• Korean Journal of Environmental Agriculture
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• v.10 no.2
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• pp.133-137
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• 1991

The inorganic constituents in flay ash such as Ca, Mg, Al and Si were extracted by water and 0.5N-Acetic acid, and changes of the physical properties of the fly ash-treated soils were examined to find out the effect of fly ash on the chemical and physical properties of the soils. The dominant day minerals of fly ash were quartz and mullite. More inorganic constituents were extracted from the fly ash by acetic acid than by water. Si and A1 in fly ash were hardly extracted by water. Addition of fly ash to soil below 10%(W/W) caused improvement in the water permeability and the field moisture capacity of the soil, but did not influence the shrinkage and hardness of the soil. Therefore, it was apparent that the effect of the fly ash on the chemical and physical properties of the soils greatly dependedon soil reaction, the organic acid contents, and the amount of fly ash used in treatment.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.376-379
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• 2004

pH has been regarded as a master variable governing the heavy metal sorption on fly ash. However, the chemical constituents in the fly ash could also suggest a potential sorption site for heavy metals. So, in this study sequential extraction method is employed to evaluate the sorption behavior of fly ash for cadmium. Two different fly ashes (S-fly ash, T-fly ash) were obtained from different power plants in Korea. First, cadmium is adsorbed under four different initial pHs. And, Cd sorbed in fly ash was sequentially desorbed following the sequential extraction method suggested by Tessier. In test results, the effect of pH increase was differently exerted in two fly ash. In S-fly ash, exchangeable fraction was dominated in low initial pH, however, as increasing initial pH, the fraction bound to carbonate increased. In the T-fly ash, regardless of initial pH the fraction bound to carbonate was major part of sorption estimated. The fraction bound to Fe/Mn oxide was about 10% in T-fly ash, and 5% in S-fly ash at high pH.

• Journal of the Korean Ceramic Society
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• v.54 no.2
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• pp.128-136
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• 2017

Fly ash from a circulating fluidized bed combustion boiler (CFBC fly ash) is very different in mineralogical composition, chemical composition, and morphology from coal ash from traditional pulverized fuel firing because of many differences in their combustion processes. The main minerals of CFBC fly ash are lime and anhydrous gypsum; however, due to the fuel type, the strength development of CFBC fly ash is affected by minor components of active $SiO_2$ and $Al_2O_3$. The initial hydration product of the circulating fluidized bed combustion fly ash (B CFBC ash) using petro coke as a fuel is Portlandite which becomes gypsum after 7 days. Due to the structural features of the portlandite and gypsum, the self-cementitious strength of B CFBC ash was low. While the hydration products of the circulating fluidized bed combustion fly ash (A CFBC ash) using bituminous coal as a fuel were initially portlandite and ettringite, after 7 days the hydration products were gypsum and C-S-H. Due to the structural features of ettringite and C-S-H, A CFBC ash showed a certain degree of self-cementitious strength.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.477-483
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• 2000

Fly ash is the unburned residue resulting from the combustion of coal in utility and industrial boilers such as thermal power plants. Annually about 5 million tons of fly ash is being produced in korea. Less than 25 percent of total volume of fly ash is currently being used effectively for some ways. In the future, the volume of fly ash discharge from thermal power stations will be increasing more and more, and the development of the utilization of high volume fly ash is required. Fly ash has a lower compacted density and specific gravity than coarse grained natural aggregates but equivalent strength properties indicating that the fly ash could be used as a structural fill materials. So, clay-fly ash mixtures can be used as a fill material in the construction of embankments. Laboratory tests have been carried out to determine the physical, chemical, and geotechnical characteristics of the clay and fly ash. The fly ash is mixed with the clay in different proportions and the geotechnical characteristics of the mixtures have been studied also. In this study describes the results of the experimental study. The implications of the use of clay and clay-fly ash mixtures on the stability of embankments are discussed.

• Journal of the Korean Society of Safety
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• v.14 no.4
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• pp.135-141
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• 1999

This study is an experimental study to investigate the possibility of the utilization of paper ash as the cover, liner in waste disposal landfill and other construction materials. The sample used in these tests was obtained from Daehan paper mill. A series of tests were peformed to evaluate basic properties, compaction, permeability, compressive strength, consolidation, leaching, and CBR of paper ash. In order to investigate the soil engineering properties of paper ash, the test results were compared with those obtained of fly ash. The results of unconfined compression tests show that paper ash had a larger strength than the fly ash. Also, the maximum dry unit weight of paper ash was approximately 59～76.9% less than that of the fly ash. It was found from the results of leaching test that paper ash is classified as non-detrimental general wastes according to the waste management law.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.4
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• pp.103-108
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• 1998

This study examines the physical and mechanical properties of the concrete using rice straw ash. Materials used for this experiment are rice straw ash, normal portland cement, superplasticizer, natural sand and gravel. Test results show that the unit weights of concrete using rice straw ash were decreased 1 ∼ 3% and the highest strengths were achieved by 5% filled rice straw ash concrete, with increase of compressive strength by 19%, tensile strength by 53% and bending strength by 16%, as compared with those of the normal cement concrete. The strength ratio of rice straw ash concrete was higher than that of the normal cement concrete. Also, the durability against sulfuric acid 5% solution was increased with increase of the content of rice straw ash. It was 1.33 times of the normal cement concrete by 10% filled rice straw ash concrete and 1.47 times by 15% filled rice straw ash concrete, respectively Accordingly, rice straw ash concrete will greatly improve the properties of concrete.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.858-865
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• 2009

Based on the proven feasibility of bottom ash and tire shred-soil mixtures as lightweight fill materials, tire shred-bottom ash mixtures were suggested as a new lightweight fill material to replace the conventional construction material with bottom ash. Therefore, we carried out the laboratory test, field compaction test and performance test of large scale embankment in order to evaluate their suitability for the use of lightweight fill materials in the before studies. We could verified that the ash, tire-shred and the mixture are able to be the useful materials as light fill materials. In this study, we estimated the long-term compressible settlements for 6 materials such as TA(Tire-Bottom Ash mixture), TBA(Tire-Bottom Ash<5mm) mixture, TWS(Tire-Weathered Soil mixture), Bottom Ash, Bottom Ash(<5mm), Weathered soils.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.426-429
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• 2010

The Influence of the character of fly ash on the fluidity of cement paste with a polycarboxylic acid type superplasticizer was investigated in connection with the particle size distribution, unburned carbon content, specific surface area and shape of the fly ash. The fluidity of the fly ash cement paste with an added 20 vol% fly ash increases with an increasing roundness of the fly ash and it decreases with an increasing n-value of the fly ash cement. There is a linear correlation between the roundness/n-value and the fluidity of fly ash cement paste.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.33-34
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• 2019

Malaysia, as a tropical rainforest country, enjoys an abundance of bamboo plant that proliferate throughout the country. The application of geopolymer technology has become a trend and preserve the environment from harm. Fly ash geopolymer concrete has low early strength and requires 24 hours for the concrete to harden. Thus, the presence of calcium and potassium content in bamboo ash could remedy this problem. Besides, there is no research regarding the use of bamboo ash as a binder in geopolymer concrete. Therefore, the presence of bamboo ash could improve the research field with the use of agriculture waste in a building construction. This research aim is to use bamboo ash in the production of fly ash geopolymer concrete. The specimens were casted in $100mm{\times}100mm{\times}100mm$ cubes and sodium based activator were used as the alkaline solutions. The binders are formulated with different binder ratio. All test specimens were cured at ambient temperature ($23^{\circ}C-25^{\circ}C$) and 100% fly ash was chosen as control specimen. To determine the mechanical properties of fly sh geopolymer concrete with the presence of bamboo ash, compressive strength test was conducted. The test results depicted that as the percentage of bamboo ash decreases, compressive strength increases. Also, the addition of 5% of bamboo ash into fly ash geopolymer concrete could improve the early strength in 7 days. The results were proven with the result explained by X-ray fluorescence (XRF) and X-ray diffraction (XRD). Therefore, it can be concluded that the addition of bamboo ash improved the properties of fly ash geopolymer concrete at early ages.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.183-189
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• 2017

The aim of the research is to provide rheological properties of cement paste with various qualities of coal ash including fly ash, raw ash, and reject ash. Generally, fly ash is the well known supplementrary cementitious materials for concrete and is used to improve various properties. Although fly ash is obtained as a byproduct of fire powder plant, still reject ash is wasted from raw ash. In this research, thus, to provide a fundamental information on using not only fly ash but also raw ash or reject ash for cementitious materials, a rheological properties of cement paste was studied with three different coal ash. This research was conducted from particle conditions of three different coal ashes to rheological properties in cement paste phase. According to the expeirment, reject ash was consisted with large and coagulated particles although fly ash was consisted with a small and spherical shaped particles. based on the particle conditions of various coal ashes, rheological behaviors were tested, and it was shown as the coal ashes improved the fluidity of cement paste. Specifically, depending on the particle distributions of cement paste, it is considered that the viscosity of paste can be controlled.