• 자원리싸이클링
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• 제12권1호
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• pp.41-47
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• 2003

대기에 방치된 생석회의 상온에서 내수화성을 향상시키기 위해 생석회의 탄산화반응과 수화반응실험을 수행하였다. 제강공정에서 사용시까지 수화반응을 억제시키기 위해서는 생석회 표면을 약 6%정도 탄산화시킬 필요가 있었다. 생석회의 탄산화를 위한 회전로 배가스 재순환이 평형연소온도 및 NOx농도에 미치는 영향을 열역학적으로 계산한 결과, 배가스 부피 백분율이 증가함에 따라 연소온도와 NOx농도는 감소하였다.

• 한국농공학회지
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• 제27권2호
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• pp.57-71
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• 1985

The characteristics of compaction and unconfined compressive strength were investigated by mixing with lime to all soils adjusted by given percentages of two kinds of clays to sand to obtain the most effective distribution of grain size and the optimum lime content for soil stabilization. In addition, unconfined compressive strength and durability tested by adding of sodium metasilicate, sodium sulfate, sodium carbonate, sodium gydroxide and magnesium oxide to lime-soil mixture mixed with 8 percent lime to adjusted soil having the mixing percentage of 60 percent of cohesive black clay and 40 percent of sand by weight to get the effect and the optimum content of chemicals. The results obtained were as follows; 1.With the addition of more lime, the optimum moisture content was increased, and the maximum dry density was decreased, whereas the more the amount of clay and the less was the maximum drt density. 2. In the soil having more fine grain size the unconfined compressive strength was larger in the earlier stage of curing period, in accordance with the longer period, the mixing percentages of sand to clay showing the maximum unconfined compressive strength, on the basis of 28-day strength, were 60% : 40% (black clay) and 40% : 60% (brown clay) respectively. 3. The reason why the soil adjusted with black clay was remarkably bigger in the unconfined compressive strength than ones adjusted with brown clay for all specimen of lime-soil mixture was the difference in the kind of clay, the amount of chemical compositions the value of pH. Black clay was mainly composed of halloysite that reacted with lime satisfactorily, whereas the main composition of brown clay was kaolinite that was less effect in the enhance of unconfined compressive strength. Also the difference of unconfined compressive strength was because black clay was larger in the amount of composition of calcium oxide and magnesium oxide in the value of pH affecting directly on the unconfined compressive strength of lime-soil mixture than brown clay. 4. In the lime-soil mixture mixed with 8 percent of lime to soil that mixing percentage of sand to black clay was 60% : 40%, on the standard of 7-day strength, the effect of chemical was arranged in the order of magnesium oxide, sodium carbonate, sodium sulfate, sodium hydroxide and sodium metasilicate. 5. The optimum amount of chemical being applicable to the maximum unconfined compressive strength of lime-chemical-soil mixture was 1 percent by weight for air dry soil in the case of adding sodium carbonated and 0.75 percent on sodium hydroxide, the unconfined compressive strength was increased continuously with increase of the amount of chemical up to 2 percent of chemical content is the lime-chemical-soil mixture added sodium metasilicate, sodium sulfate and magnesium oxide. 6. It was considered that the chemical played and accelerant role of early revelation of strength because the rate of increase of unconfined compressive strength of all of lime-chemical-soil mixtures was largest on the 7-day cured specimen. 7. The effect of test on freezing and thawing after adding suitable amount of chemical on the lime-soil mixture mixed with 8 percent of lime to soil that mixing percentage of sand to black clay was 60% : 40% was arranged in the order of magnesium oxide, sodium carbonate, sodium sulfate, sodium metasilicate and sodium hydroxide.

• 한국농공학회논문집
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• 제55권3호
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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.

• 화약ㆍ발파
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• 제29권2호
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• pp.13-31
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• 2011

국내외의 광산 및 대규모 현장에서는 노천발파 시, Air Deck 발파공법을 사용하여 발파효율성을 높이려 하고 있으나 이는 공 내부 상태에 따라 장전밀도가 달라짐으로 인해 대괴가 발생하는 등 문제점이 있다. 특히 석회석 광산의 경우 침식 용해 작용에 의해 공벽이 확공되거나 손상된 경우가 많아 Air Deck 공법 적용 시 의도하지 않은 집중장약이 발생하는 경우가 있다. 따라서 본 연구에서는 석회석 광산의 대규모 노천발파를 대상으로 사전에 공 내부를 내시경 검사한 후 공 내부에서 장약집중을 야기할 수 있는 구간을 Air Tube를 이용한 데크차지 공법으로 분상장약(Deck Charge)하여 Air Deck 발파공법의 효과가 온전히 나타나도록 유도하였고 이를 일반장약 공법과 비교하였다. 비교대상은 전체적인 발파효과, 파쇄도, 장약량 절감율 및 시공속도(장약에서 발파까지의 총 작업속도)였으며, 그 결과 시공속도를 제외한 나머지 비교대상에 있어 일반장약에 의한 발파공법 보다 Air Deck를 이용한 이중분상 발파공법이 더 효율적으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.287-292
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• 2001

This paper investigates the properties of high fluidity concrete incorporating lime stone powder and fly ash. Lime stone powder(LSP) and fly ash(FA) contents are varied with. According to test results, as LSP and FA contents increase, fluidity, air content and placeability shows a declining tendency. For the temperature history, both LSP and FA have favorable effects on reducing hydration heat, moreover, LSP reduces hydration heat more than FA. LSP shows undesirable strength loss as its content increases. FA also decreases the strength at early age, but it enhances later age strength. Accordingly LSP is expected to improve the quality at fresh concrete and reduce hydration heat, while it causes strength loss.

• 한국결정성장학회지
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• 제9권1호
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• pp.119-125
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• 1999

본 연구는 싸이클론 반응로에서 $FeS_{2}$의 반응 특성에 관한 조사를 연구하였다. 수학적인 모형도로 이 반응로에서 $FeS_{2}$의 oxidation과 suifation 등을 전개하엿다. 모형은 $FeS_{2}$에서 chemical control shrinking core로서 그리고 ${Ca(OH)}_{2}$에서 fluid film control shrinking core로서 가정하였으며 수식으로서 발전시켰다. 본 실험은 이 반응 파라메터들의 영향에 연구로서 진행하였으며 즉 반응로의 온도변화, $FeS_{2}$의 입자크기, 공기 주입비율, 시료 주입비율, 그리고 $FeS_{2}$와 ${Ca(OH)}_{2}$ 비율 등이다. Oxidation과 Sulfation에 의한 반응물들은 화학적 및 물리적으로 특성을 기술하였다.

• KIEAE Journal
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• 제11권4호
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• pp.95-101
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• 2011

Earth has been used as a building material not only our country but also many foreign countries in the world. In foreign countries, we can often find the high-storied earthen houses which have been maintained for over several hundred years, which means the fact that earth differs in durability according to the methods of utilizing earth. So, the purpose of this study is to progress the fundamental research for utilizing earth as a wall material. Also, the another purpose of this study is to utilize the optimum micro-filler effect which adjusts the grain size of earth and the lime composite which promotes chemical combining power, and so examine whether earth material ensures its high compressive strength. This study applied both of rammed earth method and pour earth method among earth architecture methods. This study investigated compressive strength, slump, and air content according to unit binder weight. On the basis of such experimental results, this study derived the following conclusions. 1) Optimum micro-filler mixtures reduce a lot of fine particles contained in earth. If optimum micro-filler mixtures are used as aggregates, they develop lower W/B and relatively higher strength than general earth. 2) In this study, which uses optimum micro-filler earth mixtures and lime composite, rammed earth method develops 29MPa and pour earth method develops 28MPa in 28 days compressive strength. Such strengths can be utilized in building walls.

• 한국구조물진단유지관리공학회 논문집
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• 제16권4호
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• pp.44-51
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• 2012

본 연구에서는 황토에 시멘트나 유기계 접착제를 첨가하지 않은 천연재료 황토결합재를 사용하여 황토경화체를 제작하고, 배합조건에 따른 강도성상을 평가하였다. 황토와 석회의 결합재에 천연재료를 첨가할 경우 사용한 천연재료는 모두 물리적 성능을 개선하는 효과가 있었다. 천연재료 중에서 석회는 황토경화체의 물성을 증가시키는데 가장 큰 영향을 미치고 있다. 황토경화체의 물리적 특성은 적용한 배합비 중에서 W/B 45%, 단위수량 $285kg/m^3$, 석회첨가율 60%일 때 가장 우수하게 나타나고 있다.

• 한국산업보건학회지
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• 제34권1호
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• pp.1-7
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• 2024

Objectives: The study was performed to investigate characteristics of hazardous factors regarding chemical(liquid lime) tank dredging workers by case survey. Methods: Field data such as working condition, MSDS and respirators applied to chemical tank dredging work were analyzed and the work environmental factors of noise and indoor air quality were measured to compare existing data with actual work situations. Results: No health hazards to workers due to working conditions were confirmed during dredging work inside the chemical storage tank. All air quality measurement data during dredging work satisfied the management standards, and there were no by-products. During dredging work, there was a significant change in noise depending on the type of work, but considering the noise reduction rate(NRR) of the earplugs worn by workers, there was no actual health hazard due to noise exposure. Conclusions: A fit test for respirator and the expiration date of the safety helmet should be observed to ensure an appropriate level of safety and health for dredging workers in the chemical storage tank.

• 한국구조물진단유지관리공학회 논문집
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• 제15권4호
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• pp.87-98
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• 2011

최근 생태 친환경 건축이 화두로 등장하면서 친환경 건축재료인 점토벽돌과 공기의 흐름과 수분의 이동이 가능한 석회모르타르의 사용이 증가하고 있다. 하지만 국내 연구는 콘크리트벽돌과 시멘트모르타르에 집중되고 있어 점토벽돌 및 석회모르타르에 대한 연구가 거의 없는 실정이며, 조적조의 국내 기준 또한 국내에서 사용되는 재료와 다른 물리적 값을 사용하고 있는 국외기준을 바탕으로 제정되어 국내 실정을 적절히 반영하지 못하고 있다. 따라서 본 연구는 프리즘압축강도, 부착강도, 전단 및 사인 장강도 실험을 통해 점토벽돌과 석회모르타르를 사용한 조적구조의 물리적 특성을 파악하고자 한다. 또한, 콘크리트벽돌과 시멘트모르타르를 사용한 조적구조와의 물리적 특성을 비교분석하여 국내 조적기준을 개정하기 위한 근거를 제시하고자 한다. 점토 벽돌과 석회모르타르를 적용한 조적구조는 콘크리트벽돌과 시멘트모르타르를 사용한 조적구조와는 다른 양상을 보이므로 점토벽돌과 석회모르타르를 적용한 조적구조의 프리즘압축강도와 탄성계수에 대한 추정식을 제안한다.