scholarly journals Species, grading, and mechanical properties of locally sourced timber in the Joyabaj region of Guatemala

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Larissa Bogle-Boesiger ◽  
Todd Davis
Keyword(s):  
Mechanical Properties ◽  
Forest Products ◽  
Modulus Of Rupture ◽  
White Pine ◽  
Eastern White Pine ◽  
Clear Wood ◽  
Visual Grading ◽  
Wood Structures ◽  
Design Values ◽  
Multiple Species

The purpose of this project was to research the timber used by Engineers without Borders (EWB) groups in the Joyabaj region of Guatemala. This project aimed to investigate the species of wood, evaluate the quality by assessing the distribution of timber grades, and determine mechanical properties. The results will aid EWB groups in the design of wood structures in the Joyabaj region of Guatemala.Samples were collected for species investigation and mechanical testing. Species investigation was triangulated from interviews with the sawmill owner, construction foreman, testing by the USDA Forest Products Laboratory, and comparisons to literature. The results were inconclusive and indicated multiple species were intermixed at the sawmill with no distinction made when purchased. Timber quality was evaluated by using a visual grading guide developed by the authors to assess the distribution of grades within a large order of lumber. Static bending and compression parallel to grain tests were conducted to obtain modulus of rupture, compression parallel to grain, and modulus of elasticity. Specific gravity was also obtained.The results indicate that three different species were collected. Ninety per cent (90%) of the timber was No. 3 or better and 50% to 80% was No. 2 or better depending on the size. Clear wood testing values were similar to those of Eastern White Pine. Structural design should be performed based on National Design Specification (NDS) design values for a No. 3 or No. 2 Eastern White Pine, depending on the degree of wood selection in the construction process.

Predicting mechanical properties of clear wood from Acacia mangium provenances using ultrasound

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 8309-8319
Author(s):  
Doan Van Duong ◽  
Masumi Hasegawa
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Significant Positive Correlation ◽  
Correlation Coefficients ◽  
Acacia Mangium ◽  
Longitudinal Direction ◽  
Modulus Of Rupture ◽  
Clear Wood

Ultrasound was considered as a means for determining mechanical properties of clear wood in six different Acacia mangium provenances from a trial forest planted in Vietnam. A total of 30 trees (5 trees from each provenance) with no major defects were selected, and a 50-cm-long log was obtained at 1.3 m above the ground from each tree for the assessment of mechanical properties. The measured average ultrasound velocities for provenances tested in the longitudinal direction ranged from 4094 m/s to 4271 m/s. The predicted average dynamic modulus of elasticity (Ed) values varied from 7.42 GPa to 8.70 GPa among provenances. The Ed indicated significant positive correlation coefficients with modulus of elasticity (0.64 to 0.96), modulus of rupture (0.44 to 0.87), and compression strength (0.54 to 0.92) for provenances examined in this study. The results indicated that the use of ultrasound was feasible to determine the mechanical properties of A. mangium provenances planted in Vietnam.

Black spruce trees from fire-origin stands have higher wood mechanical properties than those from older, irregular stands

2014 ◽  
Vol 44 (2) ◽  
pp. 118-127 ◽  
Author(s):  
Luciane Paes Torquato ◽  
David Auty ◽  
Roger E. Hernández ◽  
Isabelle Duchesne ◽  
David Pothier ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fixed Effects ◽  
Stand Structure ◽  
Black Spruce ◽  
Ring Width ◽  
Regular Structure ◽  
Modulus Of Rupture ◽  
Nonlinear Mixed Effects Models ◽  
Clear Wood ◽  
Cambial Age

In the eastern Canadian boreal forest, long fire return intervals lead to over 60% of stands having an irregular, uneven-aged structure, which is associated with slower growth. The aim of this study was to examine the effect of stand structure on the clear wood mechanical properties of black spruce (Picea mariana (Mill.) B.S.P.). A total of 128 trees were destructively sampled from stands of regular and irregular structure across Quebec, Canada. Nonlinear mixed-effects models were developed for each stand type to describe the variation in modulus of elasticity (MOE) and modulus of rupture (MOR) in small defect-free samples as functions of cambial age and annual ring width. Mechanical properties were strongly related to cambial age, with a smaller influence of ring width. After accounting for these variables, both MOE and MOR were higher in samples from stands of regular structure, although differences were less pronounced in the upper stem compared with breast height. The fixed effects of the models explained between 34% and 53% of the variation in mechanical properties. A higher incidence of mild compression wood in trees of layer origin may explain the observed differences between stand structures.

scholarly journals PENGARUH WAKTU PERENDAMAN DALAM AIR, KADAR PATI DAN KADAR LIGNIN TERHADAP SIFAT FISIK DAN MEKANIK BAMBU AMPEL (Bambusa vulgaris Schard)

2018 ◽  
Vol 7 (1) ◽  
pp. 39
Author(s):  
Abdurachman Abdurachman ◽  
Agus Ismanto
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Immersion Time ◽  
Lignin Content ◽  
Starch Content ◽  
Physical And Mechanical Properties ◽  
Forest Products ◽  
Modulus Of Rupture ◽  
Running Water ◽  
Bambusa Vulgaris

The effect of immersion time in the water, starch and lignin content physical and mechanical properties of Ampel bamboo (Bambusa vulgaris Schard)The studied effect of immersion time in the water on physical and mechanical properties of ampel bamboo had been studied  at the Forest Products Research and Development Center Bogor. Round Bamboo of ampel species (Bambusa vulgaris Schard) a length of 50 cm was immersed in running water, stagnant and in the sludge for 7, 14, 21 and 28 days. Then the changes in starch and lignin content, physical and mechanical properties were evaluated. The physical properties studied were evaluated density and moisture content, while mechanical properties were bending and parallel tensile strength of fiber. The results showed that the media and immersion time significantly affect the density and moisture content, but did not affect the physical and mechanical properties. Increased starch content in a variety of treatments, especially on immersion in water, otherwise the lignin content decreases, causing a decrease in the nature of Modulus of Elasticity (MOE) and Modulus of Rupture (MOR). Immersion in stagnant water better than by soaking in the mud and in running water.Keywords: Bambusa vulgaris Schard,  media, immersion time, physical and mechanical properties ABSTRAKPenelitian pengaruh waktu perendaman dalam air terhadap sifat fisik dan mekanik bambu ampel (bambusa vulgaris) telah dilakukan di Pusat Penelitian dan Pengembangan Hasil Hutan Bogor. Bambu bulat berukuran panjang 50 cm direndam dalam air mengalir, tergenang dan lumpur selama 7, 14, 21 dan 28 hari, kemudian diamati perubahan kadar pati,diuji sifat fisik dan mekaniknya. Sifat fisik yang diteliti adalah kerapatan dan kadar air, sedangkan sifat mekanik adalah keteguhan lentur dan tarik sejajar serat. Hasil penelitian menunjukkan bahwa media dan waktu rendaman berpengaruh nyata terhadap kerapatan dan kadar air, tetapi tidak berpengaruh terhadap sifat fisis dan mekanis bambu yang diteliti. Kadar pati meningkat pada berbagai perlakuan terutama pada rendaman dalam air mengalir, sebaliknya kandungan lignin menurun sehingga menyebabkan penurunan sifat Modulus elastisitas (MOE) dan keteguhan lentur maksimum (MOR). Perendaman dalam air tergenang lebih baik dibandingkan dengan cara perendaman dalam lumpur maupun dalam air mengalir.Kata kunci : Bambusa vulgaris Schard, media, waktu perendaman, sifat fisis dan mekanis

Evaluation of the Load-Carrying Capacity in Bending of Large Cross Section “Pitch Pine” Beams in Standing Structures

2013 ◽  
Vol 778 ◽  
pp. 410-417 ◽  
Author(s):  
Manuel C. Touza Váquez ◽  
Azahara Soilán Cañás ◽  
David Lorenzo Fouz
Keyword(s):  
Mechanical Properties ◽  
Pinus Palustris ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Load Carrying Capacity ◽  
Visual Grading ◽  
Load Carrying ◽  
Pitch Pine ◽  
Large Sections

This paper deals with the procedure followed in order to define a visual grading protocol to determine the mechanical properties of existing old pitch pine timber beams with large sections. The commercial name pitch pine comprises several species in the group of southern yellow pines, being the Longleaf pine or Georgia pitch pine (Pinus palustris) the most important. Old growth Pinus palustris, was very much appreciated for its rigidity, density, strength properties and natural durability. In Spain, many of the buildings constructed with this timber (named as pino tea) are nowadays under rehabilitation processes which, in some cases, will change the previous use of the building. All these interventions require understanding the mechanical properties of the timber. The structural properties of the aged pitch pine timber are unknown and there is not any European stress grading standard to enable the classification of the existing elements. For this reason, a total of 45 large section pitch pine pieces were visually analyzed and graded according to Spanish standard UNE EN 56.544 [. After this, the beams were tested according to UNE EN 408 [ in order to determine their modulus of rupture and flobal modulus of elasticity. All beams were tested keeping their original positions in the building and a new classification system for old beams is proposed based on a reduced number of chief visual grading parameters and taking into account their position into the beam.

Determination of the mechanical properties of radiata pine timber by means of longitudinal and transverse vibration methods

Holzforschung ◽  
2014 ◽  
Vol 68 (3) ◽  
pp. 299-305 ◽  
Author(s):  
Francisco Arriaga ◽  
Joaquin Monton ◽  
Edgar Segues ◽  
Guillermo Íñiguez-Gonzalez
Keyword(s):  
Mechanical Properties ◽  
Radiata Pine ◽  
Nondestructive Method ◽  
Modulus Of Rupture ◽  
Bending Properties ◽  
Fundamental Vibration ◽  
Visual Grading ◽  
Prediction Of Mechanical Properties ◽  
Similar Accuracy

Abstract Bending properties have been determined by mechanical testing [modulus of elasticity (MOE) and modulus of rupture (MOR)] and by means of longitudinal (L) and transverse (T) vibration nondestructive methods on 150 sawn timber pieces of Pinus radiata D. Don, with the dimensions of 80×120 mm cross-section and 2500 mm long, from Catalonia, Spain. The fundamental vibration frequency was measured by recording the sound produced by hitting the piece in L and T directions, and this signal was analyzed by fast Fourier transform sound analyzer. The dynamic MOE was obtained for both procedures and compared with static MOE and MOR. The notion of concentrated knot diameter ratio (CKDR) was introduced to improve the prediction of MOR. CKDR gives better results when this parameter is referred to the central portion of piece length. Both methods (L and T frequencies) have similar accuracy in prediction of mechanical properties, but the first one is simpler and has some practical advantages. The timber graded with this nondestructive method offers better results than the visual grading rules for the same output.

Pengaruh Tekanan dan Penggunaan Conplast terhadap Sifat Mekanik Eternit dari Abu Cangkang Sawit

2016 ◽  
Vol 8 (15) ◽  
pp. 47-54
Author(s):  
Haspiadi Haspiadi
Keyword(s):  
Mechanical Properties ◽  
Oil Palm ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Density Values ◽  
Test Result

The purpose of this research is to know the influence of pressure and use of conplast against mechanical properties which are a Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) of plasterboard. The study is done because still low quality of plasterboard made from a mixture of ashes of oil-palm shell especially of the mechanical properties compared to the controls. The method of this reserach used variation of printed pressure and the addition of conplast. Test result is obtained that the highest value of Modulus of Elasticity (MOE) 90875.94 Kg/cm2, Modulus of Rupture (MOR) 61.16 Kg/cm2 and density values in generally good printed at the pressure 60 g/cm3 and the addition of conplast 25% as well as the composition of the ash of palm shell oil 40%: limestone 40%: cement 15%: fiber 5% and 300 mL of water. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh tekanan dan penggunaan conplast terhadap sifat mekanik yaitu kuat lentur dan keteguhan patah eternit berbahan dasar abu cangkang sawit. Penelitian ini dilakukan karena masi rendahnya mutu eternit berbahan campuran abu cangkang sawit dari bolier khususnya sifat mekanik dibandingkan dengan kontrol. Metode penelitian yang digunakan adalah dengan variasi tekanan cetak dan penambahan conplast. Hasil uji diperoleh bahwa kuat lentur tertinggi sebesar 90875,94 Kg/cm2 dan keteguhan patah sebesar 61,16 Kg/cm2, yang dicetak pada tekanan 60 g/cm3 dan penambahan conplast 25% dengan komposisi  abu cangkang sawit 40 %: kapur 40 % : semen 15 %: serat 5 % dan air 300 mL.Kata Kunci :  Abu cangkang sawit, conplast, kuat lentur, keteguhan patah.

Impact of Chemical Modification on the Physical and Mechanical Properties of Tropical Wood Material

2012 ◽  
Vol 576 ◽  
pp. 314-317
Author(s):  
Sinin Hamdan ◽  
M. Saiful Islam
Keyword(s):  
Mechanical Properties ◽  
Diazonium Salt ◽  
Treated Wood ◽  
Coupling Reaction ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Ft Ir ◽  
Ir Analysis ◽  
D Values ◽  
Benzene Diazonium

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.

scholarly journals Composites from Thermoplastic Natural Rubber Reinforced Rubberwood Sawdust: Effects of Sawdust Size and Content on Thermal, Physical, and Mechanical Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Chatree Homkhiew ◽  
Surasit Rawangwong ◽  
Worapong Boonchouytan ◽  
Wiriya Thongruang ◽  
Thanate Ratanawilai
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
High Density Polyethylene ◽  
High Performance ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Shore Hardness ◽  
Thermoplastic Natural Rubber ◽  
Plastic Content

The aim of this work is to investigate the effects of rubberwood sawdust (RWS) size and content as well as the ratio of natural rubber (NR)/high-density polyethylene (HDPE) blend on properties of RWS reinforced thermoplastic natural rubber (TPNR) composites. The addition of RWS about 30–50 wt% improved the modulus of the rupture and tensile strength of TPNR composites blending with NR/HDPE ratios of 60/40 and 50/50. TPNR composites reinforced with RWS 80 mesh yielded better tensile strength and modulus of rupture than the composites with RWS 40 mesh. The TPNR/RWS composites with larger HDPE content gave higher tensile, flexural, and Shore hardness properties and thermal stability as well as lower water absorption. The TPNR/RWS composites with larger plastic content were therefore suggested for applications requiring high performance of thermal, physical, and mechanical properties.

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