Open Access Open Access  Restricted Access Subscription or Fee Access

Physical and mechanical behaviors of thermally modified rubberwood glulam beam under sustained and cyclic loading

T. Pulngern, T. Udtaranakron, K. Chanto


This study evaluated the effect of thermal modification on the physical and mechanical properties of rubberwood glued laminated (glulam) timber. The flexural creep property and cyclic loading behavior were also investigated. The obtained results indicated that the MC and specific gravity of thermally modified rubberwood decreased with an increase in modification temperature. Moreover, the flexural strength of the rubberwood glulam timber at modification temperatures of 180 and 220oC was 8.57% and 46.72%, respectively, which was less than that of the control rubberwood dried at 90oC. However, the MOE between the thermally modified rubberwood glulam timber and control specimens was not significantly changed. The flexural creep test indicated that the maximum relative creep of the thermally modified rubberwood timber equaled 0.31, which was lower than that of other natural timber and tended to decrease when increasing the stress level. Various mathematical models were also proposed, and the best-fitted model was found to be the Bailey-Norton power law model. Nevertheless, the cyclic loading results also proved that thermal modification temperature had a direct effect on the ductility index and energy dissipation of rubberwood glulam timber, but it had no significant effect on the impairment of strength.






creep; cyclic loading; glulam; thermally modified rubberwood

Full Text:



Ansell MP (2015) Wood composite. Elsevier Science & Technology, Cambridge, United Kingdom. 444 pp.

Anshari B, Guan ZW, Wang QY (2017) Modelling of glulam beams pre-stressed by compressed wood. Compos Struct 165:160-170.

ASTM (2014) D2395-14. Standard test methods of density and specific gravity (relative density) of wood and wood- based materials. ASTM, Philadelphia, PA.

ASTM (2014) D198-14. Standard test methods of static tests of lumber in structural sizes. ASTM, Philadelphia, PA.

ASTM (2015) D6815-09. Standard Specification for evaluation of duration of load and creep effects of wood and wood-based products. ASTM, Philadelphia, PA.

ASTM (2016) D4442-16. Standard test methods for direct moisture content measurement of wood and wood-based materials. ASTM, Philadelphia, PA.

American Wood Council (AWC) (2018) ANSI/AWC NDS- 2018. National Design Specification (NDS) for wood construction, 2018 edition. American Wood Council 2018 (19 September 2018).

Bailey RW (1935) The utilization of creep test data in engineering design. Proc Inst Mech Eng Transport Eng 131: 131-349.

Bakar BFA, Hiziroglu S, Tahir PMd (2013) Properties of some thermally modified wood species. Mater Des 43: 348-355.

Boresi AP, Schmidt RJ (2002) Advanced mechanics of materials, 6th edition. John Willey & Son, New York, NY. 676 pp.

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

Chanto K (2017) Mechanical properties and flexural creep behavior of Douglas-fir glued laminated timber. MS thesis, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand. 80 pp.

Chetpattananondha P, Thongpullb K, Chetpattananondh K (2017) Interdigital capacitance sensing of moisture content in rubber wood. Comput Electron Agric 142:545-551.

Dorn JE (1962) Progress in Understanding high-temperature creep, H. W. Gillett Memorial Lecture. American Society for Testing Materials, Philadelphia, PA. 22 pp.

EN (2005) 12512. Timber structures - test methods - cyclic testing of joints made with mechanical fasteners, European Committee for Standardisation, Bruxelles, Belgium.

Epmeier H, Johansson M, Kliger R, Westin M (2007) Bending creep performance of modified timber. Holz Roh Werkst 65:343-351.

Gerhards CC (2000) Bending creep and load duration of Douglas-fir 2 by 4s under constant load for up to 12-plus years. Wood Fiber Sci 32(4):489-501.

Gonzalez-Pena MM, Curling SF, Hale MDC (2009) On the effect of heat on the chemical composition and dimensions of thermally-modified wood. Polym Degrad Stab 94: 2184-2193.

Gowda S, Kortesmaa M, Ranta-Maunus A (1996) Long term creep tests on timber beams in heated and non-heated environments. VTT Publication 278, Espoo, Finland. 35 pp.

Herrera R, Arrese A, Hoyos-Martinez PL, Labidi J, Llano- Ponte R (2018) Evolution of thermally modified wood properties exposed to natural and artificial weathering and its potential as an element for façades systems. Constr Build Mater 172:233-242.

Holzer SM, Loferski JR, Dillard DA (1989) A review of creep in wood: Concepts relevant to develop long-term behavior predictions for wood structures. Wood Fiber Sci 21(4):376-392.

Issa CA, Kmeid Z (2005) Advanced wood engineering: Glulam beams. Constr Build Mater 19:99-106.

Li RR, Cao PX, Xu W, Ekevad M, Wang XD (2018) Experimental and numerical study of moisture-induced stress formation in hexagonal glulam using X-ray computed tomography and finite-element analysis. BioResources 13(4):7395-7403.

Li RR, Xu W, Wang XD, Wang CG (2018) Modeling and predicting of the color changes of wood surface during CO2 laser modification. J Clean Prod 183:818-823.

Li RR, Fang L, Xu W, Xiong XQ, Wang XD (2019) Effect of laser irradiation on the surface wettability of poplar wood. Sci Adv Mater 11(5):655-660.

Li T, Cheng Dl, Avramidis S, Walinder 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.

Mohamad WHW, Razlan MA, Ahmad Z (2011) Bending strength properties of glued laminated timber from selected Malaysian hardwood timber. Int J Civ Environ Eng 11(4): 7-12

Nadir Y, Nagarajan P (2014) The behavior of horizontally glued laminated beams using rubber wood. Constr Build Mater 55:398-405.

Norton FH (1929) The creep of steel at high temperature. McGraw-Hill, New York, NY. 67-70 pp.

Pickel TW, Sidebottom OM, Boresi AP (1971) Evaluation of creep law and flow criteria for two metals subjected to stepped load and temperature changes. Exp Mech 11(5):202-209.

Pulngern T, Chucheepsakul S, Padyenchean C, Rosapitak V, Prapuit W, Chaochanchaikul K, Sombatsompop N (2010) Effects of cross-section design and loading direction on the creep and fatigue properties of wood/pvc composite beams. J Vinyl Addit Technol 16(1):42-49.

Qiaofang Z, Chuanfu C, Xiangyu Z, Dengyun T, Kaifu L (2019) The effect of thermal modification by hot pressing on the some physical and mechanical properties in rubberwood (Hevea brasiliensis). Wood Res 64(2):361-372.

Sandberg D, Kutnar A (2016) Thermally modified timber: Recent developments in Europe and North America. Wood Fiber Sci 48:28-39.

Shen Y, Gupta R (1997) Evaluation of creep behavior of lumber. Forest Prod J 47:89-96.

Todaro L, Rita A, Cetera P, Auria MD (2015) Thermal treatment modifies the calorific value and ash content in some wood species. Fuel 140:1-3.

Tomak ED, Ustaomer D, Ermeydan MA, Yildiz S (2018) An investigation of surface properties of thermally modified wood during natural weathering for 48 months. Measurement 127:187-197.

Uzel M, Togay A, Anil O, Sogutlu C (2018) Experimental investigation of flexural behavior of glulam beams reinforced with different bonding surface materials. Constr Build Mater 158:149-163.

Weiss Chemie Technik (2018) (12 October 2018).

Yue K, Song X, Jiao X, Wang L, Jia C, Chen Z, Liu W (2020) An experimental study on flexural behavior of glulam beams made out of thermally treated fast-growing poplar laminae. Wood Fiber Sci 52(2):152-164.

Zahn JJ, Rammer DR (1995) Design of glued laminated timber columns. J Struct Eng 121(12):1789-1794.


  • There are currently no refbacks.