AN EXPERIMENTAL STUDY ON FLEXURAL BEHAVIOR OF GLULAM BEAMS MADE OUT OF THERMALLY TREATED FAST-GROWING POPLAR LAMINAE

Authors

  • Kong Yue Nanjing Tech University http://orcid.org/0000-0002-3039-638X
  • Xulei Song Nanjing Tech University
  • Xuekai Jiao Nanjing Tech University
  • Lu Wang Nanjing Tech University
  • Chong Jia Nanjing Forestry University
  • Zhangjing Chen Virginia Tech University
  • Weiqing Liu Nanjing Tech University

Abstract

In this study, to improve the structural applications of glued laminated timber (glulam) in high RH environment according to its relatively lower MOE, fast-growing poplar laminae with a thickness of 35 mm were thermally treated at 20oC for 3.5 h. The effects of thermal treatment and RH in the surrounding environment on laminae strength class was conducted. Afterward, 12 full-scale same-grade composition glulam beams made out of untreated and thermally treated poplar laminae were prepared. The four-point bending tests were conducted to reveal the effects of laminae thermal treatment and RH in the surrounding environment on flexural properties of glulam beams with a span-depth ratio of 18. The results showed that the strength class of fast-growing poplar laminae was negatively related to RH in the surrounding condition, and thermal treatment can contribute to the increase in strength class. In 90% RH, strength class increased from untreated laminae ME7 to the heat-treated ME10, according to China standard. The relationship between bending properties of glulam beams and RH in the surrounding environment was negatively correlated, as well as thermal treatment, whereas MOE was improved significantly after thermally pretreated, especially in high RH. In 90% RH, MOE of glulam beams made of thermally pretreated laminae was 29.57% higher than the untreated beams with an MOR reduction of 8.82%. The results of characteristic load-deformation curves, characteristic load-strain curves, average extreme fiber strain, and the failure mode can support each other in this study. Industrial thermal treatment technology to laminae improved the MOE of glulam beams significantly in high RH with a reduction in MOR, and glulam beam made out of thermally treated fast-growing poplar laminae can be used in construction, but need checking in MOR or be used for a limited range of structural elements.

Author Biography

Kong Yue, Nanjing Tech University

College of Civil Engineering

References

Aicher S, Dill-Langer G, Ranta-Maunus A (1998) Duration of load effect in tension perpendicular to the grain of glulam in different climates. Holz Roh Werkst 56:295-305.

Boonstra M, Acker VJ, Kegel E (2007) The effect of a two-stage heat treatment process on the mechanical properties of full construction timber. Wood Mater Sci Eng 2: 138-146.

Boonstra M, Tjeerdsma B (2006) Chemical analysis of heat-treated softwoods. Holz Roh Werkst 64:204-211.

BS EN 13183-1 (2002) Moisture content of a piece of a sawn timber–Part 1: Determination by oven dry method. European Committee for Standardization, London.

BS EN 408:2010. A1 (2012) Timber structures—Structural timber and glued laminated timber—Determination of some physical and mechanical properties. European Committee for Standardization, London.

Cademartori PHG, Santos PSB, Serrano L, Labidi J, Gatto DA (2013) Effect of thermal treatment on physicochemical properties of Gympie messmate wood. Ind Crops Prod 45: 360-366.

CNS (2011) GB/T 26899-2011. Structural glued laminated lumber. Standards Press of China, Beijing, China.

Dinwoodie JM (2000) Timber: Its nature and behaviour. Van Nostrand Reinhold, New York.

Esteves B, Domingos I, Pereira H (2007a) Improvement of technological quality of eucalypt wood by heat treatment in air at 170-200°C. Forest Prod J 57:47-52.

Esteves B, Graça J, Pereira H (2008) Extractive composition and summative chemical analysis of thermally treated eucalypt wood. Holzforschung 62:344-351.

Esteves B, Marques A, Domingos I, Pereira H (2007b) Influence of steam heating on the properties of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) wood. Wood Sci Technol 41:193-207.

Esteves B, Pereira H (2009) Wood modification by heat treatment: A review. BioResources 4:370-404.

Gaspar F, Cruz H, Gomes A (2010) Production of glued laminated timber with copper azole treated maritime pine. Holz Roh Werkst 68:207-218.

Gerhards CC (1982) Effect of moisture content and temperature on the mechanical properties of wood: An analysis of immediate effects. Wood Fiber 14:4-36.

Goodell B, Jellison J, Loferski J, Quarles SL (2007) Brownrot decay of ACQ and CA-B treated lumber. Forest Prod J 57:31-33.

Gustafsson PJ, Hoffmeyer P, Valentin G (1998) DOL behavior of end-notched beams. Holz Roh Werkst 56: 307-317.

Gunduz G, Aydemir D, Karakas G (2009) The effect of thermal treatment on the mechanical properties of wild pear (Pyrus elaeagnifolia) wood and changes in physical properties. Mater Des 30:4391-4395.

Hill CAS (2006) Wood modification: Chemical, thermal and other processes. Wiley, Chichester, UK.

Hillis WE (1984) High temperature and chemical effects on wood stability. Wood Sci Technol 18:281-293.

Humar M, Zlindra D, Pohleven F (2006) Effect of fixation time on leaching of copper-ethanolamine based wood preservatives. Holz Roh Werkst 65:329-330.

Icel B, Guler G, Isleyen O, Beram A, Mutlubas M (2015) Effects of industrial heat treatment on the properties of spruce and pine woods. BioResources 10:5159-5173.

Jamsa S, Viitaniemi P (2001) Heat treatment of wood-better durability without chemicals. Pages 9-13 in Review on heat treatments of wood, Proc. Special Seminar COST Action, Antibes, France.

Jiang J, Lu J, Zhou Y, Zhao Y, Zhao L (2014) Compression strength and modulus of elasticity parallel to the grain of oak wood at ultra-low and high temperatures. Bio-Resources 9:3571-3579.

Jonsson J (2004) Internal stresses in the cross-grain direction in glulam induced by climate variations. Holzforschung 58:154-159.

Kamdem D, Pizzi A, Jermannaud A (2002) Durability of heat-treated wood. Holz Roh Werkst 60:1-6.

Kocaefe D, Chaudhry B, Poncsak S, Bouazara M, Pichette A (2007) Thermogravimetric study of high temperature treatment of aspen: Effect of treatment parameters on weight loss and mechanical properties. J Mater Sci 42: 854-866.

Kocaefe D, Poncsak S, Tang J, Bouazara M (2010) Effect of heat treatment on the mechanical properties of north American jack pine: Thermogravimetric study. J Mater Sci 45:681-687.

Kretschmann DE (2010) Mechanical properties of wood. Pages 5-44 in: RJ Ross, ed. Wood handbook: Wood as an engineering material. USDA Forest Service, Forest Products Laboratory, Madison, WI.

Li T, Cai JB, Gu LB, Ding T, Zhou DG (2013) Correction factors for a radio frequency-type moisture meter for heat treated wood. BioResources 8:5549-5560.

Li T, Deng DL, Avramidis S, Wlinder MEP, Zhou DG (2017) Response of hygroscopicity to heat treatment and its relation to durability of thermally modified wood. Constr Build Mater 144:671-676.

Lin LD, Chen YF, Wang SY, Mingjer T (2009) Leachability, metal corrosion, and termite resistance of wood treated with copper-based preservative. Int Biodeter Biodegr 63: 533-538.

Mirzaei G, Mohebby B, Ebrahimi G (2017) Glulam beam made from hydrothermally treated poplar wood with reduced moisture induced stresses. Constr Build Mater 135:386-393.

Mitchell PH (1988) Irreversible property changes of small loblolly pine specimens heated in air, nitrogen, or oxygen. Wood Fiber Sci 20:320-335.

Moraes PD, Rogaume Y, Bocquet JF, Triboulot P (2005) Influence of temperature on the embedding strength. Holz Roh Werkst 63:297-302.

Moraes PD, Rogaume Y, Triboulot P (2004) Influence of temperature on the modulus of elasticity (MOE) of Pinus sylvestris L. Holzforschung 58:143-147.

Nuopponen M, Vuorinen T, Jamsa S, Viitaniemi P (2004) Thermal modifications in softwood studied by FT-IR and UV resonance Raman spectroscopies. J Wood Chem Technol 24:13-26.

Osmannezhad S, Faezipour M, Ebrahimi G (2014) Effects of GFRP on bending strength of glulam made of poplar (Populus deltoides) and beech (Fagus orientalis). Constr Build Mater 51:34-39.

Pearson H, Ormarsson S, Gabbitas B (2015) Nonlinear tensile creep behavior of radiata pine at elevated temperatures and different moisture contents. Holzforschung 69:915-923.

Pekka T, Mark H (2016) The effect of temperature and moisture content on the fracture behaviour of spruce and birch. Holzforschung 70:369-376.

Poncsak S, Kocaefe D, Bouazara M, Pichette A (2006) Effect of high temperature treatment on the mechanical properties of birch (Betula papyrifera). Wood Sci Technol 40:647-663.

Ranta-Maunus A (2003) Effects of climate and climate variations on strength. Pages 153-167 in S. Thelandersson and HJ Larsen, eds. Timber engineering. E-publishing Inc., Chichester, UK.

Santos JA (2000) Mechanical behaviour of eucalyptus wood modified by heat. Wood Sci Technol 34:39-43.

Sivonen H, Maunu S, Sundholm F, Jamsa S, Viitaniemi P (2002) Magnetic resonance studies of thermally modified wood. Holzforschung 56:648-654.

Sjodin J, Johansson CJ (2007) Influence of initial moisture induced stresses in multiple steel-to-timber dowel joints. Holz Roh Werkst 65:71-77.

Tjeerdsma B, Boonstra M, Pizzi A, Tekely P, Militz H (1998) Characterisation of thermally modified wood: Molecular reasons for wood performance improvement. Holz Roh Werkst 56:149-153.

Tjeerdsma B, Militz H (2005) Chemical changes in hydrothermal treated wood: FTIR analysis of combined hydrothermal and dry heat-treated wood. Holz Roh Werkst 63:102-111.

Widmann R, Beikircher W, Cabo JL, Steiger R (2014) Bending strength and stiffness of glulam beams made of thermally modified beech timber. Pages 569-576 in S. Aicher and H. Garrecht, eds. Materials and joints in timber structures. E-publishing Inc., The Netherlands.

Yang TH, Lin CH, Wang SY, Lin FC (2012) Effects of ACQ preservative treatment on the mechanical properties of hardwood glulam. Holz Roh Werkst 70:557-564.

Yildiz S, Gezer D, Yildiz U (2006) Mechanical and chemical behavior of spruce wood modified by heat. Build Environ 41:1762-1766.

Yildiz S, Gumus¸kaya E (2007) The effect of thermal modification on crystalline structure of cellulose in soft and hardwood. Build Environ 42:62-67.

Yue K, Cheng XC, Chen ZJ, Tang LJ, Liu WQ (2018) Investigation of decay resistance of poplar wood impregnated with of alkaline copper, urea-formaldehyde and phenol-formaldehyde resin. Wood Fiber Sci 50:392-401.

Yue K, Chen ZJ, LuWD, LiuWQ, LiMY, ShaoYL, Tang LJ, Wan L (2017) Evaluating the mechanical and fire-resistance of modified fast-growing Chinese fir timber with boric phenol-formaldehyde resin. Constr Build Mater 154:956-962

Yue K, Wang L, Xia J, Zhang YL, Chen ZJ, Liu WQ (2019) Experimental research on mechanical properties of laminated poplar wood veneer/plastic sheet composites. Wood Fiber Sci 51:320-331.

Zaman A, Alen R, Kotilainen R (2000) Thermal behavior of Scots pine (Pinus sylvestris) and silver birch (Betula pendula) at 200-230 °C. Wood Fiber Sci 32:138-143.

Zhang J, Kamdem DP (2000) FTIR characterization of copper ethanolamine wood interaction for wood preservation. Holzforschung 54:119-122.

Zhong Y, Zhou H, Wen L (2015) The effect of elevated temperature on bending properties of normal wood inside Chinese larch wood during fire events. BioResources 10: 2926-2935.

Published

2020-04-24

Issue

Section

Research Contributions