• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.1
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• pp.163-169
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• 1999

The object of this study is to compare properties of massive fly-ash concrete with plain concrete. Two concrete mixtures comprising two batch each $1.0m^3$ in volume, were made from ready mixed concrete batch plant. The water-to-cementitious materials ratio was kept constant at 51.4%. Therefore, massive concrete specimen($W800{\times}D800{\times}H800mm$) was cast from ready mixed concrete to analyze history of temperature and core strength properties. Bleeding, time of slump loss and time of setting of the fresh concrete were measured. In order to estimate the properties of massive fly-ash concrete in hardened concrete, non-destructive tests such as rebound hardness, ultrasonic pulse velocity and maturity were performed and analyzed.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.3
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• pp.129-140
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• 2013

Bottom Ash is industrial by-product from a thermoelectric power plant. An immense quantities of bottom ash have increased each year, but most of them is reclaimed in ash landfill. In this study, in order to raise recycling rate of Bottom Ash, it is suggested to cure Bottom Ash (BA) mixtures mixed with cement, lime, Fly Ash (FA), and oyster shell (OS). Mixtures of 5~20 % mixing ratio had been cured for 1, 3, 7, 14, and 28 days using sealed curing and air-dry curing method. Unconfined compressive strength test was conducted to determine strength and deformation modulus ($E_{50}$) change for mixtures as mixing ratio and curing day, water contents of mixtures were measured after test. As a result, strength and $E_{50}$ were increased as mixing ratio and curing days, but values and tendencies of them appeared in different as kind of mixture, mixing ratio, curing method, and curing days. The results showed the addition of cement, lime, Fly Ash, and oyster soil in Bottom Ash could improved strength and $E_{50}$ and enlarge its field of being used.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.963-968
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• 1999

This study was tried to evaluate possibilities for discriminating the mixture degree of wheat flour from buckwheat products. Buckwheat was milled into four grades of powder, i.e. whole grain flour (WGF), inner layer flour(ILF), middle layer flour(MLF) and outer layer flour(OLF)), and these powders were mixed with wheat flour(WF) to make mixed samples. Ash, protein and fat contents of the buckwheat flours were high in the order of OLF=WGF>MLF>ILF. On the other hand, WF showed a similar content to OLF in ash and protein, and to ILF in fats. Potassium and magnesium contents were higher in all the buckwheat powder than in the wheat flour. Flavonoid contents were higher in order of OLF>WGF=MLF> ILF, but it was not in wheat flour. Although the reliable correlation between mix ratio and components, i.e. mag nesium or ash analyzed were found, it did not seem to reflect sufficiently the expected variations of contents of original material components. Also, compositions of commercial buckwheat products were analyzed to evaluate the mixed ratio of buckwheat flour and wheat flour. The results suggest that the components analyzed in this study as putative marker were not good in determining whether or how much buckwheat products contained wheat flour.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.176-177
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• 2021

In order to compensate for the defects of concrete made using only Portland cement, three-component powder mixed with blast slag and fly ash, and four-component powder concrete mixed with silica fume are being produced. When each of the admixtures is used alone, the above-described excellent performance is expressed and up to 70% of the powder is used. These technologies are also contributing to the reduction of greenhouse gases under Act on Low Carbon. Green Growth. However, calcium hydroxide is consumed as a stimulator or reaction in the case of silica fume, which causes latent hydroponicity of slag, pozzolane reaction, and silica mixtures represented by fly ash. It is known that the consumption of calcium hydroxide affects the alkalinity of concrete. As a result, the carbonation resistance is significantly lower among the durability of concrete. Research on quantification of such effects is insufficient. In this study, an experiment was conducted to quantify calcium hydroxide of the three-component and four-component powder paste using thermal analysis equipment (DTG), and the effect of the mixing amount was discussed.

• Journal of Energy Engineering
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• v.27 no.2
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• pp.55-60
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• 2018

In this study investigated the Controlled Low Strength Materials using coal ash and steel slag(KR slag) as the main material in the thermal power plant classified as waste resource. Bottom ash and KR slag are mixed at a ratio of 7: 3 to expand the use of industrial by-products through carbonate($CO_2$-fixation) reactions and inhibit the exudation of heavy metals. The results showed that the water content increased as the content of bottom ash increased. It was confirmed that as the powder content increased, the bleeding ratio decreased. Also, as the content of one kind of ordinary portland cement (OPC) decreased, activation of hydration reaction decreased and compressive strength decreased. However, when the mixed composition is appropriately adjusted, the compressive strength of 2.0 MPa required for the controlled low-strength material can be satisfied.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.15-18
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• 1998

In this paper, the properties of high performance concrete with fly ash and expansive additives are investigated. According to the experimental results, when 10% of fly ash and 5% of expansive additives are mixed in concrete mixture, the improvement of the quality in the side of the fluidity, strength and the prevent of the crack caused by drying-shringkage can be accomplished.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.261-266
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• 1998

The purpose of this study is to present the reference data on the development of undispersed underwater mortar for augered pile under various replacement ratio of fly-ash. According to the experimental results, when 10% of fly-ash is mixed under mix proportion of 1:1.5(c:s), as strength and shrinkage decrease slightly, whereas fluidity increase, high quality mortar for augered pile can be achieve in case above condition is applied.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.178-179
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• 2017

In this study, the fundamental properties of cement mortar in relation to the change of the replacement ratio of the RA(Reject-Ash) were analyzed by mixing RA to the mixed aggregate consisting of poorly graded fine rock aggregate and marine aggregate for quality improvement. It was found that replacing 5% of the mixed aggregate with RA could improve the quality of the aggregate to the degree of fine rock aggregates.

• Computers and Concrete
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• v.5 no.2
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• pp.89-100
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• 2008

This research examines the engineering properties and color intensities of mortar containing different amounts of fly ash (0, 5, 10 and 20%) mixed at different water-to-binder ratios (w/b = 0.23, 0.47 and 0.59) and exposed at different temperatures (T = 25, 100, 200, 400, 600 and $800^{\circ}C$). Results show that there is greater mass loss on ignition with high w/b and higher temperatures. In addition, the color channel image analyzer (Windows software written in Delphi) is utilized to study the relationship between the curing temperature and intensity of three primary colors, red, green and blue (RGB), of the fly ash mortar specimens. The results show that the RGB intensities on the specimen surface increases from that at $25^{\circ}C$. The mortar specimen becomes white with increase in w/b but without the addition of fly ash. Moreover, for mortar specimens with greater content of fly ash, red on the specimen surface has the greatest increase in intensity at elevated temperature. Observation the variations in color on the specimen surface may help estimate the highest elevated temperatures that concrete structures can withstand.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.4
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• pp.335-344
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• 2014

The Quality of municipal solid waste incineration ash (incineration ash) was analyzed for the purpose of the reusing for concrete material. The folwability and strength properties of concrete mixed with incinerator ash were investigated. CaO component was included more than 50% in chemical component of incinerator ash, mean size of 50% accumulated particle distribution of incinerator ash was about $25{\mu}m$. Particle shape of incinerator ash ($IA_1$) was massed the round shape with fine particle, particle shape of incinerator ash ($IA_2$) was piled up the sheet shape according to manufacture procedure. The Quality of concrete was effected by use of incinerator ash. When the incinerator Ash ($IA_2$) was used, slum of concrete was increased and dosage of high range water reducing agent was reduced. However, strength development of concrete was decreased. Dosage of high range water reducing agent was increased by combined use of incinerator ash ($IA_2$) and diatomite powder, but strength development of concrete was improved. Ratio of compressive strength and tensile strength was in the range 85%~105% of CEB-FIP model code.