DOI QR코드

DOI QR Code

Evaluation of Physical and Mechanical Properties of Non-certificated Laminated Veneer Lumber (LVL) Circulated in Domestic Lumber Market

  • 투고 : 2011.06.22
  • 심사 : 2011.09.19
  • 발행 : 2011.09.25

초록

The selected physical and mechanical properties of non-certificated LVL circulated in domestic lumber market were investigated and compared to relevant standards. The tested LVL passed the moisture content and the soaking delamination rate limit as per domestic (KS) and Japanese standard (JAS). The evaluated mechanical properties were flatwise/edgewise bending strength, modulus of elasticity (MOE), horizontal shear and compressive strength. The 30 mm-thick LVL showed significantly higher bending strength than that of the 25 mm-thick LVL. The modulus of elasticity (MOE) showed same tendency in the results of bending strength. The edgewise bending strength and MOE were higher than that of flatwise bending strength and MOE. The horizontal shear strength values were also showed similar results to bending strength values. The tested results were compared each other and each products were graded according to JAS 701 grade specification. The failure mode of LVL in bending test showed the similar failure mode of solidwood that failed in a simple tension manner (splintery tension). The glue line failure was severe in 25 mm-thick specimens due to concentration of shear stress in layer discontinuity containing small voids and starved glue lines. In horizontal shear strength test, failure mode of LVL showed the typical horizontal shear failure. Compressive specimens failed with fiber crushing in company with apparent delamination that splitted along the length of the specimens. From the results, the complete bonding between lamination and consistency in thin veneer layer were considered as a critical factor in the mechanical properties of LVL. Moreover, the standard test procedure and specification for non-certificated LVL should be required to check the performance of uncertificated materials.

키워드

참고문헌

  1. American Society for Testing and Materials. 1999. Standard specification for evaluation of staructural composite lumber products. ASTM D 5456. PA.
  2. Bodig, J. and B. A. Jayne. 1982. Mechanics of wood and wood composites. Van Norstrand Reinhold Co.
  3. Burdurlu, E., M. Kilic, A. C. Ilce, and O. Uzunkavak. 2007. The effects of ply organization and loading direction on bending strength and modulus of elasticity in laminated veneer lumber (LVL) obtained from beech (Fagus orientalis L.) and lombardy poplar (Populus nigra L.). Construction and Building Materials 21(2007): 1720-1725. https://doi.org/10.1016/j.conbuildmat.2005.05.002
  4. International Standard Organization. 2010. Timber structures - Laminated veneer lumber - Structural properties. ISO/FDIS 22390, ISO.
  5. Japan Agricultural Standard. 2008. Standard specification of structural laminated veneer lumber. JAS 701.
  6. Korean Agency for Technology and Standard. 2008. Determination of resistance to soaking delamination for adhesive-bonded wood products. KS F 2160.
  7. Korean Agency for Technology and Standard. 2005. Nonstructural laminated veneer lumber. KS F 3119.
  8. Rijsdijk, J. F. and P. B. Laming. 1994. Physical and related properties of 145 timbers. Kluer Academic Publishers. Dordrecht, Netherlands.
  9. Sulaiman, O., N. Salim, R. Hashim, L. H. M. Yusof, W. Razak, N. Y. M. Yunus, W. S. Hashim, and M. H. Azmy. 2009. Evaluation on the suitability of some adhesive for laminated veneer lumber. Materials and Design 30: 3572-3580. https://doi.org/10.1016/j.matdes.2009.02.027
  10. Forest Products Lab. 1999. Woodhandbook. USDA Forest Serv., Forest Products Lab., Madison, WI.
  11. Williamson, T. G. 2002. APA Engineered wood handbook. Mcgrow Hill Co.