scholarly journals Selected Properties Of Geopolymers With Different Portions Of Ground Fly-Ash

2015 ◽  
Vol 61 (2) ◽  
pp. 1-7
Author(s):  
Miroslava Želinková
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Mechanical Activation ◽  
Polymeric Materials ◽  
Point Of View ◽  
Binding Potential ◽  
Dry Density ◽  
Polymeric Networks ◽  
Alumino Silicate ◽  
Heating Plant

Abstract Geopolymers are polymeric materials resulting from the polycondensation reaction of alumino-silicate materials in a strongly alkaline environment. In consequence, stable polymeric networks of aluminosilicates are formed. The binding potential of FA (fly ash) amorphous component can also be “activated” by mechanical activation, which unfolds new possibilities of FA utilization. Mechanical activation, such as the method, which can improve FA reactivity, is often applied for different applications for geopolymers based on ground fly ash. This paper presents possibilities of preparation of geopolymer mixtures based on modified (ground) FA (TEKO – produced by the Heating plant Kosice), which was used in varying percentages to unground (original) FA. The particle size of the original unground FA (PVT) was 84.7μm and particle size of the ground FA (T60S1) was 52.8μm. Properties to be evaluated were selected from the expected application point of view – protective coating of concrete. Next properties of geopolymer mixtures after 28 days of hardening were tested and evaluated: dry density, absorptivity, capillarity, compressive and flexural strength.

Fabrication and Properties of Glass Fibre Reinforced Fly Ash-Cement Roofing Tiles

2018 ◽  
Vol 911 ◽  
pp. 83-87 ◽  
Author(s):  
G.L.M. Ariyadasa ◽  
S. Upali Adikary ◽  
S.S.K. Muthuratne
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Glass Fibre ◽  
Coal Fly Ash ◽  
High Water ◽  
Mechanical Tests ◽  
Dry Density ◽  
Transverse Strength ◽  
Glass Fibre Reinforced ◽  
Similar Density

In this study Glass fibre reinforced fly ash -cement roofing tiles were fabricated using three different forms of coal fly ash (CFA) such as CFA as it is, CFA particle sizes below 75μm and below 45μm.The separated CFA was used to replace cement 30% by the weight and those matrices were reinforced by Alkali Resistant (AR) glass fibres adding 1% and 2% by weight.The corrugated roof tiles have dimensions of 490×250×8mm and they were hand cast using ordinary vibration. Physical and mechanical tests were performed after 28 days of aging. The tiles were tested in accordance with SLS 1189. Transverse strength increased with increasing fibre percentage. Further, the transverse strength decreased with decreasing CFA particle size. Highest characteristic transverse strength was observed in the CFA as it is sample which is 1650N and the lowest from CFA below 45µm particle size sample which is 1240N. However, all the samples satisfy the strength requirement which is 230N. High water absorption was observed in all the samples which is around 20%.The dry density was ranged in between 1.62-1.68g/cm3 .The lowest average dry density was observed in CFA as it is samples whereas CFA below 75μm particle size and CFA below 45μm particle size samples showed similar density values. The dry density of tile samples is in comparable with the dry density of asbestos cement sheets (≈1.63g/cm3) and the characteristic transverse strength is in comparable with Calicut clay tiles (1000-2000N) in Sri Lanka. Therefore, glass fibre reinforced fly ash-cement roofing tiles are promising substitute for asbestos roofing sheets.

scholarly journals Improving Strength of Porous Asphalt: A Nano Material Experimental Approach

2019 ◽  
Vol 15 (2) ◽  
pp. 75
Author(s):  
Rani Pradoto ◽  
Eliza Puri ◽  
Tri Hadinata ◽  
Qinthara D Rahman ◽  
Ryan Muhammad Az-zuchruf
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Mechanical Activation ◽  
Future Research ◽  
Aggregate Gradation ◽  
Porous Asphalt ◽  
Starting Point ◽  
Bitumen Content ◽  
Porous Pavement ◽  
High Street

Porous asphalt (PA) has potential to be utilized in many urban area in Indonesia which often faced high street runoff during rainy season. PA can be a solution for storm water management. A typical porous pavement has an open-graded surface over an underlying stone recharge bed. The water drains through the porous asphalt and into the stone bed, then, slowly, infiltrates into the soil. However, despite of the benefit of porous asphalt, there is still weaknesses, such as less of service life than dense-graded asphalt due to its lower durability and strength. In order to improve durability and strength of PA, this study investigates the effect of utilizing fly ash (FA) class F in porous asphalt (PA) mixture as replacement in aggregate gradation and perform as filler. Mechanical activation (grinding) of fly ash was performed resulting in reduction of particle size. This material gives more strength since the more of surface area that can bind in finer particle size. Utilizing fly ash into nanomaterial is one of the methods for this study. Material approaches for nanomaterial were proposed by breaking up larger particles with physical processes such as grinding or milling. This is called mechanical activation. Since asphalt pen 60/70 is mainly binder material in Indonesia, it is used as the default for all samples in this experiment. The optimum bitumen content (OBC) was determined for all the mix by Marshall mix design. In view of the nanomaterial approach, samples were then prepared for the same optimum bitumen content (5.85%) by using Bina-Marga’s PA standard in control mix as well as natural FA and modified FA as alternative filler in modified mixes. modified FA itself has been milled using transversal ball mill machine for 3 to 6 hours. This experimental study indicated higher stability value and reduction of permeability with the same OBC for the mixture having modified FA as filler content in comparison with standard mix and natural FA mix. All sample conformed with Indonesian asphalt porous Specification. This trends will become as a starting point for improvement in the future research. For further research, binder modification with added material such as rubber or nanoparticles are highly recommended to improve strength and durability of asphalt porous. However, another method need to be proposed for reduction of particle size in fly ash into nanomaterial range.

scholarly journals Fly ash morphology and surface modification via mechanical activation: A review

2020 ◽  
Vol 21 (3) ◽  
pp. 105-112
Author(s):  
A. G. Abadi ◽  
Laila Al-Shandoudi
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Mechanical Activation ◽  
Industrial Applications ◽  
Added Value ◽  
Chemical Compositions ◽  
Hydration Reaction ◽  
Structural Variations ◽  
Particle Size Range ◽  
Equipment Type

Fly ash (FA) F low reactivity, slow hydration reaction and low early strength, restricted its industrial usage to less than 25 wt %. Ash properties were modified by mechanical activation to achieve higher added value product. The activation depends on the equipment type and their particle size range of milling. This paper reviewed the milling equipment effect on particle size, surface properties, and chemical compositions of activated ash. Increasing in the surface area, pozzolana activity and the reduction of crystalline dense layers of fly ash F, leading to microstructure and structural variations which raised  the ash industrial applications.

Mechanical Activation of Fly Ash by High Energy Planetary Ball Mill and the Effects on Physical and Morphology Properties

2014 ◽  
Vol 625 ◽  
pp. 38-41
Author(s):  
Rashidah Mohammed Hamidi ◽  
Zakaria Man ◽  
Khairun Azizi Azizli ◽  
Lukman Ismail ◽  
Mohd Fadhil Nuruddin
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Mechanical Activation ◽  
Ball Mill ◽  
Low Cost ◽  
Specific Area ◽  
High Energy ◽  
Raw Material ◽  
Planetary Ball Mill ◽  
Particle Size Analyzer

Fly ash has a high potential to be converted into geopolymeric material due to its abundant supplies and low cost. However, large particle size of the fly ash caused low reactivity which results in low properties of the end product. The improvement on the fly ash properties by mechanical activation allows it as a new possible raw material in wider application besides solving the low reactivity issue which hindered its range of utilization. In this study, fly ash was mechanically activated by high energy planetary ball mill for 1 hour at different speed, ranging from 100 to 350 rpm and with varied ball to powder ratio (2:1, 3:1 and 4:1). The effects towards its particle size, specific surface area and morphology were determined by particle size analyzer and SEM. It was observed that, increasing of speed to 350 rpm and 4:1 ball to powder ratio (BPR) results in finest size of fly ash where at d (0.1), d (0.5) and d (0.9) the sizes were 1.861, 6.765 and 17.065μm respectively and largest surface specific area (1.46 m2/g).

Thermal Conductivity of Fly Ash Cenospheres for Variable Particle Size Ranges

2016 ◽  
Vol 4 (2) ◽  
pp. 19
Author(s):  
MENEZES CRAIG ◽  
RATHOD AJIT P ◽  
WASEWAR KAILAS L. ◽  
◽  
◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Fly Ash ◽  
Fly Ash Cenospheres

scholarly journals Feasibility of fly ash as fluxing agent in mid- and low-grade phosphate rock carbothermal reduction and its reaction kinetics

2021 ◽  
Vol 10 (1) ◽  
pp. 157-168
Author(s):  
Biwei Luo ◽  
Pengfei Li ◽  
Yan Li ◽  
Jun Ji ◽  
Dongsheng He ◽  
...  
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Reaction Time ◽  
Carbothermal Reduction ◽  
Industrial Waste ◽  
Phosphate Rock ◽  
Molar Ratio ◽  
Low Grade ◽  
Carbon Excess ◽  
Fluxing Agent

Abstract The feasibility of industrial waste fly ash as an alternative fluxing agent for silica in carbothermal reduction of medium-low-grade phosphate ore was studied in this paper. With a series of single-factor experiments, the reduction rate of phosphate rock under different reaction temperature, reaction time, particle size, carbon excess coefficient, and silicon–calcium molar ratio was investigated with silica and fly ash as fluxing agents. Higher reduction rates were obtained with fly ash fluxing instead of silica. The optimal conditions were derived as: reaction temperature 1,300°C, reaction time 75 min, particle size 48–75 µm, carbon excess coefficient 1.2, and silicon–calcium molar ratio 1.2. The optimized process condition was verified with other two different phosphate rocks and it was proved universally. The apparent kinetics analyses demonstrated that the activation energy of fly ash fluxing is reduced by 31.57 kJ/mol as compared with that of silica. The mechanism of better fluxing effect by fly ash may be ascribed to the fact that the products formed within fly ash increase the amount of liquid phase in the reaction system and promote reduction reaction. Preliminary feasibility about the recycling of industrial waste fly ash in thermal phosphoric acid industry was elucidated in the paper.

scholarly journals Functional Properties and Molecular Degradation of Schizostachyum Brachycladum Bamboo Cellulose Nanofibre in PLA-Chitosan Bionanocomposites

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2008
Author(s):  
Samsul Rizal ◽  
N. I. Saharudin ◽  
N. G. Olaiya ◽  
H. P. S. Abdul Khalil ◽  
M. K. Mohamad Haafiz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Moisture Content ◽  
Polymeric Materials ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Thickness Swelling ◽  
Compression Moulding ◽  
Ft Ir ◽  
Degradation Properties

The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.

scholarly journals Characterization and Comparison Research on Composite of Alluvial Clayey Soil Modified with Fine Aggregates of Construction Waste and Fly Ash

2021 ◽  
Vol 28 (1) ◽  
pp. 83-95
Author(s):  
Qu Jili ◽  
Wang Junfeng ◽  
Batugin Andrian ◽  
Zhu Hao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Clayey Soil ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Construction Waste ◽  
Comparison Research ◽  
Fine Aggregates ◽  
Optimum Water Content

Abstract Fine aggregates of construction waste and fly ash were selected as additives to modify the characteristics of Shanghai clayey soil as a composite. The laboratory tests on consistency index, maximum dry density, and unconfined compressive strength were carried out mainly for the purpose of comparing the modifying effect on the composite from fine aggregates of construction waste with that from fly ash. It is mainly concluded from test results that the liquid and plastic limit of the composites increase with the content of two additives. But their maximum dry density all decreases with the additive content. However, fine aggregates of construction waste can increase the optimum water content of the composites, while fly ash on the contrary. Finally, although the two additive all can increase the unconfined compressive strength of composites, fly ash has better effect. The current conclusions are also compared with previous studies, which indicates that the current research results are not completely the same as those from other researchers.

scholarly journals CHARACTERISTICS OF FLY ASH ADJUSTED IN PARTICLE SIZE BY CLASSIFICATION

2017 ◽  
Vol 71 (1) ◽  
pp. 626-632
Author(s):  
Kota DOI ◽  
Nobuhiko SHIRAHAMA ◽  
Makio YAMASHITA
Keyword(s):  
Particle Size ◽  
Fly Ash

scholarly journals Mechanochemically Gated Photoswitching: Expanding the Scope of Polymer Mechanochromism

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1725-1732 ◽  
Author(s):  
Ross W. Barber ◽  
Molly E. McFadden ◽  
Xiaoran Hu ◽  
Maxwell J. Robb
Keyword(s):  
Mechanical Activation ◽  
Uv Light ◽  
Cycloaddition Reaction ◽  
Polymeric Materials ◽  
Diels Alder ◽  
Information Storage ◽  
Chemical Transformations ◽  
History Of ◽  
Polymer Mechanochemistry ◽  
Stress Sensing

Mechanophores are molecules that undergo productive, covalent chemical transformations in response to mechanical force. Over the last decade, a variety of mechanochromic mechanophores have been developed that enable the direct visualization of stress in polymers and polymeric materials through changes in color and chemiluminescence. The recent introduction of mechanochemically gated photoswitching extends the repertoire of polymer mechanochromism by decoupling the mechanical activation from the visible response, enabling the mechanical history of polymers to be recorded and read on-demand using light. Here, we discuss advances in mechanochromic mechanophores and present our design of a cyclopentadiene–maleimide Diels–Alder adduct that undergoes a force-induced retro-[4+2] cycloaddition reaction to reveal a latent diarylethene photoswitch. Following mechanical activation, UV light converts the colorless diarylethene molecule into the colored isomer via a 6π-electrocyclic ring-closing reaction. Mechanically gated photoswitching expands on the fruitful developments in mechanochromic polymers and provides a promising platform for further innovation in materials applications including stress sensing, patterning, and information storage.1 Introduction to Polymer Mechanochemistry2 Mechanochromic Reactions for Stress Sensing3 Regiochemical Effects on Mechanophore Activation4 Mechanochemically Gated Photoswitching5 Conclusions

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