Effects of moisture content and specific gravity on static bending properties and hardness of six wood species

1999 ◽  
Vol 45 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Song-Yung Wang ◽  
Hon-Lin Wang
2021 ◽  
Vol 6 (2) ◽  
pp. 42-48
Author(s):  
Wahyu Dwianto ◽  
Ikuho Iida ◽  
Kazuya Minato

This paper deals with softening behaviour measurements of Indonesian wood species by static bending tests. Wood samples with a size of 110mm (R) x 10mm (T) x 4mm (L) were bending tested in air-dry at 20°C and 65% relative humidity (RH), in water saturation at 20°C, and in water saturation at 80°C to know the decreasing of modulus of elasticity (MOE) and modulus of rupture (MOR) due to moisture content (MC) and both moisture content and temperature (MCT) changes. The wood samples represented Randu (Bombax ceiba. L) as the lowest specific gravity, i.e. 0.27 to Lamtoro (Leucaena glauca (Willd) Benth) as the highest specific gravity, i.e. 0.81. The three-point static bending test was carried out by a mechanical testing machine with a load capacity of 100kgf, loading deflection speed of 5mm/min, a span distance of 80mm at a room with a temperature of 20°C and 65% RH for air-dry wood samples, and that for wet wood samples were conducted in a water bath at 20°C (change in MC) and 80°C (change in MCT), respectively. MOE and MOR increased linearly with specific gravity regardless of wood species. On the other hand, maximum deflection did not correlate with specific gravity for any MCT conditions. The relative MOE and MOR which were calculated in wet 20°C to air-dry were affected from hardly to strongly depending on the wood species. Meanwhile, they decreased extremely when saturated in water at 80°C regardless of wood species. The relative MOE and MOR due to the change in MC or MCT was independent of specific gravity, as well. Furthermore, chemical compositions of the wood species were analysed to clarify the main factors that affected the decreasing of MOE and MOR due to MC and MCT changes. The results showed that the percentage of lignin and hemicelluloses in each wood played an important role in decreasing the static bending properties. Relative MOE and MOR decreased with increasing lignin and hemicellulose contents. It can be concluded that the hygrothermal properties of lignin and hemicelluloses significantly affect the changes of elastic and strength properties of wood in softening conditions.


2020 ◽  
Vol 9 (4) ◽  
pp. e31942727
Author(s):  
João Gabriel Missia da Silva ◽  
Pedro Nicó de Medeiros ◽  
Denise Ransolin Soranso ◽  
Vinicius Peixoto Tinti ◽  
José Tarcísio da Silva Oliveira ◽  
...  

The aim of this study was to evaluate the influence of anatomical characteristics on the adhesion performance of Vatairea sp., Paulownia sp., Aspidosperma populifolium and Tectona grandis wood. Specimens for anatomical, physical and mechanical analyzes were produced from tangentially oriented boards. The treatments were joint glued from pieces of the same anatomical orientation (radial and tangential), evaluated for shear strength and glue line failure. The Vatairea sp wood had the highest specific gravity (0.74 g cm-3) and the Paulownia sp (0.34 g cm-3) wood was smaller. Aspidosperma populifolium species showed the highest shear strength in the glue line in the tangential and radial faces. The anatomical variables with higher influence on the wood adhesion process were pith ray cells and especially fibers that exhibit the greatest correlation with the shear strength of the glue line.


2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.


2015 ◽  
Vol 773-774 ◽  
pp. 1438-1442 ◽  
Author(s):  
Siti Aimi Nadia Mohd Yusoff ◽  
I. Bakar ◽  
Devapriya Chitral Wijeyesekera ◽  
Adnan Zainorabidin ◽  
Aziman Madun

This paper compares some geotechnical properties of Kaolin, Laterite and Peat. Laterite was collected from Bukit Banang while Peat sample was collected from Parit Nipah, both locations were in Batu Pahat, Johor. Meanwhile, kaolin that was used in this research was manufactured kaolin. These soil samples were subjected to routine laboratory analysis and resulting data were analyzed statistically using a correlation analysis. A laboratory testing program consists of “Basic properties test” to obtain general information on the materials (e.g Natural moisture content, Atterberg Limit, Specific gravity, grain size analysis, chemical composition and pH) and “Geotechnical properties tests” to measure specific properties that characterize soil behaviour for design and constructability assessments (e.g Standard Proctor Test, Unconfined Compressive Strength and CBR).The results showed that the Natural/initial moisture content for laterite, peat and kaolin is 22.54%, 480.61% and 0.22% respectively. Meanwhile Specific gravity for each soil was in the range 1.50-2.79.It was also found that the pH of all soil is acidic which lay in the range of 3.76-5.95.The UCS for the optimally compacted sample of laterite is 445.77 kPa, kaolin is 199.23 kPa and for peat is 58.70 kPa. This paper summarizes the result of analysis performed on all tests conducted. Based on the results, the geotechnical property of the soil is a highly dependent with the type of soil and therefore, determining the soil characterization and the soil strength should be considered during the planning phase of any earthwork construction operation.


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 ◽  
...  

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.


Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Y. Liu ◽  
A.W.C. Lee

Summary This study was conducted to explore basic physical and mechanical properties of parallel strand lumber (PSL) made exclusively from southern pine and yellow-poplar, respectively, and to examine their relationships using statistical analysis. Small specimens were prepared from commercial southern pine PSL and yellow-poplar PSL billets and tested for specific gravity, moisture content, dimensional stability, bending properties, shear strength and compressive strength. Results indicate average specific gravity of southern pine PSL is higher than that of yellow-poplar PSL, while their average moisture content and dimensional stability are very similar. Southern pine PSL has higher average modulus of elasticity but lower average modulus of rupture than yellow-poplar PSL. While average longitudinal shear strength does not exhibit differences between southern pine PSL and yellow-poplar PSL, average compressive strength of southern pine PSL is higher than that of yellow-poplar PSL. There are positive correlations among modulus of elasticity, modulus of rupture and specific gravity. PSL improves some properties of solid wood from which PSL is made.


2019 ◽  
Vol 20 (8) ◽  
Author(s):  
Nurul Chaerani ◽  
DEDE J SUDRAJAT ◽  
ISKANDAR Z SIREGAR ◽  
ULFAH J SIREGAR

Abstract. Chaerani N, Sudrajat DJ, Siregar IZ, Siregar UJ. 2019. Growth performance and wood quality of white jabon (Neolamarckia cadamba) progeny testing at Parung Panjang, Bogor, Indonesia. Biodiversitas 20: 2295-2301. The aim of this study was to evaluate the genetic parameters of growth and wood quality in white jabon progeny test at 54 months old in Parung Panjang, Bogor. The 105 half-sib families obtained from 12 provenances were evaluated in a randomized complete block design with five replications. Wood quality was assessed both in a non-destructive way using a pilodyn and by destructive method using wood sample taker. Results indicated that the mean value ranged from 5.10 to 10.15 m for height, 6.67 to 15.30 cm for diameter, 2.30 to 3.62 cm for pilodyn penetration, 0.66 to 0.82 g/cm3 for wood density, 0.33 to 0.50 for specific gravity, and 66 to 111 % for moisture content, respectively. There were significant differences among 105 families for all traits except moisture content. The high heritability estimate was found for height (0.4-0.69) and basic density (0.27-0.59). Applying 80% selection intensity on diameter and leaving 84 best families in each block will produce a high total genetic gain. Pilodyn penetration had negative correlation with diameter, wood density, and specific gravity.


2021 ◽  
Vol 3 (2) ◽  
pp. 276-285
Author(s):  
Brigita Suzanna ◽  
Irwan Lie Keng Wong ◽  
Monika Datu Mirring Palinggi

The purpose of this research is to determine the physical properties of clay soil and to analyze the effect of adding coconut shell charcoal ash to the clay soil. The soil samples used in this study came from Tanralili District, Maros Regency, two sample points were taken and the variations in the levels of addition of coconut shell charcoal ash is 0%, 4%, 6%, 8%, 10%. The test method used refers to ASTM (American Society for Testing Materials). The tests carried out were testing the physical properties of the soil in the form of moisture content, specific gravity, Atterberg boundaries, filter analysis, and hydrometer analysis, then a compaction test was carried out to determine the maximum soil density. The results of the test obtained a moisture content value of 28.811%, a specific gravity of 2.58 g / cm3 so that it is classified as organic clay. As well as the plasticity index value of 9.926% with moderate plasticity from the 7% -17% interval. Then from the test results of soil compaction testing with the addition of coconut shell ash, the dry density (gdry) equal to 0.862, 0.886, 0.914, 0.943, 0.962, this means that the soil sample experienced an increase in dry density (gdry) of 11.60%. From the research results it can be concluded that the addition of coconut shell charcoal ash can increase the value of soil dry density so that it can be used to increase the value of the carrying capacity of clay soil.


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