki binadan alınan ladin örneklerinin renk koordinatlarında L*, a* ve b * değerleri yapının ve yapı elemanın farklı noktalarından alınan örneklerde yaşlanma boyunca değişiklik göstermiştir. Bu değişiklik, b* ekseninde artış ve a* ekseninde azalma olarak tespit edilmiştir. Araştırmada yaşlanmış odun örnekleri için hesaplanan ΔE değeri (renk farkı değeri) belirgin renk farklılıklarını ortaya koymuş ve ciddi yaşlanma etkisi belirlenmiştir.

Anahtar Kelimeler

• Doğal yaşlanmış ahşap
• Tarihi ahşap yapı
• Renk parametreleri
• Renk ölçümü

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