• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.881-884
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• 2006

Wasted phosphogypsum is a by-product from the phosphoric acid process of manufacturing fertilizers. It consists mainly of $CaSO_4{\cdot}2H_2O$ and contains some impurities. The purpose of this study is to utilize wasted phosphogypsum into an admixture for concrete products cured by steam This paper is to investigate the strength properties of cement composites containing high volume phosphogypsum. The cement composites were composed of OPC, phosphogypsum, fly-ash and granulated blast-furnace slag with activators. As a result, the strength of cement composites containing high volume wasted phosphogypsum were shown high level when granulated blast-furnace slag was mixed. Therefore, PG could be used as a steam curing admixture for concrete 2th production with reduction of OPC.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.177-180
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• 2004

In these days the exhaustion of natural sand has been highlighted with the environmental damages due to excavating sea-sand. Many researchers and engineers have investigated some materials to replace natural sand with, and were interested in using the basic oxygen furnace-slag, the industrial by-product, as fine aggregate. One of the drawbacks to using BOF-slag as a aggregate is to be gradually expanded, and needed the time-consuming process, but some engineers in Korea tackled it recently. In this study, the stabilized BOF-slag was used for lean concrete under the laboratory condition. After testing the several properties - dry density, compressive strength, and young's modulus-, it was found that the dry density was proportionally governed by BOF-slag content and the 7-day compressive-strength was $110\~120\%$ of the natural sand-made. Therefore, BOF-slag is applicable to the lean concrete because they greatly satisfied the required strength, $50kgf/cm^2$.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.158-159
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• 2013

In this study, effects of supplementary cementitious materials(fly ash, blast furnace slag and waste glass) on drying shrinkage of cement mortar were compared and evaluated. The results showed drying shrinkage of cement mortar using blast furnace slag and waste glass is larger than shrinkage due to capillary pressure, while using fly ash is smaller.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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• pp.63-64
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• 2011

This study is about the mortar in which fine aggregate is substituted by low-carbon eco-friendly inorganic composite prepared by addition of alkali accelerator in industrial by-products such as blast furnace slag, red mud and silica fume as a replacement for cement. Results of experiments on flow and strength properties in mortar of inorganic composite according to replacement rate of fine aggregate showed that amount of air and table flow decreased as replacement rate of fine aggregate about inorganic composite got higher. Also, it's shown that the compressive strength was the highest at replacement rate 50% of fine aggregate about inorganic composite.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.186-187
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• 2013

Recently, high fluidity concrete is becoming more prevalent. High fluidity concrete uses admixture or thickener in order to prevent separation of materials due to increased fluidity, and, especially, BS is becoming more use for reduced heat of hydration and improved long-term strength. This study examined the effect of BS on fluidity of cement paste from a rheological viewpoint. As for BS types, materials equivalent to 1 types of KS F 2563 and the cement mass was substituted by 20, 40, 60, 80%.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.154-155
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• 2013

The aim of this work is to have a better knowledge of reactions that take place in a cement paste, blast furnace slag mixed cement paste and fly ash mixed cement paste and know about the change in chemical components exposed to elevated temperature. The results show that the dehydration reactions appeared differently in the each admixture mixed cement paste and can be used as tracers for determining the temperature history of concrete after a fire exposure.

• 한국세라믹학회지
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• 제52권2호
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• pp.150-153
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• 2015

Recently, research on geopolymeric concrete that does not use cement as a binder has been actively investigated. Geopolymeric concrete is cement-free concrete. Masato, ocher and/or soil has been solidified into geopolymeric concrete by the reaction of specifically modified silicate as an alkali activator and inorganic binding materials such as blast furnace slag, fly ash or meta-kaolin, which is cured at room temperature to exhibit high compressive strengths. Based on the results, this study shows how geopolymeric concrete that uses specifically modified silicate and inorganic binding materials is implemented as eco-cement with no cement.

• Advances in concrete construction
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• 제4권4호
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• pp.283-303
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• 2016

Several types of industrial byproducts are generated. With increased environmental awareness and its potential hazardous effects, the utilization of industrial byproducts in concrete has become an attractive alternative to their disposal. One such by-product is ground granulated blast furnace slag (GGBS), which is a byproduct of the smelting process carried out in the iron and steel industry. The GGBS is very effective in the design and development of high-strength and high-performance concrete. This paper reviews the effect of GGBS on the workability, porosity, compressive strength, splitting tensile strength, and flexural strength of concrete.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.539-541
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• 1987

P+ ion implanted poly-Si flim with doses of 10E13-10E16 ions/$cm^2$ were annealed by CO2 laser and their sheet resistances were measured and compared with thoses of furnace annealed samples. In case of lightly doped samples, the measured sheet resistance of laser annealed samples were lower several orders of magnitude than those of furnace annealed samples. The origin of this reduction of sheet resistances is supposed to be the increase of the grain size to the extent of certain critical value.

• 한국표면공학회지
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• 제37권1호
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• pp.64-70
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• 2004

Cryogenic characteristics of austenitic stainless steel based on 304 steel with nickel and nitrogen were investigated at room temperature and $-196^{\circ}C$. The alloys were fabricated by vacuum arc furnace and cold working after homogenization treatment. The addition of nickel and nitrogen decreased the stability of $\delta$-ferrite and induced the stability against the formation of martensite to result significantly in enhancing ductility at $-196^{\circ}C$. Nitrogen reduced Md temperature, which was beneficial to the tensile strength and elongation at $25^{\circ}C$ and -196$^{\circ}C$.