Proposal for visual grading criteria of structural timber of sweet chestnut from Spain
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Bending strength, modulus of elasticity and density were obtained for 981 specimens of Spanish Sweet Chestnut (Castanea sativa Mill.) sawn timber from five provenances. Four-point bending tests were made with three sizes (40 × 100 × 2,500, 40 × 150 × 3,500 and 70 × 150 × 3,500 mm) according to EN 408 (CEN EN 408:2011). Visual grading criteria were established, resulting in 82 % of the samples being classified as one structural quality, namely MEF. Characteristic values of the density and the mechanical properties were determined according to EN 384 (CEN EN 384:2010a): E 0,mean = 12.3 kN mm−2; f m,k = 28 N mm−2 and ρ k = 510 kg m−3. Therefore, a strength class D24 was assigned according to EN 338 (CEN EN 338:2010b). The relationship between the modulus of elasticity and bending strength was lower (R2 = 0.26) than for Spanish coniferous species.
KeywordsTimber Eucalyptus Strength Class Structural Timber Visual Grade
Vorschlag für die visuelle Sortierung von Bauholz aus spanischer Edelkastanie
The authors would like to thank the Ministry of Science and Innovation of Spain (MICIN) and the Plan for Science, Technology and Innovation of the Principality of Asturias (PCTI) for supporting this research through the research project “Forest and industrial valorization of Spanish chestnut” (VALOCAS) and its funding through the Singular Strategic Projects (MICIN) and Complementary Support for Singular Strategic Projects carried out in Asturias (PCTI).
- Bonamini G, Togni M, Pascucci R (1998) Classification rules for chestnut beams (in Italian). Edizioni C.L.U.T, TorinoGoogle Scholar
- Brunetti M, Cremonini C, Crivellaro A, Togni M, Zanuttini R (2009) Chestnut timber for structural use (in Italian) Castanea 2009, 5º Convegno Nazionale Castagno and 1st European Congress on Chestnut. Cuneo, ItalyGoogle Scholar
- CEN EN 1310 (1997) Round and sawn timber. Method of measurement of featuresGoogle Scholar
- CEN EN 1912 (2012) Structural timber. Strength classes. Assignment of visual grades and speciesGoogle Scholar
- CEN EN 384 (2010) Structural timber. Determination of characteristic values of mechanical properties and densityGoogle Scholar
- CEN EN 338 (2010) Structural timber. Strength classesGoogle Scholar
- CEN EN 408 (2011) Timber structures. Structural timber and glued laminated timber. Determination of some physical and mechanical propertiesGoogle Scholar
- Fernández-Golfín J, Díez R, Hermoso E, Baso C, Casas J, González O (2007) Characteristics of eucalyptus wood for structural purposes. (Caracterización de la madera de Eucalyptus globulus para uso estructural). Boletín CIDEU 4:91–100Google Scholar
- UNE 56546 (2011) Visual grading for structural sawn timber. Hardwood timberGoogle Scholar
- UNI 11035-2 (2010) Structural timber. Visual strength grading for structural timbers. Part 2: Visual strength grading rules and characteristic values for structural timber populationGoogle Scholar