Mechanical Performance of Timber-to-Timber Joints with Densified Wood Dowels
Publication: Journal of Structural Engineering
Volume 148, Issue 4
Abstract
The wooden peg made of hardwood is one of the oldest fasteners. However, the relatively poor mechanical properties (strength and ductility) compared with steel restrict their applications in modern timber construction. Through densification, low-density species can be used as an alternative to hardwood, with even higher mechanical properties than those of hardwood. In this study, poplar was densified with alkali pretreatment to produce the densified wood (DW) dowels. The bending and shear properties of DW dowels were estimated, and the mechanical behavior of timber-to-timber joints with DW dowels was tested to present favorable mechanical performance, including load capacity, stiffness, and ductility. The tight-fitting of dried DW dowel due to the hygroscopic swelling contributes to the rope effect, which significantly improves the ultimate load-carrying capacity of timber joints. This study confirmed that DW dowels as environmentally friendly products can be promising fastener alternatives to steel fasteners to develop more sustainable timber structures.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request. The listed items include density, load-carrying capacity, stiffness, and ductility.
Acknowledgments
The authors gratefully acknowledge the support of the National Natural Science Foundation of China for Grant No. 51878114.
References
ASTM. 2005. Standard test method for evaluating dowel bearing strength of wood and wood-based products. D5764-97a. West Conshohocken, PA: ASTM.
ASTM. 2013. Standard test method for determining bending yield moment of nails. F1575-03. West Conshohocken, PA: ASTM.
ASTM. 2014. Standard test methods of static tests of lumber in structural sizes. D198-14. West Conshohocken, PA: ASTM.
ASTM. 2015. Standard test methods for small clear specimens of timber. D143-14. West Conshohocken, PA: ASTM.
ASTM. 2017. Standard test methods for density and specific gravity (relative density) of wood and wood-based materials. D2395-17. West Conshohocken, PA: ASTM.
AWC (American Wood Council). 2015. National design specification for wood construction. Washington, DC: AWC.
Bulleit, W. M., L. B. Sandberg, M. W. Drewek, and T. L. O’Bryant. 1999. “Behavior and modeling of wood-pegged timber frames.” J. Struct. Eng. 125 (1): 3–9. https://doi.org/10.1061/(ASCE)0733-9445(1999)125:1(3).
CEN (European Committee for Standardization). 1991. Timber structures—Joints made with mechanical fasteners—General principles for the determination of strength and deformation characteristics. BS EN 26891. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2001. Timber structures—Test methods—Cyclic testing of joints made with mechanical fasteners. BS EN 12512. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2004. Design of timber structures. Part 1-1: General rules and rules for buildings. 1995-1-1 Eurocode 5. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2007. Timber structures—Test methods—Determination of embedding strength and foundation values for dowel type fasteners. BS EN 383. Brussels, Belgium: CEN.
Ceraldi, C., C. D’Ambra, M. Lippiello, and A. Prota. 2017. “Restoring of timber structures: Connections with timber pegs.” Eur. J. Wood Prod. 75 (6): 957–971. https://doi.org/10.1007/s00107-017-1179-6.
Church, J. R., and B. W. Tew. 1997. “Characterization of bearing strength factors in pegged timber connections.” J. Struct. Eng. 123 (3): 326–332. https://doi.org/10.1061/(ASCE)0733-9445(1997)123:3(326).
Edwards, J. D., and N. Kariouk Pecquet du Bellay de Verton. 2004. A Creole: Architecture, landscape, people. Baton Rouge, LA: LSU Press.
El-Houjeyri, I., V.-D. Thi, M. Oudjene, M. Khelifa, Y. Rogaume, A. Sotayo, and A. Guan. 2019. “Experimental investigations on adhesive free laminated oak timber beams and timber-to-timber joints assembled using thermo-mechanically compressed wood dowels.” Constr. Build. Mater. 222: 288–299. https://doi.org/10.1016/j.conbuildmat.2019.05.163.
Grönquist, P., T. Schnider, A. Thoma, F. Gramazio, M. Kohler, I. Burgert, and M. Rüggeberg. 2019. “Investigations on densified beech wood for application as a swelling dowel in timber joints.” Holzforschung 73 (6): 559–568. https://doi.org/10.1515/hf-2018-0106.
Johansen, K. W. 1949. “Theory of timber connections.” Int. Assoc. Bridge Struct. Eng. 9: 249–262.
Jung, K., A. Kitamori, and K. Komatsu. 2008. “Evaluation on structural performance of compressed wood as shear dowel.” Holzforschung 62 (4): 461–467. https://doi.org/10.1515/HF.2008.073.
Kollmann, F. F. P. 1936. Technologie des Holzes. Berlin: Verlag.
Miller, J. F., R. J. Schmidt, and W. M. Bulleit. 2010. “New yield model for wood dowel connections.” J. Struct. Eng. 136 (10): 1255–1261. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000224.
Riggio, M., J. Sandak, and A. Sandak. 2016. “Densified wooden nails for new timber assemblies and restoration works: A pilot research.” Constr. Build. Mater. 102: 1084–1092. https://doi.org/10.1016/j.conbuildmat.2015.06.045.
Sandberg, D., P. Haller, and P. Navi. 2013. “Thermo-hydro and thermo-hydro-mechanical wood processing: An opportunity for future environmentally friendly wood products.” Wood Mater. Sci. Eng. 8 (1): 64–88. https://doi.org/10.1080/17480272.2012.751935.
Sandberg, L. B., W. M. Bogue, and E. H. Reid. 2000. “Strength and stiffness of oak pegs in traditional timber-frame joints.” J. Struct. Eng. 126 (6): 717–723. https://doi.org/10.1061/(ASCE)0733-9445(2000)126:6(717).
Schmidt, R. J., and C. E. Daniels. 1999. Design considerations for mortise and tenon connections. Becket, MA: Timber Framers Guild.
Shanks, J., and P. Walker. 2009. “Strength and stiffness of all-timber pegged connections.” J. Mater. Civ. Eng. 21 (1): 10–18. https://doi.org/10.1061/(ASCE)0899-1561(2009)21:1(10).
Shanks, J. D., W.-S. Chang, and K. Komatsu. 2008. “Experimental study on mechanical performance of all-softwood pegged mortice and tenon connections.” Biosyst. Eng. 100 (4): 562–570. https://doi.org/10.1016/j.biosystemseng.2008.03.012.
Song, J., C. Chen, S. Zhu, and M. Zhu. 2018. “Processing bulk natural wood into a high-performance structural material.” Nature 554 (7691): 224–228. https://doi.org/10.1038/nature25476.
Sotayo, A., D. Bradley, M. Bather, P. Sareh, M. Oudjene, I. El-Houjeyri, A. M. Harte, S. Mehra, C. O’Ceallaigh, and P. Haller. 2020. “Review of state of the art of dowel laminated timber members and densified wood materials as sustainable engineered wood products for construction and building applications.” Dev. Built. Environ. 1: 100004. https://doi.org/10.1016/j.dibe.2019.100004.
Tanaka K., Y. Demoto, J. Ouchi, and M. Inoue. 2010. “Strength property of densified Sugi adopted as material of connector.” In Proc., 11th World Conf. Timber Eng., 1696–1701. Sesto Fiorentino, Italy: Trees and Timber Institute, National Research Council.
TFEC (Timber Frame Engineering Council). 2019. Standard for design of timber frame structures and commentary. Becket, MA: TFEC.
Witter, S. 2005. Timber frame joinery and design, volume 2. Becket, MA: Timber Framers Guild.
Xu, B.-H., C.-K. Jing, and A. Bouchaïr. 2021a. “Experimental analysis of the influence of the fastener type on the embedment strength parallel to the grain in glued laminated timber.” J. Mater. Civ. Eng. 33 (2): 06020023. https://doi.org/10.1061/(ASCE)MT.1943-5533.0003599.
Xu, B.-H., B.-L. Wang, K.-B. Yu, and A. Bouchair. 2021b. “An optional connection material in timber structures: Densified poplar.” J. Mater. Sci. 56 (25): 14114–14125. https://doi.org/10.1007/s10853-021-06194-5.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 148 • Issue 4 • April 2022
Copyright
© 2022 American Society of Civil Engineers.
History
Received: Oct 5, 2021
Accepted: Dec 8, 2021
Published online: Feb 7, 2022
Published in print: Apr 1, 2022
Discussion open until: Jul 7, 2022
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.
Cited by
- Lei Han, Andreja Kutnar, Jakub Sandak, Iztok Šušteršič, Dick Sandberg, Adhesive-and Metal-Free Assembly Techniques for Prefabricated Multi-Layer Engineered Wood Products: A Review on Wooden Connectors, Forests, 10.3390/f14020311, 14, 2, (311), (2023).
- Bo-Han Xu, Yi-Ge Zhao, Kong-Bin Yu, Abdelhamid Bouchaïr, Binsheng Zhang, Pull-Out Performance of Densified Wood Dowels Embedded into Glued Laminated Timber, Journal of Materials in Civil Engineering, 10.1061/JMCEE7.MTENG-15299, 35, 9, (2023).
- Bo-Han Xu, Tong-Tong Wang, Kong-Bin Yu, Yan-Hua Zhao, Binsheng Zhang, Physical and mechanical properties of densified poplar by partial delignification, Wood Material Science & Engineering, 10.1080/17480272.2022.2128696, (1-6), (2022).