Дисертації: "Fly-ash Composites"

1

Hung, Hsien-Hsin. "Properties of high volume fly ash concrete." Thesis, University of Sheffield, 1997. http://etheses.whiterose.ac.uk/14441/.

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This thesis presents a detailed investigation on the engineering properties and microstructural characteristics of concrete containing a high volume of fly ash (HVF A). The purpose of the project is to evaluate the concept of using relatively large volumes of fly ash in normal portland cement concrete, and hence enhance the beneficial use of fly ash in value-added products and construction. A total of eight concrete mixtures with and without fly ash was investigated. The proportion of fly ash in all the HVF A concrete mixtures varied from 50 to 80 % by weight of the cementitious materials, with a constant water-to-cementitious ratio of 0.40 for all the mixtures. A high degree of workability was maintained by the use of a superplasticizer. To optimize the pozzolanic activity in the HVF A concrete, silica fume was used in some of the mixes. The total cementitious materials content was kept constant at 350 kg/m3 and 450 kg/m3 respectively. The influence of the different replacement materials and two curing regimes was studied. The study consisted of two parts. The first part is an extensive study of the engineering properties such as strength development, modulus of elasticity, ultrasonic pulse velocity, swelling, and drying shrinkage at various ages up to 18 months. The depth of carbonation of HVF A concrete under different curing regimes was also investigated. A study of the microstructure of HVF A concretes forms the second part of the investigation. Pore structure, air permeability and water absorption of HVF A concretes with different replacement mixtures were studied. A detailed discussion dealing with the change of the morphological phase under different curing regimes is also presented. The results show that HVF A concretes exhibit excellent mechanical properties with good long-term strength development. Compressive strength in the range of 40 to 60 MPa "as achieved for all the HVF A concretes at the age of 90 days. The dynamic modulus of elasticity reached values of the order of 55 GPa at 90 days. Under similar conditions, concretes made with both fly ash and silica fume had engineering properties which were as good as those made with cement replaced by fly ash alone. The use of fly ash to replace both cement and sand has the advantage of mobilizing and combining the benefits and effects of both separate replacements. The HVF A concretes also have low permeability and exhibit good potential characteristics to resist water penetration. Reduction in the volume of large pores was observed with the progress of the pozzolanic reaction. Higher HVF A concrete strength was generally associated with a lower volume of large pores in the concrete. A decrease in the levels of calcium hydroxide was seen with progressive water curing and age in all the HVF A concretes, providing evidence of continued pozzolanic reactivity of the fly ashes. Various empirical relationships and design equations are presented and conclusions are drawn at the end of each part. It is recommended that further research is required to determine the influence on HVF A concretes of extreme curing conditions such as high or low temperature and low moisture availability, and to improve the early strength properties of the HVF A concretes.

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2

Zaeni, Akhmad Materials Science &amp Engineering Faculty of Science UNSW. "Modification of fly ash colour from grey black to near white and incoporation of fly ash in polypropylene polymer." Publisher:University of New South Wales. Materials Science & Engineering, 2009. http://handle.unsw.edu.au/1959.4/43755.

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Particulate filled polymer composites are gaining growing acceptance in the commodity industry because the properties can be adjusted according to the industry's requirements. As particulate filler, fly ash is ready to compete with other particular fillers in polymer composites industries. Although fly ash is a cheap material but the fact that fly ash is grey-black in colour, limits the application of fly ash only to product where colour is not important. As such, a method was needed to be developed to increase the whiteness of fly ash without reducing the advantages of it as a cheap material. In this research, twelve commercially provided fly ash samples from Australian thermal power stations were investigated with respect to composition. Seven of them were thermally modified and further investigated and characterized with respect to colour, size, size distribution, and density. Of these seven fly ashes a particular grade was modified to a whiteness of 93.3 in L*a*b* scale (using barium sulfate as standard), without changing other inherent properties such as particle size and density. By comparison L*a*b* value for Omy carb 20, based on calcium carbonate is 96.9. The whiteness of fly ash was increased using a one stage thermal method ensuring the related cost of production would be not a major hurdle. The next aspect of the thesis involved incorporating as-received and heat treated fly ash samples in isotactic polypropylene up to 80 parts of fly ash per hundred resins (phr), demonstrating that fly ash content in polypropylene composites can be quite high with properly maintained combination of mechanical properties -- in particular up to 200 % improvement in Young's modulus and 63 % gain in notched impact properties, as explained in the thesis. Whilst the Young's modulus properties of the fly ash PP composites match very well with Kerner model, they lie in between the Rule of Mixture series and parallel. The tensile strength properties obtained in this research are at least 25 % higher than those predicted by Nielsen, Landon and Nicolais; whereas the strain to failure values are between 25 - 50 % higher than those predicted by Nielsen, and Smith. Whilst tensile strength of the fly ash filled polypropylene composites were less than the original polypropylene samples, as normally reported in the literature, in this thesis surface modification of fly ash particles by using 10% vinyl triethoxy silane (VTES) coupling agent gave a nominal increase in tensile strength especially at higher fly ash content. The final aspect involved study of oxidation behavior of fly ash filled polypropylene composites. Fillers, including fly ash can shorten the life time of polymers from both chemical as well as physical factors. As-received fly ash contains iron based impurities which may catalyze the anti oxidant in polypropylene, therefore reducing the service life time of the polymer. In this work, thermal treatment studies showed that the iron in fly ash can be changed to a chemically inert material so the effective service life of the polymer will only be influenced by physical factors. Therefore thermal treatment of fly ash not only increases the whiteness but also it reduces the risk of the filler on the life time of the polymer, and hence the composites.

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Fizette, Hobson H. "Development of concrete composites by synergistically using Illinois PCC Bottom Ash and Class F Fly Ash /." Available to subscribers only, 2007. http://proquest.umi.com/pqdweb?did=1328063751&sid=8&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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4

Kearsley, Elizabeth Paulina. "The effect of high volumes of ungraded fly ash on the properties of foamed concrete." Thesis, University of Leeds, 1999. http://etheses.whiterose.ac.uk/287/.

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Foamed concrete is produced by combining foam and slurry thus entrapping numerous small bubbles of air in the cement paste or mortar. The density of foamed concrete is a function of the volume of foam added to the slurry and the strength decreases with decreasing density. In this study the effect on the properties of foamed concrete, of replacing large volumes of cement with both classified and unclassified fly ash (pfa) was investigated. The casting densities of the materials used in this investigation varied between 1000 and 1500 kg/m3 and 50%, 66.7% and 75% of the cement (by weight) was replaced with pfa. The properties measured included compressive strength, dry density, porosity, permeability, water absorption, drying shrinkage, elastic deformation, creep, and void size distribution. The use of high volumes of unclassified ash did not appear to have any significant detrimental effects on the measured properties of the foamed concrete. Although the rate of gain in strength was reduced by the use of large volumes of ash, up to 67% of the cement can be replaced by ash without any significant reduction in, the long-term strength. The permeability increased with increased air content but the water absorption did not appear to be influenced by the volume of air entrained. The elastic modulus of foamed concrete reduced while the creep increased with reducing density. The drying shrinkage of foamed concrete does not seem to be a function of density and the shrinkage values were similar to those of cement paste with similar water/binder ratios; these values were between two to three times greater than those of conventional concrete. An increase in ash content lead to a slight reduction in the drying shrinkage. A mathematical model was developed relating the compressive strength of the foamed concrete to age, porosity and ash/cement ratio.

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5

Puri, Rajnish. "Development of High performance Concrete Composites Using Class F Fly Ash and PCC Bottom Ash, and a Statistical Model to Predict Compressive Strength of Similar Concrete Composites." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/dissertations/1123.

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AN ABSTRACT OF THE DISSERTATION OF RAJNISH PURI, for the Doctorate of Philosophy Degree in ENGINEERING SCIENCE WITH CONCENTRATION IN CIVIL AND ENVIRONMENTAL ENGINEERING, presented on APRIL 15, 2015 at Southern Illinois University Carbondale TITLE: DEVELOPMENT OF HIGH PERFORMANCE CONCRETE COMPOSITES USING CLASS F FLY ASH AND PCC BOTTOM ASH, AND A STATISTICAL MODEL TO PREDICT COMPRESSIVE STRENGTH OF SIMILAR CONCRETE COMPOSITES ADVISOR: Dr. Sanjeev Kumar It is a common knowledge that the use of concrete is as old as the evolution of human civilization. People have always dreamed beyond the dotted lines and so does the usage of concrete. With the rapid industrialization and globalization, the journey from ordinary concrete to high performance concrete (HPC) has been swift and remarkable. The diversification and utilization of high performance concrete has given the tool in the hands of engineers and architects who can now design and execute buildings of any shape and size deemed impractical a few decades ago. The aim of this research was to develop high performance concrete composites having different percentages of Illinois Class “F” fly ash and bottom ash by replacing the appropriate proportions of Type 1 portland cement and fine aggregate, respectively. The target was to develop high performance concrete composites that have compressive strength of 8,000 psi (55 Mpa) after 28 days of curing in water with a slump of 4±½” (102mm ± 13mm) and air content between 4 and 6 percent. In order to achieve the targeted air content, an air entraining agent DARAVAIR 1400 was used. The water-cement ratio of 0.3 was maintained throughout the research and to achieve the targeted slump, high-range water reducer ADVA 140M was used. The engineering parameters of the high performance concrete composites and an equivalent control mix were evaluated by conducting a detailed laboratory study which included several tests, e.g., slump, fresh air content, compressive strength, splitting-tensile strength, flexural strength, resistance to rapid freezing and thawing, sealed shrinkage and free swelling, and rapid chloride permeability. The results presented show that all high performance concrete composites developed in this study achieved the targeted compressive strength of 8,000 psi (55 MPa) after 28 days of curing in water. The results of the durability tests show that the concrete composites developed in this study have trends similar to that of an equivalent conventional concrete. Based, on the results of this study, it was concluded that the concrete composites have potential to be used on real world projects and thus help the environment by substantially reducing the amount of fly ash and bottom ash going to ash ponds or landfills. Based on the experimental test result data, a detailed statistical analysis was conducted to develop an empirical model to predict compressive strength of similar concrete composites for a given amount of fly ash, bottom ash, and curing period. Additional laboratory tests were performed to validate the mathematical model.

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Pretorius, Jan Hendrik Christoffel. "The influence of PFA particle size on the workability of cementitious pastes." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-07082005-135427/.

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7

Song, Gao. "Matrix manipulation to study ECC behaviour." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/4647.

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Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2005.
192 leaves on CD format, preliminary i-xii pages and numbered pages 1-135. Includes bibliography, list of figures and tables.
ENGLISH ABSTRACT: As a fibre reinforced material, engineered cementitious composite (ECC) has tough, strain-hardening behaviour in tension despite containing low volumes of fibres. This property can be brought about by developments in fibre, matrix and interfacial properties. Poly Vinyl Alcohol (PVA) fibre has been developed in recent years for ECC, due to its high tensile strength and elasticity modulus. However, the strong interfacial bond between fibre surface and matrix is a challenge for its application. This study focuses on the tailoring of matrix and fibre/matrix interfacial properties by cement replacement with fly ash (FA) and Ground Granulated Corex Slagment (GGCS). In this study the direct tensile test, three point bending test, micro-scale analysis, such as X-Ray Fluorescence Spectrometry analysis (XRF), Scanning Electron Microscope (SEM), are employed to investigate the influence of cement replacement, aging, Water/Binder (W/B) ratio, workability on ECC behaviour. This study has successfully achieved the aim that cement replacement by FA and GGCS helps to improve the fibre/matrix interfacial properties and therefore enhances the ECC tensile behaviour. Specifically, a high volume FA-ECC has stable high tensile strain capacity at the age of 21 days. This enables a constant matrix design for the investigation of other matrix influences. The Slag-ECC has a higher tensile strength but lower tensile strain capacity. The combination of FA and GGCS, moderate tensile strength and strain capacity is achieved Both tensile tests and Micro-scale analyses infer that the high volume FA-ECC has an adhesive type fibre/matrix interfacial interaction, as opposed to the cohesive type of normal PVA fibre-ECC. The different tensile behaviour trend of steel fibre-ECC and PVA fibre-ECC with the FA content is presented and discussed in this research. The investigations of aging influence indicate that the high volume FA-ECC has a beneficial effect on the properties of the composite at an early stage. However, at a high age, it has some difficulty to undergo multiple cracking and then leads to the reduction of tensile strain capacity. The modified mix design is made with the combination of FA and GGCS, which successfully increases the interfacial bond and, thereby, improves the shear transfer to reach the matrix crack strength. Therefore, an improved high age tensile behaviour is achieved. The W/B and fresh state workability influence investigations show that the W/B can hardly affect the tensile strain at early age. However, the workability influences on composite tensile strain significantly, because of the influence on fibre dispersion. Other investigations with regard to the hybrid fibre influences, the comparison of bending behaviours between extruded plate and cast plate, the relation between bending MOR and tensile stress, and the relation between compression strength and tensile strength contribute to understand ECC behaviour.
AFRIKAANSE OPSOMMING: As ‘n veselversterkte materiaal, het ontwerpte sementbasis saamgestelde materiale, taai vervormingsverhardingseienskappe in trek, ten spyte van lae veselinhoud. Hierdie eienskap word bewerkstellig, deur ontwikkelings in vesel, matriks en tussenveselbindingseienskappe. Poli-Viniel Alkohol (PVA) vesels is ontwikkel vir ECC, as gevolg van die hoë trekkrag en hoë modulus van hierdie veseltipe. Die sterk binding tussen die PVA-veseloppervlak en die matriks is egter ‘n uitdaging vir sy toepassing. Hierdie studie fokus op die skep van gunstige matriks en vesel/matriks tussenvesel-bindingseienskappe deur sement te vervang met vlieg-as (FA) en slagment (GGCS).In hierdie navorsing is direkte trek-toetse, drie-punt-buigtoetse, mikro-skaal analise (soos die X-straal ‘Fluorescence Spectrometry’ analise (XRF) en Skanderende Elektron Mikroskoop (SEM))toegepas. Hierdie metodes is gebruik om die invloed van sementvervanging,veroudering, water/binder (W/B)-verhouding en werkbaarheid op die meganiese gedrag van ECC te ondersoek.Die resultate van hierdie navorsing toon dat sementvervanging deur FA en GGCS help om die vesel/matriks tussenveselbindingseienskappe te verbeter. Dus is die ECC-trekgedrag ook verbeter. Veral ‘n hoë volume FA-ECC het stabiele hoë trekvervormingskapasiteit op ‘n ouderdom van 21 dae. Dit bewerkstellig ‘n konstante matriksontwerp vir die navorsing van ander matriks invloede. Die Slag-ECC het ‘n hoër treksterkte, maar laer trekvervormingskapasiteit. Deur die kombinasie van FA en GGCS word hoë treksterkte, sowel as gematigde vervormbaarheid in trek verkry. Beide trektoetse en mikro-skaal analise dui aan dat die hoë volume FA-ECC ‘n adhesie-tipe vesel/matriks tussenvesel-bindingsinteraksie het, teenoor die ‘kohesie-tipe van normale PVA vesel-ECC. Die verskille in trekgedrag van staalvesel-ECC en PVA vesel-ECC ten opsigte van die FA-inhoud is ondersoek en word bespreek in die navorsing. Die navorsing toon verder dat die hoë volume FA-ECC goeie meganiese eienskappe het op ‘n vroeë ouderdom. Op hoër ouderdom word minder krake gevorm, wat ‘n verlaging in die trekvervormingskapasiteit tot gevolg het. Met die kombinasie van FA en GGCS, word die vesel-matriksverband verhoog, waardeur ‘n verbetering in die skuifoordrag tussen vesel en matriks plaasvind. Verbeterde hoë omeganiese gedrag word daardeur tot stand gebring. Navorsing ten opsigte van die invoed van die W/B en werkbaarheid dui daarop dat die W/B slegs geringe invloed het op die trekvormbaarheid, terwyl die werkbaarheid ‘n dominerende rol speel in hierdie verband.Verdere studies sluit in die invloed van verskillende vesels, die vergelyking van die buigingsgedrag van geëkstueerde plate en gegote plate, die verhouding tussen buigsterkte en treksterkte, en die verhouding tussen druksterkte en treksterkte dra by tot beter begrip van die gedrag van ECC.

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BONDARENKO, VLADIMIR. "The Synthesis and Study of TiO2/Aluminosilicate Composites as Components of Building Finishing Materials for Improvement of the Indoor Air Quality." Doctoral thesis, Università Politecnica delle Marche, 2017. http://hdl.handle.net/11566/251220.

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Lo studio oggetto della tesi presenta il metodo di preparazione di materiali compositi per deposizione chimica di TiO2 su matrici di alluminosilicati per deposizione da una soluzione di Titanio solfato. Materie prime relativamente economiche e facilmente disponibili sono state usate per la preparazione: i frammenti del processo di trattamento meccanico dell'alluminio per l'ottenimento della soluzione di titanio solfato, argille e cenere volante come matrice. L'analisi dei riferimenti di letteratura consente di assumere che questo metodo produca materiali compositi con una larga superficie specifica grazie all'attivazione termoacida e ad una elevata attività fotocatalitica spendibile in applicazioni indoor. Queste proprietà sono confermate dai dati sperimentali ottenuti sui campioni di materiale composito ottenuti, sui quali sono stati valutati: la composizione chimica, la morfologia superficiale con SEM, la dimensione media delle particelle in microscopia ottica, la proprietà di adsorbimento del vapore d'acqua, la capacità di adsorbimento del benzene, la struttura dei pori, l'analisi ai raggi X, l'attività fotocatalitica con metodo di rimozione del MEK con due diversi tipi di box di prova e sorgenti di luce. La stabilità nel tempo delle proprietà dei compositi sviluppati è stata valutata dopo tre anni dalla loro preparazione. Sulla base dei risultati ottenuti sono state discusse le indicazioni per l'ottenimento di Compositi stabili. La relativa semplicità della tecnologia utilizzata ha consentito di descrivere l'organizzazione della produzione industriale del materiale composito e un metodo di possibile promozione industriale. Sono stati esaminati anche compositi contenenti dopanti non metallici come metodo per fornire attività fotocatalitica nel campo della luce visibile. L'uso di cenere volante come matrice del composito è stato studiato come metodo di valorizzazione di un rifiuto industriale. Infine i materiali da costruzione preparati con i compositi a base di TiO2 sono stati testati con il metodo della rimozione del MEK.
This study offers the method for the synthesis of composite material by chemical deposition of TiO2 on aluminosilicate matrix from titanium sulfate solution (precursor). Relatively cheap and available raw materials were used during the preparation: the waste of mechanical processing of titanium (titanium shavings) for obtaining the precursor, montmorillonite, kaolinite, and fly ash as supports. The analysis of the literature sources allows assuming that such method produces the composite with a large specific surface area because of thermoacid activation and high photoactivity suitable for indoor conditions. These properties are confirmed by the experimental data for the obtained samples: Chemical contents; Morphology of surface and average particles size by SEM/optical microscopy; Adsorptive properties and parameters of porous structure, water vapor and benzene vapor adsorption capacity; X-rays analysis of phases; Photoactivity of the materials was estimated by the method of MEK removal in reactors of two different types (16 L & 0,45 L) with two types of UV-irradiation source (ULTRAVITALUX E27 lamp and DFL-5013UVC-380). The stability of the properties of the obtained composites after 3 years of storage was examine. Based on the results obtained, the recommendations for obtaining stable composites were discussed. The relative simplicity of technology allows organizing industrial production of the materials and possible upgrades of the method. Non-metal co-doping of the composites was examined as a method for providing visible light activity of the materials. The use of fly ash as matrix for composites was studied as possible way of valorization of industrial by-product. The building materials prepared with the obtained TiO2–containing component were tested by the method of methyl ethyl ketone removal.

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9

Eckl, Ondřej. "Využití některých velkoobjemově produkovaných druhotných surovin k přípravě pojiv a kompozitů na bázi geopolymerů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-216460.

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10

Baránek, Šimon. "Elektricky vodivé kompozity na bázi druhotných surovin." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2021. http://www.nusl.cz/ntk/nusl-433564.

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Electroconductive composites are modern materials that are commonly used in many industries such as the construction industry among others. For example these materials can be useful as sensors for monitoring changes in constructions. The aim of this thesis is the research of electrically conductive silicate composite based on secondary raw materials. The design of this composite is based on the development of its own mixtures and experimental verification of the effect of the structure. The introduction part consists of a detailed analysis of 15 materials. Samples of the 5 fine and 2 coarse electrically conductive fillers were tested. Composite with filler Condufit C4 was selected as representative for type of fine fillers. Composite with filler Supragraphite C300 was selected as representative for type of coarse fillers. The selection of the composites was based on the impedance of the fabricated composites with these fillers. Subsequently, the individual components of the primary mixture were substituted. The cement was replaced by high-temperature fly ash in the amount of 20, 30, and 40 %, the aggregate of a similar fraction was replaced by steel sawdust, and the primary electrically conductive fillers were replaced by secondary ones in the amount of 30 and 50 %. All proposed replacements reduced the impedance of the composite. The most effective replacement for impedance reduction was replacement with waste graphite (up to 92 % reduction), which also slightly improved the mechanical properties of the composite. The result of this thesis is an optimized electrically conductive composite based on secondary raw materials with a fine type of filler with 30 % replacement by waste graphite "odpad vysavač"which achieves an impedance of 5 ohms. The partial goal of this thesis is a verification of the influence of moisture on the impedance of composites. Results are significantly affected by moisture when using the coarse type of filler, when using the fine type are not.

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Kamaleddine, Fouad. "Developing an alternate backing system made of fly ash composite for nickel shell moulds." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ63821.pdf.

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Ayanda, Olushola Sunday. "Adsorption of organotin compounds on nano metal oxide/silica, activated carbon and fly ash composite materials." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/760.

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Thesis submitted in fulfilment of the requirements for the degree Doctor of Technology: Chemistry in the Faculty of Applied Sciences at the Cape Peninsula University of Technology 2013
In this present study, the physicochemical properties, nature and morphology of prepared composite materials involving activated carbon, fly ash, nFe3O4, nSiO2 and nZnO in the 1:1 ratio for two components composite materials and 1:1:1 for three components composite materials were investigated. The nature, morphology and elemental characterizations of these materials were carried out by means of modern analytical methods such as scanning electron and transmission electron microscopy (SEM and TEM), x-ray diffraction (XRD), x-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier transform infrared spectroscopy (FTIR). Other physicochemical characterizations undertaken were CNH analysis, ash content, pH, point of zero charge and surface area and porosity determination by Brunauer, Emmett and Teller (BET). The precursors and composite materials were then applied to the sorption (remediation) of tributyltin (TBT) and triphenyltin (TPT) from artificial seawater and wastewater and the adsorption efficiencies for the precursors and the composites compared. The adsorption of TBT and TPT onto these materials as a function of adsorbent amount, contact time, pH, stirring speed, initial adsorbate concentration and temperature was investigated. Maximum organotin adsorption was recorded within the pH range of normal saline water (pH 8). Approximately 99.95 %, 95.75 %, 96.78 %, 99.88 %, 96.96 %, 99.98 %, 99.99 %, 99.99 % and 99.99 % TBT were removed from 25 mL of 100 mg/L TBT-contaminated artificial seawater using 0.5 g adsorbents at a contact time of 60 min, pH 8, stirring speed 200 rpm and temperature of 80 oC by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/activated carbon, nSiO2/activated carbon and nZnO/activated carbon composite, respectively and the adsorption of TBT onto these adsorbents was endothermic. Approx. 99.99 %, 96.54 %, 95.50 %, 96.92 %, 97.14 %, 99.99 %, 98.44 %, 98.98 % and 99.66 % TPT were also removed from 25 mL of 100 mg/L TPT-contaminated artificial seawater using 0.5 g adsorbents at a contact time of 60 min, pH 8, stirring speed 200 rpm and a temperature of 20 oC by the activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composite, respectively. The adsorption of TPT onto activated carbon and fly ash/activated carbon composite from TPT – contaminated artificial seawater was endothermic while TPT adsorption onto fly ash, nFe3O4, nSiO2, nZnO, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composites from TPT – contaminated artificial seawater was exothermic. The adsorption of TBT and TPT onto nFe3O4/fly ash/activated carbon and nSiO2/fly ash/activated carbon composites from TBT – and TPT – contaminated water, respectively were endothermic and approx. 99.98 % and 99.99 % of TBT and TPT, respectively were removed from the initial concentration of 100 mg/L OTC by the composites at a temperature of 80 oC, 60 min contact time, pH 8 and a stirring speed of 200 rpm. The adsorption kinetics of all the precursors and composite materials fitted well with the pseudo second-order kinetic model while the adsorption isotherm data could be well described by the Freundlich isotherm model except TBT adsorption onto nZnO/activated carbon and nFe3O4/activated carbon composite from TBT contaminated artificial seawater, TPT adsorption onto activated carbon and fly ash/activated carbon from TPT contaminated artificial seawater, and TPT sorption onto nSiO2/fly ash/activated carbon composite from TPT – contaminated water which could be described by both the Freundlich and Dubinin-Radushkevich (D-R) isotherm models. Optimal conditions for the adsorption of TBT and TPT from artificial seawater were further applied to TBT and TPT removal from TBT – and TPT – contaminated natural seawater obtained from Cape Town harbour and the results obtained show that 99.71 %, 79.23 %, 80.11 %, 82.86 %, 80.42 %, 99.75 %, 99.88 %, 99.83 % and 99.88 % TBT were removed from TBT – contaminated natural seawater by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/activated carbon, nSiO2/activated carbon and nZnO/activated carbon composite, respectively while 99.90 %, 96.44 %, 95.37 %, 96.75 %, 97.03 %, 99.92 %, 98.42 %, 98.92 % and 99.58 % TPT were removed from TPT – contaminated natural seawater by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composite, respectively. Experimental results therefore show that the composite materials present higher organotin adsorption efficiency than the precursors due to the nature and improved properties of the composite materials and can therefore be utilized for the remediation of organotin contamination from industrial and/or shipyards process wastewater to > 99 % reduction before discharge into the environment.

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SILVA, JULIANA C. da. "Mobilidade de As, Cd, Mo, Pb e Zn em colunas de latossolo argiloso com cinza de carvão e contaminação do solo." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10580.

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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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14

Brýdl, David. "Dřevokompozity s alkalicky aktivovanou popílkovou matricí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225718.

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This thesis examines the possibility of creating composite mainly from waste materials. The matrix of this composite was prepared from fly ash type F, which was activated by sodium water glass. Wood chips were used as a filler. This thesis includes theoretical and experimental parts. The theoretical part deals with the most important issues of wood composites with an inorganic matrix as well as basic components of investigated composite, ie alkaline activated fly ash and wood. In the experimental part, the fly ash pastes were prepared, from which the most suitable mixture was chosen for the composite preparation. Properties of wood composite with alkali activated fly ash matrix were investigated depending on the dose of wood chips.

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15

Wermuth, Diego Pacheco. "Análise das propriedades físicas do compósito cobre e cinzas leves de carvão produzido por metalurgia do pó." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/141856.

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O presente trabalho tem como objetivo o estudo e aproveitamento de cinzas leves da queima de carvão mineral em termoelétrica, como reforço para o Compósito de Matriz Metálica de cobre. Foram estudados diferentes percentuais de cinzas leves como reforço para o cobre, sendo misturados estes pós através de m , compactando os pós em diferentes pressões e sinterizando os corpos de prova obtidos pela compactação. A amostra sinterizada que apresentou a maior dureza entre todos os corpos de prova sinterizados, atingindo 89 HV, foi utilizada como base para a formulação e obtenção de novos corpos de prova, que foram estudados sob condições de moagem dos pós por moinho de bolas e moagem de alta energia. A fabricação do compósito seguiu os padrões industriais do processo de Metalurgia do Pó, como a mistura e moagem dos pós, compactação dos pós e sinterização em atmosfera controlada. Foi realizado o estudo das propriedades físicas e elétricas do compósito formado por cobre e cinzas leves, que comprovou o aumento da dureza para 122 HV, mantendo a condutividade do cobre puro. Este trabalho proporciona uma nova aplicação para as cinzas leves, utilizando estes resíduos de usinas termoelétricas como matéria prima para reforço mecânico na composição de peças à base de cobre, na indústria metalmecânica.
This paper aims to study and use fly ash from coal-fired thermal power plant, as reinforcement for copper Metal Matrix Composite. Different fly ash percentage were studied as reinforcement for copper. The powders were mixed by "Twin V Mixer'', were compacted at different pressures and the compacted samples were sintered. The sintered sample with the highest hardness among all samples reached 89 HV and was used as basis for the formulation and obtaining of new samples, which were studied under controlled conditions of ball milling and mechanical alloying. The manufacture of the composite was made using Powder Metallurgy processes like mixing and milling of powders, compacting of the powders and sintering at controlled atmosphere. A study on the physical and electrical properties of the composite formed by copper and fly ash was carried out proving the hardness increase to 122 HV and maintaining the conductivity of pure copper. This work provides a new application for fly ash using these power plants waste as raw material for mechanical reinforcement in the composition of copper parts in the metalworking industry.

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16

Lisztwanová, Ewa. "Kompozitní materiály se silikátovou matricí do prostředí vysokých teplot." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265581.

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This thesis deals with the study and design of composite materials based on silica matrix suitable for extreme conditions, eg. for the repair of concrete structures with anticipated increased risk of fire. The theoretical part summarizes basic knowledge concerning the fire resistance of structures and the behavior of the composite system during extreme conditions. Theoretically oriented section also contains information on alkali-activated materials and their use in high temperature environments. Based on the evaluation of the theoretical part of the experiment were designed and tested different types of composite materials with increased content of raw materials from alternative sources. Laboratory research has been based on testing of basic physico-mechanical parameters including phase composition and microstructure of the proposed formulations before and after thermal exposure of 1200 ° C. Also considered was the effect of different cooling conditions.

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17

Pekárková, Jana. "Ověření termodynamické stability ettringitu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240041.

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The thesis deals with possibilities of FBC fly ash utilization for composite cements. It focuses on thermodynamic stability of ettringite, which is produced during composite cements hydration. Specific tasks are dedicated to observation of influence of outdoor environment and influence of calciumhydrosilicate environment to stability of ettringite.

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18

Hrdina, Matěj. "Ověření možnosti syntetické přípravy ettringitu a thaumasitu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227221.

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The work is focused on the possibilities of using FBC fly ash for composite cements, monitoring their hydration processes, especially the creation of AFt phase. The possibility of preparing synthetic ettringite and thaumasite and their detection.

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19

Benešová, Anna. "Optimalizace složení dřevoplastových kompozitů s ohledem na jejich využití ve stavebnictví." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-390253.

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Wood-polymer composite is a relatively new type of material that combines shattered wood mass and a thermoplastic polymer. This material is utilized especially as an alternative to hard wood in the area of non-bearing exterior elements, as it reaches better properties in terms of the basic durability and low maintenance. Raw material composition and processing of the composite enable to provide a significant modification with further matters leading to an improvement of the end-product properties. Research and development in this field focuses predominantly on the utilization of such modifying additives that either enhance the resistance to weathering or are of the recycled nature, as a significant part of the raw material mixture comprises the constituent obtained from non-renewable resources. The aim of the thesis is the evaluation of the influence of the wood-polymer composite modification separately at two levels. First of them is the modification to matrix by using a recycled polymer, the second one comprises the modification of the wood flour with a secondary spherical filler. Both types of modified composites have been assessed in terms pf the prime characteristics and the resistance to adverse ambient.

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20

Roháček, Lukáš. "Optimalizace složení matrice cementotřískových desek při využití alternativních surovinových zdrojů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-371967.

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The diploma thesis deals with possibility of utilization raw materials from alternative sources for production of cement-bonded particleboards. In theoretical part the possibilities of modifying composition of cement-bonded slabs with emphasis on their matrix are discussed in detail. On basis of the findings and their evaluation, waste from the formatting of cement-bonded particleboards, micronized limestone, heat sink and high temperature fly ash were selected to the composition modification. The mentioned raw materials were analyzed and subsequently tested as substitutes for the matrix of cement-bonded particleboards in the experimental part. The properties of the proposed materials were tested even in the longer term, including the microstructure.

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21

Ponsot, Inès. "Glasses and Glass-Ceramic Components from Inorganic Waste and Novel Processing." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3424636.

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Thanks to European environmental rules and regulations establishment, waste recycling has become a more and more relevant problematic. For manufacturing plants, especially those producing hazardous wastes, expenses linked to waste production have drastically increased over the last decades. In the proposed work, various hazardous and non-hazardous wastes, among: soda-lime and borosilicate glass cullet, cathode ray tubes glass, exhausted lime from fume abatement systems residues, sludge and slags from ferrous and non-ferrous metallurgy, and pre-stabilized municipal solid waste incinerators ashes are used to elaborate several compositions of glass-ceramics. High-temperature treatment (minimum 800 °C) associated to a Direct Sintering process (30 min) was an efficient way to stabilize chemically the final products. The impact of each waste on the final product’s mechanical properties was studied, but also their synergies between each other, when mixed together. Statistic mixture designs enabled to develop interesting products for modern building applications, such as porous tiles and lightweight panels destined to insulation, with a purpose of fulfilling multifunctional properties.
Grazie alle regole e normative ambientali europee istituite, il riciclaggio dei rifiuti è diventato una problematica sempre più rilevante. Per gli impianti di produzione, in particolare quelli che producono rifiuti pericolosi, le spese connesse allo smaltimento sono drasticamente aumentate negli ultimi decenni. Nel lavoro proposto, vari rifiuti, pericolosi o no, vengono utilizzati per elaborare diverse composizioni di vetroceramiche. Si distinguono rottami di vetro della produzione di finestre, di contenitori farmaceutici e di tubi catodici. I rifiuti non vetrosi invece sono calce esausta da residui di sistemi di filtrazione di fumi, scorie metallurgiche da leghe ferrose e non e ceneri da inceneritori. E' presentata nel presente lavoro la ricerca di un metodo di trattamento ad alta temperatura (minima 800 ° C) efficace per stabilizzare chimicamente il prodotto finale, tramite i diversi processi di sinterizzazione diretta, sinter-cristallizzazione e vetrificazione. Sono stati studiati gli effetti di ogni rifiuto sulle proprietà meccaniche del prodotto finale, ma anche le nuove funzionalità ottenute attraverso le sinergie risultanti dalla loro miscela. Miscele calibrate hanno permesso di sviluppare prodotti interessanti per applicazioni edilizie moderne, come le piastrelle porose e pannelli leggeri destinati all’isolamento.

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22

Kumar, Satyajeet. "Investigation of fly ash polymer composite." Thesis, 2014. http://ethesis.nitrkl.ac.in/6405/1/E-98.pdf.

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Industrial waste like fly-ash which is creating environmental problems, is mainly used as a building material due to its low cost and easy availability. But the main disadvantage of these bricks is its low strength. So, a lot of research is going on to increase the strength of these bricks. The present research work is carried out to develop a new systematic procedure to produce fly ash composite bricks which will have higher compressive strength. Here the fly-ash is mixed with Cold setting resin at different proportions and water treated at different temperatures to find out a solution to the brick industry. The compressive strength, Hardness, water absorption, Density and thermal conductivity of the fly ash-resin powder bricks obtained under optimum test conditions are 11.24 MPa, 47.37HV, 19.09% 1.68 g/cm3, and 0.055 W/mK respectively. The sliding wear behaviour is also investigated. The structure-property correlation of these composites are studied using X-ray diffraction, FTIR analysis and scanning electron microscopy.

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23

Jhu, Syue-De, and 朱學德. "Properties of Cementitious Composites using Circulating Fluidized Bed Co-Fired Fly Ash and Pulverized Coal Fly Ash." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/84903300536477735718.

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碩士
國立臺灣海洋大學
材料工程研究所
103
In recent years, circulating fluidized bed (CFB) boiler is widely used , there is no formal reference for using the byproduct co-firing fly ash . This industrial byproduct is derived from a CFB boiler. The combustion process which has a low combustion temperature (850 ~ 900 oC) will add limestone as a sorbent. The physical and chemical properties of CFFA are different from pulverized coal fly ash (PCFA). PCFA can be directly used in making concrete, but not CFFA. This study is divided into three phases. The first stage investigates that use CFFA for mortar’s cementitious influences. Fixed water-cement ratio 0.45. Test variable is the CFFA substitution cement amount which according to weight ratio 0%、25%、50%、75%、100%. Test project is the compressive strength test, the initial setting time test, mix water test. The second stage the performance in adding CFFA to cement mortar is also investigated and the results compared with PCFA mortar’s performance. Test variable is the water-cement ratio (0.45 and 0.55) , CFFA substitution cement amount which according to weight ratio 0%、10%、20%、30% , CFFA substitution fine aggregate amount which according to weight ratio 0%、5%、10%, PCFA substitution cement amount which according to weight ratio 0%、10%、20%、30%. Test project is the flow test, length change test, water absorption test, compressive strength test, resistance to sulphate test. The first stage investigates that mixed use CFFA and PCFA for mortar performance influences. Test variable is the water-cement ratio (0.45 and 0.55) , CFFA substitution cement amount which according to weight ratio 0%、10% , CFFA substitution fine aggregate amount which according to weight ratio 0%、5% ,PCFA substitution cement amount which according to weight ratio 0%、10%. Test project is the flow test, length change test, water absorption test, compressive strength test, resistance to sulphate test. Test results indicate. The first stage (1)CFFA replace the cement amount Increase, requires more water to maintain the same flow values (2)CFFA replace the cement amount Increase mortar compressive strength decreased, longer the initial setting time. The second stage (1)CFFA replace cement quantity 30%, 2% added plasticizer does not improve flow values (2)CFFA replace fine aggregate, help to reduce water absorption, enhances ability to resist sulfate attack and increases compressive strength; CFFA replace cementitious materials, Increase water absorption, enhances ability to resist sulfate attack and reduce compressive strength (3)The same binder substitute, CFFA mortar shrinkage less than PCFA mortar (4)The same binder substitute, CFFA mortar compressive strength higher than PCFA mortar (5) The same binder substitute, mortar wet and dry cycle test compressive strength reduction percentage, CFFA mortar below the PCFA mortar. The third stage (1)Mixes CFFA and PCFA mortar shrinkage is less than using individual CFFA and PCFA mortar under the same quantity replacement (2)Mixes CFFA and PCFA mortar compressive strength is higher than using individual CFFA and PCFA mortar under the same quantity replacement (3)CFFA mortar wet and dry cycle test compressive strength reduction percentage is lower than using mixes CFFA and PCFA mortar under the same quantity replacement.

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24

Tripathy, Shuvendu. "Studies on Aluminum–Fly-Ash Composite Produced by Impeller Mixing." Thesis, 2009. http://ethesis.nitrkl.ac.in/1499/1/207mm103.pdf.

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Metal matrix composites (MMCs) constitute an important class of design and weight-efficient structural materials that are encouraging every sphere of engineering applications. There has been an increasing interest in composites containing low density and low cost reinforcements. Among various discontinuously dispersed solids used, fly ash is one of the most inexpensive and low density reinforcement available in large quantities as solid waste by-product during combustion of coal in thermal power plants. Hence, composites with fly ash as reinforcement are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications. To produce Al matrix cast particle composites, wettaility of the ceramic particles by liquid Al is essential. To improve wettabilty, elements such as Mg and Si are added into Al melt to incorporate the ceramic particles. The present investigation has been focused on the utilization abundant available industrial waste fly ash in useful manner by dispersing it into aluminium/aluminium-magnesium/aluminium-silicon matrix to produced composites by liquid metallurgy route. Wide size range (0.1-100μm) fly ash particles were used. These composites were observed with the help of optical micrography, x ray micro analysis, x ray diffraction, wet chemical analysis, and image analysis. The dry sliding wear behavior of the composites in the cast conditions was studied at different loads and different sliding velocities with the help of Pin-On-Disc wear test machine. The worn surfaces and wear debris were analyzed using optical microscope and scanning electron microscope. The mechanical properties such as hardness and tensile strength have been investigated.

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25

Sarangi, Subhakanta. "Fabrication and Characterization of Aluminum-Fly Ash Composite Using Stir Casting Method." Thesis, 2009. http://ethesis.nitrkl.ac.in/185/1/project-subhakanta.pdf.

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Metal matrix composites (MMCs) possess significantly improved properties including high specific strength; specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. Among various discontinuous dispersoids used, fly ash is one of the most inexpensive and low density reinforcement available in large quantities as solid waste by-product during combustion of coal in thermal power plants. Hence, composites with fly ash as reinforcement are likely to over come the cost barrier for wide spread applications in automotive and small engine applications. It is therefore expected that the incorporation of fly ash particles in aluminium alloy will promote yet another use of this low-cost waste by-product and, at the same time, has the potential for conserving energy intensive aluminium and thereby, reducing the cost of aluminium products. Now a days the particulate reinforced aluminium matrix composite are gaining importance because of their low cost with advantages like isotropic properties and the possibility of secondary processing facilitating fabrication of secondary components. The present investigation has been focused on the utilization of abundantly available industrial waste fly-ash in useful manner by dispersing it into aluminium to produce composites by stir casting method.

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26

Kumar, Deepak. "Fabrication and Characterization of Al-fly Ash Composite using Stir Casting Method." Thesis, 2009. http://ethesis.nitrkl.ac.in/179/1/project-deepak.pdf.

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Анотація:

Metal matrix composites (MMCs) possess significantly improved properties including high specific strength; specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. Among various discontinuous dispersoids used, fly ash is one of the most inexpensive and low density reinforcement available in large quantities as solid waste by-product during combustion of coal in thermal power plants. Hence, composites with fly ash as reinforcement are likely to over come the cost barrier for wide spread applications in automotive and small engine applications. It is therefore expected that the incorporation of fly ash particles in aluminium alloy will promote yet another use of this low-cost waste by-product and, at the same time, has the potential for conserving energy intensive aluminium and thereby, reducing the cost of aluminium products. Now a days the particulate reinforced aluminium matrix composite are gaining importance because of their low cost with advantages like isotropic properties and the possibility of secondary processing facilitating fabrication of secondary components. The present investigation has been focused on the utilization of abundantly available industrial waste fly-ash in useful manner by dispersing it into aluminium to produce composites by stir casting method.

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27

Pattanaik, Ashutosh. "Effect of Processing Conditions on Properties of Fly ash-Epoxy Composite." Thesis, 2017. http://ethesis.nitrkl.ac.in/8678/1/2017_PhD_512MM1004_AshutoshPattanaik.pdf.

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Fly ash being generated in massive scale has minimum utilisation as compared to its rate of production. It is the waste generated from thermal power plants, which find its primary usage in road embankment, cement making, making of fly ash bricks, etc. This current research focuses on finding out the ways of utilising fly ash as reinforcement to fabricate polymer composite. Fly ash comprises of oxides of silicon, aluminum, iron and titanium along with some other minor constituents. Here investigation has been done for processing and characterization of fly ash reinforced epoxy composites. Fly ash being immiscible is mixed with the epoxy using an ultrasonic sonicator for varied time periods. Various mechanical tests viz. tensile, flexural, impact, dielectric properties and tribological analysis are carried out to find out its proper application according to its suitability. The composite is treated in different environments viz. acid, base, fuel and sea water to find its proper environmental/chemical degradation/stability. The percentage of fly ash reinforcement is varied from 10 to 40%. For composite fabrication different mixing time i.e. 10, 20 and 30 minutes are chosen to check the effect of mixing time on the mechanical behaviour of the material. The prepared samples are cured at three different conditions i.e. standard atmosphere at room temperature, inside the oven and in the micro oven. Combinations of all these variables have been taken into consideration to analyse the effect on the mechanical properties of the material. The dielectric properties of the composites are evaluated. The sliding wear behaviour of the samples was studied with a pin on disc type sliding wear testing machine of DUCOM make; by varying the parameters, viz., time, RPM and applied load, etc. Optimisation techniques have been implemented to reduce the number of experiments and to find out the percentage contribution of each parameter. Simultaneously, a suitable combination of parameters has been given and the confirmatory test has been done to determine the percentage of error in the experiments. Finally, the samples are treated with an acid solution, basic solution, fuel (Petrol), sea water and acetone for 28 days; and change in mechanical properties has been recorded periodically. From the above-detailed examinations, these fly ash reinforced epoxy composites found to be moderately suitable for the automobile industry, to be used as the dashboard, brake pads, seat assembly plates, bumpers and in the interior portion of aircraft, etc. due to its mechanical properties. Most suited for construction industry for making of floor and wall tiles partition wall etc. Out of the treatment conditions, these composites are found to be most suitable for use in the petroleum industry for fuel carrying tanks and containers. Finally, it can also be used for making of beautiful decorative articles and household appliances.

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28

Kattaguri, Rani. "Resistance of CNF Modified Glass Fiber/Epoxy Composites Towards Various Corrosive Fluids." Thesis, 2018. http://ethesis.nitrkl.ac.in/9510/1/2018_MT_216MM1426_RKattaguri_Resistance.pdf.

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Fiber reinforced composites (FRP) are increasingly being used in many applications as they owing superior properties like high specific strength, high stiffness, low density. However these composites suffer from poor out of plane properties in some applications. A Nano filler addition is a possible way to address those problems. FRP composites are used in various marine as well as chemical industries, where there is a long-term direct contact of the component with corrosive fluids. In this present, work the effects of CNF incorporation in glass fibres/epoxy composite towards various corrosive fluids are studied by aging the composite of different composition (0.1wt.%, 0.5 wt.%, 1 wt.% ) in acidic, alkaline and sea water which are having pH of 1,13 and 8.2 respectively for 5 months. The resistance towards the corrosive fluids of CNF filled glass fiber epoxy composite will be evaluated in terms of mechanical (flexural), thermal (Differential scanning calorimetry (DSC)), thermo-mechanical (differential mechanical analysis (DMA)) and factography analysis by Field Emission Scanning Electron Microscope(FESEM). It is revealed that as the immersion time increases there is decrement in flexural strength, modulus, and glass transition temperature (Tg) in all 3 solution aging irrespective to the composition. This was mainly the result of polymer hydrolysis. Compare to the CNF filled frp composite, glass/epoxy fiber composite shows more degradation in the case of alkaline aging, seawater aging. Maximum reduction in the strength of glass/epoxy fiber composite is 48% by the alkaline aging for 4monthsas alkaline being more corrosive in nature. But reverse phenomenon is observed in case acidic aging. Glass/epoxy fiber composite shows better resistance to acidic aging than CNF filled frp composite. Because presence of CNF’s in acidic environment causes oxidation of CNF thatleads in drop in mechanical properties. Fractography revealed the various modes of failure that causes to the degradation of matrix.

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29

Midathada, Sai Venkat Ravi Kishor. "Characterisation of Bricks Fabricated Using fly-ash with Different Additive Materials Namely Granite-powder,Alite- cement and Black-sand in Different Compositions for High temperature furnace lining." Thesis, 2018. http://ethesis.nitrkl.ac.in/9578/1/2018_MT_216MM2448_SVRKMidathada_Characterisation.pdf.

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Industries associated with high temperature applications such as steel making and iron making industries make use of refractory bricks to carry out their entire manufacturing process. Different steps involved in manufacturing steel involves different types of refractory bricks based on various factors like working temperature, thermal stability, strength, wear resistance, chemical resistance. These bricks are to be replaced after certain duration of time for efficient functioning of the manufacturing units.The production of these refractory bricks involves so many complicated methods which are likewise expensive. As the need of such bricks is humongous for large scale industries, instead of manufacturing these bricks they import the bricks from other countries. Fly-ash, which covers major proportion of world’s industrial waste is known to have very high silica and alumina content. These compounds are known to be some of the important mineral compounds for the manufacturing of refractory bricks which has led to the ideology of using fly-ash for manufacturing of bricks incorporated with additive materials namely granite-powder, alite-cement and black-sand. The current work is focussed on fabricating bricks using fly-ash and different additive materials to study their various chemical, thermal and mechanical properties for high temperature applications.Bricks were fabricated using fly-ash with the additive materials namely, granite-powder, alite-cement and black sand in different compositions to study the variation in various property changes in the samples. Different analysis namely,phase analysis, surface morphology, micro-hardness, apparent porosity, bulk density, high temperature microscopy, wear test.The studies revealed smoother surface for the pellets with high percentage of granite-powder. The bonding of the particles was the result of pozzolanic activity of silicates of calcium present in cement and aluminium silicates present in fly-ash. The phases such as silicates of aluminium, calcium and sodium, quartz, zirconium oxide, were most commonly observed in the samples. In addition to these, formation of phases like quartz, zircon and silicates of magnesium and aluminium was observed in samples with alite-cement additives. Zirconium oxide with silicates of calcium were majorly formed. The samples with black-sand additives have shown phases such as quartz, zirconium oxide, titanium oxide in the XRD analysis.As comparison with other types of furnace brick, fly ash brick gives a new era for dramatically reduction of the cost.

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30

Li, Ching-Feng, and 李青峰. "Study on Influence of Adding Different Percentage of Fly Ash on Mechanical Properties of Aluminum-Fly Ash Matrix Composites." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/80571645928439354026.

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Анотація:

碩士
國立臺灣海洋大學
機械與機電工程學系
103
The fly ash, a waste of the coal-fuel generated from coal-fired power plant, is added into the aluminum matrix to form a aluminum-fly ash composite. The fly ash will have chemical reaction when melting with aluminum in high temperature and to form a strengthen phase of aluminum oxide, which is an in-situ formation of strengthen phase composite. This composite exhibits better mechanical properties than that of bare aluminum, such as strength, stiffness, damping capacity and wear resistance. However, it has lower ductility and toughness than that one. In this study, the various of weight percent of fly ash (0、3、6、9、12、15wt%) were added into ADC10-2Mg alloy melting via stir casting method to produce the aluminum- fly ash composite. After reacting at 800°C for 30 hours, the observation of microstructures, the measurements of density and porosity, the tests of hardness and tensile tests on aluminum-fly ash composite were evaluated. The influences of various fly ash contents on physical and mechanical properties of aluminum-fly ash composite were discussed. 　　The results show the aluminum-fly ash composite with dispersive fly ash in the matrix can be manufactured by stir casting. The fly ash can be reacted and dissolved with aluminum matrix under high temperature and long term process. The density of aluminum matrix composite was reduced by adding fly ash, and its hardness and tensile strength were improved as well. Nevertheless, the porosity is increasing with increasing the amount of fly ash and the ductility is diminished. From the all above of the experimental results, aluminum matrix composite added with 6 wt% fly ash reveals the better condition in our testing parameters. For example, its density reduced 2%, the hardness increases 7%, the tensile strength increases 49% as compared to that of bare aluminum matrix. But, its ductility decreases 35%.

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31

Koti, Mruthyunjaya Subhas. "Design and development of ZA-27/Fly Ash particulate composites." Thesis, 2001. http://hdl.handle.net/2009/1690.

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32

Huang, Hui-Chi, and 黃暉淇. "Mechanism and Properties of Cementitious Composites using CFBC Fly Ash." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/44683993044817712208.

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Анотація:

碩士
國立臺灣海洋大學
材料工程研究所
96
In recent years, sustainable development policy has been established in many countries and it has been prevailing to reuse or recycle the industry by-products or non-tixic wastes all over the world. In construction sector, industry by-products such as coal-fired fly ash, silica fume and ground granulated blast furnace slag has been used as cement replacement materials (CRM) or supplementary cementing materials (SCM) for many years and lots of research results have been published in many journals and can be easily acquired. However, the technology information of relatively new by-product - circulating fluidized bed combustion ash (CFBC ash) is scarce and more researches are needed to investigate the mechanism and feasible application of CFBC ash. Test results indicate (1)CFBC fly ash has angular shape and rough surface; (2) CFBC fly ash does not fullfils the requirements of ASTM C618 (pozzolanic material chemical properties requirements) and ASTM C311 (strength activated index); (3) CFBC fly ash would harden in the air; (4) CFBC fly ash used as filler in the cementitious composites would reduce water absorption, increase compressive strength and improve sulphate resistance, but large amount replacement may influence workability; (5) CFBC fly ash application would change the amount of ettringites and C-S-H gel crystallization; it was also found that the non-reacted gypsum would appears as prismatic crystal in the composites; (6) mix proportions with proper amount CFBC ash would satisfy the requirements of specified CLSM.

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33

Mavundla, Sipho Enos. "Synthesis and electrochemical characterisation of conducting polyaniline-fly ash matrix composites." Thesis, 2005. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_9061_1259922060.

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The aim of this study was to produce useful composite materials from fly ash, a major waste product of coal combustion from power plants. Polyaniline-fly ash (PANI-FA) composites were prepared by in situ polymerisation of aniline in the presence of Fly Ash (FA) by two slightly different methods. In one case polystyrene sulphonic acid (PSSA) was used as a stabilizer and in another case the starting materials (aniline and FA) were aged before oxidation. The aging procedure formed nanotubes that have cross-sectional diameters of 50-110 nm. The other procedure produced nanotubes with a diameter of 100-500 nm and the length of up to 10&mu
m. The presence of metal oxides and silica in FA were responsible for the formation of nanorods in PANI-PSSA-FA.. The formation of the composites was confirmed by UV-Vis and FTIR. The UV-Vis showed maximum absorbance at 330-360 nm ( due to &pi
-&pi
* transition of benzoid rings) and 600-650 nm(due to charge transfer excitons of quinoid rings), which are characteristics of emaraldine base. The electrochemical analysis of the composites showed that the composites were conductive and electroactive. The Cyclic Voltammetry of PANI-PSSA-FA showed three redox couples which are characteristics of sulphonated PANI. The morphology of the composites was studied by Scanning Electron Microscopy (SEM) and showed that our methods gave composites with improved homogeneity as compared to other reported methods. Thermo Gravimetric analysis (TGA) showed that the presence of FA in the composites improves the thermal stability of the composites by up to 100 0C.

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34

Sudarshan, *. "Processing And Characterization Of Fly Ash Particle Reinforced A356 Al Composites." Thesis, 2004. https://etd.iisc.ac.in/handle/2005/1295.

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35

Sudarshan, *. "Processing And Characterization Of Fly Ash Particle Reinforced A356 Al Composites." Thesis, 2004. http://etd.iisc.ernet.in/handle/2005/1295.

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36

HSU, YU-CHEN, and 許育甄. "Characteristics of Ultra-fine Fly Ash Applied to Cement-based Composites." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/m4vmvs.

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碩士
國立宜蘭大學
土木工程學系碩士班
107
This study explores the characteristics of the partial replacement of cement using ultra-fine fly ash and silica fume. Ultra-fine fly ash is an industrial by-product from thermal power plants. Limestone is added as a fluxing agent during sintering at a temperature of 1500, and then the CaO of limestone is adhered to its surface (similar as a coating) as the compounds of Si-Al crystallization. It has a smaller particle size than the general type fly ash. This research is aimed to use ultra-fine fly ash and silica fume as an auxiliary cementing material to replace cement; and to understand the effect of ultra-fine fly ash on the new mixing properties, mechanical properties, durability, chemical properties and microscopic properties. The ultra-fine fly ash and silica fume were used to replace the cement by weight. The fixed water-to-binder ratio was 0.45, the replacement of cement was used as 5% and 10%, respectively. The combinations of fly ash and silica fume in composites were used as ultra-fine fly ash 5% plus silica fume 5% and ultra-fine fly ash 8% plus silica fume 2% (total of seven mixtures). The test results show that the inclusion of ultra-fine fly ash (F5, F10) was enhanced to increase the workability, and help to produce pozzolanic reaction, and generate C-S-H colloids. The colloids were filling the pore structure to increase the compactness of specimen, which is consistency with the increased the compressive strength and reduction of the dry shrinkage. It also was reduced the chloride ion penetration and non-steady state migration coefficient, which is helpful for improving the mechanical properties and permeability. The composites with 10% ultra-fine fly ash had a better performance in engineering properties. For S5 and S10 specimens, the workability was significantly reduced with the addition of silica fume. In the early age, It can be quickly consumed Ca(OH)2 and accelerated the formation of hydration products to as a pozzolanic reaction. The unreacted silica fumes had a filling effect due to the finer particles, which is promoted a denser pore structure and helped to increase the compressive strength. It had a significantly reduction on the diffusion of chloride ion penetration and migration coefficient in non-steady state; however, it had a deep influence on dry shrinkage, of which the composites with 10% silica fume had the etter performance in engineering properties.. For blending specimen (F5S5, F8S2), it was also a tendency to improve mechanical properties and durability and the combination of 5% ultra-fine fly ash and 5% silica fume in composites enhanced better performances.

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37

Anandatheerthan, J., and Sudipt Kumar. "Production and Characterisation of Aluminium-Fly ash composite using Stir Casting Method." Thesis, 2008. http://ethesis.nitrkl.ac.in/131/1/10404002.pdf.

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Metal matrix composites (MMCs) possess significantly improved properties including high specific strength; specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. Among various discontinuous dispersoids used, fly ash is one of the most inexpensive and low density reinforcement available in large quantities as solid waste by-product during combustion of coal in thermal power plants. Hence, composites with fly ash as reinforcement are likely to over come the cost barrier for wide spread applications in automotive and small engine applications. It is therefore expected that the incorporation of fly ash particles in aluminium alloy will promote yet another use of this low-cost waste by-product and, at the same time, has the potential for conserving energy intensive aluminium and thereby, reducing the cost of aluminium products. Now a days the particulate reinforced aluminium matrix composite are gaining importance because of their low cost with advantages like isotropic properties and the possibility of secondary processing facilitating fabrication of secondary components. The present investigation has been focused on the utilization of abundantly available industrial waste fly-ash in useful manner by dispersing it into aluminium to produce composites by stir casting method.

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38

Maebana, Molahlegi Orienda. "Ethylene vinyl acetate-fly ash composites: preparation, characterisation and application in water treatment." Thesis, 2012. http://hdl.handle.net/10210/5943.

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M.Tech.
In this study, ethylene vinyl acetate-fly ash (EVA-FA) composites were explored for the removal of phenols from water. The composites were prepared from EVA and untreated and acid treated fly ash via the melt-mixing technique using a rheomixer. The fly ash was characterised by X-ray fluorescence (XRF), X-ray diffraction (XRD) scanning electron microscopy (SEM) and Brunauer, Emmett and Teller (BET) surface area measurement. Fly ash is composed mainly of SiO2, Al2O3, CaO and Fe2O3. Modified fly ash gave a better specific surface area of 0.4180 m2/g, while 0.0710 m2/g was obtained for unmodified fly-ash due to the disintegration of the outer layer which resulted in smaller particles, hence a larger surface area. EVA-FA composites were prepared from fly ash loadings of 3 to 20% and further characterised by XRD, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and SEM. XRD showed successful incorporation of fly ash into the EVA matrix through the appearance of fly ash diffraction peaks on the EVA-FA composite diffraction pattern. The incorporation of fly ash into the EVA matrix resulted in an improvement in the thermal stability of EVA, but did not have an effect on the melting temperature of the composites. However, a decrease in crystallisation temperature was observed. SEM micrographs revealed uniform dispersion of fly ash particles in the polymer matrix. Adsorption studies were performed using p-chlorophenol (PCP), 2,4,6-trichlorophenol (TCP) and p-nitrophenol (PNP) as model pollutants. An increase in adsorption efficiency of EVA-FA composites was observed as fly ash loading was increased from 3 to 10%. Between 10 and 20% fly-ash loading the removal efficiencies remained constant. The effect of contact time, pH and initial concentration was investigated. Polymer composites prepared from unmodified fly ash resulted in a higher adsorption capacity of phenols. The maximum uptake of PCP was 0.18 mg/g and that for TCP was 0.19 mg/g over a pH range of pH 3 to 5 and after contact time of 8 h. However, the adsorption capacity of 0.30 mg/g for PNP was achieved at pH 5 after a period of 10 h. Equilibrium adsorption data were evaluated using Langmuir and Freundlich adsorption isotherm models. There was no significant difference in the correlation coefficients (R2) from both models for the adsorption of PCP and TCP. However, the equilibrium adsorption data for PNP were better described by the Langmuir adsorption isotherm model. The kinetics data were analysed by pseudo-first-order and pseudo-second-order kinetic models. The pseudo-second-order kinetics model gave better correlation coefficients (> 0.9) for the adsorption of the phenols and the amount adsorbed at equilibrium was comparable to that calculated from the pseudo-second-order equation. Desorption studies were performed using NaOH solution with varying concentrations (0.1 to 0.3 M) and the studies revealed that PNP was the most difficult to be desorbed. Approximately 75% of PNP was recovered while 82% of PCP and 84% of TCP were recovered.

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39

Sahoo, Alok Kumar. "Dry Sliding Wear Response of Fly Ash Filled Poly-Ether-Ether-Ketone Composites." Thesis, 2011. http://ethesis.nitrkl.ac.in/2232/1/Dry_sliding_wear_response_of_fly_ash_filled_PEEK_composite.pdf.

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This paper reports the development and wear performance evaluation of a new class of poly-ether-ether-ketone (PEEK) based composites filled with fly ash, an industrial waste. Fly ash is generated in large amounts from furnaces in coal based thermal power plants worldwide during power generation. The fly ash particles of average size 100 micron are reinforced in PEEK resin to prepare particulate filled composites of three different compositions (0, 7.5 and 15 wt% of fly ash). Dry sliding wear trials are conducted following a well-planned experimental schedule based on design of experiments (DOE) using a standard pin-on-disc test set-up. Significant control factors predominantly influencing the wear rate are identified. Effect of fly ash content on the wear rate of PEEK composites under different test conditions is studied. The results of the experiments are compared with that of results obtained from wear test of TiO2-PEEK composites under same experimental conditions. An Artificial Neural Networks (ANN) approach taking into account training and test procedure to predict the dependence of wear behavior on various control factors is implemented. This technique helps in saving time and resources for large number of experimental trials and predicts the wear response of fly ash filled PEEK composites within and beyond the experimental domain.

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40

Xue, Cheng-Shuo, and 薛丞碩. "Study on Mechanical Properties of Aluminum-Fly Ash Composites by Applying Friction Stir Processing." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/06929778614836196648.

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碩士
國立臺灣海洋大學
機械與機電工程學系
102
Aluminum-fly ash (ALFA) composites are a kind of green materials, which can reduce the density and improve the mechanical properties as compared to its original substrate. but fly ash particles density, shape, particle size affects the particle dispersion in the molten metal. With the same volume fraction of reinforcement material particles having smaller particle size allows for better composites strengthening effect, however, the small particles in the molten metal have a larger surface area and the wettability is poor, so that the particles tend to increase the difficulty with a clustering phenomenon. Thus the production of smaller -particle composite material is more difficult, and the cost of the process cost will be increased with exponential growth. Friction Stir Welding (FSW) is a technology of solid-state joining, because the temperature of welding process had not reach the melting point, there were not stay porosity and shrinkage crack inside material. However, the friction stir process for aluminum composite material will improve fly ash ash dispersion and recrystallization of the fine to get the grain. In this study, friction stir processing (FSP) was applied to further process ADC6 +5 wt% fly ash composite plate castings using a multi-path mode with an overlap ratio of 22.8%. The results showed that fly ash particles inside the ALFA composite castings under external extrusion operation resulted in fragmentation after being subjected by the friction stir processing. The size of added raw fly ash particles were refined from micro- into nano-scale levels, making the grain structure of ALFA castings achieve significant refinement and the nano-scale fly ashes was more uniformly dispersed in the aluminum substrate. This mechanism should lead effectively improve the mechanical properties of the original ALFA castings. As compared to ALFA composites, the hardness increased about 28%. The MP-FSP specimens were sampled in parallel and vertical to the processing direction for tensile specimens. Then stretched results were compared to ADC6 and ALFA specimen. The results of tensile test showed the ALFA specimen of ultimate strength rate was decrease from 241MPa to 143MPa. In addition, the elongation rate was decrease from 2.95% to 1.19%. The tensile strength test piece in parallel to the direction of the modification will be increased to 227MPa, although it slightly lower than ADC6, but significant improvement in strength for ADC6 add tensile strength composite materials 5wt% fly ash, and the elongation Tensile and significantly better than ADC6 ADC6 adding 5wt% fly ash composite increased to 7.18%; modified specimen perpendicular to the direction of the tensile strength increased to 226MPa, but tensile elongation rate of 3.12% with ADC6 similar.

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41

NG, Dickson Angsana, and 洪定仁. "Study on Wear Characteristics of Friction Stir Tools in Processing Aluminum-Fly Ash Composites." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/91397970491359599781.

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碩士
國立臺灣海洋大學
機械與機電工程學系
103
Tool wear is a key issue for the friction stir processing of aluminum matrix composites especially the higher strength and hardness of reinforcing ceramic particulates. In this study, ADC6 aluminum alloy + 5 wt.% fly ash composite was subjected to friction stir processing at rotation rates of 1500, 2000, 2500 and 3000 rpm, in which threaded frustum tools of S690 (W6Mo5CR4V4 high speed steel) and SKD61 (hot work tool steel) were used to investigate the tool wear at 30 mm/min constant traverse speed. Experimental results indicate that the tool at high rotation rates of 2500 and 3000 rpm, The rise slope of wear loss with a maximum loss about 4.5% and 18% for SKD61 tool is more precipitous than that found with a maximum loss only 2.5% and 5% for S690. However, a more dramatic feature was the tool wear of SKD61 tended to resemble with S690 tool wear at 2000 rpm and 1500 rpm. SKD61 and S690 tool wear loss observed have not over than 1 wt.%. It reveals that under 2000rpm of rotation, SKD61 steel tool is the best choice for FSP to processing Aluminum fly ash (ALFA) due to higher cost of S690 and difficult to machining.

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42

Yeh, Xu-Chin, and 葉旭勤. "Influence of Different Fly Ash Particle Sizes on Mechanical Properties of Aluminum Matrix Composites." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/14812464026229698889.

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Анотація:

碩士
國立臺灣海洋大學
機械與機電工程學系
103
The result of this paper presents the result of finding the relationship the size of aluminum-fly ash composite (ALFA). ALFA is the product from fly ash and aluminum ADC10 reacting during electric power generation process in thermal power plant. Due to the cost of metal or cost of process, most of metal matrix composites are more expensive compared to fly ash. In this research, different sizes of fly ash were used to produce ALFA by die-casting, and the sizes of fly ash were distributed to four categories; 25 - 37μm, 37 - 53μm, 53 - 106μm, and 106μm and above. During the research, the result was obtained after 30 hours of chemical reaction of metal matrix composite was done, and 6% of fly ash was added with 2wt% of magnesium. 　　The result shows fly ash size that above 106μm are mostly covering ALFA, and the smaller size of fly ash has less ALFA. In addition, the smaller size of fly ash is, the more obvious clustering phenomenon is shown. According to mechanical property, hardness and elasticity are affected significantly by using the size of particles; by using the large particle can result in increasing hardness by 10.1% and tensile strength by 45.5%, and decreasing elongation by 0.4%. Furthermore, the smaller size of fly ash has smaller contact surface. Therefore, it has lower reaction rate with aluminum, which would result holes and defects.

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43

Sheu, Shih-Wen, and 許世文. "Effect of Fly Ash Fineness and Replacement Ratio on the Properties of Cementitious Composites." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7dyskh.

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博士
國立臺灣海洋大學
河海工程學系
107
This study presents an experimental investigation on the effects of fly ash fineness and replacement ratio on properties of the blended cement mortar and concrete. Class F fly ash (FA) with fineness value of 2730 cm2/g was ground into three different fineness values of 4610 cm2/g, 5690 cm2/g, and 6300 cm2/g with ball grinding machine and was used to produce the blended cement mortars and concrete. For the blended cement mortar, mortar specimens with the various replacement ratios of 0%, 10%, 15%, 20%, 25%, 30%, 35% and 40% by weight of cement were produced. The water-to-binder ratio (w/b) and cement-to-sand ratio (c/s) were kept at 0.485 and 1:2.75, respectively. Heat of hydration, fluidity, compressive strength test, water absorption, mercury intrusion porosimetry (MIP) test, X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) were performed. Test results show that the cement replacement ratio by fly ash has a significant influence on the reduction of heat of hydration, water absorption and capillary porosity and the increase of fluidity and compressive strength. Meanwhile, the peak value of Ca(OH)2 was also reduced by XRD. The mortars with fineness value of 5690 cm2/g and FA replacement ratio of 40% has the highest compressive strength and lowest water absorption and smallest porosity. Based on the results, both the fly ash fineness and the fly ash replacement ratio have a significant influence on the properties of blended cement mortar. For the blended cement concrete, concrete specimens with the various replacement ratios of 30%, 40%, 50% and 60% by weight of cement were produced. The water-to-binder ratio (w/b) was kept at 0.485. Slump test, compressive strength test, water absorption, and rapid chloride penetration test (RCPT). Test results show that the fly ash with fineness value of 5690cm2/g has a superior efficiency on improving properties of concrete than that of fineness value of 2730cm2/g. The compressive strengths of 3F30、5F30、5F40 concrete were higher than that of OPC at the age of 91 days. Based on the results, the fly ash replacement ratio has to be less than 40%. The trend of water absorption is consistent with the compressive strength of concrete. Meanwhile, the total charge passed of concrete decreased with an increasing fly ash replacement ratio.

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44

Huang, Pei-Yang, and 黃霈煬. "Effect of SRA and Fly Ash on Shrinkage and Compressive Strength for Cement-based Composites." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/f3hhn7.

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Анотація:

碩士
國立臺灣海洋大學
河海工程學系
105
Concrete is the cement-based composites of excellent performance. Nevertheless, the stability of volume, compressive strength and durability etc. for concrete, all those are affected by shrinkage crack from casting to hardening. Those are harmful to concrete structure. Furthermore, the main affecting factor for shrinkage and compressive strength of concrete is cement paste. For these reasons, this study adopt shrinkage reducing agent(SRA) and pulverized coal fly ash(PCFA), also use experimental method to proceed investigation and analysis for the effect of shrinkage and compressive strength to mortar, and hope to improve and promote the performance and quality of concrete. This study is divided into three parts to proceed. The water-binder ratio (W/B)are 0.45 and 0.65, SRA dosage are 1% and 2% by weight of cement, and PCFA consumption is 20% by weight of cement instead of cement. All above parameters for experiment of each part. In 1st part, the effect of shrinkage and compressive strength are investigated which on blending SRA with pure mortar. In 2nd part, investigating the effects of shrinkage and compressive strength are on blending PCFA with pure mortar. Investigate the effects of shrinkage and compressive strength on blending SRA, PCFA with pure mortar in 3rd part. Testing results indicate (1) the compressive strength for the experimental groups of 1% and 2% of SRA dosage are lesser than control group as well as the shrinkage stress are for each age. The compressive strength for the experimental groups of 2% of SRA dosage are lesser than 1% of SRA dosage for each age; (2)the effect of shrinkage for for all experimental groups of PCFA 20% of replacement consumption are better than control group for each age, while the compressive strength are lesser. The compressive strength for the experimental group of 0.65 of W/B is lesser than 0.45 of W/B for each age and (3)the effect of shrinkage for all experimental groups of blending SRA with PCFA are better than control groups for each age. Meanwhile, the the experimental groups of 1% and 2% of SRA dosage with 0.65 of W/B, both of the shrinkage stress curves for which are almost superposition on each age. The compressive strength for all experimental groups of blending SRA with PCFA is lesser than control groups for each age. Key words: Concrete, Shrinkage, Compressive strength

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45

Pretorius, J. H. C. (Jan Hendrik Christoffel). "The influence of PFA particle size on the workability of cementitious pastes." Diss., 2003. http://hdl.handle.net/2263/26113.

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In this dissertation the effects of different types of Pulverized Fuel Ash (PF A)-types on the workability of cementitious pastes containing relative large amounts of PF A were investigated. The different types of PF A were produced at the same source thus they were chemically similar but differed in terms of average particle size and size distribution (grading). By using a two-point measurement technique based on flow through a J-shaped tube it was possible to detect relative small differences in workability between pastes. It was found and concluded that the different types of PFA had a significant effect on the workability of pastes containing cement and PFA as well as PF A alone. The physical differences between the PF A-types were quantified and their effects on workability investigated. It was concluded that PF A with a broader particle size distribution range produced pastes with higher workability at constant water content. It was found that compressive strength as measured after 28 days were solely a function of the water/cementitious ratio for the curing regime employed. It was concluded that for curing conditions used the type of PF A used could have a significant effect on compressive strength when constant workability is required.
Dissertation (MSc (Transportation))--University of Pretoria, 2006.
Civil Engineering
unrestricted

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46

Chang, Hsu-Shuo, and 張栩碩. "Influence of Adding Different Amount of Magnesium on Hardness And Density of Aluminum-Fly Ash Composites." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/96058021572734574153.

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Анотація:

碩士
國立臺灣海洋大學
機械與機電工程學系
103
Aluminum-Fly ash composites have characteristics of low density, good performance of resistance, high damping and rigidity etc. The sir casting is the most common way to produce the composites with the combination of liquid aluminum and solid fly ash. Aluminum-Fly ash composites mainly produce the Al2O3 as the strengthening phase by chemical reaction, but Magnesium in the aluminum alloy would react with melt to produce MgAl2O4, which do affect the materials characteristic. Thus, in this study, the Taguchi method and ANOVA analysis is used to analyze hardness and porosity of the composites by the three factors, such as Magnesium content (3 wt%, 5 wt, 7 wt), fly ash content (3 wt%, 6wt, 9 wt), and reaction temperature (700℃, 750℃, 800℃), which carrying the chemical reaction for 30 hours. Then the studied results are compared with those of Magnesium content of 0wt%, 2wt%, respectively, added fly ash 3wt%, 6wt%, 9wt% reacting for 0 hour and 30hours. 　　The results show that the reaction temperature has greater influence as compared to other two factors for the hardness. As fly ash contents less than 9wt%, the hardness of the composite improves insignificant. Thus, the Magnesium content in the composite is less than 3wt% for better improvement. Furthermore, adding 2wt% Magnesium in ALFA composites cannot increase the wettability between fly ash particle and the base material, but cause the fly ash particles unbreakable after 30 hours reaction. The hardness of composites increases nearly 8% as compared to the base material (ADC10+Mg 2 wt%). The density of composites also increases with respect to the base material, which contents no Magnesium and reacting for 30 hours. Therefore, adding Magnesium in ALFA composites produced by stir casting can achieve lightweight material and increase the material hardness.

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47

Santra, Sanjitarani. "Fabrication Of Epoxy Composites With CTBN And Fly Ash As Individual And Hybrid Fillers : Studies On Curing Schedule And Mechanical Properties Under Static And Dynamic Loading Conditions." Thesis, 2004. https://etd.iisc.ac.in/handle/2005/1296.

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48

Santra, Sanjitarani. "Fabrication Of Epoxy Composites With CTBN And Fly Ash As Individual And Hybrid Fillers : Studies On Curing Schedule And Mechanical Properties Under Static And Dynamic Loading Conditions." Thesis, 2004. http://etd.iisc.ernet.in/handle/2005/1296.

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49

Lee, Chin-Lai, and 李金來. "Effect of Silica Fume and Fly Ash on Pore Structure and Corrosion Behavior of Cement-based Composites." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/38042862436524665086.

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Анотація:

博士
國立臺灣海洋大學
材料工程研究所
101
This study is aimed to evaluate the compressive strength, permeability and microstructure of cement-based composites containing fly ash and silica fume. The relationship between pore structure and corrosion behavior was investigated and compared. Test results demonstrate that the addition of silica fume in cement-based composites was found to provide higher compressive strength, lower absorption, lower critical pore size, lower chloride diffusion coefficient and lower corrosion rate. The composites coataining 10% silica fumes provided better performance in permeability than those containing 5% silica fumes. This is because silica fumes can narrow down the size of large capillary pores and densify the pore structure. The addition of fly ash in composites also enhanced the compressive strength and permeability but is not as effective as silica fume. Unhydrated fly ash grains were observed in the porestructure and it caused the looser porestructure and reduced the permeability. The combination of fly ash and silica fume also enhanced the compressive strength and permeability and the specimens containing 5% silica fume and 10% fly ash had more increase in compressive strength and more decrease in permeability than those containing 5% silica fume or 15% fly ash and 25% fly ash. Moreover, corrosion rate, chloride diffusion coefficient and cricital pore size are suitable for evaluating the durability of cement-based composites. By regression analysis, there is high than 90% probability rebar corrosion when the corrosion rate is 11.54 μm/yr, or the chloride diffusion coefficient is 0.62x10-12 m2/s, or the cricital pore size is 26.71 nm.

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50

Wu, Shao-Hsuan, and 吳少軒. "Influence of Progressively Adding Fly Ash on Mechanical Properties of Synthesized Aluminum Matrix Composites Prepared by Stirring Casting." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/n4dg2n.

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