Experimental investigation on the effect of accelerated ageing conditions on the pull-out capacity of compressed wood and hardwood dowel type fasteners
Abstract
The widespread use of adhesives in timber construction has negative implications for the end-of-life disposal or re-use of the structural timber components. To promote the circular bioeconomy, it is preferable to substitute adhesives with more sustainable alternatives such as wood-based connectors. Today, robotic fabrication technologies facilitate the development of dowel-laminated timber (DLT) products whereby hardwood dowels are used to connect timber laminates as a substitute to adhesives. In recent years, thermo-mechanical densification of wood has resulted in significant improvements in the mechanical performance of the wood. This modified product often termed compressed wood (CW) has a shape-recovery effect which may be beneficial for the development of DLT products and timber-timber connections with improved friction fit with time. To test the hypothesis, accelerated ageing tests were carried out on CW-timber and hardwood-timber dowel type connections subjected to variable climate conditions. Finally, the capacity of the connections or friction fit was assessed using pull-out tests. Results show that the shape-recovery effect leads to the continuous expansion of the CW dowels and facilitates a friction fit with the timber substrate yielding higher pull-out loads when compared to hardwood dowels.
Funding source: Interreg NWE
Award Identifier / Grant number: Interreg North-West Europe grant 348
Acknowledgements
The contribution of the technical staff of the College of Science and Engineering, NUI Galway, in particular, Peter Fahy and Colm Walsh are gratefully acknowledged.
-
Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
-
Research funding: The study was conducted within the framework of the project “Towards Adhesive Free Timber Buildings – AFTB” at the College of Science & Engineering, National University of Ireland Galway, Ireland. The AFTB project is funded by the European Regional Development Fund (ERDF) via Interreg North-West Europe grant 348.
-
Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
References
Anshari, B., Guan, Z.W., Kitamori, A., Jung, K., Hassel, I., and Komatsu, K. (2011). Mechanical and moisture-dependent swelling properties of compressed Japanese cedar. Construct. Build. Mater. 25: 1718–1725, doi:https://doi.org/10.1016/j.conbuildmat.2010.11.095.Suche in Google Scholar
CEN. (2016). EN 1382. Timber structures – test methods – withdrawal capacity of timber fasterners. Comité Européen de Normalisation, Brussels, Belgium.Suche in Google Scholar
Conway, M., Harte, A.M., Mehra, S., and O’Ceallaigh, C. (2021). Densified wood dowel reinforcement of timber perpendicular to the grain: a pilot study. J. Struct. Integr. Mainten. 6: 177–186, https://doi.org/10.1080/24705314.2021.1906090.Suche in Google Scholar
Dauksta, D. (2014). Brettstapel. Technical Report, Wales Forest Business Partnership.Suche in Google Scholar
El-Houjeyri, I., Thi, V.D., Oudjene, M., Khelifa, M., Rogaume, Y., Sotayo, A., and Guan, Z. (2019). Experimental investigations on adhesive free laminated oak timber beams and timber-to-timber joints assembled using thermo-mechanically compressed wood dowels. Construct. Build. Mater. 222: 288–299, doi:https://doi.org/10.1016/j.conbuildmat.2019.05.163.Suche in Google Scholar
Gong, M. and Li, L. (2017). Breakeven point in ultimate thickness between moisture-reduced shrinkage and thickness recovery of densified softwood species: part 1: at room temperature. Wood Fiber Sci. 50: 373–380.10.22382/wfs-2018-049Suche in Google Scholar
Grönquist, P., Schnider, T., Thoma, A., Gramazio, F., Kohler, M., Burgert, I., and Rüggeberg, M. (2019). Investigations on densified beech wood for application as a swelling dowel in timber joints. Holzforschung 73: 559–568, doi:https://doi.org/10.1515/hf-2018-0106.Suche in Google Scholar
Guan, Z., Komatsu, K., Jung, K., and Kitamori, A. (2010). Proceedings of the world conference on timber engineering (WCTE 2010), 20–24 June 2010: structural characteristics of beam – column connections using compressed wood dowels and plates. Trentino (Italy).Suche in Google Scholar
Harte, A.M. (2017). Mass timber – the emergence of a modern construction material. J. Struct. Integr. Mainten. 2: 121–132, https://doi.org/10.1080/24705314.2017.1354156.Suche in Google Scholar
Hassel, I., Berard, P., and Komatsu, K. (2008). Development of wooden block shear wall – improvement of stiffness by utilizing elements of densified wood. Holzforschung 62: 584–590, https://doi.org/10.1515/HF.2008.091.Suche in Google Scholar
Hough, R. (2019). Rethinking timber buildings: seven perspectives on the use of timber in building design and construction. ARUP, London, UK.Suche in Google Scholar
Inoue, M., Morooka, T., Norimoto, M., Rowell, R., and Egawa, G. (1992). Permanent fixation of compressive deformation of wood. II mechanisms of permanent fixation. In: Chemical modification of lignocellulosics. Forest Research Institute, Rotorura, New Zealand, pp. 181–189.Suche in Google Scholar
ISO. (2007). ISO 12580. Timber structures — glued laminated timber — methods of test for glue-line delamination. International Organization for Standardization, Geneva.Suche in Google Scholar
Jung, K., Kitamori, A., and Komatsu, K. (2008). Evaluation on structural performance of compressed wood as shear dowel. Holzforschung 62: 461–467, https://doi.org/10.1515/hf.2008.073.Suche in Google Scholar
Jung, K., Kitamori, A., and Komatsu, K. (2010). Development of a joint system using a compressed wooden fastener II: evaluation of rotation performance for a column-beam joint. J. Wood Sci. 56: 118–126, https://doi.org/10.1007/s10086-009-1078-5.Suche in Google Scholar
Kutnar, A., Sandberg, D., and Haller, P. (2015). Compressed and moulded wood from processing to products. Holzforschung 69: 885–897, https://doi.org/10.1515/hf-2014-0187.Suche in Google Scholar
Laine, K., Belt, T., Rautkari, L., Ramsay, J., Hill, C., and Hughes, M. (2013). Measuring the thickness swelling and set-recovery of densified and thermally modified Scots pine solid wood. J. Mater. Sci. 48: 8530–8538, doi:https://doi.org/10.1007/s10853-013-7671-4.Suche in Google Scholar
Mehra, S. (2020). Development of non-metallic and adhesive-free timber-timber moment connections using compressed wood connectors, Ph.D. thesis. Galway, Ireland, National University of Ireland Galway.Suche in Google Scholar
Mehra, S., O’Ceallaigh, C., Hamid-Lakzaeian, F., Guan, Z., Sotayo, A., and Harte, A.M. (2018). Proceedings of WCTE 2018-world conference on timber engineering. Seoul, Rep. of Korea, August 20–23, 2018: evaluation of the structural behaviour of beam-beam connection systems using compressed wood dowels and plates.Suche in Google Scholar
Namari, S., Drosky, L., Pudlitz, B., Haller, P., Sotayo, A., Bradley, D., Mehra, S., O’Ceallaigh, C., Harte, A.M., El-houjeyri, I., et al. (2021). Mechanical properties of compressed wood. Construct. Build. Mater. 301: 124269, doi:https://doi.org/10.1016/j.conbuildmat.2021.124269.Suche in Google Scholar
Navi, P. and Pizzi, A. (2015). Property changes in thermo-hydro-mechanical processing. Holzforschung 69: 863–873, https://doi.org/10.1515/hf-2014-0198.Suche in Google Scholar
Ó Fátharta, C., Moreno, D.G., and Harte, A.M. (2020). Characterisation of Irish-grown Scots pine timber for structural applications. In: Civil engineering research in Ireland, CERI 2020. Cork Institute of Technology, Cork, Ireland, pp. 696–701.Suche in Google Scholar
O’Ceallaigh, C., Conway, M., Mehra, S., and Harte, A.M. (2021). Numerical investigation of reinforcement of timber elements in compression perpendicular to the grain using densified wood dowels. Construct. Build. Mater. 288: 122990, https://doi.org/10.1016/j.conbuildmat.2021.122990.Suche in Google Scholar
O’Ceallaigh, C., Sikora, K., and Harte, A.M. (2018). The influence of panel lay-up on the characteristic bending and rolling shear strength of CLT. Buildings 8: 15, https://doi.org/10.3390/buildings8090114.Suche in Google Scholar
Pelit, H., Sönmez, A., and Budakçı, M. (2014). Effects of ThermoWood® process combined with thermo-mechanical densification on some physical properties of Scots pine (Pinus sylvestris L.). BioResources 9: 4552–4567, https://doi.org/10.15376/biores.9.3.4552-4567.Suche in Google Scholar
Pelit, H., Sönmez, A., and Budakçi, M. (2015). Effects of thermomechanical densification and heat treatment on density and Brinell hardness of Scots pine (Pinus sylvestris L.) and Eastern beech (Fagus orientalis L.). BioResources 10: 3097–3111, https://doi.org/10.15376/biores.10.2.3097-3111.Suche in Google Scholar
Raftery, G., Harte, A., and Rodd, P. (2008). Qualification of wood adhesives for structural softwood glulam with large juvenile wood content. J. Inst. Wood Sci. 18: 24–34, https://doi.org/10.1179/wsc.2008.18.1.24.Suche in Google Scholar
Ramage, M.H., Burridge, H., Busse-Wicher, M., Fereday, G., Reynolds, T., Shah, D.U., Wu, G., Yu, L., Fleming, P., Densley-Tingley, D., et al. (2017). The wood from the trees: the use of timber in construction. Renew. Sustain. Energy Rev. 68: 333–359, doi:https://doi.org/10.1016/j.rser.2016.09.107.Suche in Google Scholar
Sikora, K.S., McPolin, D.O., and Harte, A.M. (2015). Shear strength and durability testing of adhesive bonds in cross-laminated timber. J. Adhes. 92: 758–777, doi:https://doi.org/10.1080/00218464.2015.1094391.Suche in Google Scholar
Skullestad, J.L., Bohne, R.A., and Lohne, J. (2016). High-rise timber buildings as a climate change mitigation measure – a comparative LCA of structural system alternatives. Energy Procedia 96: 112–123, https://doi.org/10.1016/j.egypro.2016.09.112.Suche in Google Scholar
Sotayo, A., Bradley, D., Bather, M., Sareh, P., Oudjene, M., El-Houjeyri, I., Harte, A.M., Mehra, S., O’Ceallaigh, C., Haller, P., et al. (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, doi:https://doi.org/10.1016/j.dibe.2019.100004.Suche in Google Scholar
StructureCraft. (2019). Dowel laminated timber (DLT) – design and profile guide. StructureCraft, USA.Suche in Google Scholar
TechnoWood. (2021). TWoods – the solid wood system, Available at: https://www.technowood.ch/en/solutions/twoods (Accessed 12 August 2021).Suche in Google Scholar
Thoma, A., Jenny, D., Helmreich, M., Gandia, A., Gramazio, F., and Kohler, M. (2019). Cooperative robotic fabrication of timber dowel assemblies. In: Research culture in architecture. Birkhäuser, Berlin, Boston, pp. 77–88.10.1515/9783035620238-008Suche in Google Scholar
Tellnes, L.G.F., Eide, S., Kristjansdottir, T.F., and Kron, M. (2013). Assessment of carbon footprint of laminated veneer lumber elements in a six story housing – comparison to a steel and concrete solution. In: Braganca, L., Pinheiro, M., Mateus, R. (Eds.). Portugal SB13. Contribution of sustainable building to meet EU 20-20-20 targets, Portugal, 2013. Multicomp, Portugal, pp. 817–824.Suche in Google Scholar
Thoma Holz (2018). ETA-13/0785 – solid wood slab element – element of dowel jointed timber boards to be used as a structural element in buildings. German Institute for Structural Engineering (DIBt), Berlin, Germany.Suche in Google Scholar
Wehsener, J., Brischke, C., Meyer-Veltrup, L., Hartig, J., and Haller, P. (2018). Physical, mechanical and biological properties of thermo-mechanically densified and thermally modified timber using the Vacu3-process. Eur. J. Wood Wood Prod. 76: 809–821, doi:https://doi.org/10.1007/s00107-017-1278-4.Suche in Google Scholar
Welzbacher, C.R., Wehsener, J., Rapp, A.O., and Haller, P. (2008). Thermo-mechanical densification combined with thermal modification of Norway spruce (Picea abies Karst) in industrial scale – dimensional stability and durability aspects. Holz als Roh- Werkst. 66: 39–49, https://doi.org/10.1007/s00107-007-0198-0.Suche in Google Scholar
© 2021 Walter de Gruyter GmbH, Berlin/Boston
Artikel in diesem Heft
- Frontmatter
- Original Articles
- Classification of wood knots using artificial neural networks with texture and local feature-based image descriptors
- Modeling of radial variations in wood properties and comparison of juvenile and mature wood of four common conifers in Mongolia
- Estimating moisture content variation in kiln dried Pacific coast hemlock
- Towards understanding kraft lignin depolymerisation under hydrothermal conditions
- Investigation of acid hydrolysis for carbohydrate analysis in kraft black liquor
- Wavelength-dependent photodegradation of wood and its effects on fluorescence
- Prediction model based on chemical composition change for the mechanical degradation of Korean pine (Pinus koraiensis) after brown-rot fungi (Gloeophyllum trabeum) invasion
- Mineralization treatment of European oak heartwood with calcium oxalate for improved fire retardancy
- Experimental investigation on the effect of accelerated ageing conditions on the pull-out capacity of compressed wood and hardwood dowel type fasteners
- Annual Reviewer Acknowledgement
- Reviewer acknowledgement Holzforschung volume 75 (2021)
Artikel in diesem Heft
- Frontmatter
- Original Articles
- Classification of wood knots using artificial neural networks with texture and local feature-based image descriptors
- Modeling of radial variations in wood properties and comparison of juvenile and mature wood of four common conifers in Mongolia
- Estimating moisture content variation in kiln dried Pacific coast hemlock
- Towards understanding kraft lignin depolymerisation under hydrothermal conditions
- Investigation of acid hydrolysis for carbohydrate analysis in kraft black liquor
- Wavelength-dependent photodegradation of wood and its effects on fluorescence
- Prediction model based on chemical composition change for the mechanical degradation of Korean pine (Pinus koraiensis) after brown-rot fungi (Gloeophyllum trabeum) invasion
- Mineralization treatment of European oak heartwood with calcium oxalate for improved fire retardancy
- Experimental investigation on the effect of accelerated ageing conditions on the pull-out capacity of compressed wood and hardwood dowel type fasteners
- Annual Reviewer Acknowledgement
- Reviewer acknowledgement Holzforschung volume 75 (2021)