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Journal of Wood Science

Official Journal of the Japan Wood Research Society

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Evaluation of the fire endurance of mechanically graded timber in bending

Journal of Wood Science volume 52, pages 25–32 (2006)Cite this article

Abstract

AbstractThis study examined the performance of mechanically graded timber in bending when exposed to fire at various load ratios. The test specimens were 150 pieces, each with the dimensions of 60 × 120 × 3500mm. The modulus of elasticity (MOE) of 150 specimens was measured, and 60 among them were selected to formulate the prediction equation for MOE and modulus of rupture (MOR), which was used to predict the remaining 90 specimens. These were tested under fire exposure in bending using three-point loading at 11.1%, 16.7%, 33.3%, 66.7%, and 83.3% of the ultimate load. Using mechanically graded timber, which means acknowledging the actual strength of the bending member, permits fairly precise application to the targeted design load. This research confirmed that mechanically graded timber under fire exposure has the following tendencies: under the same load ratio, time to failure is independent of strength class, and, at any load ratio, the critical strength is dependent on the timber strength class. The obtained design bending strength under fire exposure using the reduced cross section method and the reduced strength method conformed to those calculated based on Eurocode 5. Following those findings, mechanically graded timber can be applied to obtain the design bending strength when taking into account the fire attack.

References

  1. Firmanti A, Bachtiar ET, Surjokusumo S, Komatsu K, Kawai S (2005) Mechanical stress grading of tropical timbers without regard to species. J Wood Sci 51:339–347

    Article  CAS  Google Scholar 

  2. Johanson CJ (2002) Grading of timber with respect to mechanical properties, Timber engineering, Wiley, England, pp 23–43

    Google Scholar 

  3. Kretschmann DE, Green DW (1999) Timber stress grades and design properties. In: Wood handbook: wood as an engineering material. pp 6-1–6-14

  4. Firmanti A, Surjokusumo S, Komatsu K, Kawai S (2005) The establishment of strength characteristic of fast growing acacia mangium timber for structural materials. J Constr Mater (in press)

  5. Firmanti A, Subiyanto B, Takino S, Kawai S (2004) The critical stress in various stress level of bending member on fire exposure for mechanically graded timber. J Wood Sci 50:385–390

    Article  Google Scholar 

  6. Schaffer EL (1984) Structural fire design: wood. Forest Product Laboratory, FPL 450, Madison: US Department of Agriculture, p 16

    Google Scholar 

  7. White RH, Tran HC (1996) Charring rate of wood exposed to a constant heat flux. Proceedings of Wood and Fire Safety Conference, Zvolen, Slovak Republic, Technical University of Zvolen, pp 175–183

    Google Scholar 

  8. Schaffer EL (1967) Charring rates of selected wood-transverse to grain. Research paper FPL 69, US Forest Product Laboratory, Madison, Wisconsin

    Google Scholar 

  9. White RH, Nordheim V (1992) Charring rate of wood for ASTM E 119 exposure. Fire Technol 28:6–30

    Article  Google Scholar 

  10. Konig J (2002) Basic and notial charring rates. Proceeding of CIB W18/35-16-1, Swedish Institute for Wood Technology Research, Sweden

    Google Scholar 

  11. Njankouo JM, Dotreppe JC, Franssen JM (2004) Experimental study of the charring rate of tropical hardwood. Fire Mater 28:15–24

    Article  CAS  Google Scholar 

  12. Konig J (2004) Structural fire design according to Eurocode 5-design rules and their background. Fire Mater (in press)

  13. Frangi A, Fontana M (2003) Charring rates and temperature profiles of wood sections. Fire Mater 27:91–102

    Article  CAS  Google Scholar 

  14. Ministry of Forestry (1987) Standard specification of timber for building materials (in Indonesian). SKI C-bo-010:1987 Jakarta, Indonesia

  15. ASTM Standard D 198-1999 (2000) Standard test methods of static tests of timber in structural sizes. Vol. 04.10. Wood, ASTM, Philadelphia

    Google Scholar 

  16. Ministry of Public Works (2000) Proposed standard specification of timber for building materials (in Indonesian). PKKI:2000 Jakarta, Indonesia

  17. Noren JB (1988) Failure of structural timber under fire exposure. Proceedings of 1988 International Conference on Timber Engineering, Seattle, Forest Product Research Society, Madison, pp 397–406

    Google Scholar 

  18. Konig J (1992) The effect of density and loss of bending strength in fire. Proceedings of CIB-W18, meeting twenty-five, Sweden

  19. American Forest and Paper Association (1999) Calculating the fire resistance of exposed wood member. Technical report 10. American Wood Council, pp 1–23

  20. Silcock GWH, Shields TJ (2001) Relating char depth to fire severity conditions. Fire Mater 25:9–11

    Article  CAS  Google Scholar 

  21. Friedly JK, Tang RC, Soltis LA (1988) Effect of temperature on duration of load of structural lumber. Proceedings of 1988 International Conference on Timber Engineering, Seattle, Forest Product Research Society, Madison

    Google Scholar 

  22. Konig J, Kallsner B (2001) Cross section properties of fire exposed rectangular timber member. Proceedings of CIB-W18, meeting thirty four, Venice, Italy

Download references

Author information

Authors and Affiliations

  1. Research Institute For Human Settlements, Jl. Panyaungan-Cileunyi Wetan, Bandung, 40008, Indonesia

    Anita Firmanti

  2. Research and Development Unit for Biomaterials, Jl. Raya Bogor Km 46, Cibinong Bogor, 16911, Indonesia

    Bambang Subiyanto

  3. Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan

    Shuichi Kawai

Authors
  1. Anita Firmanti
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  2. Bambang Subiyanto
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  3. Shuichi Kawai
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Correspondence to Shuichi Kawai.

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Firmanti, A., Subiyanto, B. & Kawai, S. Evaluation of the fire endurance of mechanically graded timber in bending. J Wood Sci 52, 25–32 (2006). https://doi.org/10.1007/s10086-005-0721-z

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  • DOI: https://doi.org/10.1007/s10086-005-0721-z

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