Quality and Bending Properties of Scots Pine (Pinus Sylvestris L.) Sawn Timber

Abstract

The paper presents the partial research results of a mechanical properties study conducted on Scots pine from the Silesian Forestry Area in Poland. The scope of research included the visual strength grading of the timber according to the PN-D-94021:2013 standard, mechanical testing (according to EN 408:2012) and an attempt to assign visuals to the C strength classes. The EN 1912: 2012 standard assigns the visual sorting classes of individual wood species (according to national sorting standards) to the C strength classes introduced by the EN 338: 2018 standard. At the moment, this standard does not assign Polish visual sorting classes (KW, KS, and KG) to C strength classes. The obtained MOE (modulus of elasticity) and MOR (static bending strength) values were corrected according to the EN 384:2018 standard, and their characteristic values were later calculated. On this basis, we proposed a classification of the grading classes determined on the basis of PN-D-94021 into C classes described in EN 338:2018, which is necessary in the process of the transposition of Polish strength grades (KW, KS, KG, and Reject) and the qualification of them in line with EN 1912:2012. The calculated characteristic values of density, MOR and E0 (the modulus of elasticity parallel to the grain) allowed us to assign Polish visual grades KW, KS, and KG to C35, C30, and C20, respectively. The pine timber under research had high physical and mechanical parameters, which translated into high C classes to which the KW, KS, and KG timber categories were assigned.

Visual and machine strength gradings of Scots and red pine structural timber pieces from Türkiye

“…For this reason, machine strength grading is judged to be more advantageous than visual strength grading. Many European companies are working on this subject and developing new machines (Nocetti et al 2010;Ridley-Ellis et al 2016;Burawska-Kupniewska et al 2020;Krzosek et al 2020;Krzosek and Burawska 2022). In Türkiye, studies continue to produce devices that can be used for this purpose.…”

“…Therefore, by the binding legal requirements of the countries, only wood with a designated strength class can be used for applications in the construction sector. Thus, it is aimed to ensure both structural safety and economical use of the material (Faria et al 2012;Christoforo et al 2015;Ridley-Ellis et al 2016;Burawska-Kupniewska et al 2020;Krzosek et al 2020).…”

Mechanical characterization of visually graded boards from turkish fir and black pine by nondestructive and destructive tests

“…National standards such as DIN 4074-1 (2012), BS 4978: 2007+A2 (2017, UNI 11035-1 (2010) and UNE 56544 (2011) have been developed for visual grading of timber products based on knots, the slope of grain, strength, stiffness, density, and other visible parameters as described in EN 1912in EN (2012b. Timber products with a CE marking, representing the guaranteed resistance, are called strength graded timber that can be used to produce structural elements (Burawska-Kupniewska et al 2020).…”

Strength Properties of Structural Glulam Manufactured from Pine (Pinus sylvestris L.) Side Boards

“…In the EU countries many tree and wood species, both hardwood and softwood, have been tested and graded, while their suitability for the manufacture of solid structural glulam has also been assessed. This has been done, e.g., for Douglas fir originating from Ireland and the United Kingdom [ 7 , 8 ] and Germany [ 9 ], pine [ 10 , 11 , 12 , 13 , 14 ] and other softwood species [ 15 , 16 ] growing in Poland [ 10 , 17 ], while in the case of non-European countries it was, e.g., ponderosa pine from the USA [ 18 ], maple [ 19 ], black spruce from Canada [ 20 ], acacia from Indonesia [ 21 ] and Japanese larch [ 22 , 23 ]. Glulam beams may be manufactured from lamellas bonded horizontally or vertically.…”