Structural properties of Douglas fir sawn timber: Significance of distance to pith for yield in strength classesShow others and affiliations
2021 (English)In: World Conference on Timber Engineering 2021, WCTE 2021, World Conference on Timber Engineering (WCTE) , 2021Conference paper, Published paper (Refereed)
Abstract [en]
Although it is known that mechanical properties of softwood timber improve considerably with increasing distance from the pith, quantitative results are rare in the literature. This paper aims to provide clues about what are the potential strength grading yields of Douglas fir grown in France according to the board distance to pith, with two different types of non-destructive grading machines. The results from 221 boards were divided in two groups of similar size, for boards strictly located below a distance of 200 mm to the pith (called corewood), and the others (called outerwood). Although being similar in strength classes below C24, the raw yields in high strength classes were much higher for outerwood than for corewood. Regardless of the type of machine used, strength grading was more efficient for outerwood. These results can contribute to the basis for decision making, for Douglas fir forest owners and the sawmilling industry, regarding the suitable size of logs at the time for harvesting and the type of strength grading technology to use.
Place, publisher, year, edition, pages
World Conference on Timber Engineering (WCTE) , 2021.
Keywords [en]
Douglas fir, Juvenile wood, Machine strength grading, Grading, Timber, Corewood, Juvenile woods, Non-destructive grading, Quantitative result, Sawn timbers, Softwood timber, Strength class, Decision making
National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
URN: urn:nbn:se:lnu:diva-112575Scopus ID: 2-s2.0-85120743153OAI: oai:DiVA.org:lnu-112575DiVA, id: diva2:1656818
Conference
World Conference on Timber Engineering 2021, WCTE 2021, 9 - 12 August 2021
2022-05-082022-05-082022-06-16Bibliographically approved