scholarly journals Influence of a thermal treatment on the tensile strength and equilibrium moisture content of bamboo (Guadua angustifolia Kunth)

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3103-3111
Author(s):  
Ricardo Acosta ◽  
Jorge A. Montoya ◽  
Goran Schmidt
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Treatment ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Physical And Mechanical Properties ◽  
Thermal Treatments ◽  
Lignocellulosic Materials ◽  
Basal Section ◽  
Notable Increase

Thermal treatments applied to lignocellulosic materials were found to induce internal chemical reactions, which modified the physical and mechanical properties and dimensional stability of the material. A 3-year-old basal section of bamboo (Guadua angustifolia Kunth), with no nodes and no skin, was subjected to a thermal treatment at temperatures which ranged from 160 to 200 °C for 1 to 4 h. The tensile stiffness showed a slight increase with temperature and time, while the tensile strength showed a notable increase at 160 °C for 2 h. There was a 5% difference in the equilibrium moisture content at 80% relative humidity between the untreated samples and the 200 °C, 4 h treatment.

scholarly journals Characterisation of Physical and Mechanical Properties of Unthinned and Unpruned Plantation-Grown Eucalyptus nitens H.Deane & Maiden Lumber

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 194 ◽  
Author(s):  
Mohammad Derikvand ◽  
Nathan Kotlarewski ◽  
Michael Lee ◽  
Hui Jiao ◽  
Gregory Nolan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Moisture Content ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Eucalyptus Nitens ◽  
Linear Regression Models ◽  
Bending Modulus ◽  
Small Wood

The use of fast-growing plantation eucalypt (i.e., pulpwood eucalypt) in the construction of high-value structural products has received special attention from the timber industry in Australia and worldwide. There is still, however, a significant lack of knowledge regarding the physical and mechanical properties of the lumber from such plantation resources as they are mainly being managed to produce woodchips. In this study, the physical and mechanical properties of lumber from a 16-year-old pulpwood Eucalyptus nitens H.Deane & Maiden resource from the northeast of Tasmania, Australia was evaluated. The tests were conducted on 318 small wood samples obtained from different logs harvested from the study site. The tested mechanical properties included bending modulus of elasticity (10,377.7 MPa) and modulus of rupture (53 MPa), shear strength parallel (5.5 MPa) and perpendicular to the grain (8.5 MPa), compressive strength parallel (42.8 MPa) and perpendicular to the grain (4.1 MPa), tensile strength perpendicular to the grain (3.4 MPa), impact bending (23.6 J/cm2), cleavage (1.6 kN) and Janka hardness (23.2 MPa). Simple linear regression models were developed using density and moisture content to predict the mechanical properties. The variations in the moisture content after conventional kiln drying within randomly selected samples in each test treatment were not high enough to significantly influence the mechanical properties. A relatively high variation in the density values was observed that showed significant correlations with the changes in the mechanical properties. The presence of knots increased the shear strength both parallel and perpendicular to the grain and significantly decreased the tensile strength of the lumber. The results of this study created a profile of material properties for the pulpwood E. nitens lumber that can be used for numerical modelling of any potential structural product from such a plantation resource.

scholarly journals Utilization of Pitali (Trewia nudiflora) for Manufacturing Commercial Plywood in Bangladesh

1970 ◽  
Vol 43 (4) ◽  
pp. 581-587
Author(s):  
M Hasan Shahria ◽  
M Ashaduzzaman ◽  
M Iftekhar Shams ◽  
Arifa Sharmin ◽  
M Muktarul Islam
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Moisture Content ◽  
Physical Properties ◽  
Water Absorption ◽  
Linear Expansion ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Thickness Swelling ◽  
Trewia Nudiflora

The study was conducted to find out the potentiality of Pitali (Trewia nudiflora) for manufacturing commercial plywood and evaluating its physical and mechanical properties. Two 9-ply plywood of 2.4m x 1.2m x 18mm size were manufactured using liquid urea formaldehyde adhesive. The physical and mechanical properties of T. nudiflora plywood were compared with the existing market available plywood manufactured by Simul (Bombax ceiba). It was found that density were 509.82 kg/m3 and 490.96 kg/m3, moisture content after curing were 10.67% and 17.61%, thickness swelling were 6.90% and 7.29%, linear expansion were 0.19% and 0.15%, water absorption were 50.89% and 64.79%, MOR were 29.94 N/mm2 and 27.05 N/mm2, MOE were 1613.89 N/mm2 and 1160.68 N/mm2, and tensile strength were 14.75 N/mm2 and 13.12 N/mm2 for T. nudiflora plywood and market plywood respectively. The evaluated physical and mechanical properties of T. nudiflora plywood were also compared with some relevant results and standards reported earlier. Key Words: Plywood, Trewia nudiflora, Physical properties, Mechanical properties. doi: 10.3329/bjsir.v43i4.2249 Bangladesh J. Sci. Ind. Res. 43(4),581-587, 2008

scholarly journals Physical and Mechanical Properties of Fast Growing Polyploid Acacia Hybrids (A. auriculiformis × A. mangium) from Vietnam

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 717
Author(s):  
Dang Duc Viet ◽  
Te Ma ◽  
Tetsuya Inagaki ◽  
Nguyen Tu Kim ◽  
Nghiem Quynh Chi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Young’S Modulus ◽  
Equilibrium Moisture Content ◽  
Compression Strength ◽  
Young's Modulus ◽  
Basic Density ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Acacia Auriculiformis

Acacia plants are globally important resources in the wood industry, but particularly in Southeast Asian countries. In the present study, we compared the physical and mechanical properties of polyploid Acacia (3x and 4x) clones with those of diploid (2x) clones grown in Vietnam. We randomly selected 29 trees aged 3.8 years from different taxa for investigation. BV10 and BV16 clones represented the diploid controls; X101 and X102 were the triploid clones; and AA-4x, AM-4x, and AH-4x represented neo-tetraploid families of Acacia auriculiformis, Acacia mangium, and their hybrid clones. The following metrics were measured in each plant: stem height levels, basic density, air-dry equilibrium moisture content, modulus of rupture (MOR), modulus of elasticity (MOE), compression strength, and Young’s modulus. We found that the equilibrium moisture content significantly differed among clones, and basic density varied from pith-to-bark and in an axial direction. In addition, the basic density of AA-4x was significantly higher than that of the control clones. Furthermore, the MOR of AM-4x was considerably lower than the control clones, whereas the MOE of X101 was significantly higher than the control values. The compression strength of AM-4x was significantly lower than that of the control clones, but AH-4x had a significantly higher Young’s modulus. Our results suggest that polyploid Acacia hybrids have the potential to be alternative species for providing wood with improved properties to the forestry sector of Vietnam. Furthermore, the significant differences among the clones indicate that opportunities exist for selection and the improvement of wood quality via selective breeding for specific properties.

The influence of thermal treatment on the compressive strength and density of bamboo (Guadua angustifolia Kunth)

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7006-7020
Author(s):  
Ricardo Acosta ◽  
Jorge A. Montoya ◽  
Carlos A. Londoño
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Modulus Of Elasticity ◽  
Inflection Point ◽  
Physical And Mechanical Properties ◽  
Basal Area ◽  
Modulus Of Rupture ◽  
Lignocellulosic Materials ◽  
Maximum Value ◽  
Compression Stiffness

Lignocellulosic materials that are thermally treated via hydrolysis react chemically, modifying their internal structure, which in turn modifies their physical and mechanical properties, as well as their dimensional stability. Bamboo (Guadua angustifolia Kunth) samples 3 years old, without nodes and without skin, obtained from their basal area were subjected to thermal treatment with temperatures between 160 and 200 °C and duration times between 1 h and 4 h. The severity of the thermal treatment affects the modulus of rupture and modulus of elasticity in compression. The modulus of rupture increased at temperatures up to 180 °C with treatment times of 2 h, i.e., the severity, defined as the product of the temperature and the time varied between 320 (°C*h) and 360 (°C*h). An inflection point was obtained at a temperature of 180 °C after 2 h with a maximum value of 115.1 MPa. The modulus of elasticity increased as the temperature and time increased. The modulus of rupture and the modulus of elasticity of the treated samples increased up to 14.7% and 36.1%, respectively, compared to the not thermal treated samples. Additionally, when the density increased, the resistance and the compression stiffness also increased.

scholarly journals Damage Evolution of Granodiorite after Heating and Cooling Treatments

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Mohamed Gomah ◽  
Guichen Li ◽  
Salah Bader ◽  
Mohamed Elkarmoty ◽  
Mohamed Ismael
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Failure Mode ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Physical Parameters ◽  
Slow Cooling ◽  
Heating And Cooling ◽  
Natural Rock ◽  
The Impact

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

scholarly journals Thermal, Physical and Mechanical Properties of Poly(Butylene Succinate)/Kenaf Core Fibers Composites Reinforced with Esterified Lignin

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2359
Author(s):  
Harmaen Ahmad Saffian ◽  
Masayuki Yamaguchi ◽  
Hidayah Ariffin ◽  
Khalina Abdan ◽  
Nur Kartinee Kassim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Loss Modulus ◽  
Physical And Mechanical Properties ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Esterification Reaction ◽  
Butylene Succinate ◽  
Kenaf Core ◽  
Modified Lignin

In this study, Kraft lignin was esterified with phthalic anhydride and was served as reinforcing filler for poly(butylene succinate) (PBS). Composites with different ratios of PBS, lignin (L), modified lignin (ML) and kenaf core fibers (KCF) were fabricated using a compounding method. The fabricated PBS composites and its counterparts were tested for thermal, physical and mechanical properties. Weight percent gain of 4.5% after lignin modification and the FTIR spectra has confirmed the occurrence of an esterification reaction. Better thermo-mechanical properties were observed in the PBS composites reinforced with modified lignin and KCF, as higher storage modulus and loss modulus were recorded using dynamic mechanical analysis. The density of the composites fabricated ranged from 1.26 to 1.43 g/cm3. Water absorption of the composites with the addition of modified lignin is higher than that of composites with unmodified lignin. Pure PBS exhibited the highest tensile strength of 18.62 MPa. Incorporation of lignin and KCF into PBS resulted in different extents of reduction in tensile strength (15.78 to 18.60 MPa). However, PBS composite reinforced with modified lignin exhibited better tensile and flexural strength compared to its unmodified lignin counterpart. PBS composite reinforced with 30 wt% ML and 20 wt% KCF had the highest Izod impact, as fibers could diverge the cracking propagation of the matrix. The thermal conductivity value of the composites ranged from 0.0903 to 0.0983 W/mK, showing great potential as a heat insulator.

scholarly journals Effect of Moisture Content on the Processing and Mechanical Properties of a Biodegradable Polyester

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1616
Author(s):  
Vincenzo Titone ◽  
Antonio Correnti ◽  
Francesco Paolo La Mantia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Moisture Content ◽  
Mechanical Testing ◽  
Hydrolytic Degradation ◽  
Slight Reduction ◽  
Biodegradable Polyester ◽  
Molding Process ◽  
Elongation At Break ◽  
Effect Of Moisture

This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing—causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens.

Effect of Castor Oil Impregnation on the Physical and Mechanical Properties of Bacterial Cellulose

2012 ◽  
Vol 3 (1) ◽  
pp. 13-26
Author(s):  
Myrtha Karina ◽  
Lucia Indrarti ◽  
Rike Yudianti ◽  
Indriyati
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bacterial Cellulose ◽  
Young’S Modulus ◽  
Castor Oil ◽  
Young's Modulus ◽  
Physical And Mechanical Properties ◽  
Scanning Electron Micrographs ◽  
Elongation At Break ◽  
Acetone Water

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.

scholarly journals Enhancement of Mechanical Properties and Porosity of Concrete Using Steel Slag Coarse Aggregate

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2865
Author(s):  
Md Jihad Miah ◽  
Md. Munir Hossain Patoary ◽  
Suvash Chandra Paul ◽  
Adewumi John Babafemi ◽  
Biranchi Panda
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Microstructural Analysis ◽  
Steel Slag ◽  
Physical And Mechanical Properties ◽  
Length Change ◽  
Sustainable Building ◽  
Burnt Clay ◽  
Lower Porosity ◽  
Furnace Steel

This paper investigates the possibility of utilizing steel slags produced in the steelmaking industry as an alternative to burnt clay brick aggregate (BA) in concrete. Within this context, physical, mechanical (i.e., compressive and splitting tensile strength), length change, and durability (porosity) tests were conducted on concrete made with nine different percentage replacements (0%, 10%, 20%, 30%, 40%, 50%, 60%, 80%, and 100% by volume of BA) of BA by induction of furnace steel slag aggregate (SSA). In addition, the chemical composition of aggregate through X-ray fluorescence (XRF) analysis and microstructural analysis through scanning electron microscopy (SEM) of aggregates and concrete were performed. The experimental results show that the physical and mechanical properties of concrete made with SSA were significantly higher than that of concrete made with BA. The compressive and tensile strength increased by 73% when SSA fully replaced BA. The expansion of concrete made with SSA was a bit higher than the concrete made with BA. Furthermore, a significant lower porosity was observed for concrete made with SSA than BA, which decreased by 40% for 100% SSA concrete than 100% BA concrete. The relation between compressive and tensile strength with the porosity of concrete mixes are in agreement with the relationships presented in the literature. This study demonstrates that SSA can be used as a full replacement of BA, which is economical, conserves the natural aggregate, and is sustainable building material since burning brick produces a lot of CO2.

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