고로 서냉슬래그 혼합 시멘트 페이스트의 유동성

이승헌,박설우,유동우,김동현,Lee, Seung-Heun,Park, Seol-Woo,Yoo, Dong-Woo,Kim, Dong-Hyun 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.6

Air-cooled slag showed grindability approximately twice as good as that of water-cooled slag. While the studied water-cooled slag was composed of glass as constituent mineral, the air-cooled slag was mainly composed of melilite. It is assumed that the sulfur in air-cooled slag is mainly in the form of CaS, which is oxidized into $CaS_2O_3$ when in contact with air. $CaS_2O_3$, then, is released mainly as $S_2O{_3}^{2-}$ion when in contact with water. However, the sulfur in water-cooled slag functioned as a constituent of the glass structure, so the$S_2O{_3}^{2-}$ ion was not released even when in contact with water. When no chemical admixture was added, the blended cement of air-cooled slag showed higher fluidity and retention effect than those of the blended cement of the water-cooled slag. It seems that these discrepancies are caused by the initial hydration inhibition effect of cement by the $S_2O{_3}^{2-}$ ion of air-cooled slag. When a superplasticizer is added, the air-cooled slag used more superplasticizer than did the blast furnace slag for the same flow because the air-cooled slag had higher specific surface area due to the presence of micro-pores. Meanwhile, the blended cement of the air-cooled slag showed a greater fluidity retention effect than that of the blended cement of the water-cooled slag. This may be a combined effect of the increased use of superplasticizer and the presence of released $S_2O{_3}^{2-}$ ion; however, further, more detailed studies will need to be conducted.

Effect of Slag Grade and Cement Source on the Properties of Concrete

Becknell, Natalie Peterson,Hale, William Micah Korea Concrete Institute 2011 International Journal of Concrete Structures and M Vol.5 No.2

Presented in the paper are findings of a project that examined the effect of slag grade and cement source on the performance of concrete mixtures. Slag cement contents were 20, 40, and 60 percent of the total cementitious material content. Two grades of slag cement were examined (Gr. 100 and Gr. 120) along with two sources of Type I cement. Compressive strength, durability, and permeability were measured. The results showed that the cement source affected the early age strength of the mixtures. At 28 days of age, mixtures containing Gr. 120 slag cement had higher compressive strengths than mixtures containing Gr. 100 slag cement, but by 90 days of age, the trend reversed. As for the chloride ion penetrability, mixtures cast with Gr. 100 slag cement passed fewer coulombs at 28 and 90 days of age than similar mixtures containing Gr. 120 slag. Mixtures containing Gr. 120 slag had the greatest durability factors.

Self-healing properties of cement-based and alkali-activated slag-based fiber-reinforced composites

Nguyễ,n, Huy Hoà,ng,Choi, Jeong-Il,Song, Keum-Il,Song, Jin-Kyu,Huh, Jungwon,Lee, Bang Yeon Elsevier 2018 Construction and Building Materials Vol.165 No.-

<P><B>Abstract</B></P> <P>This paper presents an experimental study of the self-healing properties of cement-based and alkali-activated slag-based fiber-reinforced composites with controlled crack width. Two types of binder, i.e. cement and alkali-activated slag-based polyethylene fiber-reinforced composites with identical water-to-binder ratios, were designed. Compressive strength and uniaxial tension tests were performed to measure the mechanical properties of the composites, and the self-healing performance was investigated by observation of the crack width and by measuring resonance frequency. Scanning electron microscopy and energy-dispersive X-ray spectroscopy were also adopted to analyze the morphology and chemical composition of the healing materials. The test results showed that alkali-activated slag-based composites have advantages compared to cement-based composites in terms of a reduction of relative crack width; however, cement-based composites have a higher resonant frequency recovery than alkali-activated slag-based composites. It is also observed that calcium carbonate is the dominant healing material of cement-based and slag-based composites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The self-healing properties of cement-based and slag-based fiber-reinforced composites are investigated. </LI> <LI> Slag-based composites have advantages in terms of a reduction of relative crack width. </LI> <LI> Slag-based composites have low resonant frequency recovery. </LI> <LI> Calcium carbonate is the dominant healing material for cement-based and slag-based composites. </LI> </UL> </P>

Effect of Slag Grade and Cement Source on the Properties of Concrete

Natalie Peterson Becknell,William Micah Hale 한국콘크리트학회 2011 International Journal of Concrete Structures and M Vol.5 No.2

Presented in the paper are findings of a project that examined the effect of slag grade and cement source on the performance of concrete mixtures. Slag cement contents were 20, 40, and 60 percent of the total cementitious material content. Two grades of slag cement were examined (Gr. 100 and Gr. 120) along with two sources of Type I cement. Compressive strength, durability, and permeability were measured. The results showed that the cement source affected the early age strength of the mixtures. At 28 days of age, mixtures containing Gr. 120 slag cement had higher compressive strengths than mixtures containing Gr. 100 slag cement, but by 90 days of age, the trend reversed. As for the chloride ion penetrability, mixtures cast with Gr. 100 slag cement passed fewer coulombs at 28 and 90 days of age than similar mixtures containing Gr. 120 slag. Mixtures containing Gr. 120 slag had the greatest durability factors.

고로슬래그 함유량에 따른 고로슬래그 시멘트의 중금속 함량 변화연구

김용준,엄남일,김우일,오정근,신선경,이영기,김기헌 한국폐기물자원순환학회 2018 한국폐기물자원순환학회지 Vol.35 No.4

This study investigated the concentration of heavy metals in blast-furnace slag cement by changing the content ratio between blast-furnace slag and ordinary Portland cement for the safe recycling of blast-furnace slag in the cement industry. The analysis of the three main materials of the cement (ordinary Portland cement, blast-furnace slag, and the alternative raw materials), resulted in the ordinary Portland cement having the highest concentration of heavy metals. Also, it is concluded that the heavy metal content of blast-furnace slag cement is mainly attributed to the content of ordinary Portland cement. As the content of furnace slag during the manufacture of cement increases, the overall heavy metal content of the furnace slag cement becomes low. This was highly evaluated as a resource in the cement-production process, in respect of the effective recycling of resources and the safe management of hazardous materials.

Statistical Analysis of the Physical Properties in a Slag-OPC-Gypsum System as a Compound Mixing Ratio

You, Kwang-Suk,Lee, Kyung-Hoon,Han, Gi-Chun,Kim, Hwan,Ahn, Ji-Whan The Korean Ceramic Society 2007 한국세라믹학회지 Vol.44 No.9

The effect of the mixing ratio of compounds in a slag-OPC-Gypsum system on the physical properties of Slag cement is investigated in this study. $Na_2SO_4$ was used as an alkali activator. Blast furnace slag cement was prepared from a mixture of blast furnace slag, ordinary Portland cement and anhydride gypsum. The fluidity and the compressive strength according to the ratio of each mixture were analyzed in statistical analyses in order to discover the parameters influencing the fluidity and compressive strength. The results showed that the hydration of blast furnace slag took place with the addition of $Na_2SO_4$ and that column-crystalline ettringite was created as the main hydration product of the blast furnace slag. In addition, it was found that the compressive strength of blast furnace slag cement tends to increase when the ordinary Portland cement content is higher up to three days. However, it is known that the compressive strength tends to increase as the blast furnace slag content becomes higher with increases in the level of OPC after 28 days. As a result of this analysis, it is believed that the ordinary Portland cement content influences the initial compressive strength of blast furnace slag cement, and that in later days this is highly influenced by the slag content.

전기로 슬래그를 치환한 고로 슬래그 시멘트의 특성

이승헌,황해정,권성구,Lee, Seung-Heun,Hwang, Hae-Jeong,Kwon, Sung-Ku 한국세라믹학회 2006 한국세라믹학회지 Vol.43 No.7

Properties of slag cement that contained 50 wt% of blast furnace slag were studied when replaced blast furnace slag powder with electric arc furnace slag powder. Electric arc furnace slag was aged for about 2 months in the air by being crushed to be 1-3 mm in size. As a result of the experiment, it was proven that the water content for obtaining the same consistency became decreased as slag is replaced with electric arc furnace slag instead of blast furnace slag. Also, the workability of mortar increased about 30% at the same ratio of water to binder when blast furnace slag was completely replaced with electric arc furnace slag. The compressive strength of mortar on the 28 days increased when a slag replacement rate became 10 wt%, however, it rather decreased when the slag replacement rate exceeded 10 wt%. The heat of hydration became higher for the first 14 h in case of the replacement of slag cement by electric arc furnace slag. Yet, it decreased when 14 h had passed. Therefore, when all blast furnace slag was replaced with electric arc furnace slag, about 15 cal/g heat of hydration decreased when it passed about 72 h.

산업폐기물 중의 유해중금속의 환경친화적 안정화 처리(II)

원종한,최광휘,최상흘,이훈하,손진군,심광보,Won, Jong-Han,Choi, Kwang-Hui,Choi, Sang-Hul,Lee, Hun-Ha,Sohn, Jin-Gun,Shim, Kwang-Bo 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.12

유해 중금속을 함유하고 있는 제철 폐기물 슬러지를 안전하게 처리하기 위하여 고로 수쇄 슬래그와 포틀랜드 시멘트를 이용한 중금속 고화용 슬래그 시멘트, 고황산염 시멘트를 제조하여 폐슬러지의 고화를 시도하였다. 고로 수쇄 슬래그와 보통포틀랜드 시멘트를 6:4로 혼합하고 여기에 자극제로서 CaO를 10% 가한 슬래그 시멘트 재료를 사용한 경우, STS 슬러지는 C-S-H 그리고 ettringite와 monosulfate 등의 수화물이 생성되면서 강도가 지속적으로 증가함을 보여주고 있지만 성상과 성분이 다른 BF 슬러지와 COREX 슬러지에 적용하였을 때는 강도 발현이 좋지 않았다. 하지만 고화처리용 슬래그 시멘트를 이용하여 STS에 BF 및 COREX 슬러지를 각각 5:5로 혼합한 혼합슬러지에 적용한 경우 고화체의 강도는 슬래그 시멘트를 이용한 경우 폐기물 고화 처리 기준을 상회하는 충분한 강도를 보였다. 한편, 수쇄슬래그, 반수석고, 보통 포틀랜드 시멘트에 자극제를 혼합한 폐기물 처리용 고황산염계 시멘트를 이용하여 고화가 힘들었던 COREX 슬러지에 적용한 결과, 3일 강도가 이미 고화처리기준을 상회하는 좋은 결과를 얻어, 이 시멘트 재료로서 COREX 슬러지의 고정/안정화도 가능함을 보여주고 있다. Slag cement and supersulfated slag cement were fabricated by mixing blast furnace slag and ordinary portland cement and adapted to solidify/stabilize heavy metal contained hazardous waste sludge. In case of slag cement, it showed continuous increase of their compressive strengths, which is attributed to the formation of the C-S-H, ettringite and monosulfate with STS sludge. However, BF and COREX sludge has a different shape and composition. therefore, adequate compressive strength could not be achieved with this slag cement. In case of the mixture of the each sludge like the STS-BF or the STS-COREX, the compressive strength over the standard level for disposing the wastes could be obtained with slag cement. The supersulfated slag cement that contain accelerators was very effective in solidifying the COREX sludge, which was difficult to solidify using different cement and obtained high compressive strength only for 3 days.

괴재 및 전로슬래그를 이용한 CO₂ 저감 및 칼슘 추출 후 슬래그 활용

유영석 ( Yeongsuk Yoo ),최홍범 ( Hongbeom Choi ),방준환 ( Jun-hwan Bang ),채수천 ( Soochun Chae ),김지환 ( Ji-whan Kim ),김진만 ( Jin-man Kim ),이승우 ( Seung-woo Lee ) 한국공업화학회 2017 공업화학 Vol.28 No.1

광물탄산화 기술은 천연광물 및 산업부산물에 포함된 칼슘이나 마그네슘을 이산화탄소와 반응시켜 탄산염을 생성하는 기술로 이산화탄소를 열역학적으로 안정한 형태로 저장할 수 있는 기술이다. 본 연구는 철강슬래그를 이용한 이산화탄소 저감 및 추출 후 슬래그 재활용을 통해 환경적 부담 및 공정 비용 절감을 절감할 수 있는 광물탄산화 상용화 기술 개발을 목표로 설정하였다. 추출 용매(염화암모늄)를 사용하여 괴재 및 전로슬래그로부터 칼슘을 추출하고 추출된 칼슘을 이산화탄소와 반응시켜 순도 98% 이상의 탄산칼슘을 합성하였다. 또한 칼슘 추출 후 슬래그를 건축자재(패널)로 활용하는 기술을 개발하였다. 슬래그의 칼슘 추출효율에 따라 상이한 결과를 보였지만 광물탄산화 전체 공정에 있어 중량 비(약 80-90%)를 차지하는 칼슘 추출 후 슬래그(잔여슬래그)의 활용을 통해 광물탄산화 공정으로부터 배출되는 산업부산물의 양을 최소화하고자 하였다. 잔여슬래그는 시멘트 패널 제작에 활용되는 규사미분 대체 물질로서 이용하였고 기존 시멘트 패널과 물성평가(압축강도 및 휨강도)를 상호 비교하였다. 용액 내 칼슘 농도는 유도결합 플라즈마 분광분석기(Inductively coupled plasma optical emission spectrometer, ICP-OES)를 사용하여 분석하였다. 합성한 탄산칼슘은 X선 회절 분석법(X-ray diffraction, XRD)을 이용하여 결정학적 특성 및 정량 분석하였고 주사 전자 현미경(Field emission scanning electron microscope, FE-SEM)을 사용하여 표면 형상을 확인하였다. 시멘트 패널평가는 KS LISO 679에 준하여 패널 제작 및 패널의 압축강도와 휨강도를 측정하였다. Mineral carbonation is a technology in which carbonates are synthesized from minerals including serpentine and olivine, and industrial wastes such as slag and cement, of which all contain calcium or magnesium when reacted with carbon dioxide. This study aims to develop the mineral carbonation technology for commercialization, which can reduce environmental burden and process cost through the reduction of carbon dioxide using steel slag and the slag reuse after calcium extraction. Calcium extraction was conducted using NH₄Cl solution for air-cooled slag and convert slag, and ≥ 98% purity calcium carbonate was synthesized by reaction with calcium-extracted solution and carbon dioxide. And we conducted experimentally to minimize the quantity of by-product, the slag residue after calcium extraction, which has occupied large amount of weight ratio (about 80-90%) at the point of mineral carbonation process using slag. The slag residue was used to replace silica sand in the manufacture of cement panel, and physical properties including compressive strength and flexible strength of panel using the slag residue and normal cement panel, respectively, were analyzed. The calcium concentration in extraction solution was analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). Field-emission scanning electron microscope (FE-SEM) was also used to identify the surface morphology of calcium carbonate, and XRD was used to analyze the crystallinity and the quantitative analysis of calcium carbonate. In addition, the cement panel evaluation was carried out according to KS L ISO 679, and the compressive strength and flexural strength of the panels were measured.

High Sulfated Calcium Silicate 시멘트 콘크리트의 염소이온침투저항성 평가

정석만,양완희,김현수,이건철 한국건축시공학회 2022 한국건축시공학회지 Vol.22 No.1

The aim of this work was to a comparative review the performance of high calcium silicate cement(HSCSC) and that of ordinary Portland cement(OPC) and blast furnace slag cement(S/C). The result ofthe compressive test confirmed that the compressive strength development rate of high calciumsilicate cement concrete at the age of 3 days was 73.6% that of ordinary Portland cement concrete. However, at the age of 28 days, the strength development rate of high calcium silicate cement increasedto about 107.0% compared to ordinary Portland cement. In addition, the test of the chloride ionpenetration resistance of concrete showed that at the age of 28 days, the passed charge decreased by73.4% and 93.0%, respectively, in blast furnace slag cement and high calcium silicate cement comparedto ordinary Portland cement, and at the age of 56 days, it decreased by 79.1% and 98.3%, exhibitingexcellent resistance to chloride ion penetration. In particular, it was confirmed that the rate of decreasein the passed charge with age was higher in high calcium silicate cement than in ordinary Portlandcement and blast furnace slag cement. High Sulfated Calcium Silicate cement(HSCSC) 콘크리트의 성능을 보통포틀랜드시멘트(OPC), 고로슬래그시멘트(S/C)와 비교 검토하고자 하였다. 콘크리트 압축강도 실험결과 초기 3일 재령에서의 High Sulfated Calcium Silicate cement 콘크리트 압축강도 발현율이 보통포틀랜드시멘트 콘크리트의 73.6% 수준으로 다소 적게 확인되었으나, 28일 재령에서 HighSulfated Calcium Silicate cement의 강도 발현율이 상승하여 보통포틀랜드시멘트 대비 약 107.0% 수준으로 소폭 상승하는것을 확인할 수 있었다. 또한, 콘크리트의 염소이온침투저항성 실험결과 재령 28일의 경우 보통포틀랜드시멘트 대비 고로슬래그시멘트, High Sulfated Calcium Silicate cement 순서로 각각 73.4%, 93.0% 감소하였으며, 재령 56일의 경우 79.1%,98.3% 감소하여, 우수한 염소이온 침투 저항성능을 확인하였다. 특이사항으로는 보통포틀랜드시멘트, 고로슬래그시멘트보다 High Sulfated Calcium Silicate cement의 재령 경과에 따른 통과 전하량 감소율이 더 높은 것을 확인할 수 있었다.