• 한국건설순환자원학회논문집
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• 제2권4호
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• pp.345-353
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• 2014

This study was evaluated influence of fluidity properties according to basalt fiber and high volume fly ash in the mortar level, as part of a basic study for development of fiber reinforced concrete using basalt fiber and high volume fly ash. In the first step, it was evaluated that fluidity properties of mortar according to replacement ratio 6 level of fly ash(10, 20, 30, 40, 50 and 60mass%) and fluidity properties of mortar according to content 5 levels of SP(1.3, 1.5, 1.7, 1.9 and 2.1%) and content 5 levels of VA(0.2, 0.4, 0.6, 0.8 and 1.0%) for dispersion of the basalt fiber, in the second step, it was evaluated that fluidity properties of mortar using High-volume fly ash (50mass%) on 3 levels of basalt fiber length (6, 20 and 30mm). Results of assessment, if after a fiber mixed, it showed that viscosity agent is more effective to improve the fluidity and fiber dispersion than superplasticizer, high volume fly ash (50%) applying the mixing, due to three properties of fly ash, showed that the improved fiber dispersibility and flow improvement.

• 콘크리트학회논문집
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• 제26권4호
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• pp.525-532
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• 2014

화력발전소에서 발생되는 플라이애쉬는 콘크리트의 첨가재로 사용되는 것이 석탄회 재활용 방안 중 최선으로 알려져 있다. 이러한 석탄회는 최근 더 이상 매립이 불가능하여 콘크리트에 다량 첨가가 시도되고 있다. 그럼에도 불구하고 현재까지 하이볼륨 플라이애쉬(high volume fly ash: HVFA) 시멘트 콘크리트의 연구분야는 주로 재료적인 분야에 대해서만 수행되어지고 있는 실정이다. 그러나 하이볼륨 플라이애쉬 시멘트 콘크리트의 구조재료로의 적용을 위해서는 구조 부재 전단거동 등에 대한 연구가 필수적이다. 이를 위하여 이 논문에서는 플라이애쉬 치환율 0, 35% 및 50%, 압축강도 20, 40 및 60 MPa 그리고 전단철근량 3수준을 실험변수로 하여 플라이애쉬 시멘트 철근콘크리트 보 27개를 제작하여 이들의 전단거동을 실험적으로 평가하였다. 실험 결과에 의하면 플라이애쉬를 첨가하지 않은 일반 콘크리트(FA=0%)와 35%, 50% 플라이애쉬 시멘트 콘크리트 부재의 전단거동은 크게 차이나지 않음을 알 수 있었다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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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.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.67-70
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• 2007

In this study, the characteristic of strength development of high volume fly ash concrete(HVFAC) was experimentally investigated. The production of one ton of portland cement releases about 0.87ton of CO2 into the atmosphere. HVFAC is an emerging material technology and is environmentally friendly because of its reduced use of portland cement, reduced CO2 emissions. For this purpose, two levels of W/B were selected. Seven levels of fly ash replacement ratios and two levels of silica fume replacement ratios were adopted. In the concrete mix, the water content of 125kg/m3 was used, which is less than that of usual water content. As a result, it was observed that the slump of concrete was increased with the increasing fly ash replacement ratio and when the silica fume was incorporated into the concrete, the slump was significantly decreased at the same condition. It appeared that the compressive strength gradually decreased with increasing fly ash replacement ratio at the early age, but the difference of strength up to replacement ratio of 50% was little at the age of 91 days because of the pozzolanic reaction of fly ash.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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• pp.105-110
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• 1998

The purpose of this was to examine the used of fly ash as a type of construction material. In this paper the results from a recent study on development of a cement composite utilizing relatively large amount of fly ash are presented. The flowable fly ash-cement sand composite was investigated for strength and flowability characteristics. The independent variable considered were: fly-ash content, sand content, and ratio of water to cementitious materials. Results of this study show that high volume fly-ash composite can be proportioned to obtain 10~15kg/$\textrm{cm}^2$ compressive strength at 28 days. For applications requiring strength between 10kg/$\textrm{cm}^2$ and 15kg/$\textrm{cm}^2$, the mixture with fly ash-cement ratio of 5.6 and sand-cement ratio of 28 with relatively high water content may be used. Slump was held at 25$\pm$1cm for all mixtures produced compressive strength at 28 days were found to range from 5kg/$\textrm{cm}^2$ to 13.7kg/$\textrm{cm}^2$.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2001년도 학술논문발표회
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• pp.82-87
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• 2001

The purpose of this study is for the active use of the fly ash, which is a by-product of the combustion pulverizes coal thermal power plants, to compensate for the lack of landfill and for conservation of energy, by using fly ash as the supplementary cementitious material, and to prove its possibility as the related products of the cement. First of all, the ordinary fly ash is grinded in a special method and its fineness is controlled from 6000$\textrm{cm}^2$/g to 8000$\textrm{cm}^2$/g, then replaced it with the 10% to 80% of the cement mortar in order to test physics characteristics. The first experiment conducts on the strength development in fly ash replacing content and fineness. and the changes of the flow values, incorporating fly ash into cement. The second one is about the slow development of the strength of the fly ash mortar in early ages, and improves its strength with the activator $Na_{2}SO_{4}$, using high volume fly ash.

• 콘크리트학회논문집
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• 제26권3호
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• pp.323-329
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• 2014

화력발전소에서 발생되는 플라이애쉬는 콘크리트의 첨가재로 사용되는 것이 석탄회 재활용 방안 중 최선으로 알려져 있다. 이러한 석탄회는 최근 더 이상 매립이 불가능하여 콘크리트에 다량 첨가가 시도되고 있다. 그럼에도 불구하고 현재까지 하이볼륨 플라이애쉬(High Volume Fly Ash: HVFA) 시멘트 콘크리트의 연구분야는 주로 재료적인 분야에 대해서만 수행되어지고 있는 실정이다. 그러나 하이볼륨 플라이애쉬 시멘트 콘크리트의 구조재료로의 적용을 위해서는 탄성계수, 응력-변형률 관계 및 구조 부재 거동 등에 대한 연구가 필수적이다. 이를 위하여 이 논문에서는 플라이애쉬 치환율 0, 35 및 50%, 압축강도 20, 40 및 60 MPa 그리고 인장철근비 2수준을 실험변수로 하여 플라이애쉬 시멘트 철근콘크리트 보 18개를 제작하여 이들의 휨거동을 실험적으로 평가하였다. 실험결과에 의하면 플라이애쉬를 첨가하지 않은 일반 콘크리트(FA=0%)와 35, 50% 플라이애쉬 시멘트 콘크리트 부재의 휨거동은 크게 차이나지 않음을 알 수 있었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.142-147
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• 2000

Durability characteristics of controlled low strength material(flowable fill) with high volume fly ash content was examined. The mix proportions used for flowable fill are selected to obtain low-strength material in the 10 to 15kgf/㎥ range. The optimized flowable fill was consisted of 60kgf/㎥ cement content, 280kgf/㎥ fly ash content, 1400kgf/㎥sand content, and 320kgf/㎥water content. Subsequently, durability tests including permeability warm water immersion, repeated wetting & drying, freezing & thawing for high volume fly ash-flowable fill are conducted The test results indicated that flowable fill has has acceptable durability characteristics.

• Corrosion Science and Technology
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• 제13권6호
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• pp.209-213
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• 2014

Due to the increasing of interest about the eco-friendly concrete, it is increased to use concretes containing by-products of industry such as fly ash(FA), ground granulated blast furnace slag(GGBFS), silica fume(SF), and etc. Especially, these are well known for improving the resistances to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance against corrosion of reinforcement of high volume fly ash(HVFA) concrete which is replaced with high volume fly ash for cement volume. For this purpose, the concrete test specimens were made for various strength level and replacement ratio of FA, and then the compressive strength and diffusion coefficient for chloride ion of them were measured for 28, 91, and 182 days, respectively. Also, corrosion monitoring by half cell potential method was carried out for the made lollypop concrete test specimens to detect the time of corrosion initiation for reinforcement in concrete. As a result, it was observed from the test results that the compressive strength of HVFA concrete was decreased with increasing replacement ratio of FA but long-term resistances against reinforcement corrosion and chloride ion penetration of that were increased.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.549-554
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• 2000

Generally, it is indicated that concrete using fly ash as a part of cement content has lower early strength, and faster carbonation velocity. To improve these problems and provide useful information for high volume fly ash concrete, the properties of concrete - those include slump, bleeding, setting time, compressive strength and carbonation depth etc. - which contained large amount of fly ash as a part of fine aggregate were investigated experimentally. According to test results, it was found that the compressive strength of the concrete increased in early age as well as in long term age with the increase of the fly ash content. And the carbonation depth of concrete using fly ash as a part of fine aggregate was lower than that of plain concrete(FA 0kg/ $\textrm{m}^3$).