scholarly journals Optimal density for balancing the thermal conductivity and compressive strength of foamed ceramic

2021 ◽  
Vol 2069 (1) ◽  
pp. 012211
Author(s):  
Yue Lei ◽  
Xing Zheng ◽  
Mei Dou ◽  
Lihong Zheng ◽  
Mingfang Tang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Nonlinear Regression ◽  
Mechanical Performance ◽  
National Standard ◽  
Strength Increase ◽  
Density Range ◽  
Optimal Density ◽  
Building Engineering ◽  
The Relationship

Abstract Foamed ceramic becomes increasingly popular in building engineering due to its thermal, acoustic and other advantages. However, conflicts often exist between its different properties. In this paper, we seek a balance between the thermal conductivity and the compressive strength of foamed ceramic. Experiments are performed on foamed ceramic with different densities. Nonlinear regression is then adopted to quantify the relationship between the thermal conductivity/compressive strength and the bulk density. The results indicate that both the thermal conductivity and the compressive strength increase with the rising density. Based on the requirements in the Chinese national standard, the optimum density range of foamed ceramic is proposed, satisfying a balance between the thermal and mechanical performance.

scholarly journals Effect of microstructure on the properties of polystyrene microporous foaming material

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 103-110
Author(s):  
Anfu Guo ◽  
Hui Li ◽  
Jie Xu ◽  
Jianfeng Li ◽  
Fangyi Li
Keyword(s):  
Thermal Conductivity ◽  
Compression Modulus ◽  
Cell Diameter ◽  
Compressive Property ◽  
Strength Increase ◽  
Compression Performance ◽  
Negative Linear Correlation ◽  
Sample Density ◽  
Foaming Temperature ◽  
The Relationship

AbstractThe performance of Polystyrene microporous foaming (PS-MCF) materials is influenced by their microstructures. Therefore, it is essential for industrializing them to investigate the relationship between their microstructure and material properties. In this study, the relationship between the microstructure, compressive property, and thermal conductivity of the PS-MCF materials was studied systematically. The results show that the ideal foaming pressure of PS-MCF materials, obtaining compression performance, is around 20 MPa. In addition, the increase of temperature causes the decrease of sample density. It effects that the compression modulus and strength increase with the decrease of foaming temperature. Because the expansion rate and cell diameter of the PS-MCF materials reduce the thickness of cell wall, they are also negatively correlated with their mechanical properties. Moreover, there is a negative linear correlation between the thermal conductivity and cell rate, whereas the cell diameter is positively correlated with the thermal conductivity.

scholarly journals Evaluation of the Performance of Bio-Based Rigid Polyurethane Foam with High Amounts of Sunflower Press Cake Particles

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5475
Author(s):  
Agnė Kairytė ◽  
Sylwia Członka ◽  
Renata Boris ◽  
Sigitas Vėjelis
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Polyurethane Foam ◽  
Mechanical Performance ◽  
Positive Impact ◽  
Press Cake ◽  
Rigid Polyurethane Foam ◽  
Average Cell

In the current study, rigid polyurethane foam (PUR) was modified with 10–30 wt.% sunflower press cake (SFP) filler, and its effect on performance characteristics—i.e., rheology, characteristic foaming times, apparent density, thermal conductivity, compressive strength parallel and perpendicular to the foaming directions, tensile strength, and short-term water absorption by partial immersion—was evaluated. Microstructural and statistical analyses were implemented as well. During the study, it was determined that 10–20 wt.% SFP filler showed the greatest positive impact. For instance, the thermal conductivity value improved by 9% and 17%, respectively, while mechanical performance, i.e., compressive strength, increased by 11% and 28% in the perpendicular direction and by 43% and 67% in the parallel direction. Moreover, tensile strength showed 49% and 61% increments, respectively, at 10 wt.% and 20 wt.% SFP filler. Most importantly, SFP filler-modified PUR foams were characterised by two times lower water absorption values and improved microstructures with a reduced average cell size and increased content in closed cells.

The Relationship of the Main Properties of Desulphurization Gypsum Based Inorganic Thermal Insulation Mortar

2013 ◽  
Vol 357-360 ◽  
pp. 1120-1123
Author(s):  
Yong Lai ◽  
Yan Liu ◽  
Zhi Gang Luo
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Bulk Density ◽  
Thermal Insulation ◽  
Relationship Of ◽  
The Relationship ◽  
Linear Correlations

This paper studies the relationship of the main properties of desulphurization gypsum based inorganic thermal insulation mortar. The results show that there are different linear correlations between fresh bulk density, hardened bulk density, compressive strength, volume water absorption, thermal conductivity and dry bulk density that is from 240 kg·m-3 to 500 kg·m-3. The linear correlations can provide some useful reference for the research and application of desulphurization gypsum based inorganic thermal insulation mortar.

scholarly journals Mechanical Performance of Concrete Exposed to Sewage—The Influence of Time and pH

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 544
Author(s):  
Justyna Czajkowska ◽  
Maciej Malarski ◽  
Joanna Witkowska-Dobrev ◽  
Marek Dohojda ◽  
Piotr Nowak
Keyword(s):  
Compressive Strength ◽  
Mechanical Performance ◽  
Negative Influence ◽  
Concrete Compressive Strength ◽  
Active Sludge ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
And Performance ◽  
The Relationship ◽  
Microstructure And Performance

Contact of concrete with aggressive factors, technological structures, reduces their durability through microstructural changes. This work presents the results of research on determining the influence of post grit chamber sewage and sewage from the active sludge chamber in three different environments, i.e., acidic, neutral, and alkaline, on the structure and compressive strength of concrete. Compressive strength tests were carried out after 11.5 months of concrete cubes being submerged in the solutions and compared. To complete the studies, the photos of the microstructure were done. This made it possible to accentuate the relationship between the microstructure and performance characteristics of concrete. The time of storing the cubes in both acidic environments (sewage from post grit chamber and active sludge chamber) has a negative influence on their compressive strength. The compressive strength of cubes decreases along with the time. Compressive strength of cubes increases with increasing pH of the environment.

scholarly journals Mechanical Properties and Thermal Conductivity of Aerogel-Incorporated Alkali-Activated Slag Mortars

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Levent Bostanci ◽  
Ozlem Celik Sola
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Conductivity Coefficient ◽  
Experimental Studies ◽  
Strength Test ◽  
Strength Increase ◽  
Alkali Activated Slag ◽  
Compressive Strength Test ◽  
Activated Slag ◽  
Alkali Activated

Compressive strength, thermal conductivity coefficient, and porosimetric properties of alkali-activated slag (AAS) mortars containing silica aerogel were investigated experimentally in this study. For this purpose, slag mortar mixtures at 0.75% and 1.0% aerogel content ratios were prepared, and these mortar mixtures were activated with lithium carbonate (Li2CO3) at 0.03% and 1.50% dosage rates. Mortar samples were exposed to curing process in water for 2, 7, and 28 days, and the samples, which completed the curing stage, were subjected to the compressive strength test. The porosimetry test and the thermal conductivity coefficient measurement were carried out following the compressive strength test on 28-day samples. The varying aerogel content rate in the mixtures and the effects of the dosage of Li2CO3 on the gel, capillary, and macropore distributions, and the effect of changing porosimetric properties on compressive strength and thermal conductivity coefficient were analyzed in detail. Experimental studies have shown that AAS mortars including an optimum 0.75% aerogel content rate and 0.03% Li2CO3 activation provided a compressive strength of 34.1 MPa and a thermal conductivity coefficient of 1.32 W/mK. Aerogel addition provides a partial compressive strength increase at 7- and 28-day samples while it also causes maximum strength loss of 5.0% at 2-day samples.

scholarly journals Effect of Al2O3–SiO2 Addition on Gehlenite Growth and the Mechanical Performance of Steel Slag

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 936
Author(s):  
Ying Xu ◽  
Pan Song ◽  
Weigang Cao ◽  
Hui Li ◽  
Jinglong Liang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Performance ◽  
Steel Slag ◽  
Phase Changes ◽  
Morphology Evolution ◽  
Industrial Solid Waste ◽  
Increasing Temperature ◽  
Relationship Of ◽  
The Relationship

Steel slag, as industrial solid waste, is difficult to recycle owing to its complex components and poor mechanical properties. However, steel slag can be modified by adding Al2O3–SiO2 through high temperature sintering, which would improve the mechanical properties and expand the scope of its application. The phase changing, morphology evolution and the mechanical properties of the modified steel slag were investigated. The results indicate that the main phase changes to gehlenite occur with increasing temperature. The compressive strength increases to 115 MPa at 1350 °C. The relationship of the quantity of gehlenite and the compressive strength were explored.

scholarly journals THE INFLUENCE OF GLASS CONTAINING COMPONENT ON GYPSUM BINDER AND DRY MIX MORTAR PROPERTIES

2020 ◽  
Vol 22 (5) ◽  
pp. 129-138
Author(s):  
G. V. Sopegin ◽  
N. S. Semeynykh ◽  
D. Ch. Rustamova
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Adhesive Strength ◽  
Foam Glass ◽  
Strength Increase ◽  
Ceramic Brick ◽  
Initial Setting ◽  
Softening Coefficient ◽  
Insulating Properties

 The paper studies the properties of the gypsum binder after the addition of glass containing component (crushed granulated foam glass) and the suitability of the latter for the development of a new composition of the heat-insulated gypsum mixture.It is shown that the addition of the glass containing component (GCC) fraction of 0.14–1.25 mm in the amount of 5–15 % provides the highest strength increase of the gypsum binder. The presence of GCC fractions of 0.063–0.14 mm in the composition of the gypsum binder increases its softening coefficient from 0.42 to 0.48.The main properties of the gypsum mixture are studied after the addition of the GCC fraction of 0.063–4.0 mm in the amount of 30, 40 and 50 % of the binder mass. The initial setting of the GСС-containing mortar mixture occurs no later than in 6 minutes. The introduction of 50 % GCC significantly reduces the water retaining power to 85 %. An increase in the GСС content from 30 to 50 % in the composition of the gypsum mixture leads to a decrease in the thermal conductivity of the samples from 0.279 to 0.209 W/(m×°С). The compressive strength reduces from 15.85 to 9.273 MPa as the GСС content increases to 50 %. The adhesive strength to ceramic brick for compositions containing 30 and 40 % GСС ranges from 0.44 to 0.69 MPa.In relation to physical, mechanical and heat insulating properties, compositions containing 30 and 40 % of GСС are the most effective. These compositions can be modified by the addition of various setting retardants, water-retaining and plasticizing additives.

scholarly journals Mechanical Behavior of Fine Recycled Concrete Aggregate Concrete with the Mineral Admixtures

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2264
Author(s):  
Minkwan Ju ◽  
Jae-Gwon Jeong ◽  
Martin Palou ◽  
Kyoungsoo Park
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Mechanical Performance ◽  
Total Porosity ◽  
Recycled Concrete ◽  
Mineral Admixtures ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
The Relationship ◽  
Normal Dosage

The paper describes the mechanical behavior of fine recycled concrete aggregate (FRCA) concrete according to the mineral admixtures. Three types of the mineral admixtures, i.e., fly ash (FA), ground-granulated blast-furnace slag (GGBS), and silica fume (SF), are used and the replacement ratios of FRCA are 50% and 100%. The dosages of the admixtures of FA, GGBS, and SF are determined with the normal dosage (30%, 40%, and 5.0%, respectively) based on the ACI committee reports (No. 232, 233, and 234) and half-normal dosage. The mechanical performance is investigated with the compressive and splitting tensile strength, and elastic modulus. Additionally, the total porosity is measured in natural fine aggregate (NFA) and FRCA 100% replaced specimens by mercury intrusion porosimetry (MIP) for investigating the relationship with the compressive strength. Based on the experimental test results, the mineral admixtures improve the mechanical performance of FRCA concrete. The effective dosages of FA, GGBS, and SF for FRCA concrete are investigated according to the replacement ratio of the FRCA. In particular, FRCA 100% replaced concrete may be possible to be used for the structural concrete members with the specific dosage of the mineral admixtures. The prediction of the splitting tensile strength and the elastic modulus by the codes or previous formulas exhibits underestimated and overestimated results, respectively. The relationship between the total porosity and the compressive strength of the FRCA concrete should be modified with more experimental tests.

Experimental Study on the Mechanical Properties of Rubber Concrete

2014 ◽  
Vol 915-916 ◽  
pp. 685-689 ◽  
Author(s):  
Hong Quan Sun ◽  
Wen Hui Zhou ◽  
Chao Yi Wei
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Substitution Rate ◽  
Mechanical Performance ◽  
Replacement Rate ◽  
Conventional Concrete ◽  
Rubber Powder ◽  
Axial Compressive Strength ◽  
Relationship Of ◽  
The Relationship

With the methods of studying conventional concrete mechanical performance, the influence of concrete performance on the rubber powder replacement rate is investigated. Based on the test data, the relationship of between the elastic modulus and the rubber powder replacement rate is fitted. The results show that the concrete slump decreases with the rubber substitution rate increasing. The compressive strength of the cube of the concrete, the axial compressive strength and the elastic modulus go down in different degree with the increment of the rubber substitution rate.

The influence of the addition of ground olive stone on the thermo-mechanical behavior of compressed earth blocks

2020 ◽  
Vol 108 (2) ◽  
pp. 203
Author(s):  
Samia Djadouf ◽  
Nasser Chelouah ◽  
Abdelkader Tahakourt
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Agricultural Waste ◽  
Hydraulic Press ◽  
Dry Density ◽  
Olive Stone ◽  
Compressed Earth Blocks ◽  
Clay Matrix ◽  
Earth Blocks

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.

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