Grading of recovered Norway spruce (Picea abies) timber for structural purposes

Llana, Daniel F. (author), Íñiguez-González, Guillermo (author), Plos, Mitja (author), Turk, Goran (author)

Linear regression models were constructed for chestnut beams of Spanish origin (Asturias, Galicia, Catalonia and Extremadura) using the global modulus of elasticity (MOE g ) and bending strength (MOR), both obtained by destructive tests, as dependent variables, and the results of non-destructive measurements, visual grading parameters and density as independent variables. The variables selected were density, wave velocity, sample length, dynamic modulus of elasticity, maximum knot diameter in relation to height and concentrated knot diameter ratio. Linear regression models were constructed to indirectly estimate the mechanical properties of the beams. Ultrasonic velocity, density and sample length were the best predictors of MOE g (R 2 = 0.740 and 0.734 SE). Regression adjustments for MOR presented low coefficients of determination and high errors. The visual grading parameters of the beams did not play a significant role in the prediction of either MOE g or MOR.

• Language: English
• Keywords: cascading, circular economy, non-destructive testing, reclaimed, recycling, resistograph, reuse, salvaged, secondary timber
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: Str. 1-10
• Numbering: Vol. 398, art. 132440
• PID: 20.500.12556/RUL-151729
• UDC: 691
• ISSN on article: 0950-0618
• DOI: 10.1016/j.conbuildmat.2023.132440
• COBISS.SI-ID: 159319555
• Publication date in RUL: 18.10.2023

Record is a part of a journal

• Title: Construction & building materials
• Shortened title: Constr. build. mater.
• Publisher: Scientific & Technical Press
• ISSN: 0950-0618
• COBISS.SI-ID: 25270784

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Title: Razvrščanje že uporabljenega lesa smreke (Picea abies) za konstrukcijske namene

Abstract

Ob rušenju konstrukcij pridobivamo vse večje količine lesa, ki mu je mogoče dodati vrednost s ponovno uporabo ali recikliranjem za konstrukcijske namene. Ta študija raziskuje možnosti uporabe vizualnih in nedestruktivnih parametrov za oceno mehanskih lastnosti predelanega lesa, tako da ga je mogoče razvrstiti za novo uporabo. Proučevali smo devetnajst obnovljenih špirovcev navadne smreke (Picea abies (L.) Karst.). Uporaba dveh vizualnih standardov za razvrščanje je povzročila zavrnitev 95 % vzorcev. Ocena modula elastičnosti je bila izvedena z ultrazvočno in vibracijsko tehniko, pri čemer smo dosegli determinacijska koeficienta (R2) 0,66 oziroma 0,75. V primeru ocene upogibne trdnosti je bil R2 0,60 oziroma 0,77. Izmed vizulanih parametrov je bil delež grč v prerezu bil edini parameter, ki je statistično značilno vplival na vrednost lokalnega modula elastičnosti. Gostota je bila ocenjena z uporabo odvzema vrtalnih ostružkov in odporno sti proti prebijanju z R2 0,66 oziroma 0,58.

• Keywords: krožno gospodarstvo, nedestruktivno preizkušanje, recikliranje, rezistograf, ponovna uporaba, sekundarni les

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0260
• Name: Mehanika konstrukcij