木質板在衫木結構牆護板之水平剪力抵抗性能

Performance of Horizontal Shear Resistance on China Fir Wood-framed Wall Sheathed with Wood-based Panels

葉民權(Min-Chyuan Yeh)

《林產工業》 19卷2期 (2000/06) Pp. 219-227

摘要

本研究以2×4輕型木結構框架作為2.4 m×2.4 m尺寸剪力牆之主體結構，探討以廢材及中小徑木加工製成之商用木質複合板材作為牆面護板，框架材採用窯乾之國產造林木杉木材，以評估木質環保建材所組成之剪力牆，在室內及室外對水平載重之抵抗效能，作為業者施工設計時之參考。結果顯示3.2 mm厚硬質纖維板結構牆之最大水平剪斷強度值367 kgf/m為最低，6.1 mm中密度纖維板結構牆以及9.3 mm厚粒片板結構牆次之，分別為545 kgf/m及555 kgf/m，而9.3 mm厚中密度纖維板以及12.4 mm厚粒片板所組成之結構牆為最佳，分別為723 kgf/m及627 kgf/m。在施力第三階段計算所得之剪斷剛性係數值，結果顯示除了3.2 mm厚硬質纖維板結構牆最低外，其餘各木質板結構牆之間並無明顯差別。在室外白蟻暴露試驗八個月後，以硬質纖維板及粒片板所組成之牆面，受到自蟻蛀蝕的面積及牆面數最多。對牆面水平剪斷強度的影響，亦以3.2 mm厚硬質纖維板結構牆為最大，其強度降低64%，其次為中密度纖維板牆平均降低32%，粒片板由於厚度較大，所受到之影響較小，平均降低18%。白蟻對牆面之蛀蝕，亦造成3.2 mm厚硬質纖維板牆之剪斷剛性係數降低58%，但對12.4mm厚之粒片板牆面則無明顯差別。

關鍵字

木質板 ； 木構造框架牆 ； 杉木 ； 水平剪斷強度

並列摘要

The shear walls constituting of 2×4 light structural framing and sheathed with wood -based composite panel s are under investigation for indoor and outdoor performance of horizontal shear resistance in the study. Lumbers of China fir from plantation are used as framing materials for constructing 2.4 m × 2.4 m sizes of specimens. The results indicate that the lowest value of racking strength, 367 kgf/m, can be obtained for the structural wall sheathed with 3.2 mm thick hardboards (HB). And followed by the walls sheathed with 6.1 mm thick medium density fiberboard (MDF) and 9.3 mm thick particleboards (PB), 545 kgf/m and 555 kgf/m, respectively. The higher values of racking strength, 723 kgf/m and 627 kgf/m, can be found for the wall sheathed with 9.3 mm thick MDF and 12.4 mm thick PB, respectively. The shear stiffness obtained from the load-displacement relationship during the third stage of load applications indicates that insignificant difference can be found among various types of sheathing materials except 3.2 mm thick HB, which shows the lower rigidity. After 8-month exposure to termites in the field, both the walls sheathed with HB and PB have more pieces of wall and larger areas of wall surface under termite attacks. The highest reduction in maximum racking strength, 64%, can be found for the wall sheathed with 3.2 mm thick HB and attacked by termite s. The average reduction in maximum racking strength is 32% for the walls sheathed with MDF, while lower value of 18% for the walls sheathed with PB due to thicker panels used. The reduction in shear stiffness also can be found after the walls exposed to the termite attacks. There are 58% reduction for the walls sheathed with 3.2 mm thick HB, but no significant reduction in 12.4 mm thick PB walls.

並列關鍵字

Wood-basedpanels ； Wood-framed wall ； China fir ； Racking strength