EVALUATION OF THE DECAY LEVELS OF WOODEN COMPONENTS IN ARCADE BUILDINGS IN THE ANCIENT TOWN CHIKAN VIA POLARIZED LIGHT, FLUORESCENCE AND FTIR SPECTRA

In order to classify the decay levels of Chinese fir (Cunninghamia lanceolata) wood components in arcade buildings in the ancient town Chikan and to provide basic data for future protection measures, the extent of decay of the samples was determined via polarized light, fluorescence, and Fourier-transform infrared spectroscopy. The results were as follows: (1)Thetotal birefringence brightness of crystalline cellulose and the green fluorescence brightness of the lignins were reducedto different degreesin almost all samples. (2)Theabsorption peaks at 1731 cm-1representing hemicellulose and at 891 cm-1representing cellulose in all samples disappeared. The absorption peak heights at 1370 cm-1, 1159 cm-1and 1058 cm-1which represents holocellulose,and at 1508 cm-1, 1424 cm-1, and 1262 cm-1which represents lignin decreased to varying degrees. (3)From the analysis, the decay level of wooden components in arcade buildings was divided into three classes, i.e., Level I (severe decay), Level II (moderate decay), and Level III (mild decay).