European Journal of Wood and Wood Products

, Volume 76, Issue 3, pp 833–841 | Cite as

The evaluation of panel bond quality and durability of hem-fir cross-laminated timber (CLT)

  • Jianhe Brad Wang
  • Peixing Wei
  • Zizhen Gao
  • Chunping Dai


To better use the second-growth wood resources in value-added applications, this work addressed the manufacturing aspects of cross-laminated timber (CLT) products from western hemlock (Tsuga heterophylla (Raf.) Sarg) and amabilis fir (Abies amabilis (Dougl.) Forbes) (or hem-fir) harvested from coastal British Columbia, Canada. Small CLT billets (nominal 610 mm × 610 mm) were made to examine CLT bond quality and durability through block shear and delamination tests. Two types of adhesives, single-component polyurethane (PUR) and emulsion polymer isocyanate (EPI) and two critical applied pressure parameters (0.28 and 0.83 MPa) were adopted to manufacture hem-fir CLT. It was found that the adhesive type and applied pressure significantly affected wood failure percentage (WFP) and delamination of hem-fir CLT. When PUR adhesive was used, CLT made at 0.83 MPa pressure yielded significantly higher WFP and lower delamination than that made at 0.28 MPa pressure. The results demonstrated that despite the fact that hem-fir lumber is not particularly specified in the current North American CLT standard, it could be used for manufacturing CLT with the required panel bond quality.



The authors would like to thank Natural Resources Canada (Canadian Forest Service) and the Province of British Columbia for their guidance and financial support for this research. This work was also supported by the natural science research general project of Jiangsu Province of China (16KJD220001), the science project of Jiangsu Vocational College of Agriculture and Forestry (2017kj04), and Ningbo major social development project entitled “Development of new green prefabricated building materials for demonstration buildings” (2017C510004). The authors thank Ciprian Pirvu, Conroy Lum, Romulo Casilla, John Hoffmann, and Gordon Chow, among others at FPInnovations, for their help in this work.


  1. Aicher S, Reinhardt HW (2007) Delamination properties and shear strength of glued beech wood laminations with red heartwood. Holz Roh Werkst 65(2):125–136CrossRefGoogle Scholar
  2. ANSI/AITC A190.1 (2007) Structural glued laminated timber, American Institute of Timber Construction, USAGoogle Scholar
  3. ANSI/APA PRG 320 (2012) Standard for performance-rated cross-laminated timber, The Engineered Wood Association, USAGoogle Scholar
  4. ASTM D 905–08 (2013) Standard test method for strength properties of adhesive bonds in shear by compression loading, American Society for Testing and Materials (ASTM)Google Scholar
  5. BCMFR (2007) Coastal Forest Action Plan, British Columbia Ministry of Forests and Range, Victoria. Accessed 10 March 2009
  6. Bejtka I, Lam F (2008) Cross laminated timber as innovative building material. In: Proceedings of Canadian Society of Civil Engineering (CSCE) 2008 annual conference, Québec-QC, CanadaGoogle Scholar
  7. Betti M, Brunetti M, Lauriola MP, Nocetti M, Ravalli F, Pizzo B (2016) Comparison of newly proposed test methods to evaluate the bonding quality of cross-laminated timber (CLT) panels by means of experimental data and finite element (FE) analysis. Constr Build Mater 125:952–963CrossRefGoogle Scholar
  8. Brandner R, Flatscher G, Rignhofer A, Schickhofer G, Thiel A (2016) Cross laminated timber (CLT): overview and development. Eur J Wood Prod 74(3):331–351CrossRefGoogle Scholar
  9. Canada Wood (2016) The world first large-dimension hemlock CLT production CLT line was put into use.
  10. CSA O112.10–08 (2008) Evaluation of adhesives for structural wood products (limited moisture exposure), Canadian Standards Association, MississaugaGoogle Scholar
  11. CSA O122–06 (2006) Structural glued-laminated timber, Canadian Standards Association, MississaugaGoogle Scholar
  12. CSA O177–06 (2006) Qualification code for manufacturers of structural glued-laminated timber, Canadian Standard Association, MississaugaGoogle Scholar
  13. Custodio J, Broughton J, Cruz H (2009) A review of factors influencing the durability of structural bonded timber joints. Int J Adhes Adhes 29(2):173–185CrossRefGoogle Scholar
  14. EN 14080 (2013) Timber structures-glued laminated timber and glued solid timber-requirements. European Committee for Standardization CEN, BruxellesGoogle Scholar
  15. EN 302 (2013) Adhesives for load-bearing timber structures-Test methods, European Committee for Standardization, BruxellesGoogle Scholar
  16. FPL (1999) Wood handbook-Chap. 4 Mechanical properties of wood. Forest Products Laboratory, U.S. Department of Agriculture (USDA), Forest Service, Forest Products Laboratory, MadisonGoogle Scholar
  17. Gong Y, Wu G, Ren H (2016) Block shear strength and delamination of cross-laminated timber fabricated with Japanese larch. BioResources 11(4):10240–10250CrossRefGoogle Scholar
  18. Knorz M, Schmidt M, Torno S, van de Kuilen JWG (2014) Structural bonding of ash (Fraxinus excelsior L.): resistance to delamination and performance in shearing tests. Eur J Wood Prod 72(3):297–309CrossRefGoogle Scholar
  19. Lavisci P, Berti S, Pizzo B, Triboulot P, Zanuttini R (2001) A shear test for structural adhesives used in the consolidation of old timber. Holz Roh Werkst 59(1/2):145–152CrossRefGoogle Scholar
  20. Li RR, Cao PX, Guo XL, Ekevad M (2015) Comparison of different standard test methods for compressive shear strength of bondline in glulam. China For Sci Technol 29(4):86–89Google Scholar
  21. Liao YC, Tu DY, Zhou JH, Zhou HB, Yun H, Gu J, Hu CS (2017) Feasibility of manufacturing cross-laminated timber using fast-grown small diameter eucalyptus lumbers. Constr Build Mater 132:508–515CrossRefGoogle Scholar
  22. Okkonen AE, River BH (1989) Factors affecting the strength of block-shear specimens. Forest Prod J 39(1):43–50Google Scholar
  23. Pizzo B, Lavisci P, Misani C, Triboulot P, Macchioni N (2003) Measuring the shear strength ratio of glued joints within the same specimen. Holz Roh Werkst 61(4):273–280CrossRefGoogle Scholar
  24. Raftery G, Harte A, Rodd P (2008) Qualification of wood adhesives for structural softwood glulam with large juvenile wood content. J Inst Wood Sci 18(1):24–34CrossRefGoogle Scholar
  25. SAS Institute (2017) JMP statistical discovery software. SAS Campus Drive, Cary
  26. Schmidt M, Glos P, Wegener G (2010) Gluing of European beech wood for load bearing timber structures. Eur J Wood Prod 68(1):43–57CrossRefGoogle Scholar
  27. Serrano E (2004) A numerical study of the shear-strength-predicting capabilities of test specimens for wood-adhesive bonds. Int J Int J Adhes Adhes 24(1):23–35CrossRefGoogle Scholar
  28. Sikora KS, McPolin DO, Hare AM (2015) Shear strength and durability testing of adhesive bonds in cross-laminated timber. J Adhes 92(7–9):758–777Google Scholar
  29. Steiger R, Gehri E, Richter K (2010) Quality control of glulam: shear testing of bondlines. Eur J Wood Prod 68(3):243–256CrossRefGoogle Scholar
  30. Wang BJ, Dai C (2008) Present utilization and outlook of BC Hem-fir for composite products. BC coastal forest sector development program report, Department of Engineered Wood Products, FPInnovations, VancouverGoogle Scholar
  31. Wang BJ, Dai C (2013) Development of structural laminated veneer lumber from stress graded short-rotation hem-fir veneer. Constr Build Mater 47:902–909CrossRefGoogle Scholar
  32. Wang BJ, Dai C, Middleton G, Munro D (2010a) Characterizing short-rotation coastal hemlock and amabilis fir veneer properties: preliminary results. BC coastal forest sector development program report, Department of Engineered Wood Products, FPInnovations, VancouverGoogle Scholar
  33. Wang BJ, Dai C, Middleton G (2010b) Manufacturing and performance evaluation of LVL made from stress graded hem-fir veneer. BC coastal forest sector development program report, Department of Engineered Wood Products, FPInnovations, VancouverGoogle Scholar
  34. Wang BJ, Pirvu C, Lum C (2011) CLT Handbook: Chap. 2 Cross-laminated Timber manufacturing, Canadian ed. FPInnovations, VancouverGoogle Scholar
  35. Wernersson H (1994) Fracture characterization of wood adhesive joints. Report TVSM 1006, Division of Structural Materials. Lund University, LundGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Jianhe Brad Wang
    • 1
    • 2
  • Peixing Wei
    • 1
  • Zizhen Gao
    • 2
  • Chunping Dai
    • 3
  1. 1.Jiangsu Vocational College of Agriculture and ForestryJurongPeople’s Republic of China
  2. 2.Ningbo Sino-Canada Low-Carbon Technology Research Institute Co. Ltd.NinghaiPeople’s Republic of China
  3. 3.FPInnovationsVancouverCanada

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