Journal of the Korean Wood Science and Technology

The Korean Society of Wood Science & Technology (한국목재공학회)
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Evaluation of Bearing Strength of Self-Tapping Screws according to the Grain Direction of Domestic Pinus densiflora

  • LEE, In-Hwan (Wood Engineering Division, Forest Products and Industry Department, National Institute of Forest Science) ;
  • KIM, Keonho (Wood Engineering Division, Forest Products and Industry Department, National Institute of Forest Science) ;
  • SHIM, Kug-bo (Wood Engineering Division, Forest Products and Industry Department, National Institute of Forest Science)
  • Received : 2021.11.11
  • Accepted : 2021.12.23
  • Published : 2022.01.25
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Abstract

To evaluate the bearing strength of red pine cross-laminated timber (CLT) with self-tapping screw (STS), which is widely used as a fastener for connection in CLT building, the bearing test was conducted. Accoring to the STS's diameters (8, 10, 12 mm), the bearing test specimens with half hole were manufactured. Bearing strength was compared and reviewed in consideration of the configuration in STS and the loading direction to the grain of red pine. As a result of the bearing test on the STS's diameter, the yield bearing load increases as the larger diameter of the STS in all directions of the red pine. The bearing strength of the thread part (thread + tip) was higher than the shank part (shank + shank cutter). In compared with the directions to the grain of red pine, the bearing strength of the cross section parallel to the loading direction was the highest, and the tangent section was the lowest bearing strength. The average bearing strength of the loading direction in parallel to the grain was 23.43 MPa, which was about 45% higher than the average 16.16 MPa in perpendicular to the grain. The predicted bearing strength calculated by Eurocode (EN) and Korean Building Code (KBC)'s equation was lower than the experimental value. It is nessesary to propose the new equations of bearing strength reflected the configuration information of STS.

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References

  1. Bedon, C., Fragiacomo, M. 2019. Numerical analysis of timber-to-timber joints and composite beams with inclined self-tapping screws. Composite Structures 207: 13-28. https://doi.org/10.1016/j.compstruct.2018.09.008
  2. British Standards Institution. EN 1995-1-2:2004: Eurocode 5: Design of Timber Structures - Part 1-2: General - Structural Fire Design. British Standards Institution, London, UK.
  3. Choi, G.W., Yang, S.M., Lee, H.J., Kim, J.H., Choi, K.H., Kang, S.G. 2020. A study on the block shear strength according to the layer composition of and adhesive type of Ply-lam CLT. Journal of the Korean Wood Science and Technology 48(6): 791-806. https://doi.org/10.5658/WOOD.2020.48.6.791
  4. Choi, G.W., Yang, S.M., Lee, H.J., Kim, J.H., Choi, K.H., Kang, S.G. 2021. Evaluation of flexural performance according to the plywood bonding method of Ply-lam CLT. Journal of the Korean Wood Science and Technology 49(2): 107-121. https://doi.org/10.5658/WOOD.2021.49.2.107
  5. Dietsch, P., Brandner, R. 2015. Self-tapping screws and threaded rods as reinforcement for structural timber elements: A state-of-the-art report. Construction and Building Materials 97: 78-89. https://doi.org/10.1016/j.conbuildmat.2015.04.028
  6. Hong, M.K., Park, B.D., Kim, K.H., Shim, K. 2017. Performance of melamine-urea-formaldehyde resin adhesives at various melamine contents for bonding glued laminated timber under high frequency heating. Journal of the Korean Wood Science and Technology 45(4): 409-418. https://doi.org/10.5658/WOOD.2017.45.4.409
  7. Hwang, K., Komatsu, K. 2002. Bearing properties of engineered wood products I: Effects of dowel diameter and loading direction. Journal of Wood Science 48(4): 295-301. https://doi.org/10.1007/BF00831350
  8. Jang, S.S., Lee, H.W. 2019. Lateral resistance of CLT wall panels composed of square timber larch core and plywood cross bands. Journal of the Korean Wood Science and Technology 47(5): 547-556. https://doi.org/10.5658/wood.2019.47.5.547
  9. Jung, H., Song, Y., Hong, S. 2020. Effect of glass fiber-reinforced connection on the horizontal shear strength of CLT walls. Journal of the Korean Wood Science and Technology 48(5): 685-695. https://doi.org/10.5658/WOOD.2020.48.5.685
  10. Kang, C.W., Jang, S.S., Kang, H.Y., Li, C. 2019. Sound absorption rate and sound transmission loss of CLT wall panels composed of larch square timber core and plywood cross band. Journal of the Korean Wood Science and Technology 47(1): 33-39. https://doi.org/10.5658/WOOD.2019.47.1.33
  11. Kim, G.C. 2012. Study on the change of physical and anatomical properties in the pine wood by accelerated weathering test. Journal of the Korea Furniture Society 23(3): 324-331.
  12. Kim, H.K., Oh, J.K., Jeong, G.Y., Yeo, H.M., Lee, J.J. 2013. Shear performance of PUR adhesive in cross laminating of red pine. Journal of the Korean Wood Science and Technology 41(2): 158-163. https://doi.org/10.5658/WOOD.2013.41.2.158
  13. Kim, K.H., Kim, S.J., Yang, S.Y., Yeo, H., Eom, C.D., Shim, K. 2015. Bonding performance of adhesives with lamina in structural glulam manufactured by high frequency heating system. Journal of the Korean Wood Science and Technology 43(5): 682-690. https://doi.org/10.5658/WOOD.2015.43.5.682
  14. Korea Forest Service. 2020. Statistical Yearbook of Forestry. Korea Forest Service, Daejeon, Korea.
  15. Korean Construction Standard Center. 2018. KDS 41 33 05:2018: Design of the timber construction joint. Korea Construction Standards Center, Seoul, Korea.
  16. Korean Standards Association. 2017. KSF 2156: Method of Dowel-Bearing Strength Test for Wood and Wood-based Products. Korean Standards Association, Seoul, Korea.
  17. National Institute of Forest Science. 2020. Market Survey of Timber Product. National Institute of Forest Science, Seoul, Korea.
  18. Park, B.S., Park, J.H., Han, S.U. 2006. Variation of material properties of Korean red pine of superior families - tracheid length, microfibril angle, resin canal and specific gravity. Journal of Korea Forestry Energy 25(2): 9-15.
  19. Ringhofer, A., Brandner, R., Schickhofer, G. 2015. Withdrawal resistance of self-tapping screws in unidirectional and orthogonal layered timber products. Materials and Structures 48(5): 1435-1447. https://doi.org/10.1617/s11527-013-0244-9
  20. Santos, C.L., De Jesus, A.M.P., Morais, J.J.L., Lousada, J.L.P.C. 2010. A comparison between the EN 383 and ASTM D5764 test methods for dowel-bearing strength assessment of wood: Experimental and numerical investigations. Strain 46(2): 159-174. https://doi.org/10.1111/j.1475-1305.2008.00570.x
  21. Sullivan, K., Miller, T.H., Gupta, R. 2018. Behavior of cross-laminated timber diaphragm connections with self-tapping screws. Engineering Structures 168: 505-524. https://doi.org/10.1016/j.engstruct.2018.04.094
  22. Yang, S.M., Lee, H.H., Kang, S.G. 2021. Research trends in hybrid cross-laminated timber (CLT) to enhance the rolling shear strength of CLT. Journal of the Korean Wood Science and Technology 49(4): 336-359. https://doi.org/10.5658/WOOD.2021.49.4.336