The Technical Quality of the Wood of Scots Pine (Pinus sylvestris L.) of Diverse Genetic Origin

This work contains the preliminary results of research into the technical quality of the wood from Scots pine trees of diverse genetic origin, grown on an experimental plot at the Forest Experimental Station in Rogów. The following are the parent stands, numbered: 5 (the Tucholskie Forest 130 m a.s.l.), 7 (the Napiwodzko–Ramuckie Forest 145 m a.s.l.), 10 (the Piska Forest 145 m a.s.l.), 12 (the Biała Forest 95 m a.s.l.), 13 (the Namysłowsko–Ostrzeszowskie Forest 190 m a.s.l.), 15 (the Knyszyńska Forest 165 m a.s.l.), and 16 (the Nowotarskie Forest 590 m a.s.l.). The tested wood was obtained in 2018 from trees aged 52 years. The research material came from 100 trees in total. After felling, two logs approximately 0.5 m in length were cut from each tree. The height on the tree from which the material was taken ranged from breast height (1.3 m) to approximately 2.5 m. Next, planks were cut from the logs in a north–south direction; these were precisely described and then left to season. The work included the measurement and statistical analysis of one physical property, wood density (kg/m3), and of the following mechanical properties: compressive strength along the fibres, Rc12 (MPa); static bending strength, Rg12 (MPa); modulus of elasticity under static bending, Eg12 (MPa); and indices of strength quality of the tested mechanical properties, JRc12, JRg12, and JEg12 (km). The origin of the logs was shown to have a significant influence on wood density, compressive strength, static bending strength, and modulus of elasticity under static bending. The highest mean density was found for trees originating from stand 10 (537 kg/m3). The highest values of compressive strength were obtained for trees originating from stands 5 (45 MPa), and the highest static bending strength and modulus of elasticity under static bending were obtained for trees originating from stand 12 (102 and 9825 MPa, respectively).

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The Effect of Borax Solution as Preservative to the Mechanical Properties of Bamboo

International Journal of Sustainable Construction Engineering Technology ◽

10.30880/ijscet.2020.11.02.009 ◽

2020 ◽

Vol 11 (2) ◽

Author(s):

M.A.P Handana ◽

◽

Besman Surbakti ◽

Rahmi Karolina ◽

◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Compressive Strength ◽

Bending Strength ◽

Environmentally Friendly ◽

Preservative Solution ◽

Borax Solution ◽

Preservative Solutions

The use of borax solution as a preservative in wood and bamboo materials is well known in the community. A borax solution is an environmentally friendly liquid that can dissolve in water, so it is suitable to be used as a preservative within cold or hot soaking techniques. The ability of borax to resist insects and fungus attacks on bamboo has been proven, but the effect of the solution on the strength of bamboo must also be investigated. This study conducts to investigate the effects of borax and its additives as preservative solutions to the mechanical properties of bamboos. The bamboos preservations were conducted by cold conditions of immersion, while the mechanical properties were performed to understand the effects of preservatives. The result of this study indicated that 30% to 50% borax in the preservative solution is sufficient to provide significant increase in strength for compressive strength, tensile strength, and bending strength of bamboo specimen. From this study, the use of borax solution in preserving the bamboos materials improved the quality of bamboos based on its mechanical properties.

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The Technical Quality of Wood of Scots Pine (<em>Pinus sylvestris </em>L.) of Diverse Genetic Origin

10.3390/iecf2020-07901 ◽

2020 ◽

Author(s):

Eliza Konofalska ◽

Hubert Lachowicz ◽

Paweł Kozakiewicz ◽

Włodzimierz Buraczyk

Keyword(s):

Pinus Sylvestris ◽

Scots Pine ◽

Technical Quality ◽

Genetic Origin

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Quality and Bending Properties of Scots Pine (Pinus Sylvestris L.) Sawn Timber

Forests ◽

10.3390/f11111200 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1200

Author(s):

Izabela Burawska-Kupniewska ◽

Sławomir Krzosek ◽

Piotr Mańkowski ◽

Marek Grześkiewicz

Keyword(s):

Mechanical Properties ◽

Scots Pine ◽

Modulus Of Elasticity ◽

Bending Strength ◽

Mechanical Parameters ◽

Bending Properties ◽

Characteristic Values ◽

Sawn Timber ◽

The Moment

The paper presents the partial research results of a mechanical properties study conducted on Scots pine from the Silesian Forestry Area in Poland. The scope of research included the visual strength grading of the timber according to the PN-D-94021:2013 standard, mechanical testing (according to EN 408:2012) and an attempt to assign visuals to the C strength classes. The EN 1912: 2012 standard assigns the visual sorting classes of individual wood species (according to national sorting standards) to the C strength classes introduced by the EN 338: 2018 standard. At the moment, this standard does not assign Polish visual sorting classes (KW, KS, and KG) to C strength classes. The obtained MOE (modulus of elasticity) and MOR (static bending strength) values were corrected according to the EN 384:2018 standard, and their characteristic values were later calculated. On this basis, we proposed a classification of the grading classes determined on the basis of PN-D-94021 into C classes described in EN 338:2018, which is necessary in the process of the transposition of Polish strength grades (KW, KS, KG, and Reject) and the qualification of them in line with EN 1912:2012. The calculated characteristic values of density, MOR and E0 (the modulus of elasticity parallel to the grain) allowed us to assign Polish visual grades KW, KS, and KG to C35, C30, and C20, respectively. The pine timber under research had high physical and mechanical parameters, which translated into high C classes to which the KW, KS, and KG timber categories were assigned.

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The physical and mechanical properties of recycled gypsum and potential application of pre-molded panels

Revista Brasileira de Engenharia e Sustentabilidade ◽

10.15210/rbes.v4i2.11743 ◽

2017 ◽

Vol 4 (2) ◽

pp. 21

Author(s):

Olindo Savi ◽

Rafael Alves Souza ◽

Nilson Tadeu Mascia ◽

Mateus Henrique Souza

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Physical Properties ◽

Bending Strength ◽

Mechanical Performance ◽

Physical And Mechanical Properties ◽

Strength Testing ◽

Recycled Gypsum ◽

Potential Use

This study analyses the physical properties of recycled gypsum and mechanical performance of pre-molded gypsum panels made of recycled gypsum. A compatation with commercial gypsum physical properties and mechanica behavior of pre-molded commercial gypsum panels is also carried out. After collection, recycling and grinding gypsum residues, the quality of the powder produced was evaluated in terms of units of mass and fineness modulus. Additional tests of the dry paste were conducted for assessment of hardness, water absorption, and compressive strength of recycled gypsum. The commercial potential of the material was evaluated by the bending strength testing pre-molded panels. The results demonstrate that gypsum recycling is sustainable, ecologically correct and feasible for the production of pre-molded elements with great potential use in civil construction. Keywords: gypsum panels, mixed pastes, sustainable, gypsum pastes.

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Influence of Scots Pine (Pinus sylvestris L.) Veneers Quality on Selected Properties of Layered Composite for Flooring Materials

Forests ◽

10.3390/f12081017 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1017

Author(s):

Izabela Burawska-Kupniewska ◽

Paweł Mycka ◽

Piotr Beer

Keyword(s):

Mechanical Properties ◽

Pinus Sylvestris ◽

Scots Pine ◽

Modulus Of Elasticity ◽

Bending Strength ◽

Deformation Modulus ◽

Physical And Mechanical Properties ◽

Production Costs ◽

Base Layer ◽

Class A

The article concerns the quality issues in wood industry, and especially the advisability of removing defects from veneers. The research purpose of the study was to analyse the influence of the layered structure of plywood base layer made of low-quality wood on selected mechanical properties of floor composites. The utilitarian purpose is to analyse the possibility of producing floors from low-quality materials reducing waste. Four quality classes of Scots pine veneers (Pinus sylvestris L.) were taken into account: A, B, C, D, from the highest class-A without defects to the lowest class-D characterized by a lot of knots (including broken and falling out ones) and cracks. The base layer of the floors was made of these wood quality classes. The value of the modulus of elasticity in elastic deformation, modulus of elasticity in the dynamic and fatigue tests, stiffness and static bending strength were investigated. The test results showed that, as expected, the samples made of class A had the highest values of the measured parameters (static bending strength, static and dynamic modulus of elasticity, and stiffness). However, the values of the tested parameters for the remaining classes B, C, and D did not significantly differ. It was concluded from the research that the change of the plywood base layer conditions regarding the quality of veneers does not significantly affect the physical and mechanical properties of composites. Hence, it is possible to use wood of lower quality classes for production without verification of which class they belong to, which will significantly reduce the production costs.

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

Jurnal Riset Teknologi Industri ◽

10.26578/jrti.v8i15.1552 ◽

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.

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Undergraduate Research Program to Recycle Composite Waste

Education Sciences ◽

10.3390/educsci11070354 ◽

2021 ◽

Vol 11 (7) ◽

pp. 354

Author(s):

Waleed Ahmed ◽

Essam Zaneldin ◽

Amged Al Hassan

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Carbon Fiber ◽

Undergraduate Students ◽

Research Program ◽

Modulus Of Elasticity ◽

Undergraduate Research ◽

Undergraduate Research Program ◽

Structural Applications ◽

Cfrp Composite

With the rapid growth in the manufacturing industry and increased urbanization, higher amounts of composite material waste are being produced, causing severe threats to the environment. These environmental concerns, coupled with the fact that undergraduate students typically have minimal experience in research, have initiated the need at the UAE University to promote research among undergraduate students, leading to the development of a summer undergraduate research program. In this study, a recycling methodology is presented to test lab-fabricated Carbon-Fiber-Reinforced Polymer (CFRP) for potential applications in industrial composite waste. The work was conducted by two groups of undergraduate students at the UAE University. The methodology involved the chemical dissolution of the composite waste, followed by compression molding and adequate heat treatment for rapid curing of CFRP. Subsequently, the CFRP samples were divided into three groups based on their geometrical distinctions. The mechanical properties (i.e., modulus of elasticity and compressive strength) were determined through material testing, and the results were then compared with steel for prompt reference. The results revealed that the values of mechanical properties range from 2 to 4.3 GPa for the modulus of elasticity and from 203.7 to 301.5 MPa for the compressive strength. These values are considered competitive and optimal, and as such, carbon fiber waste can be used as an alternate material for various structural applications. The inconsistencies in the values are due to discrepancies in the procedure as a result of the lack of specialized equipment for handling CFRP waste material. The study concluded that the properties of CFRP composite prepreg scrap tend to be reusable instead of disposable. Despite the meager experimental discrepancies, test values and mechanical properties indicate that CFRP composite can be successfully used as a material for nonstructural applications.

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Influence of the surface treatment of tire rubber residues added in mortars

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952008000200001 ◽

2008 ◽

Vol 1 (2) ◽

pp. 113-120 ◽

Cited By ~ 11

Author(s):

A. C. Marques ◽

J. L. Akasaki ◽

A. P. M. Trigo ◽

M. L. Marques

Keyword(s):

Mechanical Properties ◽

Aqueous Solution ◽

Tensile Strength ◽

Compressive Strength ◽

Surface Treatment ◽

Water Absorption ◽

Modulus Of Elasticity ◽

Tire Rubber ◽

Flow Test ◽

Made In

In this work it was evaluated the influence tire rubber addition in mortars in order to replace part of the sand (12% by volume). It was also intended to verify if the tire rubber treatment with NaOH saturated aqueous solution causes interference on the mechanical properties of the mixture. Compressive strength, splitting tensile strength, water absorption, modulus of elasticity, and flow test were made in specimens of 5cmx10cm and the tests were carried out to 7, 28, 56, 90, and 180 days. The results show reduction on mechanical properties values after addition of tire rubber and decrease of the workability. It was also observed that the tire rubber treatment does not cause any alteration on the results compared to the rubber without treatment.

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Effect of Post-Process Curing and Washing Time on Mechanical Properties of mSLA Printouts

Materials ◽

10.3390/ma14174856 ◽

2021 ◽

Vol 14 (17) ◽

pp. 4856

Author(s):

Bartłomiej Nowacki ◽

Paweł Kowol ◽

Mateusz Kozioł ◽

Piotr Olesik ◽

Jakub Wieczorek ◽

...

Keyword(s):

Mechanical Properties ◽

Bending Strength ◽

Curing Time ◽

Cross Sectional ◽

Post Process ◽

Order Of Magnitude ◽

Static Tensile ◽

High Roughness ◽

Ambiguous Effect

The article discusses the influence of the post-process on the mechanical properties of elements produced with the use of the mask stereolithography (mSLA) method. Printed samples were subjected to the following post-process steps: Washing and post-curing, at various times. Then, static tensile and static bending tests were carried out, as well as Shore D hardness measurements for the inner and surface part of the sample, as well as profilographometric analysis of the surface. The post-curing time has been found to strongly affect the tensile and bending strength of printouts, and to improve their surface quality. Washing has an ambiguous effect on the strength of the printouts, but, in the end, it was found that extended washing slightly reduces the strength. Washing significantly affects the quality of the printout surface. A washing time that is too short results in a surface that strongly resembles the printing process, with high roughness. Increasing the washing time to 10 min lowers the roughness by one order of magnitude. Post-curing has also been shown to be beneficial for the cured sample with the application of shielding water. This approach results in an improvement in the flexural strength of the printouts. In general, the obtained research results indicate that, for printouts with cross-sectional dimensions of several mm, the optimal washing time is no more than 10 min and the post-curing time is at least 30 min.

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Mechanical Properties of Concrete with Various Water-Cement Ratio After High Temperature Exposure

Jurnal Teknik Sipil ◽

10.28932/jts.v2i2.1262 ◽

2019 ◽

Vol 2 (2) ◽

pp. 126-136

Author(s):

M.I Retno Susilorini ◽

Budi Eko Afrianto ◽

Ary Suryo Wibowo

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

High Temperature ◽

Modulus Of Elasticity ◽

Building Materials ◽

Heating Process ◽

High Temperature Exposure ◽

Cement Ratio ◽

Water Cement Ratio ◽

Temperature Exposure

Concrete building safety of fire is better than other building materials such as wood, plastic, and steel,because it is incombustible and emitting no toxic fumes during high temperature exposure. However,the deterioration of concrete because of high temperature exposure will reduce the concrete strength.Mechanical properties such as compressive strength and modulus of elasticity are absolutely corruptedduring and after the heating process. This paper aims to investigate mechanical properties of concrete(especially compressive strength and modulus of elasticity) with various water-cement ratio afterconcrete suffered by high temperature exposure of 500oC.This research conducted experimental method and analytical method. The experimental methodproduced concrete specimens with specifications: (1) specimen’s dimension is 150 mm x 300 mmconcrete cylinder; (2) compressive strength design, f’c = 22.5 MPa; (3) water-cement ratio variation =0.4, 0.5, and 0.6. All specimens are cured in water for 28 days. Some specimens were heated for 1hour with high temperature of 500oC in huge furnace, and the others that become specimen-controlwere unheated. All specimens, heated and unheated, were evaluated by compressive test.Experimental data was analyzed to get compressive strength and modulus of elasticity values. Theanalytical method aims to calculate modulus of elasticity of concrete from some codes and to verifythe experimental results. The modulus elasticity of concrete is calculated by 3 expressions: (1) SNI03-2847-1992 (which is the same as ACI 318-99 section 8.5.1), (2) ACI 318-95 section 8.5.1, and (3)CEB-FIP Model Code 1990 Section 2.1.4.2.The experimental and analytical results found that: (1) The unheated specimens with water-cementratio of 0.4 have the greatest value of compressive strength, while the unheated specimens with watercementratio of 0.5 gets the greatest value of modulus of elasticity. The greatest value of compressivestrength of heated specimens provided by specimens with water-cement ratio of 0.5, while the heatedspecimens with water-cement ratio of 0.4 gets the greatest value of modulus of elasticity, (2) Allheated specimens lose their strength at high temperature of 500oC, (3) The analytical result shows thatmodulus of elasticity calculated by expression III has greater values compares to expression I and II,but there is only little difference value among those expressions, and (4)The variation of water-cementratio of 0.5 becomes the optimum value.

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