전기로 환원슬래그는 가장 처리하기 곤란한 부산물이였지만, 공기급냉에 의해 수화 활성도를 높임으로서 자원으로서 활용하는 것이 가능하다. 본 연구팀은 용융상태의 슬래그를 공기 급냉하여 비드상으로 응고시킨 후, 이를 일정한 크기의 미분으로 분쇄한 후 적절한 첨가제를 사용하여 국내의 시장에서 요구되는 속경성과 강도를 만족하는 제품을 개발하였다.

현재 우리나라에서는 매년 약 67만대의 사용종료 자동차(End of Life Vehicles)가 발생하고 있다. 자원순환법에 따라 국내 자동차업계에서는 폐 자동차에 대하여 2014년까지 중량 대비 85%, 2015년부터 95%의 재활용율 목표를 달성하여야 하는데 이러한 재활용율 목표 달성을 위해서는 자동차 파쇄 잔재물(ASR)의 적정재활용이 관건이라고 할 수 있다. 폐 자동차 처리과정에서 최종 배출 되는 ASR은 연간 약 15만톤으로 승용차 1대당 약 15% 정도가 발생하고 있으며, 총 발생량의 극히 일부분만이 소각･매립 처리되고 있지만 물질 자체의 발열량이 높고 난연성이기 때문에 효율적으로 소각되지 못하고 특히 그중에 함유된 염소화합물이나 중금속류 등의 영향으로 유해 가스상 오염물질들을 다량으로 배출하기 때문에 처리에 어려움이 많은 실정이다. 금속 제련 용융 시설에서 열원으로 사용되는 Lump coal 대체 연료로써 처리 상용화가 실현 될 경우, ASR의 안정적인 처리와 열에너지 및 유가금속 회수를 통한 물질 재활용 등이 가능할 것으로 사료되며, 이에 따라 폐 자동차의 재활용율 또한 향상될 것으로 기대된다. 따라서 본 연구에서는 국내의 폐 자동차 파쇄 재활용 업체 1곳을 선정하여, 폐 자동차 파쇄 재활용 과정에서의 물질 수지 및 ASR 배출 공정(heavy fluff, light fluff, glass & soil)에 따라 각각의 발생량, 구성 물질, 입도, 발열량 분석, 원소 분석, 공업 분석, 열 중량 분석, 중금속 분석 등의 물리･화학적 특성 및 환경유해성 평가를 실시하여 ASR의 기초적인 특성을 파악하였으며, ASR의 최적용융조건 및 유가금속 회수 가능성을 도출하기 위하여 원 시료와 ASR의 배합비율, 용융온도 등의 조건을 설정하여 용융 가능성을 평가하였다. 또한, 용융 후, 혼합비율 별 발생된 용융 슬래그에서 black copper와 discard slag 분리 후 온도에 따른 구리함량을 측정하여 유가 금속 회수 가능성 및 2차 폐기물 발생 최소화를 위해 ASR 용융슬래그에 대한 특성 분석 후 콘크리트(인터로킹) 블록, 점토블록의 원료로 적용 가능성 여부 검증･평가해 보았다.

Carbon dioxide generated from construction materials and construction material industry among the fields ofconstruction is approximately 67million tons. It is about 30% of the carbon dioxide generated in the fields of construction.In order to reduce carbon dioxide in the fields of construction, it is necessary to control the use of fossil fuel consumedand decrease carbon emission by reducing the secondary and tertiary curing generating carbon dioxide in constructionmaterial industry. Therefore, this study produced an extrusion panel by using cement as the base materials and substitutingbinding materials up to 40% to analyze strength characteristics. According to the results of strength characteristics bythe replacement binder (Low energy curing Admixture) showed an apparent active strength improvement. In particular,specimens substituting binder as 45% indicated the greatest strength improvement. When binding materials was used withsubstitution, it showed strength characteristics similar or higher than specimens made from tertiary autoclave curing assecondary steam curing.

Reaction degree of ground granulated blast furnace slag(GGBFS) in cement paste was measured by water-binder ratio and GGBFS replacement ratio, curing temperature with ages using selective dissolution. In result of experimental, when water-binder ratio and curing temperature were high and replace ratio of GGBFS was low, reaction degree was estimated high.

This study evaluated compressive strength on the slurry for HPFRCC using blast- furnace slag with various blain as a basic study for developing alternative technology of the existing HPFRCC.

This research provides the analyzing case of abnormal expanding of concrete including steel slag aggregate as a recycled aggregate. To determine the reason of abnormal expansion, the components of concrete were searched and the aggregate was found out as a reason of this expansion. The aggregate used was a type of steel slag aggregate without any specific treatment for volumetric stability such as fast-cooling or aging. SEM observation of the aggregate and XRD analysis of the cement paste were conducted and it was found out that the surface of the aggregate is very rough and the cement paste contained a lot of calcium and magnesium. From this research, it is considered to contribute on providing the actual case of failure using steel slag aggregate for concrete.

The objective of this paper is to investigate the effect of spreading time of waste cooking oil (WCO) on durability of high volume blast furnace slag concrete. Carbonation and resistance to chloride attack were measured according to spreading time of WCO. WCO was spreaded on the surface of the concrete with different curing condition after demolding. Blast furnace slag with 60% was incorporated into concrete with 45% of W/B. Test results indicated that carbonation and penetration resistance of chloride attack had favorable results with the condition of 28days water curing and spreading WCO.

This study investigated the effect of cement type and ground granulated blast furnace slag (GGBS) on the mechanical properties and workability of grout for offshore PSC structures. As the replacement ratio of GGBS increased, the flowability of the grout increased and both intial and final setting times of grout was delayed regardless of cement type. However, the effects of GGBS on the bleeding of grout were different according to the type of cement: as the ratio of GGBS increased, less bleeding was observed for the grout with typeⅠ cement whereas higher bleeding was generated for the grout with type Ⅲ cement. However, there was no significant difference in their compressive strength at 28 day according the different replacement ratio of GGBS from 0 to 40%.

In this study, it was evaluated the permeability of cold joint concrete, to evaluated the permeability considering slag concrete and OPC. In addition, the water permeability was evaluated by comparing the sound and cold joint concrete. As a result, OPC-Joint(3.76×10-10m/s), Slag-Joint(3.36×10-10m/s), OPC(2.65×10-10m/s), Slag(2.36×10-10m/s) was evaluated in this order. The OPC-joint is the most highly evaluated. This is estimated to be because the density of the pore structure.

In this study, high performance fiber composites has developed using GGBS and Flyash with PVA fiber. Thus, four mixtures was determined accoding to the ratio of binder. A series of experiments, including slump flow, compressive strength, uniaxial tensile strength tests were carried out to characterize the mechanical properties of the fiber composites. The result of tests, slump flow showed an average 428mm and tensile strain 2% of behavior strain hardening of due to the occurrence multiple micro crack.

In this study, the concrete compressive strength test conducted according to the replacement ratio of electronic arc furnace oxidizing slag. As higher substitution rate of the electronic arc furnace oxidizing slag aggregates, early concrete compressive strength development is effective and the higher the concrete compressive strength as too.

In this study, from the material properties of the aggregates into the actual applications were evaluated for utilizingthe air-cooled blast furnace slag as the coarse aggregates (SG) in PHC piles. The physical and chemical characters ofthe SG were satisfied the standards presented in KS F 2544 for concrete blast furnace slag aggregates. And it was satisfiedthe environmental-factor-evaluation, including the soluble, heavy metal elution and total mercury content, and etc. In casethe non-washed type SG is used, the S/A ratio adjustment according to micro-powder of the aggregate surface and chemicaladmixture adjustment are needed in order to satisfy the aimed material properties. As the replacement ratio of SGincreased, the manifestation rate of compressive strength of the PHC piles was decreased. Particularly, in case non-washingtype SG, the manifestation rate more decreased. Therefore, the elimination of the pop-out materials and cleaning processare necessary for the production process for using the SG as coarse aggregates of PHC Piles

본 연구는 환경부하 저감을 위해 슬래그 시멘트를 사용하고 플라스틱 섬유보강재(폴리프로필렌, 나일론, 유리섬유)를 혼입하여 고강도 간격재를 개발하고 현장적용성을 평가하는 연구이다. 이를 위해 예비실험을 통하여 4가지 섬유 복합재의 첨가량이 결정되었다. 또한 역학적 시험(압축, 휨, 인장) 및 내구성 시험(흡수율, 투수율, 길이변화율, 균열저항성, 탄산화, 동결융해)을 통하여 최적의 섬유재를 도출하였으며, 이를 이용한 고강도 섬유재 간격재의 배합 및 생산시스템을 개발하였다. 또한 현장적용성 평가를 통하여 개발된 간격재의 구체 콘크리트 일체성을 확인하였다.

본 연구에서는 제강슬래그를 이용하여 수용액상에서 혼합 중금속의 흡착능을 평가하였다. 게다가, 제강슬래그를 안정화제로 활용하 여 해양오염퇴적물 내 Ni, Zn, Cu, Pb 및 Cd에 대하여 중금속 안정화 실험을 수행하였다. 중금속 흡착 특성은 Freundlich 및 Langmuir 방정식 을 이용하여 해석하였으며, 평형흡착 실험결과는 Langmuir 모델에 잘 부합되었고 Pb2+ > Cd2+ > Cu2+ > Zn2+ > Ni2+순으로 평형흡착량이 많았 다. 안정화 방법은 오염퇴적물에 제강슬래그 첨가 후 150일간 습윤 양생 하였다. 연속추출 실험결과로부터, 미처리 오염퇴적물과 비교해서 Ni, Zn, Cu, Pb 및 Cd의 이온교환, 탄산염, 산화물 형태는 제강슬래그에 의해 각각 13%, 6.0%, 1.3%, 17% 및 50% 감소하였다.

최근 골재 수급불균형 문제 및 천연자원 고갈에 관한 사회적 관심이 집중되는 가운데, 종래 철강공정에서 부산물로 발생하는 슬래그 중 전기로 산화슬래그는 그 물리적 특성이 일반 골재와 유사한 특성이 있어 콘크리트용 골재로서 활용가능성이 높게 평가되나 슬래그 중 함유되어 있는 free-CaO에 의한 표면결함을 야기하는 문제를 내재하고 있다. 본 연구는 이러한 전기로 산화슬래그 골재의 화학적 안정성 확보 방안을 도출하고 이를 통해 안정화된 슬래그 골재를 용도별 콘크리트용 잔골재로 활용하여 콘크리트의 역학적 성능 및 내구성능을 실험적으로 평가함으로서 최종적으로 전기로 산화슬래그 잔골재의 활용방안을 제시하는 데 그 목적이 있다. 본 연구결과, 전기로 산화슬래그의 골재입경 조정, 소정 기간 동안의 자연 에이징 처리에 의해 팝아웃 등의 표면결함을 대폭 저감할 수 있는 것으로 나타났으며, 콘크리트 용도별 대체율에 따른 역학적 성능 및 내구성능은 일반 골재와 비교하여 동등 또는 동등 이상의 성능을 발현하는 것으로 평가되었다. 향후 전기로 산화슬래그 잔골재 활용시에는 콘크리트의 미관저해 현상이 나타나지 않도록 충분한 사전 에이징 또는, 가공처리 등 안정성 확보를 위한 품질관리가 선행되어야 할 것이다. 또한, 철강부산물의 친환경적인 자원순환 시스템을 확립하기 위해서는 전기로 산화슬래그 골재에 대한 품질관리방안 확립과 더불어 다양한 용도개발이 이루어져야 하며 각종 공학적 특성 및 내구성에 관한 지속적인 연구개발이 이루어져야 할 것이다.

Geopolymer foam block was prepared and its characteristics discussed to evaluate the possibility of replacing blastfurnace slag (below BFS) with melting slag in this study. 10~20wt% of BFS was replaced with melting slag. And also10wt% of mine tailing was replaced with fly ash discharged from municipal solid waste incinerator (below MSWI). Thecompressive strength of foam block prepared was similar to that of foam block prepared without replacing BFS. Andalso it was increased by replacing 10wt% of mine tailing with MSWI fly ash. Considering these results, melting slagmay be used instead of BFS without damaging the quality of foam block.

In this study, Blast furnace-based has been manufactured by utilizing recycled aggregates and gypsum as alkali activator. Comparing with the common geopolymer concrete, Using recycled aggregates and gypsum as activator could be identified to applied in low strength concrete.

To evaluate the durability characteristics of low permeable concrete using ground granulated blast-furnace slag with fineness 4,650 cm2/g, carbonation depth was measured. From the test results, persisting period of that was calculated. And it was found that carbonation depth of concrete was proceed 29.5 mm for 100 years.

Mortar laboratory tests were conducted for analyzing fundamental properties of tunnel shotcrete materials used the furnace blast slag power and the surry-type accelerating admixture. This study tested and compared the shotcrete materials used various accelerating admixtures.

This paper reported the effect of blended activator on the compressive strength of alkali-activated slag cement(AASC) mortar. The alkalis combinations made using sodium hydroxide(NaOH), calcium hydroxide(Ca(OH)2) and potassium hydroxide(KOH) with calcium carbonate(CaCO3). The compressive strength was increase as the dosage of caustic alkali increase.