Warp Requirements and Yield Efficiency in the Visual Grading of Sawn Radiata Pine Timber

Montón, Joaquín; Arriaga, Francisco J.; Íñiguez-González, Guillermo; Segués, Edgar

doi:10.15376/biores.10.1.1115-1126

Cited by 5 publications

(4 citation statements)

References 5 publications

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“…Likewise, the dimensions of the pieces are a factor to be considered after the sawing and drying processes. Warp defects can be influenced by the cross-section size of lumber pieces [44]. For twist warping, a total loss of 29 boards with a thickness of 30 mm was found.…”

Section: Wood Warping According To the Thickness Of Boardmentioning

confidence: 99%

Characterization and Yield of Eucalyptus regnans F. Muell Logs for Lumber Production

Rozas,

Zapata,

Muñoz

et al. 2023

Forests

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The yield of Eucalyptus regnans logs for lumber production was evaluated. Crack width and length at each log end were measured. Two log-cutting plans were used to obtain sawn lumber. The first plan (PA) considered logs with diameters varying from 28 to 40 cm, and in the second plan (PB), the log diameters ranged from 42 to 56 cm (PB). Lumber yield was determined using two log volume methods: the Japanese Agricultural Standards (JAS) and Smalian’s equation. The deformations of E. regnans lumber were measured. The Australian and Chilean standards were used to classify sawn lumber. The results showed that logs had radial cracks at both log ends. Cracks were classified into two groups, considering the crack length. Regarding the lumber deformations, most boards exhibited level B bows and crooks in both cutting plans. Levels A and B twists were prevalent in PA, whereas in PB, level A significantly outnumbered level B. The lumber yield of E. regnans in PB was higher than in PA. The lumber yield determined by Smalian’s equation was higher than that determined by the JAS method. This research provides insight into the characterization of E. regnans for lumber production, highlighting its relevance in the forestry industry.

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Section: Wood Warping According To the Thickness Of Boardmentioning

confidence: 99%

Characterization and Yield of Eucalyptus regnans F. Muell Logs for Lumber Production

Rozas,

Zapata,

Muñoz

et al. 2023

Forests

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show abstract

“…As distortion (mainly twist) has the highest influence on rejection of dry graded timber, results from wet grading (mainly based on knots) are not comparable with the ones expected when timber is dry-graded. However, according to Montón et al (41) distortion has almost no influence in mechanical properties, but reduces the end-use possibilities because the lack of straightness makes difficult the structural high quality uses. EN 14081-1:2016 (35) also shows that in clause A.2.2 "Even if warp of timber does not directly influence strength, it is strongly recommended that timber for building purposes should be subject to some restrictions in this respect".…”

Section: Comparison Between Wet and Dry Gradingmentioning

confidence: 99%

“…There was a moderate decrease in case of maritime pine (from 84% to 80%) and similar rejection decreases were found when defining a 2 mm twist limit value in the DIN 4074-1 (Figure 2). According to Montón et al (41) studying the high influence of distortion in the rejection rate for radiata pine, moderating twist specification from 1 mm to 2 mm has no important consequence for mechanical properties. Therefore, if this new maximum permissible twist limit of 2 mm, according to EN 14081-1:2016 (35), is included in future versions of both studied standards, rejection will be reduced without significant reduction of the mechanical properties.…”

Section: Comparison Between Une 56544 and Din 4074-1mentioning

confidence: 99%

Comparison between wet and dry timber visual strength grading according to the Spanish (UNE 56544) and German (DIN 4074-1) standards

et al. 2019

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Visual strength grading is widely used to estimate mechanical properties of structural timber. National visual grades are allocated to strength classes according to European standard EN1912. The recent discussion about the proper function of visual strength grading standards and the assignment of strength classes shows the need for further research in this field. Spanish-sourced radiata, Scots, Salzmann and maritime pine timber samples were visually graded in wet and dry condition according to the Spanish UNE56544 (2011) and German DIN4074-1 (2012) standards. Rejection was far higher dry due to distortion (warping) parameters. However, this rejection could be significantly mitigated by adopting a higher twist limit (2 mm / 25 mm width). UNE 56544 is more suitable for visually grading these species because it was specifically designed for them and a Spanish source. However, both standards underestimated the Scots pine rejection pieces which mechanical properties fulfill the MEG and S10 grades.

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“…Notably, many of these species can adapt to low-nutrient, dry, and erodible soils, providing additional financial and environmental benefits from harsher environments [11]. However, fast-growing species have more negative properties on wood quality than non-fast-growing species, such as shorter fiber length, more significant growth stress [12], reduced strength and durability, more defects, loose and uneven texture, and deformation of logs or stock wood [13][14][15]. These characteristics limit their engineering applications in building structures.…”

Section: Introductionmentioning

confidence: 99%

Bending Properties of Cold-Formed Thin-Walled Steel/Fast-Growing Timber Composite I-Beams

Chen,

Liu

et al. 2024

Forests

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A cold-formed, thin-walled steel/fast-growing timber composite system has recently been presented for low-rise buildings. It aims to increase the use of fast-growing wood as a green building material in structures, thus contributing to the transformation of traditional buildings. This study proposed a composite I-beam combined with fast-growing radiata pine and cold-formed thin-walled U-shaped steel. A four-point bending test was used to measure the bending properties of steel–timber composite I-beams under various connection methods. Based on experimental results, this study examined the specimen’s failure mechanism, mechanical properties, and strain development. In addition, a method for calculating flexural bearing capacity based on the superposition principle and transformed section method was suggested. It is evident from the results that fast-growing timber and cold-formed thin-walled steel can have significant composite effects. Different connecting methods significantly impact beams’ failure mode, stiffness, and bearing capacity. Furthermore, the theoretical method for calculating the flexural bearing capacity of composite beams differs from the test value by less than 10%. This paper’s research encourages the applications of fast-growing wood as light residential components, and it serves as a reference for the development, production, and engineering of steel–timber composite structural systems.

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Warp Requirements and Yield Efficiency in the Visual Grading of Sawn Radiata Pine Timber

Cited by 5 publications

References 5 publications

Characterization and Yield of Eucalyptus regnans F. Muell Logs for Lumber Production

Characterization and Yield of Eucalyptus regnans F. Muell Logs for Lumber Production

Comparison between wet and dry timber visual strength grading according to the Spanish (UNE 56544) and German (DIN 4074-1) standards

Bending Properties of Cold-Formed Thin-Walled Steel/Fast-Growing Timber Composite I-Beams

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