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Abstract: This paper deals with results of preliminary analysis to determine the bending strength of approximately 150 year old oak timber obtained from structural elements used in construction. The test procedures were those specified in the PN-EN 408 standard. The experiments involved subjecting specimens to four-point static loading using three different loading rates: 5, 7 and 10 mm/min. The specimens were sampled from full-size timber beams. The experimental data revealed that after such a long period of use the structural oak timber elements had retained high strength. The failure mode and the behaviour of the beams during tests were dependent on the location of wood defects as well as the rate of deflection gain in time.
B I B L I O G R A F I A1. Kossakowski P.G.: Influence of anisotropy on the energy release rate Gi for highly orthotropic materials. Journal of Theoretical and Applied Mechanics 45(4) (2007), pp. 739-752.
2. Stefanczyk B.: Budownictwo ogolne. Matenaly i wyroby budowlane. Tom 1, Arkady, Warszawa, 2005.
3. Rudzinski L.: Konstrukcje drewniane. Naprawy, wzmocmema, przyklady obhczeii., Skrypt Pohtechniki Switokrzyskiej, Kielce, 2010.
4. Mazars J.: A descnption of micro- and macroscale damage of concrete structures. Engineering Fracture Mechanics 25(5-6) (1986), pp. 729-737.
5. Yazdani S., Schreyer H.: Combined Plasticity and Damage Mechanics Model for Plain Concrete, Journal of Engineering Mechanics 116(7) (1990), pp. 1435-1450.
6. Bazant Z. P.: Nonlocal damage theory based on micromechanics of crack interaction. Journal of Engineering Mechanics ASCE 120(3) (1994), pp. 593-617.
7. Chaboche J. L., Lesne P. M., Maire J. F.: Continuum Damage Mechanics, Anisotropy and Damage Deactivation for Brittle Materials Like Concrete and Ceramic Composites, International Journal of Damage Mechanics 4(1) (1995), pp. 5-22.
8. Sandhaas C., Van de Kuilen J.W., Blass H.J.: Constitutive model for wood based on continuum damage mechanics, WCTE, World conference on timber engineering, Auckland, New Zealand, 15-19 July 2012, pp. 159-167.
9. Kossakowski P.G.: Microstructural failure criteria for S235JR steel subjected to spatial stress states, Archives of Civil and Mechanical Engineering 15(1) (2015), pp. 195-205.
10. Kossakowski P.G., Wciślik W., Experimental determination and application of critical void volume fraction fc for S235JR steel sudjected to multi-axial stress state, in: T. Łodygowski, J. Rakowski, P. Litewka (Eds.), Recent Advances in Computational Mechanics, CRC Press/Balkema, London, 2014, pp. 303-309.
11. Kossakowski P.G., Wciślik W.: Effect of critical void volume fraction fF on result of ductile fracture simulation for S235JR steel under multi-axial stress states, Key Engineering Materials - Fracture and Fatigue of Materials and Structure 598 (2014), pp. 113-118.
12. Brol L., Dawczyński S., Malczyk A., Adamczyk K.: Testing timber beams after 130 years of utilization, Wiadomości Konserwatorskie - Journal of Heritage Conservation nr 32 (2012), pp. 100-104.
13. Nowak T., Brol J., Jaseńko J.: Estimation of the strength parameters of wood in building structures - preliminary studies, Annals of WULS - SGGW Forestry and Wood Technology No. 83 (2013), pp. 303-306.
14. PN-EN 408:2004 Konstrukcje drewniane. Drewno konstrukcyjne i klejone warstwowo. Oznaczanie niektórych właściwości fizycznych i mechanicznych.
15. PN-EN 384:2004 Drewno konstrukcyjne. Oznaczanie wartości charakterzystycznych właściwósci mechanicznych i gęstości.
16. PN-EN 338:2004 Drewno konstrukcyjne. Klasy wytrzymałości.