Grading of Portuguese Maritime Pine Small-Diameter Roundwood
Publication: Journal of Materials in Civil Engineering
Volume 29, Issue 2
Abstract
This paper presents work carried out with the aim of characterizing the mechanical behavior and developing visual and machine-strength grading systems for Portuguese maritime pine roundwood for structural applications. Two samples of forty maritime pine logs each were collected, one in a northern region of Portugal and another in an interior central region. After drying, the logs were visually graded and subjected to nondestructive tests, using vibration and ultrasounds, for determination of dynamic modulus of elasticity. The logs were then subjected to destructive tests for determining bending and compression strength and bending modulus of elasticity. These results were analyzed in order to identify the features to be considered in the strength grading process. From this analysis, a proposal was developed to visually grade Portuguese maritime pine roundwood in two strength grades. According to the European strength class standard for solid timber, the upper grade has similar mechanical properties to the C50 class, whereas the lower grade is similar to the C35. The machine grading showed good potential as a result of the good correlation presented between the dynamic modulus of elasticity and the mechanical properties. However, the ultrasounds showed slightly better correlation than the vibration method, whereas the last one is more practical.
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Acknowledgments
This study has been supported by Fundação para a Ciência e Tecnologia, with the scholarship SFRH/BD/44909/2008, and by the research project PTDC/ECM/099833/2008.
References
Boren, H., and Barnard, G. (2000). “Analysis of the strength and stiffness properties for small diameter round Scots pine timber tested in bending and compression parallel to the grain.” Paperi ja Puu—Paper and Timber, 82(1), 48–56.
Brookhuis. (2009). Timber grader MTG, Brookhuis applied technologies WOOD, Enschede, Netherlands.
CEN (European Committee for Standardization). (1995). “Round and sawn timber—Method of measurement of features.” EN 1310, Brussels, Belgium.
CEN (European Committee for Standardization). (2003a). “Structural round timber—Test methods.” EN 14251, Brussels, Belgium.
CEN (European Committee for Standardization). (2003b). “Structural timber—Strength classes.” EN 338, Brussels, Belgium.
CEN (European Committee for Standardization). (2003c). “Timber structures—Structural timber and glued laminated timber—Determination of some physical and mechanical properties.” EN 408, Brussels, Belgium.
CEN (European Committee for Standardization). (2004). “Structural timber—Determination of characteristic values of mechanical properties and density.” EN 384, Brussels, Belgium.
CEN (European Committee for Standardization). (2011). “Timber structures—Strength graded structural timber with rectangular cross section—Part 1: General requirements.” EN 14081-1, Brussels, Belgium.
Chui, Y. H., Barclay, D. W., and Cooper, P. A. (1999). “Evaluation of wood poles using a free vibration technique.” J. Test. Eval., 27(3), 191–195.
Farnell. (2000). Pundit plus, CNS Farnell, Elstree Business Centre, Borehamwood, Hertfordshire, U.K.
Gard, W. F., Vries, P. D., and Lanvin, J. D. (1998). “Methods to determine mechanical properties in order to grade roundwood.” World Conf. on Timber Engineering, Lausanne, Switzerland, 634–641.
Green, D. W., Evans, J. W., Murphy, J. F., Hatfield, C. A., and Gorman, T. M. (2005). Mechanical grading of 6-inch-diameter Lodgepole pine logs for the travelers’ rest and rattlesnake creek bridges, USDA Forest Service, Washington, DC.
Green, D. W., Gorman, T. M., Evans, J. W., and Murphy, J. F. (2004). “Improved grading system for structural logs for log homes.” Forest Prod. J., 54(9), 52–62.
Green, D. W., Gorman, T. M., Evans, J. W., and Murphy, J. F. (2006). “Mechanical grading of round timber beams.” J. Mater. Civ. Eng., 1–10.
Green, D. W., Gorman, T. M., Evans, J. W., Murphy, J. F., and Hatfield, C. A. (2007). “Grading and properties of small-diameter Douglas-fir and ponderosa pine tapered logs.” Forest Prod. J., 58(11), 33–41.
IPQ (Instituto Português da Qualidade). (1995). “Madeira de pinheiro bravo para estruturas.”, Portugal (in Portuguese).
Morgado, T., Rodrigues, J., Machado, J., Dias, A., and Cruz, H. (2009). “Bending and compression strength of Portuguese Maritime pine small-diameter poles.” Forest Prod. J., 59(4), 23–28.
Pellerin, R. F., Koch, P., and Vogt, J. J. (1989). “Mechanical properties of lodgepole pine: 3-inch diameter stems.” Forest Prod. J., 39(4), 62–66.
Prieto, E. H., Seco, J. I. F.-G., Barra, M. R. D., and Pérez, R. M. (2007). “Aplicación de los ultrasonidos a la avaluación de las propiedades mecánicas de la madera en rollo de pequeño diámetro.” Informes de la Construcción, 59(506), 87–95.
Ranta-Maunus, A. (1999). “Round small-diameter timber for construction.”, Technical Research Centre of Finland, Espoo, Finland.
Rodrigues, J., and Vries, P. D. (2010). “Visual and strength grading of Dutch larch and Portuguese maritime pine small diameter roundwood timber.”, Coimbra, Portugal.
Sandoz, J. L. (1991). “Form and treatment effects on conical roundwood.” Wood Sci. Technol., 25(3), 203–214.
Vries, d. P. A. (2009). “Strength class determination of cloeziana round wood poles.”, Lisbon, Portugal.
Vries, d. P. A., and Gard, W. F. (2006). “Development of a strength grading system of small diameter round wood.” World Conf. on Timber Engineering, Portland, OR.
Vries, P. (1998). “Strength granding of small-diameter Larch.”, Delft Univ. of Technology, Netherlands.
Wang, X., et al. (2001). “Several nondestructive evaluation techniques for assessing stiffness and MOE of small-diameter logs.”, USDA Forest Service, Washington, DC.
Wolfe, R., and Moseley, C. (2000). “Small-diameter log evaluation for valued added structural applications.” Forest Prod. J., 50(10), 48–58.
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Published In
Journal of Materials in Civil Engineering
Volume 29 • Issue 2 • February 2017
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Mar 18, 2016
Accepted: Jun 17, 2016
Published online: Aug 31, 2016
Discussion open until: Jan 31, 2017
Published in print: Feb 1, 2017
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