Wooden trusses using metal plate connections and fabricated with Gmelina arborea, Tectona grandis and Cupressus lusitanica timber from forest plantations

Rivera-Tenorio, Monzerrath; Moya, Róger; Navarro-Mora, Ángel

doi:10.1007/s13196-020-00271-z

Cited by 3 publications

(6 citation statements)

References 28 publications

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“…Wood is mainly made up of cellulose molecules (C 6 H 10 O 5 ) n , hemicelluloses (xylan, D-glycans, βglucans, and xyloglycans) and lignin polymers, besides other organic and inorganic substances like secondary compounds like fats, waxes, resin acids, terpenoids, steroids, flavonoids, tannins, and water. These compounds in the heartwood area cause the resistance to biological deterioration, e.g., the arboreal species Tectona grandis L.f., (Teak) is a timber species capable of persisting, dominating, and regenerating against biological deterioration; it is one of the most valuable and best valued tropical woods and it has been planted extensively to produce wood for construction, fine furniture, and general carpentry [3,4]. It is a precious wood because of its durability, appreciated color, mechanical resistance, and endurance to water deterioration [5].…”

Section: Introductionmentioning

confidence: 99%

Antifungal Activity of Crude Extracts of Tectona grandis L.f. against Wood Decay Fungi

C醨camo-Ibarra¹,

Mart韓ez-Pacheco²,

Munro-Rojas³

et al. 2022

Phyton

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Wood is mainly made up of cellulose, hemicelluloses, lignin polymers and other organic and inorganic substances, making it susceptible to deteriorate by various biological agents. Tectona grandis L.f. (Teak) is a timber species with high resistance to biological deterioration, valued for its durability, beauty, and mechanical resistance. The purpose of this work was to evaluate the antifungal activity of crude extracts from teak on various fungi that cause wood deterioration. For this, Teak heartwood was obtained, then fragmented and pulverized until obtaining a flour which was used for compounds extraction using the Soxhlet technique coupled to a rotary evaporator through solvents of increasing polarity (hexane, dichloromethane, tetrahydrofuran, and acetone). The extracts obtained were tested against fungal organisms collected in the field, and the LC 50 was determined using teak crude extracts on Artemia salina as a biological model. The results obtained showed that a high flour yield was obtained with hexane (0.951 g), followed by tetrahydrofuran (0.446 g), dichloromethane (0.348 g), and acetone (0.152 g). By using nine fungal organisms that predominantly correspond to the genus Aspergillus, the extractable compounds were tested, inhibiting 25% of mycelial growth with tetrahydrofuran (T. versicolor), and 40.9% with dichloromethane (G. trabeum). Likewise, the biological model of A. salina showed an LC 50 of 84.9 μg/mL with hexane, 43.3 μg/mL with dichloromethane, 59.6 μg/mL with tetrahydrofuran, and 54.7 μg/mL with acetone. For this reason, it is concluded that Teak wood contains many extractable compounds in relation to its weight, besides having antimicrobial activity when extracted through polar compounds such as dichloromethane and tetrahydrofuran.

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Section: Introductionmentioning

confidence: 99%

Antifungal Activity of Crude Extracts of Tectona grandis L.f. against Wood Decay Fungi

C醨camo-Ibarra¹,

Mart韓ez-Pacheco²,

Munro-Rojas³

et al. 2022

Phyton

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“…Tectona grandis is used in commercial reforestation in Latin America [29,30], while Gmelina arborea is widely used in Central America [31]. This specie, as G. arborea, are important in Costa Rica market, however their structural uses are limited [32]. Currently, many industries present the conditions and the capacity for the development of innovative products fabricated with wood from forest plantations in Costa Rica, which can be implemented in the construction sector, specifically in the development of structural elements [33].…”

Section: Introductionmentioning

confidence: 99%

“…Currently, many industries present the conditions and the capacity for the development of innovative products fabricated with wood from forest plantations in Costa Rica, which can be implemented in the construction sector, specifically in the development of structural elements [33]. These industries can promote the development of engineering products fabricated with wood from plantation species, thus increasing the use of their species [32].…”

Section: Introductionmentioning

confidence: 99%

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CLT Fabricated with Gmelina arborea and Tectona grandis Wood from Fast-Growth Forest Plantations: Physical and Mechanical Properties

Mu駉z¹,

Moya²,

Moya³

et al. 2022

Journal of Renewable Materials

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Fabrication and use of Cross Laminated Timber (CLT) using tropical woods is still limited at present. Therefore objective of the present study aims to determine the possibility of using CLT panels of 3 and 5 layers, fabricated with Tectona grandis and Gmelina arborea wood using adhesive of isocyanate polymer emulsion system catalyzed with polymeric isocyanate. Delamination, water absorption, density, flexure test, compression and glue-line shear were evaluated using ANSI/APA PRG320-2012 ASTM D198 and ASTM D4761 standard. The results showed that CLT panels of T. grandis presented higher values of density, less water absorption and lower delamination, with no evident differences between the CLT of 3 and 5 layers. The high density of T. grandis resulted in higher values of the mechanical properties. The flatwise and edgewise flexure tests in 5-layer CLT panels of both species presented higher values of bending stiffness compared to those of 3-layer CLT panels. Further the bending stress values in 3-layer CLT panels were higher than for 5-layer CLT panels. As for shear stress in bending flatwise, in both species, 3-layer CLT surpassed 5-layer CLT panels, but in the edgewise test no differences were observed. The MOE and Fc in the compression test were superior in relation to the edgewise test. MOE and Fc in compression flatwise in 3-layer CLT was greater than in 5-layer CLT in both species, but edgewise these values were higher in 5-layer CLT panels. The most common failures were stress and delamination in the flexure test, whereas in the compression test these were: shearing, splitting and crushing. In the glue-line shear test no differences were observed between CLT panels of 3 and 5 layers for both species.

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“…The connection in the form of an articulated joint in individual truss members needs to be designed so as to carry the assumed load with no loss of system stiffness [ 27 ]. As it was mentioned above, it may be relatively easily attained with punched metal plate fasteners or previously used carpentry joints, but steel fasteners assembled using nails or screws may also be used for that purpose [ 29 ]. Nevertheless, punched metal plate fasteners seem to serve this purpose most effectively.…”

Section: Introductionmentioning

confidence: 99%

Influence of the Structure of Lattice Beams on Their Strength Properties

et al. 2021

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This paper presents the strength properties of wooden trusses. The proposed solutions may constitute an alternative to currently produced trusses, in cases when posts and cross braces are joined with flanges using punched metal plate fasteners. Glued carpentry joints, although requiring a more complicated manufacturing process, on the one hand promote a more rational utilisation of available structural timber resources, while on the other hand they restrict the use of metal fasteners. The results of the conducted analyses show that the proposed solutions at the current stage of research are characterised by an approx. 30% lower static bending strength compared to trusses manufactured using punched metal plate fasteners. However, these solutions make it possible to produce trusses with load-bearing capacities comparable to that of structural timber of grade C24 and stiffness slightly higher than that of lattice beams manufactured using punched metal plate fasteners. The strength of wooden trusses manufactured in the laboratory ranged from nearly 20 N/mm2 to over 32 N/mm2. Thus, satisfactory primary values for further work were obtained.

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Wooden trusses using metal plate connections and fabricated with Gmelina arborea, Tectona grandis and Cupressus lusitanica timber from forest plantations

Cited by 3 publications

References 28 publications

Antifungal Activity of Crude Extracts of Tectona grandis L.f. against Wood Decay Fungi

Antifungal Activity of Crude Extracts of Tectona grandis L.f. against Wood Decay Fungi

CLT Fabricated with Gmelina arborea and Tectona grandis Wood from Fast-Growth Forest Plantations: Physical and Mechanical Properties

Influence of the Structure of Lattice Beams on Their Strength Properties

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