- 期刊
柳杉與杉木單板層積材之基本性質研究
Studies on the Basic Properties of Laminated Veneer Lumber Made from Japanese Cedar and China Fir Woods
摘要
本報告係探討由2mm及4mm厚度之柳杉及杉木旋切單板所構成的五種不同單板配置類型（Type A ~ Type E）之單板層積材的各種基本性質。其結果可歸納於次；單板層積材之比重，含水率均會隨膠合層數增加而增大。在靜曲強度，H型試片，柳杉LVL係以Type D及Type E，杉木LVL則以Type D較佳。而V型試片，柳杉及杉木LVL均以Type B較為良好。（三）縱向壓縮強度，柳杉及杉木LVL均以Type D，Type B及Type E較佳。（四）衝擊彎曲吸收能量系以H型試片優於V型，但五種類型LVL間無顯著性差異。（五）徑面剪斷強度以Type B LVL為最大，但弦面剪斷強度則以Type B LVL為最小，其他四種類型LVL間無顯著性差異。（六）膠合剪力在五種類型LVL間無顯著性差異。（七）普通鐵釘與木螺釘之釘著力均以橫切面為最小，弦面與徑面差不多，但不同引導孔穴間，其木螺釘保持力為2.38mm＜2.80mm＜3.18mm。但五種類型LVL間無顯著性差異。（八）柳杉與杉木LVL之靜曲強度，靜曲彈性係數與縱向壓縮強度，彈性係數均會随比重增加而比例增大。
並列摘要
The purpose of this paper was investigated the basic properties of five various construction laminated veneer lumber (LVL) made from 2 mm and 4 mm thick of rotary cut veneers. The veneers were peeled from Japanese cedar (Cryptomeria japonica D. Don.) and China-fir (Cunninghamia lanceolata) grown in Chi-Tou area, Experimental Forest, National Taiwan University. The urea fomaldehyde resin were used as a binder. The results were summarized as follows: (1) The specific gravity and moisture content of LVL increased with glued layers. (2) In the case of bending strength, when the direction of span was parallel to the glued layers of LVL (H type specimens), Type D and Type E were better than other types in the Japanese cedar LVL, Type Dwas better than other types in the China-fir LVL. However, as the direction of span was vertical to the glued layers of LVL ( V type specimens), Type B was better than other types in the Japanese cedar and China fir LVL. (3) The longitudinal compression strengh of Type B. Type D and Type E were better than those of other types in Japanese cedar and China fir LVL. (4) The impact bending strength of H type specimens of LVL were better than that of V type specimens, there is no significant difference in five various type LVL. (5) The strongest shearing strength in the radial section was Type B LVL, but in the tangential section, Type B showed the weakest shearing strength. From the results of Duncan's new multiple ranage test, a significant difference existed between radial and tangential section, Type B revealed very clear difference. (6) There is no significance difference in bonding strength among five various types LVL. (7) End section appear to be the weakest nail and screw holding force. In between radial and tangential section, there is no significant difference in nail and screw holding force. The order of holding strength of three pilot hole was 2.38 mm, 2.80 mm and 3.18 mm. (8) The values of MaR, MOE, σ_c and E_e increased with linearly increasing the (Cryptomeria cumminghamia).