防腐藥劑處理對杉木集成材物理及力學性質影響

Abstract

本研究以目視分等、超音波法、打音法及抗彎試驗評估杉木（China fir, Cunninghamia lanceolata）集成元各項非破壞性質及各項彈性模數之間相關性後，進行銅烷基銨化合物（Ammoniacal Copper Quaternary, ACQ）不同防腐藥劑注入量處理（K4、K5等級），並規劃同等級與異等級配置組合之集成材進行抗彎、膠合剪斷、煮沸剝離、縱向壓縮及尺寸安定性等試驗，藉此評估ACQ防腐處理與分級配置對杉木集成材之影響。試驗結果顯示未處理與防腐處理後之集成元利用非破壞試驗及抗彎試驗所得之動彈性模數（Dynamic modulus of elasticity, DOME）與靜彈性模數（Modulus of elasticity, MOE）之間相關性高，R2值為0.60～0.78，且DOME均高於MOE值（DMOEu＞DMOEf＞MOE），其中打音法所得之DMOEf更接近實際之MOE值（R2值0.78），防腐處理前與處理後之杉木均可利用非破壞試驗進行強度分等作業。 集成元經防腐處理有效吸收量達K4、K5等級後之平均MOE及DMOE值較對照組下降約±15 %。而同等級與異等級集成材在經過防腐處理後其抗彎破壞強度（Modulus of rupture, MOR）與MOE值均下降，經過統計分析後是無顯著差異的。以同等級集成材進行縱向壓縮試驗，防腐處理試材較未處理者下降25.63-32.18%，各組之間有顯著差異，由此顯示防腐處理對集成材之抗彎性質影響並不顯著但對抗壓性質則有影響。在尺寸安定性之試驗結果中防腐處理組與對照組間也無顯著差異。評估防腐處理前後各項性質，防腐處理影響並不顯著，所得試驗結果可提供杉木應用於結構用材設計使用參考。 另外同等級集成材之MOE與MOR大於異等級集成材，但經統計分析顯示皆無顯著差異。透過異等級結構用材配置，中間層以較低彈性模數集成元配置，仍符合CNS 11031結構用集成材強度標準，且可以有效利用中低等級之集成元，提升木材利用率。

The purpose of this study was to investigate and analysis the correlation between the dynamic and static bending properties of China fir (Cunninghamia lanceolata) laminae using visual grade method, ultrasonic wave method, tap tone method and static bending test. Laminae after ACQ preservative treatment (K4 and K5 grade) was to construct homogeneous and heterogeneous-grade structural glued laminated timber, and evaluate the effect of preservative treatment and laminae configuration on the bending properties, shear properties, delaminating properties, longitudinal compressive properties, radial and tangential shrinkage. The correlation between the dynamic and static bending properties determined by non-destructive method and static bending test of control groups and ACQ-treated laminae was high (R2 = 0.60-0.78). The result also showed that the dynamic MOE is higher than the static MOE of laminae (DMOEu＞DMOEf＞MOE), however, the values of DMOEf determined by tap tone method were very close to the values of MOE. It is feasible to use the non-destructive method for mechanical grading of laminae and preservative treated laminae. The variation of the average MOE and DMOE values of ACQ preservative-treated laminae (K4 and K5 grade) compared with the control group were about ±15 %. The MOE and MOR of preservative-treated homogeneous and heterogeneous-grade structural glued laminated timber were lower than the control groups by about 12.06-20.13%. However, the differences of MOE and MOR values between preservative-treated groups and control groups were not significant according to ANOVA analysis. The longitudinal compressive strengths of preservative-treated homogeneous-grade glulam were lower than the control groups by about 25.63-32.18%, and there was a significant difference among preservative-treated groups and control groups. It is speculated that the effect of preservative treatment on the bending properties of glulam was not significant. The difference of the average radial and tangential shrinkages between most preservative-treated China fir laminae and control groups was not significant according to ANOVA analysis. To evaluate the physical properties and mechanical properties of China fir glulam, the effect of preservative treatment is not significant. And the result of this study maybe can provide reference for the use of China fir structural glued laminated timber. In addition, the MOE and MOR of homogeneous-grade structural glued laminated timber were higher than heterogeneous-grade structural glued laminated timber, but there was not a significant difference among homogeneous-grade glulam and heterogeneous-grade glulam. Design the configuration of heterogeneous-grade glulam, placing the laminae of lower MOE grades in the middle layer which strengths still can conform the standard of CNS 11031 structural glued-laminated timber. And it also can effectively utilize the medium-to-low grades laminae.