探討臺灣櫸作為柳杉結構材補強材料之性質－以評估實大樑之補強性能為例

Assessing the Properties of Taiwan zelkova as Reinforcement Material in Structural Lumber of Japanese cedar - A Case Study on the Reinforcing Performance of Real Beam

莊閔傑(Min-Jay Chung) ； 楊茜諭(Chien-Yu Yang) ； 林法勤(Far-Chin Lin)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 36卷1期 (2022/03) Pp. 27-42

https://doi.org/10.6542/EFNTU.202203_36(1).0003

摘要

本研究利用臺灣櫸（Zelkova serratu）做為柳杉（Cryptomeria japonica）實尺寸結構用材之補強材料，以抗彎彈性模數（MOE）試驗進行集成元之強度性質評估，計算出膠合樑之抗彎彈性模數預測值（E_(bp)），經配置後膠合成樑進行抗彎強度（MOR）性質、膠合剪斷性質、剝離性質及縱向壓縮強度性質之評估。試驗結果顯示依據集成元之MOE值進行分等配置，並依據彎曲剛性（EI）相等之原則，計算各層集成元配置過後膠合樑之E_(bp)，與抗彎彈性模數實驗值（E_(bo)）做相關性分析，其R^2值為0.74，顯示具有顯著正相關，並可達到預測效果。再者，由抗彎試驗結果顯示，將17 mm厚度之臺灣櫸於柳杉上下兩側做為補強材料時，其E_(bo)及MOR值分別為9.7 GPa及74.8 MPa，相較柳杉對照組分別提升14.5%及49.8%。另外，實大樑及小尺寸之相同比例試材，比較E_(bo)時則具有相似之結果，若比較MOR時，實大樑以17mm臺灣櫸補強於上方之試材可顯著提升強度，小尺寸試材則無差異。於膠合樑之抗壓強度分析結果顯示各組之間無顯著差異，其破壞模式依照ASTM D143-94表示主要為膠合層破壞型。

關鍵字

臺灣櫸 ； 柳杉 ； 補強 ； 膠合樑 ； 結構用材

並列摘要

This s tudy e valuated t he pro perties of Zelkova serrata as re inforcement m aterial in structural lumber of Cryptomeria japonica. The strength properties of the laminae were evaluated by bending t est. N ext, t he pre diction of t he modulus of e lasticity (E_(bp)) was cal culated t o predict the bending stiffness of reinforced glulam. The bending properties evaluated the properties of the glulam also. The bending stiffness data were calculated by using the modulus of elasticity (MOE) of laminae. The study learned that MOE of reality (E_(bo)) increased when the E_(bp) increased, and the R^2 value was 0.74, which indicated positive and significant relationship to be used for the prediction of E_(bp) based on E_(bo). Furthermore, results showed that E_(bo) and MOR of beams with 17-mm Z. serrata glued to both upper and lower sides were 9.7 GPa and 74.8 MPa, respectively, which were 14.5% and 49.8% higher than those of non-reinforced control beams, indicating outstanding reinforcement effect. In addition, the actual ratio of the large beam and the small-scale samples had similar results when compared with E_(bo). When c ompared with MOR, the l arge be am was s ignificantly s trengthened by t he 17 mm Z. serrata, but the small size samples showed no difference. The compressive strength analysis results of the glulam beams showed no significant difference between the groups, and the failure mode was mainly characterized by the failure of the gluing layer according to ASTM D143-94.

並列關鍵字

Zelkova serrata ； Cryptomeria japonica ； Reinforcement ； Glulams ； Structural material