柳杉材等級區分法及ACQ防腐處理之集成材性質

Abstract

連續式應力分等設備（Continuous mechine stress rating equipment, MSR）可透過密集量測整支木材多個點位之抗彎彈性模數（Modulus of elasticity, MOEStatic），以客觀且更全面的方式瞭解材料的機械性質，因此本試驗以連續式應力分等機、抗彎試驗、超音波法及打音頻譜法評估柳杉（Cypertomeria japonica）集成元各項動彈性模數（Dynamic modulus of elasticity, DMOE）與彈性模數之相關性。另一方面，探討柳杉造林木之原木形質與製材利用率及集成元品質之關係，且為提升木材耐久性並使其符合使用環境，以銅烷基銨化合物系木材防腐劑（Alkaline Copper Quat, ACQ）進行柳杉集成元防腐處理，探討 ACQ 防腐處理對柳杉機械性質之影響。此外，製備對稱異等級集成材，並進行抗彎、抗壓、膠合剪斷、煮沸剝離等試驗，以評估集成材配置對抗彎強度之影響及其膠合性質。 結果顯示，未處理與ACQ防腐處理柳杉集成元之抗彎試驗彈性模數（MOEStatic）與連續式應力分等機平均抗彎彈性模數（MOEMSR(Avg.)）之間相關性高，其R2分別為0.75及0.88，且MOEMSR(Avg.) >MOEStatic，此外ACQ防腐處理柳杉集成元之DMOE亦與MOEStatic及MOEMSR(Avg.)之相關性高，其R2為0.82 – 0.91，且DMOE均高於MOE（DMOEu > DMOEt >MOEMSR(Avg.) >MOEStatic）。另一方面，柳杉原木依CNS 442（2017）進行造林木原木目視等級區分，以1等原木之比例最高，而製材利用率不受原木目視等級影響，但隨原木徑級之增加，製材利用率有上升之趨勢。 本試驗集成材之MOE及MOR分別為7.2 GPa – 11.12GPa及30.9 MPa – 62.7MPa，利用集成理論以MOEMSR(Avg.)可有效預測集成材之抗彎彈性模數，其預測值與實測值之R2為0.85，且集成材外層配置之集成元機械等級對抗彎及抗壓性質之影響較大，因此透過在集成材外層配置高機械等級集成元，內側配置低機械等級集成元，可使集成元之強度仍符合標準，又可提高木材的利用率。此外，本試驗之集成材具有良好的膠合性質，其膠合剪斷強度、木破率及膠合層剝離率均可符合CNS 11031（2014）結構用集成材之標準，且於抗彎試驗中，沒有發生膠合層破壞。

Using continuous mechine stress rating equipment (MSR) could know the mechanical properties of lumbers in an objective and exhaustive way by intensively measuring multiple points on whole lumbers to get modulus of elasticity(MOE). Therefore, use continuous stress grading machine, bending test, ultrasonic wave method and tap tone method to assess the correlation between dynamic modulus of elasticity (DMOE) and MOE of Japanese cedar (Cypertomeria japonica) laminae. On the other hand, discuss sawing lumber yield and laminae quality of different log grade. In order to improve the durability of lumbers and coincide the use environment, use ACQ wood preservative to treat on Japanese cedar laminae. Then discuss the effect on mechanical properties of preservative treated laminae. Furthermore, prepare symmetric composition of heterogeneous-grade glulam, and discuss the effect of configuration of laminae on bending strength and compressive strength by the tests of bending, compression, adhesive bonding shearing and adhesive boil-delaminated. The results show that both MOE of bending test (MOEStatic) and MOE of continuous stress grading machine (MOEMSR(Avg.)) have high correlation between untreated and ACQ preservative treated laminae, while R2 is 0.75and 0.88 respectively. In addition, the dynamic modulus of elasticity (DMOE) of ACQ treated laminae also has a high correlation on MOEStatic and MOEMSR(Avg.) , and R2 is 0.82 and 0.91 respectively while DMOE is higher than MOE (DMOEu > DMOEt >MOEMSR(Avg.) >MOEStatic). On the other hand, visually grading cedar logs by CNS 442 (2017), the highest proportion is first-class logs. Although the sawing lumber yield is not affected by visual grade of logs, it has an upward trend as log diameter increasing. The MOE and MOR of glulam are 7.24 - 11.12 GPa and 30.86 - 62.69MPa respectively. Using integration theory could effectively predict MOE of glulam. The R2 between the predicted value and the actual value is 0.85, and the bending property and compression property are affected by the mechanical grade of lamina which is configured on the outer layer of glulam. The strength of glulam could still meet the standard and the recovery of lumber could improve by arranging high mechanical grade laminae on the outer layer and low mechanical grade laminae on the inner side of glulam. In addiction, there are good adhesive bonding properties of glulam, such as the adhesive bonding shear strength, wood failure rate and adhesive boil-delaminated are all in line with CNS 11031(2014), and there’s no adhesive layer destruction in glulam bending test.