scholarly journals Influence of Four Ageing Methods on the Mechanical Properties of Bamboo Scrimber

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hongyan Wang ◽  
Shaofei Yuan ◽  
Jian Zhang ◽  
Qin Li
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Modulus Of Rupture ◽  
Accelerated Ageing ◽  
Horizontal Shear ◽  
Testing Methods ◽  
Holding Power ◽  
Bamboo Scrimber ◽  
Sequence Method ◽  
Weather Resistance

In this study, the six-cycle accelerated ageing method (method I), the 6 h boiling-freezing-drying method (method II), the wet circulation method (method III), and the boiling-testing method (method IV), which are accelerated ageing testing methods, were used to study the ageing resistance of bamboo scrimber. Changes in the nail-holding power of the plane, the side, and the end face of untreated/treated bamboo scrimber were analyzed systematically, including other changes in mechanical properties, such as the horizontal shear strength, the modulus of rupture (MOR), and the modulus of elasticity (MOE) along the smooth grain, etc. The results show that all mechanical properties decreased after treatment with the four accelerated ageing testing methods: the nail-holding power decreased by 4%~42% on the plane, 8%~40% on the side, and 5%~66% on the end face. The horizontal shear strength decreased by 3.1%~16.7%, the MOR decreased by 15%~27.2%, and the MOE decreased by 2.6%~12.8%. The nail-holding power of the three sides and the MOR were the most affected properties after treatment. So, the nail-holding power and the MOR can be chosen as important indices to evaluate bamboo scrimber’s weather resistance. For the four accelerated ageing testing methods, the degree of influence on the nail-holding power was in this sequence: method I > method III > method IV > method II. However, after comprehensive consideration, the degree of influence on the mechanical properties was in this sequence: method I > method IV > method III > method II.

Effect of Compression Ratio and Lay Angle of Metal Net on the Mechanical Properties of Metal Net-LVL Composite

2011 ◽  
Vol 418-420 ◽  
pp. 505-508
Author(s):  
Jin Li ◽  
Ying Cheng Hu
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Mechanical Strength ◽  
Compression Ratio ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Horizontal Shear ◽  
Fast Growing

In order to improve the mechanical strength of LVL, metal net was inserted into the LVL (metal net-LVL composite) made of fast-growing poplar. In this study, the effects of compression ratio and lay angle of metal net (which is lay angle for short in this paper) on the mechanical properties of the metal net-LVL composite was investigated in a comparative way. In order to find out the optimum compression ratio and lay angle, the modulus of rupture (MOR), modulus of elasticity (MOE) and horizontal shear strength of the metal net-LVL composite were tested. The results showed that the effects of the compression ratio on MOR, MOE and horizontal shear strength were significant, with increasing of compression ratio, the values of MOR and MOE showed an earlier raised and later decreased state, and had the maximum values at 31%. The effects of lay angle on MOR and MOE were significant, the values of MOR and MOE increased first and then decreased with lay angle increasing, and the maximum values were obtained at 20°, though there were no significant effects on horizontal shear strength, there were the maximum values at 20°. Therefore, when the compression ratio was 31% and the lay angle was 20°, the metal net-LVL composite could obtain the optimal overall mechanical properties.

Research on Mechanical Properties of Bambusa Distegia Thread Plywood

2012 ◽  
Vol 482-484 ◽  
pp. 1394-1397
Author(s):  
Yun Shui Yu ◽  
Wei Hong Zhou ◽  
Xue Liu ◽  
Xue Liang Xiong
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Shear Strength ◽  
Modulus Of Elasticity ◽  
Hot Pressing ◽  
Modulus Of Rupture ◽  
Pressing Pressure ◽  
Horizontal Shear ◽  
Concrete Form

Bambusa distegia were used to make bamboo thread plywood by the process of producing thread, dipping thread into glue, assembling pattern and pressing. Influence of hot pressing pressure on mechanical properties of bambusa distegia thread plywood was investigated, which was 2.0MPa，2.5MPa，3.0MPa，3.5MPa and 4.0MPa respectively. The results indicate that the modulus of rupture(MOR), modulus of elasticity(MOE), compressive strength(CS), and horizontal shear strength(HSS) increase with the increasing of hot pressing pressure. Mechanical properties of the Bambusa distegia thread plywood are higher than the indices of plywood for concrete form and the indices of plywood for container flooring.

scholarly journals Improved strength properties of LVL glued using PVAc adhesives with physical treatment-based Rubberwood (Hevea brasiliensis)

2020 ◽  
Vol 5 (1) ◽  
pp. 711-725
Author(s):  
Sutrisno ◽  
Eka Mulya Alamsyah ◽  
Ginanjar Gumilar ◽  
Takashi Tanaka ◽  
Masaaki Yamada
Keyword(s):  
Shear Strength ◽  
Hevea Brasiliensis ◽  
Formaldehyde Emission ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Horizontal Shear ◽  
Physical Treatment ◽  
Cold Pressing ◽  
Laminated Veneer Lumber ◽  
Pressing Time

AbstractThe properties of the laminated veneer lumber (LVL) composed of the boiled veneer of Rubberwood (Hevea brasiliensis) using polyvinyl acetate (PVAc) adhesives in various cold-pressing time and various conditioned time with loaded and unloaded were studied. Five-ply LVL was produced by boiling veneer at 100°C for 90 min as pretreatment and cold-pressing time at 12 kgf cm−2 for 1.5, 6, 18, and 24 h then conditioned at 20°C and 65% relative humidity (RH) with loaded (12 kgf cm−2) and unloaded for 7 days as physical treatment. Especially for the delamination test, the specimens were immersed at 70 ± 3°C for 2 h and dried in the oven at 60 ± 3°C for 24 h; then, the specimens were solidified at room temperature (20°C and 65% RH) with loaded (12 kgf cm−2) and unloaded for 7, 10, 12, and 14 days. To determine the performance of LVL, the density, moisture content (MC), delamination, modulus of elasticity (MOE), modulus of rupture (MOR), horizontal shear strength, and formaldehyde emission tests were conducted according to the Japanese Agricultural Standard (JAS 2008) for structural LVL. The MOE and MOR values were significantly influenced by the physical treatment, however, neither to horizontal shear strength nor to formaldehyde emission. The best performance of LVL has resulted from unloaded LVL with cold-pressed time for 18 h; the MOE and MOR values were 9,345.05 ± 141.61 N mm−2 and 80.67 ± 1.77 N mm−2, respectively. The best value of the horizontal shear strength was obtained from the LVL with 18 h cold-pressing time and conditioned with loaded (13.10 ± 1.47 N mm−2) and unloaded (12.23 ± 1.36 N mm−2). The percentage of delamination values decreased with an increase in the cold-pressing time and conditioning time. The lowest value of delamination (19.06%) was obtained from the LVL with 24 h cold-pressing time and conditioned with loaded for 14 days. Except the delamination test, all other properties fulfilled the JAS.

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.

scholarly journals Physical and mechanical properties of impregnated polystyrene jabon (Anthocephalus cadamba) glulam

2021 ◽  
Vol 891 (1) ◽  
pp. 012007
Author(s):  
Y S Hadi ◽  
E N Herliyana ◽  
I M Sulastiningsih ◽  
E Basri ◽  
R Pari ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Physical And Mechanical Properties ◽  
Solid Wood ◽  
Hot Water ◽  
The Other ◽  
Modulus Of Rupture ◽  
Glued Laminated Timber ◽  
Anthocephalus Cadamba

Abstract Jabon (Anthocephalus cadamba) laminas were impregnated with polystyrene and reached 21.2% polymer loading. The laminas were manufactured for three-layer glued laminated timber (glulam) using isocyanate glue with glue spread 280 g/m2 and cold-press process. For comparison purposes, untreated glulam as control and also solid wood were prepared. The physical-mechanical properties were evaluated according to the Japanese Agricultural Standard (JAS) 234-2003. The results showed that the color of glulam was not different from polystyrene glulam. The density of polystyrene glulam was higher than untreated glulam and solid wood, but the moisture content was lower than the other. The product kinds of solid wood, untreated glulam, and polystyrene glulam did not affect shear strength and modulus of rupture (MOR), while the modulus of elasticity (MOE) of untreated glulam and hardness of polystyrene glulam were the highest values and the other products were not different one each other. Both kinds of glulam fulfilled the Japanese standard in terms of moisture content, MOR, and delamination in hot water, but MOE and shear strength did not. Regarding its advantages, polystyrene glulam could be further developed using a higher wood density.

Effect of Core Temperature on Some Important Properties of Poplar Scrimber Boards during the Heat Curing Process

2019 ◽  
Vol 69 (3) ◽  
pp. 210-216
Author(s):  
Fei Rao ◽  
Jinguang Wei ◽  
Yue Qi ◽  
Yahui Zhang ◽  
Wenji Yu
Keyword(s):  
Mechanical Properties ◽  
Core Temperature ◽  
Large Scale ◽  
Phenol Formaldehyde ◽  
Formaldehyde Emission ◽  
Modulus Of Rupture ◽  
Curing Process ◽  
Horizontal Shear ◽  
Heat Curing ◽  
Swelling Rate

Abstract In this study, poplar wood and a phenol-formaldehyde (PF) resin were used to produce a large-scale scrimber product by a combined cold pressing and heat curing method. The water resistance, mechanical properties, and formaldehyde emission of the scrimber boards prepared at different core temperatures (100°C, 110°C, 115°C, and 120°C) were investigated. The results showed that the peak core temperature had a significant effect on the scrimber performance. The thickness swelling rate and width swelling rate of the scrimber boards prepared at a core temperature of 100 °C were significantly higher than other samples. The formaldehyde emission from the surface layer of the scrimber boards prepared at a high core temperature (115°C and 120°C) was much lower than that at a core temperature of 100°C and 110°C. These results can be explained by the correlation between curing degree and temperature of the PF resin in the scrimber. With increasing core temperature, the modulus of rupture, compression strength, and horizontal shear strength of the scrimber boards first increased and then decreased, suggesting that core temperature during the heat curing process also played an important role in determining mechanical properties. The scrimber boards with the best mechanical properties were prepared at a core temperature of 115°C. The results of the study demonstrated that the optimal core temperature necessary to produce a low-cost and high-performance scrimber was 115°C.

scholarly journals PENGARUH PERENDAMAN PARTIKEL TERHADAP SIFAT FISIS DAN MEKANIS PAPAN PARTIKEL DARI AMPAS TEBU (Saccharum officinarum)

PERENNIAL ◽  
2008 ◽  
Vol 4 (1) ◽  
pp. 6
Author(s):  
Apri Heri Iswanto ◽  
Zahrial Coto ◽  
Kurniawansyah Effendy
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Internal Bond ◽  
Physical And Mechanical Properties ◽  
Saccharum Officinarum ◽  
Hot Water ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Holding Power

The objective of this research is to research the effect of particle soaking to physical and mechanical properties particleboard that resulted. The best result of particleboard is particleboard with treatment of hot water soaking. From this result obtained average of physical properties of particleboard (i.e. density, moisture content, water absorption, and thickness swelling) are 0.7 g/cm3; 9.58%; 52.27%; 10.05%. While the result average of mechanical properties of particleboard (i.e. Modulus of Rupture, Modulus of Elasticity, Internal Bond and Screw Holding Power) are 118.79 kg/cm2; 8.909 kg/cm2; 1.85 kg/cm2; 28.40 kg. Key words: Soaking, bagasse, particleboard, physical and mechanical properties References

Mechanical properties of Ficus vallis-choudae (Delile), a lesser utilized species in Nigeria

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6550-6560
Author(s):  
Lawrence Aguda ◽  
Babatunde Ajayi ◽  
Sylvester Areghan ◽  
Yetunde Olayiwola ◽  
Aina Kehinde ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
High Strength ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Impact Bending ◽  
Timber Market

Declining availability of the prime economic species in the Nigerian timber market has led to the introduction of Lesser-Used Species (LUS) as alternatives. Their acceptability demands information on the technical properties of their wood. The aim of this study was to investigate the mechanical properties of Ficus vallis-choudae to determine its potential for timber. Three mature Ficus vallis-choudae trees were selected and harvested from a free forest area in Ibadan, Oyo State, Nigeria. Samples were collected from the base (10%), middle (50%), and top (90%) along the sampling heights of each tree, which was further partitioned into innerwood, centrewood, and outerwood across the sampling radial position. Investigations were carried out to determine the age, density, moisture content, impact strength, modulus of elasticity, modulus of rupture, compressive strength parallel-to-grain, and shear strength parallel-to-grain. The mean impact bending strength, modulus of rupture, modulus of elasticity, maximum shear strength parallel-to-grain, and maximum compression strength parallel-to-grain for Ficus vallis-choudae at 12% moisture content were 20.4 N/mm2, 85.8 N/mm2, 709 N/mm2, 10.7 N/mm2, and 33.6 N/mm2, respectively. The study found the species to be dense with high strength properties in comparison with well-known timbers used for constructional purposes.

Influence of veneer thickness, mat formation and resin content on some properties of novel poplar scrimbers

Holzforschung ◽  
2018 ◽  
Vol 72 (8) ◽  
pp. 673-680 ◽  
Author(s):  
Yahui Zhang ◽  
Yue Qi ◽  
Yuxiang Huang ◽  
Yanglun Yu ◽  
Yanjun Liang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Compression Strength ◽  
Surface Texture ◽  
Absorption Rate ◽  
Resin Content ◽  
Modulus Of Rupture ◽  
Thickness Swelling ◽  
Bending Modulus ◽  
Swelling Rate

AbstractThick poplar veneers (4–8 mm) have been finely fluffed to manufacture novel scrimbers by two paving ways, namely by random and laminated mat formations. The following properties of the scrimbers were evaluated: modulus of rupture (MOR) via static bending, modulus of elasticity (MOE), compression strength (CS), shear strength (SS), water absorption rate, thickness swelling rate (TSR) and width swelling rate. The results show that utilization of fluffed thicker veneers reduced the mechanical properties to a certain extent. The TSR of the scrimber was first improved and then weakened by increasing the thickness of the veneers. The scrimber prepared from 6-mm-thick veneers showed the best waterproof performance. The random and laminated mat formations affected the surface texture significantly but the mechanical properties and dimensional stability to a lesser extent. With increasing resin content, the waterproof performance of the scrimbers was improved, which was not otherwise expected. The mechanical properties remained essentially unchanged except for the shear strength.

scholarly journals Agricultural Residues of Lignocellulosic Materials in Cement Composites

2020 ◽  
Vol 10 (22) ◽  
pp. 8019
Author(s):  
Patrícia Ferreira Ponciano Ferraz ◽  
Rafael Farinassi Mendes ◽  
Diego Bedin Marin ◽  
Juliana Lobo Paes ◽  
Daiane Cecchin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Building Materials ◽  
Testing Machine ◽  
Coconut Shell ◽  
Modulus Of Rupture ◽  
Accelerated Ageing ◽  
Cement Composites ◽  
Lignocellulosic Materials ◽  
Lignocellulosic Material ◽  
Coffee Husk

Lignocellulosic material residues in cement composites are a favourable option for new fibre cement formulations in building materials, because they combine good mechanical properties with low density. This study aimed to evaluate the chemical, physical, anatomical, and mechanical properties of five cement panels reinforced with the following lignocellulosic materials: eucalyptus, sugarcane bagasse, coconut shell, coffee husk, and banana pseudostem. Lignocellulosic cement panels were produced with each lignocellulosic material residue, and three replicates of each type of lignocellulosic material were examined (15 panels in total). The lignin, extractives, ash, and holocellulose were examined. After 28 days of composite curing, the following physical properties of the panels were evaluated: density, porosity, water absorption after immersion for 2 and 24 h, and thickness swelling after immersion for 2 and 24 h. Mechanical tests (compression strength, internal bonding, modulus of rupture, and modulus of elasticity) were performed before and after the accelerated ageing test with a universal testing machine. Scanning electron microscopy and supervised image classification were performed to investigate the morphologies of the different materials and the filler/matrix interfaces. Eucalyptus and sugarcane panels had the best results in terms of the evaluated properties and thus, could potentially be used as non-structural walls. However, banana pseudostem, coconut shell, and coffee husk panels had the worst results and therefore, under these conditions, should not be used in building.

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