Mechanical properties of sapwood versus heartwood, in three different oak species

Merela, Maks (author), Čufar, Katarina (author)

The aim of this study was to investigate the main mechanical properties of sapwood and heartwood in white and red oaks. Samples of wood were taken from 26 oak beams prepared to be used for railway sleepers, of which 62 % were from white oak (either Quercus petraea or. Q. robur) and 38 % from red oak group, represented by Q. cerris. For both oak groups, the following parameters were determined: the density, bending strength, modulus of elasticity (MOE), compression strength and Brinell hardness of sapwood and heartwood. Multiple analyses were done to compare the properties of sapwood and heartwood, as well as the properties of white vs. red oaks. The results revealed no significant differences between sapwood and heartwood properties but statistically significant differences were found between the properties of white and red oaks. The research results contradict the common opinion of users that the mechanical properties of sapwood are inferior to those of heartwood. Investigations revealed that Q. cerris had even better mechanical properties than Q. robur or Q. petraea, which also contradicts the common opinion that its mechanical properties are inferior to those of white oaks. The results help to understand better wood variability for optimal selection of timber for construction.

• Language: English
• Keywords: Quercus, mehanske lastnosti, gostota, beljava, jedrovina
• Work type: Not categorized
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publisher: Šumarski fakultet, Sveučilišta u Zagrebu: Hrvatsko šumarsko društvo
• Year: 2013
• Number of pages: Str. 323-334
• Numbering: Vol. 64, no. 4
• PID: 20.500.12556/RUL-68584
• UDC: 630*812
• ISSN on article: 0012-6772
• DOI: 10.5552/drind.2013.1325
• COBISS.SI-ID: 2172041
• Publication date in RUL: 10.07.2015

Record is a part of a journal

• Title: Drvna industrija : scientific journal of wood technology = znanstveni časopis za pitanja drvne tehnologije
• Shortened title: Drv. ind.
• Publisher: University of Zagreb, Faculty of Forestry and Wood Technology
• ISSN: 0012-6772
• COBISS.SI-ID: 2858754

Secondary language

• Language: Croatian
• Title: Density and mechanical properties of oak sapwood versus heartwood in three different oak species

Abstract

Cilj ovog istraživanja bio je ispitati osnovna mehanička svojstva drva bjeljike i srži bijeloga i crvenog hrasta. Uzorci su uzeti od 26 hrastovih greda spremnih za izradu željezničkih pragova, od čega je 62 % greda od bijelog hrasta (Quercus petraea ili Q. robur ), a 38 % od skupine crvenih hrastova, čiji je predstavnik Q. cerris. Za drvo bjeljike i drvo srži obiju skupina hrasta određena je gustoća, čvrstoća na savijanje, modul elastičnosti (MOE), tlačna čvrstoća i tvrdoća prema Brinellu. Napravljene su višestruke analize radi usporedbe svojstava bjeljike i srži, kao i usporedbe svojstava drva bijelih i crvenih hrastova. Rezultati su pokazali da nema značajne razlike između svojstava drva bjeljike i srži, ali statistički značajne razlike pokazale su se između svojstava drva bijeloga i crvenog hrasta. Rezultati istraživanja proturječe uvriježenome mišljenju korisnika da su mehanička svojstva bijeljike lošija od mehaničkih svojstava drva srži. Istraživanja su pokazala da drvo Q. cerris ima čak i bolja mehanička svojstva nego drvo Q. robur i Q. petraea, što je također suprotno ustaljenom mišljenju da su njegova svojstva lošija od svojstava drva bijelog hrasta. Rezultati će pridonijeti boljem razumijevanju varijabilnosti svojstava drva i optimalnom izboru drva za gradnju.