國產孟宗竹材密度分布特性對其基礎性質之影響

Effects of wood density on fundamental properties of domestic Moso bamboo

本研究旨為建立國產孟宗竹材基礎性質資料，以竹材密度作為評估基準，分析各種物理及力學性質關係，提供竹材選材利用之依據。本研究以4年生國產孟宗竹為材料，製備及調濕完成後進行物理、力學及生物耐久性能試驗，結果顯示用孟宗竹材密度分布差異大，且與物理性質具有相關性，可做為未來開發新型工程材料選材之依據。透過孟宗竹抗彎強度與抗彎彈性模數力學性質試驗與分析，孟宗竹平均抗彎強度為126.8-152.8 Mpa，隨氣乾密度增加平均抗彎強度有上升趨勢；平均抗彎彈性模數10.6-12.2 Gpa，經統計分析不同密度間無顯著差異。生物耐久性能試驗結果顯示隨竹材密度增加，白蟻食害質量減少率有下降趨勢，但白蟻致死率與竹材密度無顯著趨勢關係，而經4種腐朽菌試驗後隨竹材密度增加，質量損失率有下降趨勢，其中以 Trametes versicolor降解竹材能力最高。

This study investigated the effects of density variation on the selected physicomechanical properties and biological resistance ability of 4-year-old domestic Moso bamboo. Wood density has been shown to be a critical indicator for predicting bamboo properties, the knowledge of its variation is vital for future processing and utilization. The results showed that while densities of the Moso bamboo differed greatly, the distribution still conformed a typical normal distribution pattern. Relationships among density and selected properties were also determined to provide fundamental information for selecting suitable materials to develop bamboo products. For the bending properties of Moso bamboo, the modulus of rupture of bamboo ranged from 126.8 to 152.8 MPa and increased with increasing air-dry density. However, there was no significant correlation between bamboo's density and modulus of elasticity (10.6 to 12.2 GPa). There correlation between bamboo density and mortality of termites after 21-day termite testing was also not significant. However, in decay testing, the mass loss decreased with increasing bamboo air-dry density. Among four fungi species, Trametes versicolor had the highest degrade bamboo ability.