柞木弦/径切面胶合强度的试验研究

The study on strength of radial and tangential surfacesand bonding strength of radial and tangential glued blocks with API adhesive

对柞木木材自身弦／径面强度及其水性高分子异氰酸酯(API)胶粘剂胶合试件弦／径面胶接强度进行了研究。结果表明:柞木木材API胶粘剂弦／径面胶合试件常态压缩剪切强度存在着差异;柞木径切面API胶合试件的常态压缩剪切强度比弦切面胶合试件的常态压缩剪切强度高;径切面API胶合试件的常态压缩剪切强度是弦切面的1.22倍;而柞木弦、径面API胶合试件的反复煮沸压缩剪切强度没有显著性的差别。柞木木材本身弦／径面顺纹抗剪强度试验结果表明:柞木木材径向的顺纹抗剪强度为14.41MPa,柞木木材弦向的顺纹抗剪强度为14.97MPa,尽管弦径向间差别不大,但经t-检验证明:柞木的弦／径向间顺纹抗剪强度有显著性的差别,柞木的径向顺纹抗剪强度比弦向顺纹抗剪强度小。

Bonding strengths of Oak glued block with radial surface and tangential surface bonded with API adhesive and shear strength to the grain of Oak were studied in this paper. The results showed that: there was significant difference in dry compressing shear strength between radial and tangential glued blocks bonded with API adhesive. Dry compressing shear strength of glued block with Oak radial surface was bigger than that with Oak tangential surface. Dry compressing shear strength of glued block with Oak radial surface was 1.22 times that with Oak tangential surface, but there was no significant difference in wet bonding strength between radial and tangential glued blocks for repeatedly boiling samples. The results of strength of solid Oak wood showed that shear strength to the grain of radial surface was 14.41MPa, shear strength of tangential surface was 14. 97MPa. Though this difference was very small, the t-test showed there was significant difference in shear strength to the grain between radial surface and tangential surface for Oak. Shear strength to the grain of radial surface was smaller than that of tangential surface for Oak.