Compression creep model for Nigeria grown &lt;i&gt;Terminalia ivorensis&lt;/i&gt; (black afara) timber

Mohammed, Auwalu I.; Ocholi, Amana; Ejeh, Stephen; Amartey, Yusuf Dada

doi:10.4314/njt.v38i2.6

Cited by 3 publications

(4 citation statements)

References 11 publications

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“…These names can be confusing since some softwoods exhibits greater strength properties than some hardwoods and vice versa (Ohagwu & Ugwuishiwu, 2011). Subjecting Nigerian grown timbers to engineering investigations is to establish adequate data and sufficient information for it to be adequately managed and help in building more confidence in identifying their specific areas of usage for structural safety (Aguwa et al, 2015;Mohammed, 2017;Rahmon & Jimoh, 2020). This is expected to lessen the over-dependence on foreign materials for structural applications and to create more employment opportunities that will impact the country's economy (Aguwa et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

STRENGTH CHARACTERISATION AND CLASSIFICATION OF COMBINED GLULAM BEAM MADE FROM OPEPE (Nauclea diderrichii) AND OBECHE (Triplochiton scleroxylon) TIMBERS

Jibril Oyebode Bashir,

Ocholi,

Lawan

et al. 2023

FJS

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Quality timber species are declining due to over-exploitation in Nigeria. This has propelled the utilisation of low-grade timbers species that are considered for low-end constructions in the past which called for concern. This study establishes the viability of a typical beam made from locally sourced non-durable Obeche (Triplochiton scleroxylon) with highly durable Opepe (Nauclea diderrichii) timber specie in a combined glulam form, using polyvinyl acetate (PVA) adhesive which serves the impact of environmental sustainability and reduced cost of engineering construction. Seasoned timber samples and PVA adhesive were all obtained locally in Nigeria. Beam specimens were tested in the Department of Civil Engineering, Ahmadu Bello University, Zaria according to EN 338 (2009). Based on tests, it is evident that solid Opepe and Obeche timber specimens exhibited more durable characteristics than their homogenous glulam when fabricated with PVA adhesive. The combined Opepe/Obeche (GLc OP/OB) glulam beam specimen was proposed into GL18c strength class according to EN 338 based on minimum constraints which it satisfies, reflecting a 41 % greater Modulus of Elasticity (MoE) in comparison with EN 338 experimental value. This study recommends the enhancement of the bending strength, density and modulus of elasticity of a typical non-durable solid Obeche timber beam by 38 %, 47 % and 35 % respectively with 40 % durable Opepe timber in a combined glulam form using PVA adhesive for engineering construction purposes.

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Section: Introductionmentioning

confidence: 99%

STRENGTH CHARACTERISATION AND CLASSIFICATION OF COMBINED GLULAM BEAM MADE FROM OPEPE (Nauclea diderrichii) AND OBECHE (Triplochiton scleroxylon) TIMBERS

Jibril Oyebode Bashir,

Ocholi,

Lawan

et al. 2023

FJS

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“…There are also studies that deal with the time-dependent clamping forces and therewith creep behavior of wood materials. [12][13][14][15][16][17] Furthermore, there is a European standard 18 which recommends a procedure to determine the creep of solid wood and engineered wood products. Nonetheless, only a few studies have dealt with the investigation of the long-term clamping forces that appear in the screwed wood members, in direct relation to the applied screw torques.…”

Section: Introductionmentioning

confidence: 99%

“…Especially, the forces that occur within a long period of time are important features for the effective design of the screw‐connections. There are also studies that deal with the time‐dependent clamping forces and therewith creep behavior of wood materials 12‐17 . Furthermore, there is a European standard 18 which recommends a procedure to determine the creep of solid wood and engineered wood products.…”

Section: Introductionmentioning

confidence: 99%

Study on torque and clamping forces of screw‐connected plywood

Kumpenza

Schmidt²,

Sotayo

et al. 2020

Engineering Reports

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In various engineering applications, screws are commonly used to connect wood and engineered wood products to each other. To describe the axial loads which may be transmitted with these components, it is important to quantify the resulting clamping forces in relation to the applied screw torques. In this initial study, birch plywood panels with thicknesses of t = 12, 16, and 20 mm connected with screws (major thread diameter d ≈ 5 mm) are experimentally tested to establish screw driving, tightening and stripping torques. In addition to that, the resulting clamping forces that occur over a time period of 120 hours are monitored and analyzed. A good agreement was found between the established time-dependent clamping force functions compared to the regression model, which are recommended in the literature.

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“…For example, even T. superba from the same genus could attain 1.8 m in height within one year [6]. Terminalia ivorensis is used for construction and other timber-based uses [7]. It's also can be used for reforestation and afforestation species especially where woodbase timber are needed as well as for forest ecosystem replenishment [8].…”

Section: Introductionmentioning

confidence: 99%

Effect of Provenance Variations on the Growth and Development of Terminalia ivorensis (A Chev)

Ojo

Ajayi

2019

CJAST

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Indigenous tree species like Terminalia ivorensis has multiple uses; from timber products to medicinal condiments for treating different ailments. This species is self-incompatible. Thus, habitat protection is a key to its survival and sustenance. This study evaluated the effect of provenance variations on the growth and development of T. ivorensis. Three provenances of T. ivorensis were selected; FRIN Arboretum, Onigambari Forest Reserve and J1 Forest Reserve. Thirty (30) seedlings of T. ivorensis were selected and marked at each provenance for assessment of growth parameters for a period of twelve weeks. The growth parameters included: seedling height, collar diameter, leaf count and leaf area. Also, soil samples were collected from each provenance to test for nutrient composition. Results showed that J1 Forest Reserve had best performance across the growth parameters assessed with 10.4 cm plant height, 2.02 mm collar diameter, 11 leaves count and 20.5 cm2 leaf area respectively. This growth parameter result differs significantly from the other two provenances. This was also attributed to the nutrient offered by J1 Forest Reserve with 1.18% and 2.20% of organic carbon and organic matter in the soil respectively. Also, the available phosphorus which is involved in photosynthesis, respiration, energy storage and transfer, cell division and enlargement as well as promotion of root formation was about 15.7 mg/kg in the soil and is considered high because it is higher than the critical level of 8.50mg/kg. J1 Forest Reserve is recommended as the best provenance for raising T. ivorensis amongst assessed natural habitats.

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Compression creep model for Nigeria grown <i>Terminalia ivorensis</i> (black afara) timber

Cited by 3 publications

References 11 publications

STRENGTH CHARACTERISATION AND CLASSIFICATION OF COMBINED GLULAM BEAM MADE FROM OPEPE (Nauclea diderrichii) AND OBECHE (Triplochiton scleroxylon) TIMBERS

STRENGTH CHARACTERISATION AND CLASSIFICATION OF COMBINED GLULAM BEAM MADE FROM OPEPE (Nauclea diderrichii) AND OBECHE (Triplochiton scleroxylon) TIMBERS

Study on torque and clamping forces of screw‐connected plywood

Effect of Provenance Variations on the Growth and Development of Terminalia ivorensis (A Chev)

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