Influence of anatomy on the adhesion performance of four wood species

2020 ◽  
Vol 9 (4) ◽  
pp. e31942727
Author(s):  
João Gabriel Missia da Silva ◽  
Pedro Nicó de Medeiros ◽  
Denise Ransolin Soranso ◽  
Vinicius Peixoto Tinti ◽  
José Tarcísio da Silva Oliveira ◽  
...  
Keyword(s):  
Shear Strength ◽  
Specific Gravity ◽  
Wood Species ◽  
Tectona Grandis ◽  
Glue Line ◽  
Anatomical Characteristics ◽  
Ray Cells ◽  
Adhesion Performance ◽  
Adhesion Process

The aim of this study was to evaluate the influence of anatomical characteristics on the adhesion performance of Vatairea sp., Paulownia sp., Aspidosperma populifolium and Tectona grandis wood. Specimens for anatomical, physical and mechanical analyzes were produced from tangentially oriented boards. The treatments were joint glued from pieces of the same anatomical orientation (radial and tangential), evaluated for shear strength and glue line failure. The Vatairea sp wood had the highest specific gravity (0.74 g cm-3) and the Paulownia sp (0.34 g cm-3) wood was smaller. Aspidosperma populifolium species showed the highest shear strength in the glue line in the tangential and radial faces. The anatomical variables with higher influence on the wood adhesion process were pith ray cells and especially fibers that exhibit the greatest correlation with the shear strength of the glue line.

Influence of Moisture Content in some Mechanical Properties of Two Brazilian Tropical Wood Species

2014 ◽  
Vol 1025-1026 ◽  
pp. 42-45 ◽  
Author(s):  
Luiz A. Melgaço N. Branco ◽  
Eduardo Chahud ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Rosane A.G. Battistelle ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Analysis Of Variance ◽  
Wood Species ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Tropical Wood ◽  
Fiber Saturation ◽  
Brazilian Standard

This study aimed, with the aid of analysis of variance (ANOVA), to investigate and quantify the influence of moisture ranging between 12% and over 30% (fiber saturation) on the mechanical properties: strength and modulus of elasticity in compression and in tension parallel to grain; modulus of rupture and modulus of elasticity in static bending; shear strength parallel to grain considering wood species Ipê (Tabebuia sp) and Angelim Araroba (Vataireopsis araroba). Tests were performed according to the assumptions and calculating methods Brazilian standard ABNT NBR 7190, Anexx B, totalizing 400 tests. Results of ANOVA revealed a significant reduction (16% on average) for mechanical properties wood due to the increase in moisture content from 12% to over 30% (fiber saturation). The same behavior also occurred when assembly containing the two species was considered.

Selected Properties of Parallel Strand Lumber Made from Southern Pine and Yellow-Poplar

Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Y. Liu ◽  
A.W.C. Lee
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Specific Gravity ◽  
Moisture Content ◽  
Dimensional Stability ◽  
Modulus Of Rupture ◽  
Southern Pine ◽  
Yellow Poplar ◽  
Average Modulus ◽  
Parallel Strand Lumber

Summary This study was conducted to explore basic physical and mechanical properties of parallel strand lumber (PSL) made exclusively from southern pine and yellow-poplar, respectively, and to examine their relationships using statistical analysis. Small specimens were prepared from commercial southern pine PSL and yellow-poplar PSL billets and tested for specific gravity, moisture content, dimensional stability, bending properties, shear strength and compressive strength. Results indicate average specific gravity of southern pine PSL is higher than that of yellow-poplar PSL, while their average moisture content and dimensional stability are very similar. Southern pine PSL has higher average modulus of elasticity but lower average modulus of rupture than yellow-poplar PSL. While average longitudinal shear strength does not exhibit differences between southern pine PSL and yellow-poplar PSL, average compressive strength of southern pine PSL is higher than that of yellow-poplar PSL. There are positive correlations among modulus of elasticity, modulus of rupture and specific gravity. PSL improves some properties of solid wood from which PSL is made.

The Strength of Fly Ash-Bottom Ash (FA-BA) Mixtures as Backfill Material in Ground Improvement Works

2013 ◽  
Vol 465-466 ◽  
pp. 937-943
Author(s):  
Abd Rahim bin Hj. Awang ◽  
Wan Hilmi bin Wan Mansor ◽  
Ahmad Yusri Bin Mohamad
Keyword(s):  
Shear Strength ◽  
Fly Ash ◽  
Specific Gravity ◽  
Ground Improvement ◽  
Bottom Ash ◽  
Friction Angle ◽  
Soil Improvement ◽  
Geotechnical Properties ◽  
Raw Material ◽  
Fa Composition

In Malaysia, coal has been used as a raw material to generate electricity since 1988. In the past, most of the wastage of coal burning especially the bottom ash was not managed properly as it was dumped in the waste pond and accumulated drastically. This research has been conducted to explore the physical characteristic and geotechnical properties of fly ash-bottom ash (FA-BA) mixtures that consist of 30% FA, 50% FA, 70% FA and 90% FA by weight. The physical characteristics, that include the specific gravity, particle size distribution and compaction, were tested for each mixture without any curing. However, the geotechnical properties of the mixtures that include the permeability and shear strength had been studied at various curing periods (0, 14 and 28 days) to review the effect of time on the geotechnical properties of the mixtures. The results show that mixtures with higher FA composition have lower value of specific gravity, well-graded, and need less moisture to be compacted efficiently compared to those mixtures with lower FA composition. The results also show that mixtures with higher FA composition have less drainage characteristics but can be improved by prolonging the curing period. The maximum shear strength was obtained at mixture with 50%FA and the value increased with curing periods. The friction angle obtained ranged from 270to 370. It is also found that the mixtures with lower FA composition are more compressible compared to the mixtures with higher FA composition. The results obtained could be used by others to determine the suitability of different FA-BA mixtures for various usage in Geotechnical Engineering work such as for soil improvement work in weak soils or as backfill materials in embankment construction.

Analytical tools to predict changes in properties of oriented strandboard exposed to the fungus Postia placenta

Holzforschung ◽  
2006 ◽  
Vol 60 (3) ◽  
pp. 332-338 ◽  
Author(s):  
Scott M. Kent ◽  
Robert J. Leichti ◽  
Jeffrey J. Morrell ◽  
David V. Rosowsky ◽  
Stephen S. Kelley
Keyword(s):  
Weight Loss ◽  
Shear Strength ◽  
Specific Gravity ◽  
Near Infrared ◽  
Oriented Strand Board ◽  
Nir Spectroscopy ◽  
Coefficient Of Determination ◽  
Multivariate Statistical ◽  
X Ray ◽  
Bearing Strength

Abstract Weight loss, specific gravity and strength are traditional measures of how wood changes after fungal exposure. This study investigated the effects of fungal decay on properties of oriented strand board (OSB) made of aspen including weight loss, specific gravity, dowel-bearing strength, shear strength, and alkali solubility. Shear strength and alkali solubility were strongly correlated with specific gravity. In addition, X-ray densitometry and near-infrared (NIR) spectroscopy were used to study the decay process. X-Ray densitometry was used to assess localized density around the dowel-bearing embedment zone of a nail. A statistical model using the specific gravity directly under the nail from dowel-bearing strength tests as the explanatory variable had a higher coefficient of determination than models using the gross specific gravity of the sample. Predictive models using NIR spectro-scopy, in combination with multivariate statistical methods, showed promise as predictors of weight loss, shear strength, dowel-bearing strength, and solubility.

scholarly journals Anatomical characteristics of Tectona grandis L.f from different sites in Mato Grosso state

2019 ◽  
Vol 29 (4) ◽  
pp. 1528
Author(s):  
Roberta Santos Souza ◽  
Joaquim Carlos Gonçalez ◽  
Edilene Silva Ribeiro ◽  
Alexandre Bahia Gontijo
Keyword(s):  
Tectona Grandis ◽  
Mato Grosso ◽  
Anatomical Characteristics

As características anatômicas da madeira são influenciadas pelas qualidades dos sítios de procedência do material, que por consequência leva a alterações em suas propriedades físicas e mecânicas. O objetivo deste trabalho foi avaliar e caracterizar as propriedades organolépticas e anatômicas da madeira de teca (Tectona grandis), proveniente de diferentes sítios do Estado do Mato Grosso, Brasil. Para as características anatômicas foram avaliados comprimento, largura, diâmetro e espessura da parede para fibra; comprimento e diâmetro dos vasos; comprimento, largura e frequência dos raios. Os resultados mostraram que as propriedades organolépticas não apresentaram diferenças entre os diferentes sítios. O efeito sítio, no qual estão estabelecidos os plantios de teca produziram variações significativas nos parâmetros das fibras (comprimento, largura da fibra, diâmetro do lume e espessura da parede) e nos raios (comprimento, largura e frequência). No entanto, não foram evidenciadas mudanças significativas relacionadas aos vasos.

scholarly journals Service Life of Railway Wood Sleepers in Indonesia

2018 ◽  
Vol 6 (1) ◽  
pp. 1-7
Author(s):  
Djarwanto Djarwanto ◽  
Sihati Suprapti ◽  
Sri Rulliaty
Keyword(s):  
Service Life ◽  
Wood Species ◽  
Schizophyllum Commune ◽  
Tectona Grandis ◽  
Wood Material ◽  
Railway System ◽  
Force Impact ◽  
Natural Wood ◽  
Wood Resistance ◽  
Eusideroxylon Zwageri

Wood offers natural advantages tremendously such as their elasticity, flexibility and resistance against compression as well as force impact.  Therefore, wood material is astonishingly better material than concrete for railway sleepers. In spite of wood material’s advantages, the material is susceptible to attack by organisms. This paper observes the service life of wood sleepers in Java, Indonesia. Wood sleepers were observed visually from the ground railway system, Banten Province includes wood species identification macroscopically and organism’s attack. Results reveal that natural wood resistance of the sleepers are relatively high, then sleepers were predicted to be last long. Sleepers wood species are teak (Tectona grandis), balau (Hopea sp.), merbau (Intsia bijuga), and ulin (Eusideroxylon zwageri). Sleepers were also found deteriorated by fungus during five months instalment. Decaying fungi observed are Dacryopinax sp., D. spathularia, Lentinus sp., Panus sp., Pycnoporus sp., P. sanguineus, Polyporus spp., Schizophyllum commune, and Trametes sp.

scholarly journals THE USE OF Eucalyptus camaldulensis AND Eucalyptus urophylla WOOD IN THE PRODUCTION OF EDGE GLUED PANELS

FLORESTA ◽  
2019 ◽  
Vol 49 (2) ◽  
pp. 317 ◽  
Author(s):  
Setsuo Iwakiri ◽  
Rosilani Trianoski ◽  
Angela Stüpp ◽  
Bruna Mulinari Cabral ◽  
Jéssika Alvares Coppi Arruda Gayer
Keyword(s):  
Shear Strength ◽  
Eucalyptus Camaldulensis ◽  
Glue Line ◽  
Eucalyptus Urophylla ◽  
Shear Tests ◽  
Minimum Requirement ◽  
Dry And Wet Conditions ◽  
Lower Percentile

This study aimed to evaluate the shear strength of bonded wood joints of Eucalyptus camaldulensis and Eucalyptus urophylla with vinyl polyacetate (PVA) and isocianate polymeric emulsion (EPI) adhesives with the amount of glue of 150 and 180 g/m². The specimens were submitted to shear tests in dry and wet conditions, based on the procedure described in standard EN 13354 (2008). The results of the 5th lower percentile were compared with the requirements of EN 13353 (2008). Among the studied species, Eucalyptus camaldulensis showed better glue line shear strength when compared to Eucalyptus urophylla. However, both species are potentially viable for the edge glued panel (EGP) production, since they meet the minimum requirement of 2.5 MPa, referring to the 5th lower percentile, as established by EN 13353-2008 standard. Based on the results, it is recommended the use of EPI adhesive with the amount of glue of 150 g/m² for the bonding of the wood of these species, aiming at the production of EGP. 

First evidence for the conifer Pinus, as Pinuxylon selmeierianum sp. nov., during the Paleogene on Wootton Peninsula, northern Ellesmere Island, Nunavut, Canada

2020 ◽  
Vol 57 (1) ◽  
pp. 25-39 ◽  
Author(s):  
Martina Dolezych ◽  
Lutz Reinhardt
Keyword(s):  
New Species ◽  
Wood Species ◽  
Fossil Wood ◽  
Ellesmere Island ◽  
High Latitudes ◽  
Pinus Lambertiana ◽  
Anatomical Characteristics ◽  
Fine Grained ◽  
Petrified Wood

We describe a new fossil wood species of pine, Pinuxylon selmeierianum sp. nov., for a piece of petrified wood encased within a concretion that was recovered in marine, fine-grained sandstones of the Paleogene Eureka Sound Group on Wootton Peninsula, Ellesmere Island. The fossil wood is allochthonous, having drifted in from a nearby landmass. Within the fossil wood genus Pinuxylon Gothan, 1905, Pinuxylon selmeierianum sp. nov. shares anatomical characteristics with the haploxylon sections Parrya Mayr, 1890 and Strobus Little and Critchfield, 1969. The new species is most closely related to the extant Pinus lambertiana Douglas, 1827, a species belonging to section Strobus. Our study provides the first evidence for a fossil Pinus Linné, 1753 on Wootton Peninsula, supporting the idea that Pinus was an “Arctic conifer”, and providing insights into Paleogene vegetation at high latitudes.

Physical strength and its relation to leaf anatomical characteristics of nine forage grasses

2004 ◽  
Vol 52 (6) ◽  
pp. 799 ◽  
Author(s):  
Ji Min Zhang ◽  
Akio Hongo ◽  
Masahiro Akimoto
Keyword(s):  
Shear Strength ◽  
Festuca Arundinacea ◽  
Dactylis Glomerata ◽  
Cross Sectional Area ◽  
Vascular Bundles ◽  
Sectional Area ◽  
Forage Grasses ◽  
Cross Sectional ◽  
Anatomical Characteristics ◽  
Physical Strength

Nine species of forage grasses (five C3 species and four C4 species) were planted in a controlled-environment glasshouse. The C3 plants were Festuca arundinacea Schreb, Dactylis glomerata L., Phleum pratense L., Lolium perennel L. and Poa pratensis L.; the C4 plants were Chloris gayana Kunch., Cynodon dactylon (L.) Pers., Paspalum dilatatum Poir. and Sorghum halenpense (L.) Pers. The number of major vascular bundles and minor vascular bundles, cross-sectional area, the area and proportion of sclerenchyma in a cross-section, thickness of leaf blade, and tensile and shear strength were investigated in order to determine the relationship between physical strength and anatomical characteristics. Physical strength and anatomical characteristics of leaf blades showed significant (P < 0.01) variation between species. Significant correlations were detected between tensile strength and cross-sectional area in forage grasses except Festuca arundinacea. Festuca arundinacea, Dactylis glomerata, Phleum pratense, Chloris gayana and Sorghum halenpense showed significant correlations of tensile strength with the number of major vascular bundles. Festuca arundinacea, Dactylis glomerata and Lolium perennel showed significant correlations of shear strength with cross-sectional area. Festuca arundinacea, Dactylis glomerata and Paspalum dilatatum showed significant correlations of shear strength with the number of major vascular bundles. The proportion of sclerenchyma in a cross-section showed poor correlations with tensile and shear strength. Thickness of leaf blade showed poor correlations with tensile and shear strength except in Dactylis glomerata. Physical strength and anatomical characteristics of leaf blades of the C3 group differed significantly (P < 0.01) when compared with the C4 group except for cross-sectional area. Tensile and shear strength showed significant correlations with cross-sectional area, sclerenchyma area and the number of vascular bundles when all nine species were treated as one group.

Characterizing Star-sawn Pattern–Produced and Orthogonally Glued Specimens of Southern Pine

2019 ◽  
Vol 69 (1) ◽  
pp. 53-60
Author(s):  
Guangmei Cao ◽  
Rubin Shmulsky ◽  
Ming Liu ◽  
Edward D. Entsminger ◽  
Brian K. Via ◽  
...  
Keyword(s):  
Shear Strength ◽  
Dimensional Change ◽  
Good Alternative ◽  
Glue Line ◽  
Wood Failure ◽  
Formaldehyde Resin ◽  
Southern Pine ◽  
Resorcinol Formaldehyde ◽  
Lower Shear ◽  
Pinus Spp

Abstract In this study, triangular specimens of southern pine (Pinus spp.; SP) generated by a star-sawn process were characterized according to knots and deformation. SP specimens were used to understand the differences among glue-line combinations of radial-to-radial, radial-to-tangential, and tangential-to-tangential faces bonded with phenol resorcinol formaldehyde resin. The specimens were tested for shear strength, dimensional stability, wood failure, and delamination rate in accordance with ASTM D1037 and D2559 standards. Among the star-sawn triangular samples studied, bows in tangential-face sections occurred the most. The radial-face sections of SP triangular specimens had more knots but a much lesser degree of deformation than the tangential-face sections. The tangential-to-tangential face glue-line samples showed a lower shear strength, more wood failure, and a greater tendency of delamination and dimensional change, especially when subjected to wet conditions. Confocal microscopic pictures revealed that the tangential-to-tangential glue line showed a greater tendency of deformation in the earlywood part and helped to explain the reason for poor glue-line durability and low shear strength. This article revealed that the star-sawn–process generated wood radial-face samples were more stable than others tested and are perhaps a good alternative for massive panel manufacturing.

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