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

Abstract

The aim of this study was to assess the static bending strength of pine glulam manufactured when obtaining the main yield, i.e., structural timber or timber to be used in the production of structural glulam. Analyses were conducted on pine timber harvested from three different locations in Poland. Two beam variants were manufactured, differing in the timber arrangement, horizontal vs. vertical. It was shown that the static bending strength of beams manufactured in the vertical timber arrangement variant is slightly higher than that of beams produced from horizontally arranged layers, with the latter beams characterised by a smaller confidence interval for this strength. Moreover, it was found that the difference in the value of the 5th percentile for both beam types is slight and both beam types are considered to exhibit a high bending strength of over 40 N/mm2.

The Effect of Periodic Loading of Glued Laminated Beams on Their Static Bending Strength

“…Plywood 21 mm thick (Biaform S.A., Bialystok, Poland) was used in this study and its characteristics were given in an earlier publication [ 37 ]. In addition, previous work [ 18 , 38 , 39 ] suggests that it is more advantageous to sort lumber visually and determine its linear elastic modulus sonically or mechanically, and then form beams with the assumption that the closer to the center of the designed beam, the lower quality lumber can be used. For these reasons, beams fabricated from lumber graded according to the linear modulus of elasticity as determined by the 4-point bending test were subjected to the same test.…”

“…The individual lamellas were tested in terms of a modulus of elasticity according to the method presented in the previous study [ 27 ]. On the other hand, the middle layer was a low-quality sawn timber and would be classified as C16 according to EN 338 [ 39 ]. On the larger/wider surface of the board, there may be healthy knots occupying not more than half of the cross-section or broken knots up to one-third of the cross-section.…”

Caracterização da madeira do clone de eucalipto para aplicação em elementos colados

“…O método é considerado eficaz quando aplicado em grande volume de madeira para a produção de elementos colados estruturais em grande escala (Glavinic et al, 2020). Entretanto, a inspeção visual possui suas limitações e não deve ser usada isoladamente (Mirski et al, 2021), já que não possibilita uma avaliação numérica da resistência da peça. Sendo assim, a classificação visual teve como objetivo o descarte de peças com defeitos.…”

“…A combinação de condições genéticas e ambientais são os principais fatores que influenciam as mudanças nas características da madeira (Rocha et al, 2020). Portanto, a aplicação da madeira está condicionada ao conhecimento de suas propriedades físicas e mecânicas de forma a garantir seu bom desempenho (Mirski et al, 2021).…”

The Strength of Pine (Pinus sylvestris L.) Sawn Timber in Correlation with Selected Wood Defects

“…The timber assessment systems used to ensure optimal wood processing into structural semifinished products are most often based on visual assessment, determination of the dynamic modulus of elasticity, or both methods combined together. The identified anatomical defects, which include, among others, knots, slopes of grain, and resinosis, play a decisive role in classification systems as well as defects occurring due to secondary processing, i.e., cracks, discolorations, rots, and curvatures [ 3 , 4 ]. In the group of the abovementioned coniferous wood defects, knots most often play a crucial role in the process of optimizing the obtainment of structural semifinished products.…”