Journal of Wood Science

, Volume 56, Issue 6, pp 444–451 | Cite as

Strength properties of glued laminated timber made from edge-glued laminae I: strength properties of edge-glued karamatsu (Larix kaempferi) laminae

  • Kiyohiko Fujimoto
  • Yasushi Hiramatsu
  • Atsushi Miyatake
  • Kenta Shindo
  • Masahiko Karube
  • Masaki Harada
  • Seiichiro Ukyo
Original Article

Abstract

The object of this study was to investigate the strength properties of edge-glued laminae and to propose a suitable grading method based on the lamina modulus of elasticity (MOE). Edge-glued laminae composed of lumber with similar MOEs (uniform laminae) and edge-glued laminae produced by randomly gluing lumber independent of MOE (random laminae) were made from karamatsu (Larix kaempferi) lumber having the same thickness and length, but various widths. For both the uniform and random laminae, there was a strong correlation between MOE values measured using the longitudinal vibration technique, the static bending test, and a grading machine. The average values of bending, tensile, and compressive strengths of the uniform laminae were similar to those of the random laminae. On the other hand, the average strength of laminae without end joints was significantly higher than that of finger-jointed laminae for both uniform and random laminae. Finger-joints and knots played a significant role in the failure of specimens, but the edge-gluing and the difference in MOE within an edge-glued lamina did not appear to affect the strength properties. The bending, tensile, and compressive strengths of edge-glued laminae were strongly correlated to the lamina MOE.

Key words

Edge gluing Lamina Strength property Modulus of elasticity Glued laminated timber 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    McAlister RH (1974) Edge-glued dimension lumber from low-grade southern pine. Forest Prod J 24(7):17–22Google Scholar
  2. 2.
    Ohashi Y, Sato T, Taguchi T, Toda M, Matsumoto K, Takayama M (2003) Development of a floor joist for wood frame construction using todomatsu lumber (in Japanese). J Hokkaido Forest Prod Res Inst 17:7–14Google Scholar
  3. 3.
    Johnson JW (1978) Edge-gluing Douglas-fir lumber to improve strength properties. Forest Prod J 28:37–43Google Scholar
  4. 4.
    Johnson JW (1980) Bending strength of lodgepole pine lumber increases after edge-gluing. Forest Prod J 30:35–36Google Scholar
  5. 5.
    Johnson JW (1980) Tension laminations from edge-glued lodgepole pine and machine-rated hem-fir lumber. Forest Prod J 30:23–27Google Scholar
  6. 6.
    Yanagawa Y, Ueda M (1992) Tensile strength of Douglas-fir laminae for glued-laminated timber (in Japanese). Bull Nara Pref Forest Exp Sta 22:36–44Google Scholar
  7. 7.
    Yanagawa Y, Ueda M (1993) Tensile strength of sugi laminae for glued-laminated timber (in Japanese). Bull Nara Pref Forest Exp Sta 23:1–6Google Scholar
  8. 8.
    Hayashi T, Miyatake A (1993) Effects of defect randomization on the strength properties of wood laminates (1): Increase of lower exclusion limit of the strength by edge-jointing (in Japanese). Wood Ind 48:472–476Google Scholar
  9. 9.
    Fujita M, Miyoshi S, Takechi M (1998) Usage techniques of sugi structural wood (in Japanese). Bull Ehime Pref Exp Sta 19:108–119Google Scholar
  10. 10.
    Shibata N, Itoh Y, Hashizume T (2001) Influence of finger shape and un-overlapped finger joints within edge-glued lumber (in Japanese). Bull Nagano Pref Forestry Res Center 15:48–58Google Scholar
  11. 11.
    Shibata N, Hashizume T, Itoh Y (2004) Strength properties of karamatsu (Larix kaempferi) glued laminated timber using edge-glued lumber with un-overlapped finger joints on tensile side lamination (in Japanese). Bull Nagano Pref Forestry Res Center 18:103–110Google Scholar
  12. 12.
    Sobue N (1986) Measurement of Young’s modulus by the transient longitudinal vibration of wooden beams using a fast Fourier transformation spectrum analyzer. Mokuzai Gakkaishi 32:744–747Google Scholar
  13. 13.
    The Ministry of Agriculture, Forestry and Fisheries of Japan (2007) Japanese agricultural standard for glued laminated timber. The Ministry, TokyoGoogle Scholar
  14. 14.
    British Standards Institution (2003) Timber structures — structural timber and glued laminated timber — determination of some physical and mechanical properties. BS EN 408:2003Google Scholar
  15. 15.
    Hashizume T, Yoshida T, Saito T, Ishihara S (1997) Properties of laminae from a planted Japanese larch tree and the mechanical properties of glued laminated timber II: grading for laminae and estimation of the strength grade for glulam (in Japanese). Mokuzai Gakkaishi 43:940–947Google Scholar
  16. 16.
    Hashizume T, Yoshida T, Takeda T, Ishihara S (1998) Properties of laminae from a planted Japanese larch tree, and the mechanical properties of glued laminated timber IV: bending and tensile strength properties of laminae (in Japanese). Mokuzai Gakkaishi 44:49–58Google Scholar

Copyright information

© The Japan Wood Research Society 2010

Authors and Affiliations

  • Kiyohiko Fujimoto
    • 1
  • Yasushi Hiramatsu
    • 1
  • Atsushi Miyatake
    • 1
  • Kenta Shindo
    • 1
  • Masahiko Karube
    • 1
  • Masaki Harada
    • 1
  • Seiichiro Ukyo
    • 1
  1. 1.Forestry and Forest Products Research InstituteTsukubaJapan

Personalised recommendations