Influence of Hemp Shives Size on Hygro-Thermal and Mechanical Properties of a Hemp-Lime Composite

Different fractions of hemp shives are used in the mixtures of the hemp–lime composite. The market offers shives of different granulation. It depends on the type of industrial hemp and on the capabilities of decortication machines. The aim of the research presented in the article is to check differences in the mechanical and hygro-thermal properties of composites with different shives fractions. The research part of the paper presents the preparation method and investigation on hemp–lime composites. Apparent density, total porosity, thermal conductivity, capillary uptake, vapor permeability, specific heat, mass absorptivity, flexural and compressive strength were examined. The results confirm that the shives fraction influences the individual properties of the composites. Hemp–lime composites with fine shives are characterized by higher water absorption, thermal conductivity, mechanical strength, vapor permeability as well as lower capillary-lifting capacity and specific heat than composites with thick shives.

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Influence of the Direction of Mixture Compaction on the Selected Properties of a Hemp-Lime Composite

Materials ◽

10.3390/ma14164629 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4629

Author(s):

Przemysław Brzyski ◽

Piotr Gleń ◽

Mateusz Gładecki ◽

Monika Rumińska ◽

Zbigniew Suchorab ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Temperature Distribution ◽

Preparation Method ◽

Thermal And Mechanical Properties ◽

Compaction Process ◽

External Wall ◽

Capillary Uptake ◽

Parallel Direction ◽

The Individual

The aim of the research presented in the article was to check the differences in the hygro-thermal and mechanical properties of hemp-lime composites with different shives fractions, depending on the direction of mixture compaction. The research part of the paper presents the preparation method and investigation on the composites. Thermal conductivity, capillary uptake, as well as flexural and compressive strengths were examined. Additionally, an analysis of the temperature distribution in the external wall insulated with the tested composites was performed. The results confirm that the direction of compaction influences the individual properties of the composites in a similar way, depending on the size of the shives. The differences are more pronounced in the case of the composite containing longer fractions of shives. Both thermal conductivity of the material and the capillary uptake ability are lower in the parallel direction of the compaction process. Composites exhibit greater stiffness, but they fail faster with increasing loads when loaded in the direction perpendicular to compaction.

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Effects of h-BN on the thermal and mechanical properties of PBT/PC/ABS blend based composites

RSC Advances ◽

10.1039/c5ra09746k ◽

2015 ◽

Vol 5 (72) ◽

pp. 58171-58175 ◽

Cited By ~ 5

Author(s):

Xing Jin ◽

Nian Fu ◽

Huili Ding ◽

Nan Zhao ◽

Jianbing Sang ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Thermal And Mechanical Properties ◽

Obvious Effect ◽

Properties Of Composites

H-BNMPs were shown to have an obvious effect on the thermal conductivity of the blend. The addition of h-BN hybrids enhanced the mechanical properties of composites with remarkably improvement of the thermal conductivity.

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SPECIFIC HEAT AND THERMAL CONDUCTIVITY OF TmVO4 AND DyVO4 WITH AN APPLIED MAGNETIC FIELD

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1981681 ◽

1981 ◽

Vol 42 (C6) ◽

pp. C6-277-C6-279 ◽

Cited By ~ 1

Author(s):

B. Daudin ◽

B. Salce ◽

S. H. Smith

Keyword(s):

Magnetic Field ◽

Thermal Conductivity ◽

Specific Heat ◽

Applied Magnetic Field

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Thermal Characterization of Carbon-Carbon Composites

Volume 10: Heat and Mass Transport Processes, Parts A and B ◽

10.1115/imece2011-64061 ◽

2011 ◽

Author(s):

Messiha Saad ◽

Darryl Baker ◽

Rhys Reaves

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Thermal Diffusivity ◽

Specific Heat ◽

Critical Role ◽

Carbon Composite ◽

Flash Method ◽

Carbon Composites ◽

Energy Storage Devices ◽

Graphitized Carbon

Thermal properties of materials such as specific heat, thermal diffusivity, and thermal conductivity are very important in the engineering design process and analysis of aerospace vehicles as well as space systems. These properties are also important in power generation, transportation, and energy storage devices including fuel cells and solar cells. Thermal conductivity plays a critical role in the performance of materials in high temperature applications. Thermal conductivity is the property that determines the working temperature levels of the material, and it is an important parameter in problems involving heat transfer and thermal structures. The objective of this research is to develop thermal properties data base for carbon-carbon and graphitized carbon-carbon composite materials. The carbon-carbon composites tested were produced by the Resin Transfer Molding (RTM) process using T300 2-D carbon fabric and Primaset PT-30 cyanate ester. The graphitized carbon-carbon composite was heat treated to 2500°C. The flash method was used to measure the thermal diffusivity of the materials; this method is based on America Society for Testing and Materials, ASTM E1461 standard. In addition, the differential scanning calorimeter was used in accordance with the ASTM E1269 standard to determine the specific heat. The thermal conductivity was determined using the measured values of their thermal diffusivity, specific heat, and the density of the materials.

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Influence of alkaline modification on selected properties of banana fiber paperbricks

Scientific Reports ◽

10.1038/s41598-021-85106-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Abayomi A. Akinwande ◽

Adeolu A. Adediran ◽

Oluwatosin A. Balogun ◽

Oluwaseyi S. Olusoju ◽

Olanrewaju S. Adesina

Keyword(s):

Thermal Conductivity ◽

Heat Capacity ◽

Specific Heat ◽

Specific Heat Capacity ◽

Moisture Absorption ◽

Water Volume ◽

Banana Fiber ◽

Fiber Loading ◽

Banana Fibers ◽

Alkaline Modification

AbstractIn a bid to develop paper bricks as alternative masonry units, unmodified banana fibers (UMBF) and alkaline (1 Molar aqueous sodium hydroxide) modified banana fibers (AMBF), fine sand, and ordinary Portland cement were blended with waste paper pulp. The fibers were introduced in varying proportions of 0, 0.5, 1.0 1.5, 2.0, and 2.5 wt% (by weight of the pulp) and curing was done for 28 and 56 days. Properties such as water and moisture absorption, compressive, flexural, and splitting tensile strengths, thermal conductivity, and specific heat capacity were appraised. The outcome of the examinations carried out revealed that water absorption rose with fiber loading while AMBF reinforced samples absorbed lesser water volume than UMBF reinforced samples; a feat occasioned by alkaline treatment of banana fiber. Moisture absorption increased with paper bricks doped with UMBF, while in the case of AMBF-paper bricks, property value was noted to depreciate with increment in AMBF proportion. Fiber loading resulted in improvement of compressive, flexural, and splitting tensile strengths and it was noted that AMBF reinforced samples performed better. The result of the thermal test showed that incorporation of UMBF led to depreciation in thermal conductivity while AMBF infusion in the bricks initiated increment in value. Opposite behaviour was observed for specific heat capacity as UMBF enhanced heat capacity while AMBF led to depreciation. Experimental trend analysis carried out indicates that curing length and alkaline modification of fiber were effective in maximizing the properties of paperbricks for masonry construction.

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Thermophysical Properties of Cement Mortar Containing Waste Glass Powder

Crystals ◽

10.3390/cryst11050488 ◽

2021 ◽

Vol 11 (5) ◽

pp. 488

Author(s):

Oumaima Nasry ◽

Abderrahim Samaouali ◽

Sara Belarouf ◽

Abdelkrim Moufakkir ◽

Hanane Sghiouri El Idrissi ◽

...

Keyword(s):

Thermal Conductivity ◽

Specific Heat ◽

Thermophysical Properties ◽

Glass Powder ◽

Cement Mortar ◽

Soda Lime ◽

Waste Glass ◽

Soda Lime Glass ◽

Volumetric Specific Heat ◽

Waste Glass Powder

This study aims to provide a thermophysical characterization of a new economical and green mortar. This material is characterized by partially replacing the cement with recycled soda lime glass. The cement was partially substituted (10, 20, 30, 40, 50 and 60% in weight) by glass powder with a water/cement ratio of 0.4. The glass powder and four of the seven samples were analyzed using a scanning electron microscope (SEM). The thermophysical properties, such as thermal conductivity and volumetric specific heat, were experimentally measured in both dry and wet (water saturated) states. These properties were determined as a function of the glass powder percentage by using a CT-Meter at different temperatures (20 °C, 30 °C, 40 °C and 50 °C) in a temperature-controlled box. The results show that the thermophysical parameters decreased linearly when 60% glass powder was added to cement mortar: 37% for thermal conductivity, 18% for volumetric specific heat and 22% for thermal diffusivity. The density of the mortar also decreased by about 11% in dry state and 5% in wet state. The use of waste glass powder as a cement replacement affects the thermophysical properties of cement mortar due to its porosity as compared with the control mortar. The results indicate that thermal conductivity and volumetric specific heat increases with temperature increase and/or the substitution rate decrease. Therefore, the addition of waste glass powder can significantly affect the thermophysical properties of ordinary cement mortar.

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