Deterioration of Microstructures and Properties in Ancient Architectural Wood from Yingxian Wooden Pagoda (1056 AD) during Natural Aging

• Published in: Forests Vol. 14; no. 2; p. 393
• Main Authors: Long, Keying, Chen, Kaiqiang, Lin, Lanying, Fu, Feng, Zhong, Yong
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.02.2023
• Subjects: Aging; Aging (natural); ancient architectural wood; Architecture; Atomic force microscopy; Biodegradation; Cell walls; Cellulose; Chemical degradation; Cultural heritage; Cultural resources; deterioration; Forestry research; Fourier transforms; Hemicellulose; Historical structures; Humidity; Infrared analysis; Infrared spectroscopy; Investigations; Laboratories; Larix principis-rupprechtii; Light microscopy; Lignin; Magnetic resonance spectroscopy; Materials; Mechanical properties; Microscopy; Microstructure; Modulus of elasticity; Nanoindentation; natural aging; NMR; NMR spectroscopy; Nuclear magnetic resonance; Optical microscopy; Pagodas; Physiological aspects; Preservation; Properties; Solids; Spectrum analysis; Structure; Technology assessment; Timber construction; Wood; wood cell wall; X-ray diffraction; Xylan; Yingxian Wooden Pagoda; China; New York; United States > US; Japan; Germany
• ISSN: 1999-4907; 1999-4907
• DOI: 10.3390/f14020393

The Yingxian Wooden Pagoda (1056 AD), located in Shanxi province, China, is a unique architectural pure-wooden artifact standing for a millennium. Despite its longevity, the structures and properties of the ancient architectural woods used in its construction have been significantly degraded due to long-term natural aging, which has profoundly impacted the preservation of this valuable cultural heritage. To better understand this degradation, we studied the deterioration of a baluster (Larix principis-rupprechtii Mayr.) from Yingxian Wooden Pagoda. The study employed various analytical techniques, including optical microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy, X-ray diffraction, and nanoindentation technology, to evaluate the microstructures and properties of the ancient architectural woods. Results indicated that the destruction of wood cell walls was primarily transverse transwall destruction and interfacial debonding and that the degradation of chemical components was primarily in the hemicellulose (xylan) and amorphous region of cellulose. The reduced elastic modulus and hardness of tracheid cell walls in the ancient architectural woods were higher than in recent larch woods. This study would help deepen understanding of wood deterioration during long-term natural aging for the subsequent preservation and protection of wooden cultural heritages and longer use of ancient timber constructions.