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18 records – page 1 of 2.

Predicting the Average Compression Strength of CLT by Using the Average Density or Compressive Strength of Lamina

https://research.thinkwood.com/en/permalink/catalogue3020
Year of Publication
2022
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Tian, Zhaopeng
Gong, Yingchun
Xu, Junhua
Li, Mingyue
Wang, Zhaohui
Ren, Haiqing
Organization
Chinese Academy of Forestry
Editor
Elustondo, Diego
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Compressive Strength
Density
Linear Regression Analysis
Monte Carlo Simulation
Plated Larch
Prediction Model
Research Status
Complete
Series
Forests
Summary
The compressive strength in the major direction of cross-laminated timber CLT is the key to supporting the building load when CLT is used as load-bearing walls in high-rise wood structures. This study mainly aims to present a model for predicting the average compressive strength of CLT and promoting the utilization of CLT made out of planted larch. The densities and compressive strengths of lamina specimens and CLT samples with widths of 89 and 178 mm were evaluated, and their relationship was analyzed to build a prediction model by using Monte Carlo simulation. The results reveal that the average density of the lamina and CLT were about equal, whereas the average compressive strength of the CLT was just about 72% of that of the lamina. Width exerted no significant effect on the average compressive strength of the CLT, but homogenization caused the wider CLT to have a smaller variation than that of the lamina. The average compressive strength of the lamina could be calculated by using the average density of lamina multiply by 103.10, and the average compressive strength of the CLT could be calculated according to the compression strength of lamina in major and minor direction, therefore, a new prediction model is determined to predict the average compression strength of CLT by using the average density of lamina or CLT, the average compression strength of CLT made in this study is about 74.23 times of the average density of the lamina. The results presented in this study can be used to predict the average compressive strength of CLT by using the average density of lamina and provide a fundamental basis for supporting the utilization of CLT as load-bearing walls.
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Carbon Analysis of Wood Composite Panels

https://research.thinkwood.com/en/permalink/catalogue3323
Year of Publication
2022
Topic
Environmental Impact
Author
Puettmann, Maureen Elaine
Organization
Woodlife Environmental Consultants
Year of Publication
2022
Format
Technical Note
Topic
Environmental Impact
Keywords
Carbon
Particleboard
Medium Density Fiberboard
Hardboard
Research Status
Complete
Series
Forest Products Journal
Summary
Wood composite panels (WCP) are well known for their environmentally friendly attributes of being sustainable, renewable, biodegradable, and predominantly made from wood residues generated during lumber and plywood production. This paper focuses on the ability of WCPs to store carbon for long periods of time in nonstructural applications such as cabinets, furniture, and flooring. WCPs, include particleboard, medium density fiberboard (MDF), and hardboard–engineered wood siding and trim (EWST). These panels are anticipated to have an average service life of 25–30 years. In 2019, there was an estimated 291 million cubic meters (m3) of WCPs in use in North America that corresponds to a carbon pool of 354 million metric tons of carbon dioxide equivalents. This WCP carbon pool is enough to offset 24 years of cradle-to-gate cumulative carbon emissions (fossil and biogenic sources) emitted during production of these panels. In other words, producing and using WCPs stores carbon for long periods because the amount of carbon emitted during the production of the panels is far less than what the panels themselves are capable of storing over their lifetime of product use.
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Influence of Board Density on the Physical and Mechanical Properties of Bamboo Oriented Strand Lumber

https://research.thinkwood.com/en/permalink/catalogue2512
Year of Publication
2020
Topic
Design and Systems
Mechanical Properties
Material
OSL (Oriented Strand Lumber)
Other Materials
Application
Wood Building Systems
Author
Sun, Yuhui
Zhang, Yahui
Huang, Yuxiang
Wei, Xiaoxin
Yu, Wenji
Organization
Chinese Academy of Forestry
Publisher
MDPI
Year of Publication
2020
Format
Journal Article
Material
OSL (Oriented Strand Lumber)
Other Materials
Application
Wood Building Systems
Topic
Design and Systems
Mechanical Properties
Keywords
Bamboo
Density
Physical Properties
Microscale Morphology
BOSL
Research Status
Complete
Series
Forests
Summary
The process of bamboo-oriented strand lumber (BOSL) represents one of the best opportunities for automation, property control and consistency, and high utilization of material from abundant, fast-growing, and sustainable bamboo. In this study, BOSLs were prepared, with reference to the preparation process of bamboo scrimber, by compressing and densifying constituent units under the action of moisture-heat-force and resin polymerization, and then the effects of density variation on their physical and mechanical properties were investigated. The results revealed that the modulus of rupture, modulus of elasticity, compressive strength and shear strength of BOSL with density of 0.78–1.3 g/cm3 ranged from 124.42 to 163.2 MPa, 15,455 to 21,849 MPa, 65.02 to 111.63 MPa, and 9.88 to 18.35 MPa, respectively. The preparation of BOSL with bamboo as raw material could retain the good mechanical properties of natural bamboo, and produce bamboo-based structural products with different properties by controlling the density. The high strength of BOSL with high density was primarily due to the increased volume fraction of elementary fibers, the reduced porosity, and the enhanced gluing interface. The performance of BOSL can be comparable to, or surpass that of, wood or bamboo products. This study provided necessary basic research for the engineering design and application of BOSL.
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Analysis of Glue Line and Correlations Between Anatomical Characteristics of Eucalyptus grandis × Eucalyptus urophylla Glued-Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue2435
Year of Publication
2019
Topic
Design and Systems
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Author
Oliveira, Rafael
Gonçalves, Fabricio
Segundinho, Pedro
Oliveira, José Tarcísio
Paes, Juarez
Chaves, Izabella Luzia
Brito, Alice
Organization
Federal University of Espírito Santo
Publisher
bioRxiv
Year of Publication
2019
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Keywords
Adhesive
Glue Lines
Eucalyptus
Glue-line Thickness
Density
Research Status
Complete
Summary
The main goal of this study was to analyze glue line on eucalyptus wood. In order to do that, thickness of main and secondary glue lines were measured as well their interaction with apparent density of elements glued with resorcinol-formaldehyde (RF) and castor polyurethane (CP) adhesives. Anatomical wood characterization of Eucalyptus grandis × Eucalyptus urophylla was performed by correlating glue line thickness. According to normative instruction, specimens were produced for delamination tests. The experiment was conducted in a completely random 2 × 2 design factorial scheme (two classes of apparent density and two adhesives). Pearson correlation was performed among variables. It was found that there was adhesive penetration into wood pots and rays. Glue line thickness was higher in woods with density higher than 0.58 g cm-3 glued with RF adhesive. There was low correlation among density, vessel diameter, main and secondary glue lines.
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Evaluation of Uniformity of Bamboo Bundle Veneer and Bamboo Bundle Laminated Veneer Lumber (BLVL)

https://research.thinkwood.com/en/permalink/catalogue2475
Year of Publication
2019
Topic
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Other Materials
Author
Zhou, Haiying
Wei, Xin
Smith, Lee
Wang, Ge
Chen, Fuming
Organization
International Centre for Bamboo and Rattan
University of North Texas
Publisher
MDPI
Year of Publication
2019
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Other Materials
Topic
Mechanical Properties
Keywords
Density
Light Transmittance
Stiffness
Research Status
Complete
Series
Forests
Summary
The lack of an effective and practical quality control method for industrialized bamboo bundle veneers is the key restriction in the application of bamboo bundle composite materials in the field of construction. In this work, the density uniformity and mechanical properties of bamboo bundle veneers were systematically evaluated by the combination of light transmittance and mechanical stiffness. It was found that the number of broomings, dippings, and high-temperature heat treatments had different effects on the bamboo bundle veneers. On this basis, the uniformity of the density and mechanical properties of the bamboo scrimber (BS) that underwent hybrid paving, and the bamboo bundle laminated veneer lumber (BLVL), were analyzed. The results showed that the performance stability of bamboo bundle composites could be greatly improved by bamboo bundle veneer laminated paving. A large-scale quality evaluation system for bamboo bundle veneers was established in this work, and it provides conditions for the manufacture of bamboo bundle composites with stable and controllable performance.
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Comparison of Bonding Performance Between Plywood and Laminated Veneer Lumber Induced by High Voltage Electrostatic Field

https://research.thinkwood.com/en/permalink/catalogue2487
Year of Publication
2019
Topic
Mechanical Properties
Design and Systems
Material
LVL (Laminated Veneer Lumber)
Other Materials
Application
Wood Building Systems
Author
He, Qian
Zhan, Tianyi
Zhang, Haiyang
Ju, Zehui
Hong, Lu
Brosse, Nicolas
Lu, Xiaoning
Organization
Nanjing Forestry University
University of Lorraine
Publisher
EDP Sciences
Year of Publication
2019
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Other Materials
Application
Wood Building Systems
Topic
Mechanical Properties
Design and Systems
Keywords
High Voltage Electrostatic Field
Bonding
Masson
Pine
Plywood
Surface Characteristics
Density
Research Status
Complete
Series
MATEC Web of Conferences
Summary
High voltage electrostatic field (HVEF) was applied in order to improve wood surface characteristics, bonding and mechanical properties of wood composites. Masson pine (Pinus massoniana Lamp.) plywood and laminated veneer lumber (LVL) were selected in this study. Surface characteristics were conducted by the electron spin resonance (ESR) and X-ray photoelectron spectra (XPS). Bonding interphase and mechanical properties were investigated by fluorescence microscopy and vertical density profile (VDP), bonding strength, wood failure ratio, MOE and MOR. The results indicated that more increments were obtained in free radicals, O/C ratios and C2-C4 components. This is because electrons broke more wood chemical groups and new ions occurred among wood surface under HVEF. Significantly decreased PF adhesive penetration depth (PD) and increased density at bonding interphase was achieved in HVEF treated composites. More decrease of PD and increment of density were observed in plywood than that of LVL. This was attributed to cross linked wood fibers among bonding interphase in plywood. Mechanical properties of bonding strength, wood failure ratio, MOE and MOR were significantly increased under HVEF treatment both for two composites. Higher bonding strength, MOE and MOR were obtained in plywood and their increments were as 98.53%, 33.33%, 18.55% and 12.72%.
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Study the Influence of Perpendicular to Grain Compression and Creep in 4 to 8 Storey Lightweight Timber Framed Buildings

https://research.thinkwood.com/en/permalink/catalogue1925
Year of Publication
2018
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Walls
Organization
Timber Development Association
Publisher
Forest & Wood Products Australia
Year of Publication
2018
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Walls
Topic
Mechanical Properties
Keywords
Creep
Compression
Density
Deformation
Research Status
Complete
Summary
The aim of this project was to validate the assumption used within the Australian Standard AS1720.1 for calculating compression perpendicular to grain for common timber species and develop practical methods to reduce compression deformation. The project was successful in demonstrating that perpendicular to grain displacement of wall plates by studs can be reduced. It found that stud on stud connection was the best method as it removed the wall plates out of the load path altogether. The study also found where this is not possible, replacement of the wall plate with a stiffer timber such as a high density hardwood, softwood or cross laminated timber reduces this deformation. The investigation also found that the method used in AS1720.1 to assign perpendicular to grain bearing capacities for various timber species by “strength group” or stress grade over predicted low to medium density timber species whilst under predicting high density timber species. Accordingly, it is recommended that perpendicular to grain bearing capacity be assigned by the timber species’ density and that the characteristic values of commonly used timber species be re-established.
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An Innovative Method Based on Grain Angle Measurement to Sort Veneer and Predict Mechanical Properties of Beech Laminated Veneer Lumber

https://research.thinkwood.com/en/permalink/catalogue1286
Year of Publication
2018
Topic
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Author
Viguier, Joffrey
Bourgeay, Christophe
Rohumaa, Anti
Pot, Guillaume
Denaud, Louis
Publisher
ScienceDirect
Year of Publication
2018
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Topic
Mechanical Properties
Keywords
Modulus of Elasticity
Beech
Grain Angle
Grading
Density
Research Status
Complete
Series
Construction and Building Materials
Summary
Cross-Laminated Timber (CLT) structures exhibit satisfactory performance under seismic conditions. This ispossible because of the high strength-to-weight ratio and in-plane stiffness of the CLT panels, and the capacity ofconnections to resist the loads with ductile deformations and limited impairment of strength. This study sum-marises a part of the activities conducted by the Working Group 2 of COST Action FP1402, by presenting an in-depth review of the research works that have analysed the seismic behaviour of CLT structural systems. Thefirstpart of the paper discusses the outcomes of the testing programmes carried out in the lastfifteen years anddescribes the modelling strategies recommended in the literature. The second part of the paper introduces theq-behaviour factor of CLT structures and provides capacity-based principles for their seismic design.
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Process Optimization of Large-Size Bamboo Bundle Laminated Veneer Lumber (BLVL) by Box-Behnken Design

https://research.thinkwood.com/en/permalink/catalogue1807
Year of Publication
2018
Topic
Mechanical Properties
Material
Other Materials
LVL (Laminated Veneer Lumber)
Author
Niu, Xiaoyi
Pang, Jiuyin
Cai, Hanzhong
Li, Shan
Le, Lei
Wu, Junhua
Publisher
North Carolina State University
Year of Publication
2018
Format
Journal Article
Material
Other Materials
LVL (Laminated Veneer Lumber)
Topic
Mechanical Properties
Keywords
Process Optimiazation
Box-Behnken Design
Lengthening Technology
Three-Factor
Lap-Joints
Board Density
Thickness
Optimum Pareto Solutions
Genetic Algorithma Method
Modulus of Rupture
Shearing Strength (SSI)
Elastic Modulus
Dimensional Stability
Bamboo
Research Status
Complete
Series
BioResources
Summary
This work focuses on optimization of the laminated lap-joint lengthening technology that is used to produce large-size bamboo bundle laminated veneer lumber (BLVL). A three-factor Box-Behnken design was developed in which lap-joint length (x1), board density (x2), and thickness of lap veneer (x3) were the three factors. Multi-objective optimization of response surface model was used to obtain 17 optimum Pareto solutions by a genetic algorithms method. The mechanical properties of BLVL predicted using the model had a strong correlation with the experimental values (R2 = 0.925 for the elastic modulus (MOE), R2 = 0.972 for the modulus of rupture (MOR), R2 = 0.973 for the shearing strength (SS)). The interaction of the x1 and x3 factors had a significant effect on MOE. The MOR and shearing SS were significantly influenced by the interaction of x2 and x3 factors. The optimum conditions for maximizing the mechanical properties of BLVL lap-joint lengthening process were established at x1 = 16.10 mm, x2 = 1.01 g/cm3, and x3 = 7.00 mm. A large-size of BLVL with a length of 14.1 m was produced with the above conditions. Strong mechanical properties and dimensional stability were observed.
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Performance of Glue-Laminated Beams from Malaysian Dark Red Meranti Timber

https://research.thinkwood.com/en/permalink/catalogue1822
Year of Publication
2018
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Ong, Chee Beng
Organization
University of Bath
Year of Publication
2018
Format
Thesis
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Malaysian Dark Red Meranti (DRM)
Production
Phenol-Resorcinol Formaldehyde
Fabrication
Bonding Performance
Carbon Fiber Reinforced Polymer
Tension Face
Unreinforced
Fire Test
Failure
Finger Joints
Softwood
Europe
Density
End Pressure
Cramping Pressure
Strength
Charring Rate
Fire Performance
Polyurethane
Bending Strength
Research Status
Complete
Summary
In this study, Malaysian Dark Red Meranti (DRM) was used to manufacture glulam beams, following closely the requirements of BS EN 14080:2013 so as to emulate commercial production. Phenol resorcinol formaldehyde (PRF), commonly used in structural glulam production, was used in the fabrication of finger joints and laminations of the glulam beams. Factors influencing the mechanical properties of finger joints and bonding performance of laminations were investigated. Full size glulam beams were manufactured and tested in bending with partial and complete carbon fibre reinforced polymer (CFRP) reinforcement on the tension face and compared with the performance of unreinforced beams. A bench-scale fire test was proposed to describe the behaviour of DRM finger joints in tension under fire condition, in order to simulate the failure of finger joints on the tension side of a glulam beam in a standard fire test. Overall, DRM finger joints exhibited better bending strength than Spruce finger joints which represented softwood used in European glulam. Wood density and end pressure were shown to affect the strength properties of the finger joints. Higher cramping pressure was needed to produce DRM laminations with higher shear strength. The glulam beam with CFRP reinforcement had a higher bending strength than the unreinforced glulam beams but partial reinforcement had an adverse effect on beam strength. In the bench-scale fire test, DRM finger-jointed specimens exhibited lower charring rate than Spruce. Furthermore, PRF finger-jointed specimens showed better fire performance than finger-jointed specimens bonded with polyurethane (PUR) adhesive. In conclusion, it is hoped that results from this research will motivate engineers and architects in Malaysia to design and build structures from less-utilised local timber, specifically in the form of glulam, encouraging the timber industry in Malaysia to produce them commercially.
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18 records – page 1 of 2.