THERMAL CONDUCTIVITY AND FROST RESISTANCE OF FOAMED CONCRETE WITH POROUS AGGREGATE

The paper reports a study, which was carried out to examine thermal and frost resistance properties of foamed concrete (FC) with porous aggregate (expanded glass (EG) granules and cenospheres). By adding lightweight and porous aggregate to the FC mixture, it is possible to improve important physical, mechanical, and thermal properties of the prepared FC specimens. In the framework of this study the coefficient of thermal conductivity and frost resistance of hardened FC samples were determined. The structure of FC matrix and used aggregates were characterised by using a method of optical microscopy.

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The Steel Slag Fly Ash Foamed Concrete Thermal Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.852.1398 ◽

2016 ◽

Vol 852 ◽

pp. 1398-1403

Author(s):

Shui Jun Yu ◽

Bin Li ◽

Xiao Li Chen

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Fly Ash ◽

Specific Heat ◽

General Model ◽

Steel Slag ◽

Industrial Emissions ◽

Foam Concrete ◽

Coefficient Of Thermal Conductivity ◽

Foamed Concrete

Industrial emissions used as admixture in foam concrete not only save resources, but also improve the properties of foam concrete. In this paper the thermal properties of steel slag fly ash foamed concrete was studied through experiments, and the results were analyzed. This paper included several of them and validated them using test dates, compared the results with other researchers. The result is the general model can predict the thermal conductivity of foam concrete better. Maxwell-Eucken model can regard as the boundaries’ formula to predict the coefficient of thermal conductivity of foam concrete and determine the limits. For the same density with the increasing of the steel slag thermal conductivity increases, specific heat decreases. The porosity is linear to the density of foam concrete.

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Mechanical and thermal properties of glass fibre-reinforced ceramsite-foamed concrete

Indoor and Built Environment ◽

10.1177/1420326x17694421 ◽

2017 ◽

Vol 27 (7) ◽

pp. 890-897 ◽

Cited By ~ 5

Author(s):

Guoxin Chen ◽

Kang Wang

Keyword(s):

Thermal Conductivity ◽

Hydrogen Peroxide ◽

Tensile Strength ◽

Compressive Strength ◽

Thermal Properties ◽

Glass Fibre ◽

Splitting Tensile Strength ◽

Mechanical And Thermal Properties ◽

Foamed Concrete ◽

Glass Fibre Reinforced

This study investigated the mechanical and thermal properties of glass fibre-reinforced ceramsite-foamed concrete with a volume of entrained air generated by hydrogen peroxide. The effects of hydrogen peroxide content, glass fibre content, glazed hollow bead content and ceramsite content on the compressive strength, splitting tensile strength and thermal conductivity were investigated. The results indicated that with the addition of hydrogen peroxide and an increase in glazed hollow bead and ceramsite content, there was a significant increase in the brittleness of foamed concrete. Glass fibre can obviously improve the splitting tensile strength and reduce the thermal conductivity of foamed concrete. In addition, an empirical compressive strength formula of glass fibre-reinforced ceramsite-foamed concrete was recommended.

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Mechanical and Thermal Properties of Magnesia Binder Based on Natural and Technogenic Raw Materials

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.320.181 ◽

2021 ◽

Vol 320 ◽

pp. 181-185

Author(s):

Elvija Namsone ◽

Genadijs Sahmenko ◽

Irina Shvetsova ◽

Aleksandrs Korjakins

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Raw Materials ◽

High Strength ◽

Strength Properties ◽

Waste Materials ◽

Mechanical And Thermal Properties ◽

Experimental Part ◽

Technogenic Raw Materials ◽

Caustic Magnesia

Because of low calcination temperature, magnesia binders are attributed as low-CO2 emission materials that can benefit the environment by reducing the energy consumption of building sector. Portland cement in different areas of construction can be replaced by magnesia binder which do not require autoclave treatment for hardening, it has low thermal conductivity and high strength properties. Magnesium-based materials are characterized by decorativeness and ecological compatibility.The experimental part of this research is based on the preparation of magnesia binders by adding raw materials and calcinated products and caustic magnesia. The aim of this study was to obtain low-CO2 emission and eco-friendly material using local dolomite waste materials, comparing physical, mechanical, thermal properties of magnesium binders.

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Determination of the Thermal Properties of a PCB by Coupled Numerical and Experimental Approach

Volume 11: Heat Transfer and Thermal Engineering ◽

10.1115/imece2020-24049 ◽

2020 ◽

Author(s):

Yener Usul ◽

Mustafa Özçatalbaş

Keyword(s):

Thermal Conductivity ◽

Heat Capacity ◽

Thermal Properties ◽

Numerical Analysis ◽

Specific Heat ◽

Specific Heat Capacity ◽

Thermal Analyses ◽

Analysis Model ◽

Linear Temperature ◽

Coefficient Of Thermal Conductivity

Abstract Increasing demand for usage of electronics intensely in narrow enclosures necessitates accurate thermal analyses to be performed. Conduction based FEM (Finite Element Method) is a common and practical way to examine the thermal behavior of an electronic system. First step to perform a numerical analysis for any system is to set up the correct analysis model. In this paper, a method for obtaining the coefficient of thermal conductivity and specific heat capacity of a PCB which has generally a complex composite layup structure composed of conductive layers, and dielectric layers. In the study, above mentioned properties are obtained performing a simple nondestructive experiment and a numerical analysis. In the method, a small portion of PCB is sandwiched from one side at certain pressure by jaws. A couple of linear temperature profiles are applied to the jaws successively. Unknown values are tuned in the analysis model until the results of FEM analysis and experiment match. The values for the coefficient of thermal conductivity and specific heat capacity which the experiment and numerical analysis results match can be said to be the actual values. From this point on, the PCB whose thermal properties are determined can be analyzed numerically for any desired geometry and boundary condition.

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Bio-based rigid polyurethane foam prepared from apricot stone shell-based polyol for thermal insulation application – Part 2: Morphological, mechanical, and thermal properties

BioResources ◽

10.15376/biores.15.3.6080-6094 ◽

2020 ◽

Vol 15 (3) ◽

pp. 6080-6094

Author(s):

Muhammed Said Fidan ◽

Murat Ertaş

Keyword(s):

Thermal Conductivity ◽

Compressive Strength ◽

Thermal Properties ◽

Thermogravimetric Analysis ◽

Polyurethane Foam ◽

Flame Retardants ◽

Compressive Modulus ◽

Cell Diameter ◽

Mechanical And Thermal Properties ◽

Rigid Polyurethane Foam

The procedure for the liquefaction of apricot stone shells was reported in Part 1. Part 2 of this work determines the morphological, mechanical, and thermal properties of the bio-based rigid polyurethane foam composites (RPUFc). In this study, the thermal conductivity, compressive strength, compressive modulus, thermogravimetric analysis, flammability tests (horizontal burning and limited oxygen index (LOI)) in the flame retardants), and scanning electron microscope (SEM) (cell diameter in the SEM) tests of the RPUFc were performed and compared with control samples. The results showed the thermal conductivity (0.0342 to 0.0362 mW/mK), compressive strength (10.5 to 14.9 kPa), compressive modulus (179.9 to 180.3 kPa), decomposition and residue in the thermogravimetric analysis (230 to 491 °C, 15.31 to 21.61%), UL-94 and LOI in the flame retardants (539.5 to 591.1 mm/min, 17.8 to 18.5%), and cell diameter in the SEM (50.6 to 347.5 μm) of RPUFc attained from liquefied biomass. The results were similar to those of foams obtained from industrial RPUFs, and demonstrated that bio-based RPUFc obtained from liquefied apricot stone shells could be used as a reinforcement filler in the preparation of RPUFs, specifically in construction and insulation materials. Moreover, liquefied apricot stone shell products have potential to be fabricated into rigid polyurethane foam composites.

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Influence of Mesocarp Fibre Inclusion on Thermal Properties of Foamed Concrete

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences ◽

10.37934/arfmts.87.1.111 ◽

2021 ◽

Vol 87 (1) ◽

pp. 1-11

Author(s):

Siti Shahirah Suhaili ◽

Md Azree Othuman Mydin ◽

Hanizam Awang

Keyword(s):

Thermal Conductivity ◽

Heat Capacity ◽

Thermal Properties ◽

Thermal Diffusivity ◽

Specific Heat ◽

Specific Heat Capacity ◽

Volume Fraction ◽

Thermal Constant ◽

Volume Fractions ◽

Foamed Concrete

The addition of mesocarp fibre as a bio-composite material in foamed concrete can be well used in building components to provide energy efficiency in the buildings if the fibre could also offer excellent thermal properties to the foamed concrete. It has practical significance as making it a suitable material for building that can reduce heat gain through the envelope into the building thus improved the internal thermal comfort. Hence, the aim of the present study is to investigate the influence of different volume fractions of mesocarp fibre on thermal properties of foamed concrete. The mesocarp fibre was prepared with 10, 20, 30, 40, 50 and 60% by volume fraction and then incorporated into the 600, 1200 and 1800 kg/m3 density of foamed concrete with constant cement-sand ratio of 1:1.5 and water-cement ratio of 0.45. Hot disk thermal constant analyser was used to attain the thermal conductivity, thermal diffusivity and specific heat capacity of foamed concrete of various volume fractions and densities. From the experimental results, it had shown that addition of mesocarp fibre of 10-40% by volume fraction resulting in low thermal conductivity and specific heat capacity and high the thermal diffusivity of foamed concrete with 600 and 1800 kg/m3 density compared to the control mix while the optimum amount of mesocarp fibre only limit up to 30% by volume fraction for 1200 kg/m3 density compared to control mix. The results demonstrated a very high correlation between thermal conductivity, thermal diffusivity and specific heat capacity which R2 value more than 90%.

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Effect of Phenolic Particles on Mechanical and Thermal Conductivity of Foamed Sulphoaluminate Cement-Based Materials

Materials ◽

10.3390/ma12213596 ◽

2019 ◽

Vol 12 (21) ◽

pp. 3596 ◽

Cited By ~ 1

Author(s):

Xiuzhi Zhang ◽

Qing Yang ◽

Qinfei Li ◽

Heng Chen ◽

Guofa Zheng ◽

...

Keyword(s):

Thermal Conductivity ◽

Pore Structure ◽

Dry Density ◽

Mechanical And Thermal Properties ◽

Foaming Agent ◽

Cement Ratio ◽

Water Cement Ratio ◽

Performance Indexes ◽

Foamed Concrete ◽

Inorganic Matrix

Foamed concrete materials based on sulpoaluminate cement were prepared by the chemical foaming method. The effects of water–cement ratio, foaming agent, and foaming stabilizer on the mechanical and thermal properties of foamed concrete were studied. Meanwhile, a portion of cement was replaced with foamed phenolic particles to further optimize the performance of foamed concrete; the results show that when the water–cement ratio was 0.53, the foaming agent content was 5%, the foam stabilizer was 1%, and the substitution of phenolic particles was 20%, the performance indexes of foamed concrete were the best. Methods, describing briefly the main methods or treatments applied: dry density was 278.4 kg/m3, water absorption was 19.9%, compressive strength was 3.01 MPa, and thermal conductivity was 0.072 W/(m·K). By the pore structure analysis of the foamed concrete suing Micro-CT, it was found that when the replacement amount of phenolic particles was 20%, the pore size of foamed concrete was relatively uniform, the minimum D90 was 225 μm respectively. The combination of organic and inorganic matrix and optimized pore structure improved the performance of foamed concrete.

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Physical, mechanical and thermal properties of Crushed Sand Concrete containing Rubber Waste

MATEC Web of Conferences ◽

10.1051/matecconf/201814901076 ◽

2018 ◽

Vol 149 ◽

pp. 01076

Author(s):

Guendouz Mohamed ◽

Boukhelkhal Djamila

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Flexural Strength ◽

Municipal Solid Waste ◽

Solid Waste ◽

Bulk Density ◽

Mechanical And Thermal Properties ◽

The Past ◽

Rubber Waste ◽

And Performance

Over the past twenty years, the rubber wastes are an important part of municipal solid waste. This work focuses on the recycling of rubber waste, specifically rubber waste of used shoes discharged into the nature and added in the mass of crushed sand concrete with percentage (10%, 20%, 30% and 40%). The physical (workability, fresh density), mechanical (compressive and flexural strength) and thermal (thermal conductivity) of different crushed sand concrete made are analyzed and compared to the respective controls. The use of rubber waste in crushed sand concrete contributes to reduce the bulk density and performance of sand concrete. Nevertheless, the use of rubber aggregate leads to a significant reduction in thermal conductivity, which improves the thermal insulation of crushed sand concrete.

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Experimental investigations into mechanical and thermal properties of rapid manufactured copper parts

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406219875483 ◽

2019 ◽

Vol 234 (1) ◽

pp. 82-95 ◽

Cited By ~ 11

Author(s):

Gurminder Singh ◽

Pulak M Pandey

Keyword(s):

Thermal Conductivity ◽

Tensile Strength ◽

Thermal Properties ◽

Ultimate Tensile Strength ◽

Heating Rate ◽

Sintering Temperature ◽

Mechanical And Thermal Properties ◽

Surface Porosity ◽

Soaking Time ◽

Ultrasonic Assisted

In the present paper, mechanical and thermal properties of rapidly manufactured copper parts were studied. The combination of three-dimensional printing and ultrasonic assisted pressureless sintering was used to fabricate copper parts. First, the ultimate tensile strength and thermal conductivity were compared between ultrasonic assisted and conventional pressureless sintered samples. The homogenously mixing of particles and local heat generation by ultrasonic vibrations promoted the sintering driving process and resulted in better mechanical and thermal properties. Furthermore, response surface methodology was adopted for the comprehensive study of the ultrasonic sintering parameters (sintering temperature, heating rate, and soaking time with ultrasonic vibrations) on ultimate tensile strength and thermal conductivity of the fabricated sample. Analysis of variance was performed to identify the significant factors and interactions. The image processing method was used to identify the surface porosity at different parameter levels to analyse the experimental results. High ultimate tensile strength was obtained at high sintering temperature, long soaking time, and slow heating rate with low surface porosity. After 60 min of soaking time, no significant effect was observed on the thermal conductivity of the fabricated sample. The significant interactions revealed less effect of soaking time at low sintering temperatures for ultimate tensile strength and less effect of heating rate at low sintering temperatures for thermal conductivity. Multi-objective optimization was carried out to identify parameters for maximum ultimate tensile strength and maximum thermal conductivity.

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