九種戶外用材之物理力學性質及其抗生物劣化性評估

Evaluation of the physicomechanical properties and biodeterioration resistance of nine commercial wood in outdoor applications

本研究主要評估九種戶外常見來自南洋與中南美產木材之基本物理與力學性質及其抗生物劣化性（抗家白蟻性與耐腐朽性），相關試驗依國家標準進行。結果指出，九種木材之徑向全收縮率與弦向全收縮率分別介於3.97%~12.31%與6.58%~14.56%間，其中以蒜果木（Scorodocarpus borneensis）之橫向收縮率值最高，顯示較差之尺寸安定性。九種木材之抗彎強度與彈性模數、抗壓強度與抗剪強度性質方面，其值介於100.0~175.2 MPa、10.0~17.5 GPa、47.8~84.1 MPa以及12.3~21.5 MPa間。經過21天家白蟻試驗與12週的腐朽菌試驗後，可發現婆羅洲鐵木（Eusideroxylin spp.）具有較佳的抗生物劣化性。 This study evaluated the physico-mechanical properties, decay and termite resistance of the commercial wood which were used widely in outdoor applications. Nine commercial hardwood species from Southeast Asia and Latin America were selected and tested for their fundamental properties and resistance to termite (Coptotermes formosanus) and fungi (Laetiporus sulphureus, Lenzites betulina) by the CNS standards. Among the all species, Ungsunah wood (Scorodocarpus borneensis) showed the highest transverse shrinkage, and the shrinkage were about 3.97% to 12.31% in the radial direction and 6.58% to 14.56% in the tangential direction, respectively. In addition, the bending strength and modulus of the selected wood were ranged from 100.0 MPa to 175.2 MPa and 10.0 GPa to 17.5 GPa, respectively. The compression strength and shear strength of the selected wood were ranged from 47.8 MPa to 84.1 MPa, and 12.3 MPa to 21.5 MPa. After 21 days termite testing, the mass loss percentage of all specimens could meet the standard as specified in CNS 15756, similar results were also found in 12 weeks anti-fungi testing. The results also revealed that Belian wood (Eusideroxylin spp.) had the better biodeterioration resistance ability.