• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.209-210
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• 2012

Cement is an essential material for social infrastructure. Cement production process for cement itself is energy-intensive and requires a large amount of natural resources for fuel and raw materials. This study is to development of recycled cement from waste concrete powder in manufacturing process of recycled aggregate concrete. Recycled cement is low carbon and green growth materials concept for eco friendly construction environment. From the test results, waste concrete powder is same chemical proportion regardless of manufacturing process of recycled aggregate concrete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.248-249
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• 2014

Photocatalytic cement is receiving attention due to its high oxidation power that oxidizes nitrogen oxides (NOx), thus contributing to clean atmospheric environment. However, there has not been a thorough investigation on durability of a parent material, cementitious material, as a result of photocatalytic reactions. In this study, durability of photocatalytic cementitious materials exposed to nitrogen dioxide (NO₂) gas was examined. Titanium dioxide (TiO₂) nanoparticles containing cement paste samples were exposed to cycles of NO₂ with UV light, followed by wetting and drying to simulate environmental condition. The surface of samples was characterized mechanically, chemically, and visually during the cycling. The results indicate that the photocatalytic efficiency decreased with continued NO₂ oxidation due to calcium carbonate formation. The pits found from SEM demonstrate that chemical deterioration have occurred, such as acid attack or leaching. In conclusion, the photocatalytic reactions and its product could alter cementitious materials chemically and mechanically which could further affect long-term durability.

• 한국산업융합학회 논문집
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• 제25권4_2호
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• pp.549-563
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• 2022

Continuous global warming is causing ecosystem destruction and direct damage to human life. The main cause of global warming is greenhouse gases, which account for more than 90 % of carbon dioxide. The leaders of each country signed the Paris Agreement at the United Nations Convention on Climate Change (UNFCCC) to reduce greenhouse gas emissions. Currently, the total amount of CO₂ emitted from South Korea is 664.7 million tons as of 2018, ranking eighth in the world. 37 % of South Korea's total CO₂ emissions come from the construction & building field, especially the cement production, which is a construction material. Carbon reduction technologies can be largely divided into four types: carbon reduction (CC), carbon reduction and storage technology (CCS), carbon reduction and utilization technology (CCU), and carbon reduction, storage and utilization technology (CCUS). Overseas, CCUS technology is mainly applied to reduce and store CO₂ emitted from construction and construction field. A technology for permanently storing CO₂ through mineralization by capturing CO₂ and utilizing CO₂ into a cement production process was developed, and this technology is applied to the entire cement industry. However, the development of CCUS technology applicable to the cement industry is still insignificant in South Korea. In this study, carbon dioxide reduction technology and methods for reducing carbon dioxide emitted during the cement manufacturing process, which is the main component of concrete mainly used in civil engineering construction, were investigated. Overseas, it has reached the commercialization stage beyond the demonstration stage as a way to reduce carbon dioxide by vomiting carbonation reactions. Accordingly, if carbon dioxide reduction plan technology generated during cement manufacturing is developed based on domestic technology differentiated from foreign technology, it is expected to contribute one more step to the carbon neutrality policy.

• 한국건설순환자원학회논문집
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• 제9권4호
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• pp.553-560
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• 2021

본 연구에서는 순수시료를 사용한 시멘트 클링커와 석탄재를 7% 적용한 클링커를 1050~1500℃의 온도로 소성하여 소성온도별 시멘트 광물의 함량 변화와 미세구조의 변화를 검토하였다. 시멘트 클링커의 원료로서 석탄재의 적용은 알루미나 및 규산질의 공급원으로 적용이 가능하였으며, 석탄재를 적용한 시멘트 클링커는 1350℃ 이상의 소성온도에서 순수원료를 적용한 시멘트 클링커와 동등 수준의 광물량을 나타내었고, 미세구조 또한 유사한 상태를 나타내어 시멘트 원료로서 석탄재의 활용이 가능함을 확인하였다. XRD-Reitveld 분석에서 1250℃에서 Belite의 최대량이 생성되어 1350℃에서부터 Belite에서 Alite로의 전환이 나타났다. 1350℃에서부터 간극상과 Alite로 추정되는 광물상이 구분되며, 1400℃에서부터 명확하게 구분되었다. 소성온도가 증가함에 따라 결정상의 형상과 경계가 명확해지며, 결정상의 크기도 증가되는 것이 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.53-54
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• 2023

In recent decades, climate change has become an issue of global importance. The calcium sulfoaluminate (CSA) cement emits lower CO₂ than the Portland cements while manufacturing. However, ettringite, which is a main hydration product of CSA cement, starts dehydrating at a temperature above 100℃, hence it may limit the CSA cement for high temperature application. Recently, an early carbonation curing of cement-based material has been extensively studied in terms of carbon neutralization. The carbonation curing of CSA cement has a potential to transform the AFt and AFm phases into calcium carbonate, and the transformation of unstable hydrates to stable hydrates can increase the resistance to elevated temperature. This review study summarizes and discusses the carbonation curing effect of CSA cement and the thermal stability of CSA cement exposed to elevated temperatures.

• 지질공학
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• 제26권1호
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• pp.101-115
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• 2016

관정의 시멘팅 재료로 사용될 수 있는 두 시멘트 물질(KS-1 보통 포틀랜드, Class G)의 물/고체(고체=시멘트) 중량비와 첨가제인 비산재의 부피함량 변화에 따른 이들 물질들의 물리역학적 물성 변화를 파악하기 위해 실내물리역학실험을 실시하였다. KS-1 보통 포틀랜드 시멘트의 경우 물/고체(고체=시멘트) 중량비를 변화시키며, Class G 시멘트의 경우 물/고체(고체=비산재+시멘트)을 고정한 채 비산재:시멘트의 부피비를 변화시키며 시료를 제작하였다. KS-1 보통 포틀랜드 시멘트의 경우 물/고체 중량비가 증가할수록, Class G 시멘트의 경우 비산재의 함량이 증가할수록, 공극률 증가, 밀도감소, 음파속도(P, S파) 감소. 탄성상수(영율, 포아송비) 감소, 압축 및 인장강도 저하, 열전도도 감소, 비열 증가의 경향을 보였다. 또한 구속압(σ₃)의 증가와 비산재 함량의 증가는 재료의 소성파괴거동을 초래하였다. 이 실내실험결과를 이용하여, 여러 주입공 페라미터(케이싱, 시멘트층의 두께, 주입압, 주입공 경사방향 및 경사각, 주입공 심도)등을 변화 시키면서, 시멘트층의 안정성 분석을 실시하였다. 분석결과 낮은 주입압과 경사정 혹은 수평정에서는 시멘트층이 안정하였으나, 다른 조건에서는 시멘트층에서 주로 인장파괴가 관찰 되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.240-241
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• 2014

The environmental pollution problem the globally related to global warming arises. In the construction industry the cement mostly use material, generates the great quantity of CO₂ among the fired process and the global warming is more aggravated. In addition, the polysilicon that is the main raw material used in the solar power generation, produces 1 ton and the industrial by-product of 2 tons is generated. In this way, the arising sludge there is not method recycling and it is all discarded. Therefore, in this research, try to present as the fundamental research material for using the polysilicon sludge as the admixture of the cement in order to reduce the amount of the cement. The based on 'KS L ISO 679' was progressed mortar test. the liquidity, air flow rate, setting time, water absorption ratio, flexural and compression strength was measured. According to, appropriate replacement ratio of the polysilicon sludge tries to analyze.

• Journal of Microbiology and Biotechnology
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• 제25권8호
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• pp.1328-1338
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• 2015

Years of research have shown that the application of microorganisms increases the compressive strength of cement-based material when it is cured in a culture medium. Because the compressive strength is strongly affected by the hydration of cement paste, this research aimed to investigate the role of the microorganism Sporosarcina pasteurii in hydration of cement paste. The microorganism's role was investigated with and without the presence of a urea-CaCl₂ culture medium (i.e., without curing the specimens in the culture medium). The results showed that S. pasteurii accelerated the early hydration of cement paste. The addition of the urea-CaCl₂ culture medium also increased the speed of hydration. However, no clear evidence of microbially induced calcite precipitation appeared when the microorganisms were directly mixed with cement paste.

• 한국구조물진단유지관리공학회 논문집
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• 제24권4호
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• pp.1-9
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• 2020

본 연구는 철근콘크리트 구조물의 염해 내구성 향상의 일환으로써, 보통 포틀랜드 시멘트에 실험체별 다른 비율의 칼슘 알루미네이트 시멘트와 합성 CA₂를 혼입하여 혼입 비율에 따른 염소이온 고정능력을 평가하였다. 침지 후 실험체의 물리·화학적 특성을 압축강도, 공극 구조, 수화물 분석으로 염소이온침투깊이를 EPMA를 통하여 고찰하였다. 클링커 조성에 CA가 34%미만일 경우 실험체의 조밀성이나 강도 발현 양상이 구조재료로서 사용 제한이 없을 것이라고 판단되었으며 CAC와 CA₂를 5:5비율로 혼입하여 실험체에 치환한 실험체가 CAC 혹은 CA₂만 치환한 실험체보다 염소이온 침투억제능력 과 AFm상 및 프리델 염 생성이 높은 것으로 확인할 수 있었다. 결과적으로, 시멘트 페이스트 대비 칼슘 알루미네이트 클링커 치환율이 증가함에 따라 일반적으로 염소이온 고정능력이 향상하였고, CA-CA₂비율에 따라 염소이온 고정 능력 및 염소이온 침투억제 능력에 차이가 있음을 확인할 수 있었다. 실험 범위 내에서 CA-CA₂비율이 39:60이며 시멘트 페이스트 대비 10% 치환한 실험체인 M 10 가 가장 우수한 것으로 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.93-94
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• 2023

Through the industrial revolution that began in the 18th century, the amount of carbon dioxide in the atmosphere increased rapidly as humans used fossil energy such as coal and oil as fuel for steam engines and factory machines. The amount of carbon dioxide emitted while producing cement, the main material of concrete used in construction, is large enough to account for 5-8% of the world's carbon dioxide emissions. In this study, Non cement-based matrix were used to reduce carbon dioxide emissions from cement production. Red mud is an industrial by-product generated in the manufacturing process of aluminum hydroxide using bauxite, and more than 120 million tons are produced worldwide. In addition, red mud is a porous material that can be physically adsorbed, and causes a photocatalytic reaction of TiO₂ to remove harmful substances such as nitrogen oxide formaldehyde in the air and chemically adsorbs ammonia and hydrogen sulfide. Therefore, this study aims to examine the physical properties of the matrix by mixing red mud, an industrial by-product with good adsorption performance, into the Non cement-based matrix.