• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.259-260
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• 2018

This study evaluated the compressive strength, freeze-thaw and sulfate resistance characteristics of concrete using CFBC-Ash. The CFBC-Ash was adjusted to a particle size of 75 ㎛ or less and using by increasing the fineness of powder through milling. As a result, it was confirmed that the concrete using CFBC-Ash shows a high compressive strength, durability. Also, it is confirmed that CFBC-ash can be used as a concrete binder.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.69-75
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• 2014

Accurate analysis of fly ash particles is not trivial because of complex nature in physical and chemical properties. SPLITT fractionation (SF) was employed to fractionate the fly ash particles into subpopulations in large quantities. Then the SF-fractions were analyzed by the steric mode of sedimentation field-flow fractionation (Sd/StFFF) for size analysis. The SF-fractions were also analyzed by ICP-OES. The results showed that the fly ash is mainly composed of Fe, Ca, Mg and Mn. No particular trends were observed between the particle size and the concentrations of Fe, Ca, Mg, while Mn, Cu and Zn were in higher concentrations in smaller particles. Sample preparation procedures were established, where the fly ash particles were sieved to remove large contaminants, and then washed with acetone to remove organics on the surface of particles. The sample preparation and analysis methods developed in this study could be applied to other environmental particles.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.781-786
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• 1995

석탄화력발전소 산업부산물인 Fly ash를 이용한 고준위방사성폐기물의 붕규산 유리고화 가능성을 분석하였다. Fly ash SiO$_2$, NaNO$_3$, B$_2$O$_3$에 DUPIC 핵연료 제조공정으로부터 발생되는 모의 scrap waste를 20 wt% 혼합하여, l15$0^{\circ}C$ 에서 3시간 용융시켜 붕규산유리화시켰다. 또한 붕규산유리고화체의 침출성을 평가하기 위하여 2일동안의 soxhlet 침출실험결과 양호한 내침출성을 보였다. 또한 고체폐기물의 안정화물질로 fly ash를 사용할 경우 fly ash 함량을 57%까지 첨가하여도 붕규산유리고화체의 제조가 가능함을 확인하였으며, fly ash의 첨가로 인한 유리화원료 재료비를 30% 까지는 절감시킬 수 있을 것으로 예상된다.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.324-329
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• 1999

This study is performed to evaluate an elastic properties of rice straw ash concrete . The following conclusions are drawn ; The ultrasonic pulse velocity is in the range of 4.084 ∼4.336㎧, which has showed abuot the same compared to that of the normal cement concrete. The highest ultrasonic pulse velocity is showed by 5% rice straw ash filled reice straw ash concrete. The dynamic and static modulus of elasticity i sin the range of 294 ${\times}$103 ∼ 347 ${\times}$103 and 266${\times}$ 103 ∼347${\times}$ 103 kgf/$\textrm{cm}^2$ , respectively. It is showed about the same compared to that of the normla cement concrete. The poisson's number of rice straw ash concrete is less than that of the normal cement concrete . The stress-strain curve of concrete which is contained rice straw ash within 10% appear slowly and over 10% appear almost straightly.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.276-282
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• 1996

This study dealt with the properties for fly ash of combined heat power plant and application for concrete industry. For this purpose, fly ash of ulsan combined heat power plant was analyzed for physical and chemical properties and tested the properties of the super flowing concrete. As results of fly ash, contents of SiO2 and Al2O3 in the fly ash of Ulsan were less than those of thermal power plant(Boryung), but contents of CaO were ten times as much as those of Boryung. In order to satisfy the properties of the Super Flowing Concrete using class C fly ash, mixing conditions were determined the optimum water-binder(w/b), volume ratio of fine aggregates(Sr) and coarse aggregates(Gv).

• Journal of Environmental Science International
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• v.12 no.10
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• pp.1061-1069
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• 2003

The adsorption behaviors of strontium and cesium ions on fly ash, natural zeolites, and zeolites synthesized from fly ash were investigated. The zeolites synthesized from fly ash had greater adsorption capabilities for strontium and cesium ions than the original fly ash and natural zeolites. The maximum adsorption capacity of synthetic zeolite for strontium and cesium ions was 100 and 154 mg/g, respectively, It was found that the Freundlich isotherm model could fit the adsorption isotherm. The distribution coefficients (K$\_$d/) for strontium and cesium ions were also calculated from the adsorption isotherm data, The distribution coefficients decreased with increasing equilibrium concentration of strontium and cesium ions in solution. By studying the removal of cesium and strontium ions in the presence of calcium, magnesium, sodium, potassium, sulfate, nitrate, nitrite, and EDTA (in the range of 0.01 - 5 mM) it was found that these coexistence ions competed for the same adsorption sites with strontium and cesium ions.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1353-1358
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• 2008

An elementary particle of bottom ash is similar to fine sand. so which expected from replace expensive sand. Especially, If using for improvement of soft ground, It will need of study about strength, permeability and environment of the bottom ash. In this study, the bottom ash operate of physical quality, direct shear test and triaxial compression test so analyze and compare with standard sand.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.48-49
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• 2015

High-calcium fly ash (FH) is widely used as mineral admixtures in concrete industry. In this paper, a hydration model is proposed to describe the hydration of high-calcium fly ash blended-cement. This model takes into account the hydration reaction of cement, the chemical reaction of fly ash, and reaction of free CaO in fly ash. Using the proposed model, the development of compressive strength of FH blended concrete is predicted using the amount of calcium silicate hydrate (CSH). The agreement between simulation and experimental results proves that the new model is quite effective.

• 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.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.713-716
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• 2006

The main purpose of this research was to enhance the durability in both the design and construction of dams. Especially, in case of rockfill dams, the durability of tunnel concrete in a concrete-faced rockfill dam(CFRD) is achieved by optimizing the fly ash replacement for cement and application of steel fiber. The effect on durability and thermal property corresponding to the increasing replacement of fly ash and application of steel fiber was evaluated, and the optimum value of fly ash replacement and steel fiber application was recommended. The results show that 15% of fly ash replacement and $20kg/m^3$ of steel fiber application was found to be an optimum level and demonstrated excellent performance in durability and thermal property.